Co-reporter:Xavier Aparicio-Anglès;Brandon Q. Mercado;Marilyn M. Olmstead;Josep M. Poblet;Luis Echegoyen;Antonio Rodríguez-Fortea;Anna Clotet;Bevan Elliott;Manuel N. Chaur
The Journal of Physical Chemistry C August 5, 2010 Volume 114(Issue 30) pp:13003-13009
Publication Date(Web):2017-2-22
DOI:10.1021/jp104352d
Structural and electrochemical property correlations of metallic nitride endohedral metallofullerenes (MN EMFs) were studied in detail. The electrochemical properties of these compounds are strongly dependent on the symmetry of the carbon cage and, except for the Sc3N cluster, are independent of the nature of the metallic cluster due to the localization of the HOMO and LUMO on the carbon cage. The X-ray structure of Gd3N@C86 shows that the cage obeys the isolated pentagon rule and uses a cage with D3 symmetry, in agreement with previously published data for Tb3N@C86, the only other structurally characterized C86 MN EMF. The electrochemical properties of different MN EMFs are used to probe the structural features of these compounds. Electrochemistry was used to determine the relative abundances of the D5h and Ih isomers of M3N@C80 compounds, whereas HPLC allowed the analysis of larger MN EMFs. The binding energies (BEs) were computed for different MN EMFs, and a strong correlation between the BE (of the cluster and fullerene cage) and the corresponding abundance of the given MN EMF was obtained. The results account for the different template stages and for the relative abundances observed for MN EMFs.
Co-reporter:Hua Yang, Hongxiao Jin, Xinqing Wang, Ziyang Liu, Meilan Yu, Fukun Zhao, Brandon Q. Mercado, Marilyn M. Olmstead, and Alan L. Balch
Journal of the American Chemical Society August 29, 2012 Volume 134(Issue 34) pp:14127-14136
Publication Date(Web):August 3, 2012
DOI:10.1021/ja304867j
Three isomers of Sm@C82 that are soluble in organic solvents were obtained from the carbon soot produced by vaporization of hollow carbon rods doped with Sm2O3/graphite powder in an electric arc. These isomers were numbered as Sm@C82(I), Sm@C82(II), and Sm@C82(III) in order of their elution times from HPLC chromatography on a Buckyprep column with toluene as the eluent. The identities of isomers, Sm@C82(I) as Sm@Cs(6)-C82, Sm@C82(II) as Sm@C3v(7)-C82, and Sm@C82(III) as Sm@C2(5)-C82, were determined by single-crystal X-ray diffraction on cocrystals formed with Ni(octaethylporphyrin). For endohedral fullerenes like La@C82, which have three electrons transferred to the cage to produce the M3+@(C82)3– electronic distribution, generally only two soluble isomers (e.g., La@C2v(9)-C82 (major) and La@Cs(6)-C82 (minor)) are observed. In contrast, with samarium, which generates the M2+@(C82)2– electronic distribution, five soluble isomers of Sm@C82 have been detected, three in this study, the other two in two related prior studies. The structures of the four Sm@C82 isomers that are currently established are Sm@C2(5)-C82, Sm@Cs(6)-C82, Sm@C3v(7)-C82, and Sm@C2v(9)-C82. All of these isomers obey the isolated pentagon rule (IPR) and are sequentially interconvertable through Stone–Wales transformations.
Co-reporter:Xian B. Powers;Kamran B. Ghiassi;Joshua T. Greenfield;Marilyn M. Olmstead
CrystEngComm (1999-Present) 2017 vol. 19(Issue 24) pp:3244-3253
Publication Date(Web):2017/06/20
DOI:10.1039/C7CE00638A
Conditions for the crystallization and interconversion of the green and brown polymorphs of bis(3-ethylamino-1-phenyl-but-2-en-1-ono)nickel(II) (Ni(B–Et)2), which contain planar and tetrahedral complexes in accord with previous magnetic and spectroscopic studies, have been determined. Additionally, the series of β-diketoamine-containing complexes, M(B–Et)2 and M(B–Bn)2, (M = CoII, NiII, CuII, ZnII) obtained from condensation of benzoylacetone (B) with either ethylamine (Et) or benzylamine (Bn) followed by treatment with [MCl4]2− under basic conditions has been prepared and their structures characterized crystallographically. In contrast to Ni(B–Et)2, Ni(B–Bn)2 has been crystallized only in the planar form. M(B–Et)2 and M(B–Bn)2 (M = Co or Zn) have similar, nearly tetrahedral structures, while Cu(B–Et)2 and Cu(B–Bn)2 have structures that are decidedly intermediate between tetrahedral and planar. Despite the abilities of these complexes to exist in tetrahedral, planar, or intermediate structures in solution, it has not been possible to induce much structural variation in crystalline forms. While two polymorphs of Zn(B–Bn)2 have been obtained, both have similar, tetrahedral structures. Only Ni(B–Et)2 crystallizes in both planar and tetrahedral forms. None of the complexes formed cocrystals with fullerenes or solvates in which structural variation as seen in Ni(B–Et)2 occurred.
Co-reporter:Amineh Aghabali;Sharon Jun;Marilyn M. Olmstead
Dalton Transactions 2017 vol. 46(Issue 11) pp:3710-3715
Publication Date(Web):2017/03/14
DOI:10.1039/C7DT00026J
The reaction of the piperazine mono-adduct, N(CH2CH2)2NC60, with diiodine produced well ordered, black crystals of (I2N(CH2CH2)2NI2)C60·2.884(C6H6)·0.116I2, which contains two nearly linear N–I–I units. Reaction of N(CH2CH2)2NC60 with iodine monochloride produced two materials: the dihalogen adduct, (ClIN(CH2CH2)2NICl)C60·2.3(CS2)·0.7(CH2Cl2), when crystallization occurred rapidly from carbon disulfide/dichloromethane solution or the salt, [(N(CH2CH2)2NH)C60+][ICl2−]·CS2, when crystallization happened more slowly from toluene/dichloromethane solution where hydrolysis of the iodine monochloride by adventitious water presumably occurred.
Co-reporter:Marilyn M. Olmstead, Tianming Zuo, Harry C. Dorn, Tinghui Li, Alan L. Balch
Inorganica Chimica Acta 2017 Volume 468(Volume 468) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.ica.2017.05.046
•Structures of Er3N@Ih-C80 and Ho3N@Ih-C80 were determined by single crystal X-ray diffraction.•For M3N@Ih-C80 the thermal ellipsoids of the nitrogen elongate as the size of the metal ion increases.•The M3N unit becomes pyramidalized when the sum of the crystal radii of the metal ions exceeds 3.05 Å.The structures of Er3N@Ih-C80 and Ho3N@Ih-C80 have been determined by single crystal X-ray diffraction in the cocrystals Er3N@Ih-C80·Ni(OEP)·2benzene and Ho3N@Ih-C80·Ni(OEP)·2benzene where OEP is the dianion of octaethylporphyrin. Comparison of the structural data for M3N@Ih-C80.with M = Gd, Tb, Dy, Ho, Er, Tm, and Sc reveals that, as the ionic radii of the metal ions increase, the anisotropic thermal ellipsoid of the nitrogen becomes more and more elongated until it is better to refine it as split and isotropic as in the cases of Gd3N@Ih-C80 and Tb3N@Ih-C80. The data also indicate that the M3N unit becomes pyramidalized to some extent when the sum of the Shannon-Prewitt crystal radii for six-coordinate M3+ of the three metal ions involved exceeds 3.05 Å. There is a gradual progression in the degree of distortion as the metal ion sizes increase. This statement holds true for both homometallic and heterometallic endohedrals of the type M3N@Ih-C80.Download high-res image (92KB)Download full-size image
Co-reporter:Chia-Hsiang Chen, Laura Abella, Maira R. Cerón, Miguel A. Guerrero-Ayala, Antonio Rodríguez-Fortea, Marilyn M. Olmstead, Xian B. Powers, Alan L. Balch, Josep M. Poblet, and Luis Echegoyen
Journal of the American Chemical Society 2016 Volume 138(Issue 39) pp:13030-13037
Publication Date(Web):September 5, 2016
DOI:10.1021/jacs.6b07912
Co-reporter:Maira R. Cerón, Marta Izquierdo, Amineh Aghabali, Sophie P. Vogel, Marilyn M. Olmstead, Alan L. Balch, Luis Echegoyen
Carbon 2016 Volume 105() pp:394-400
Publication Date(Web):August 2016
DOI:10.1016/j.carbon.2016.04.044
Four easily isolable bis-pyrrolidine-C70 regioisomers were synthesized and characterized by spectroscopic techniques. The four [70]fullerene bis-adducts were unambiguously assigned using spectroscopic techniques and X-ray crystallography, as the β-2-β, α-2-α, α-1-β and α-1-α regioisomers.
Co-reporter:Steven Stevenson, Kristine D. Arvola, Muska Fahim, Benjamin R. Martin, Kamran B. Ghiassi, Marilyn M. Olmstead, and Alan L. Balch
Inorganic Chemistry 2016 Volume 55(Issue 1) pp:62-67
Publication Date(Web):September 30, 2015
DOI:10.1021/acs.inorgchem.5b01814
While several nonchromatographic methods are available for the isolation and purification of endohedral fullerenes of the type M3N@Ih-C80, little work has been done that would allow other members of the M3N@C2n family to be isolated with minimal chromatography. Here, we report that Gd3N@D2(35)-C88 can be isolated from the multitude of endohedral and empty cage fullerenes present in carbon soot obtained by electric-arc synthesis using Gd2O3-doped graphite rods. The procedure developed utilizes successive precipitation with the Lewis acids CaCl2 and ZnCl2 followed by treatment with amino-functionalized silica gel. The structure of the product was identified by single-crystal X-ray diffraction.
Co-reporter:Lipiao Bao, Muqing Chen, Wangqiang Shen, Changwang Pan, Kamran B. Ghiassi, Marilyn M. Olmstead, Alan L. Balch, Takeshi Akasaka, and Xing Lu
Inorganic Chemistry 2016 Volume 55(Issue 9) pp:4075
Publication Date(Web):April 21, 2016
DOI:10.1021/acs.inorgchem.6b00631
Highly regioselective 1,3-dipolar cycloaddition of 3,5-dichloro-2,4,6-trimethoxybenzonitrile oxide (1) to Sc3N@Ih-C80 or C60 affords the corresponding isoxazoline-ring-fused derivatives Sc3N@Ih-C80(C10H9O4NCl2) (2a) and C60(C10H9O4NCl2) (2b). 2a represents the first example of an endohedral metallofullerene derivative with an isoxazoline ring. Crystallographic and NMR spectroscopic studies reveal a [5,6]-bond addition pattern in 2a but a [6,6]-bond addition manner in 2b.
Co-reporter:Kamran B. Ghiassi, Xian B. Powers, Joseph Wescott, Alan L. Balch, and Marilyn M. Olmstead
Crystal Growth & Design 2016 Volume 16(Issue 1) pp:447-455
Publication Date(Web):December 7, 2015
DOI:10.1021/acs.cgd.5b01449
Two related nickel(II) porphyrins, etioporphyrin-I (Etio-I) and octaethylporphyrin (OEP), were cocrystallized with C70 to produce the new cocrystal structures C70·Ni(Etio-I)·2C6H6 and C70·Ni(OEP)·2C6H6. Etio-I is a variant of OEP, where four alternating ethyl groups from OEP are replaced with methyl substituents. This isomer of etioporphyrin has the potential to act as an agent in chiral sorting of asymmetric fullerenes. However, the replacement of four ethyl groups has nontrivial structural consequences. Further host–guest investigation of M(Etio-I) (M = Co, Ni, Cu, Zn) with C60 or C70 was conducted, producing new X-ray structures of Co(Etio-I) and Zn(Etio-I), and a redetermination of Ni(Etio-I). Despite numerous and varied attempts, C60 cocrystallized with M(Etio-I) could not be obtained.
Co-reporter:Daniel T. Walters, Kellie R. England, Kamran B. Ghiassi, Fikerete Z. Semma, Marilyn M. Olmstead, Alan L. Balch
Polyhedron 2016 Volume 117() pp:535-541
Publication Date(Web):15 October 2016
DOI:10.1016/j.poly.2016.06.031
Crystals in the isostructural series Au2(μ-dppe)X2 (dppe is 1,2-bis(diphenylphosphino)ethane, X = Cl, Br, I) form centrosymmetric, dimeric structures with two short Au⋯Au contacts between the component molecules. We found no evidence for a second polymorph for any member of the Au2(μ-dppe)X2 series, although two polymorphs were observed previously for the related Au2(Ph2As(CH2)2AsPh2)X2 series. Crystals of Au2(μ-dcpe)X2 (where dcpe is 1,2-bis(dicyclohexylphosphino)ethane) show structures that differ appreciably from those of Au2(μ-dppe)X2. The bulky cyclohexyl substituents appear to be playing a major role in eliminating the formation of polymeric or dimeric structures. Au2(μ-dcpe)Cl2 has a monomeric structure without aurophilic interactions. In contrast, Au2(μ-dcpe)Br2 and Au2(μ-dcpe)I2 have similar structures with intramolecular aurophilic interactions. Au2(μ-dcpe)I2 displays a form of aggregation-induced emission. It displays a red-pink luminescence in crystalline form but is non-emissive in solution.Aurophilic interactions in the crystal structures of the series Au2(μ-1,2-bis(diphenylphosphino)-ethane)X2 and Au2(μ-1,2-bis(dicyclohexylphosphino)ethane)X2 (X = Cl, Br, I) trade off with steric effects as a function of halogen atom and phenyl vs. cyclohexyl substituent. The shortest Au⋯Au distance of these is observed in Au2(μ-dcpe)I2.
Co-reporter:Amineh Aghabali, Sharon Jun, Marilyn M. Olmstead, and Alan L. Balch
Journal of the American Chemical Society 2016 Volume 138(Issue 50) pp:
Publication Date(Web):November 21, 2016
DOI:10.1021/jacs.6b10394
The reactions of the open-cage fullerene, MMK-9, with an open 12-membered ring on its surface and silver(I) salts have been examined. The structure of MMK-9 itself has been determined by single-crystal X-ray diffraction. MMK-9 reacts with silver trifluoroacetate in air to form the dimer, {MMK-9(OCH3)5Ag(AgO2CCF3)}2. Remarkably, five MeO groups have added to the surface of the open cage in a pattern that surrounds a pentagon immediately adjacent to the opening in the cage. Dioxygen has been implicated as the oxidant in this unusual addition of five groups to the open cage. Two silver ions connected to each other by a short argentophillic interaction reside at the core of the centrosymmetric dimer. The reaction of silver nitrate with MMK-9 yields the crystalline polymer, [{MMK-9(OCH3)5Ag(AgOCH3)}2·H2O]n. This polymer consists of dimeric {MMK-9(OCH3)5Ag}2 units that are connected into strands through silver ions, which are chelated by the amine functions of one open cage and bound in η2-fashion to a pair of carbon atoms on an adjacent open cage.
Co-reporter:Maira R. Cerón; Marta Izquierdo; Amineh Aghabali; Juan A. Valdez; Kamran B. Ghiassi; Marilyn M. Olmstead; Alan L. Balch; Fred Wudl;Luis Echegoyen
Journal of the American Chemical Society 2015 Volume 137(Issue 23) pp:7502-7508
Publication Date(Web):May 18, 2015
DOI:10.1021/jacs.5b03768
The regioselective synthesis of easily isolable pure bismethano derivatives of C60 and C70 with high steric congestion is described using 1,3-dibenzoylpropane bis-p-toluenesulfonyl hydrazone as the addend precursor. When the addition occurs at two [6,6] ring junctions within the same hexagon, bisadducts with mirror symmetry are obtained for both C60 and C70. When the addition occurs at two [5,6] ring junctions in C60, a symmetrical adduct is formed, which readily undergoes photo-oxygenation and ring opening to yield a fullerene with a hole in the cage. In this work, we also propose a simple and general system to name all of the possible [6,6] bisadduct isomers on C70.
Co-reporter:Chia-Hsiang Chen; Kamran B. Ghiassi; Maira R. Cerón; Miguel A. Guerrero-Ayala; Luis Echegoyen; Marilyn M. Olmstead
Journal of the American Chemical Society 2015 Volume 137(Issue 32) pp:10116-10119
Publication Date(Web):August 3, 2015
DOI:10.1021/jacs.5b06425
The synthesis, isolation, and characterization of a new endohedral fullerene, Sc2C88, is reported. Characterization by single crystal X-ray diffraction revealed that it is the carbide Sc2C2@C2v(9)-C86 with a planar, twisted Sc2C2 unit inside a previously unseen C2v(9)-C86 fullerene cage.
Co-reporter:Kamran B. Ghiassi, Daniel T. Walters, Michael M. Aristov, Natalia D. Loewen, Louise A. Berben, Melissa Rivera, Marilyn M. Olmstead, and Alan L. Balch
Inorganic Chemistry 2015 Volume 54(Issue 9) pp:4565-4573
Publication Date(Web):April 10, 2015
DOI:10.1021/acs.inorgchem.5b00461
New insight into the complexity of the reaction of the prominent catalyst RuCl2(PPh3)3 with carbon disulfide has been obtained from a combination of X-ray diffraction and 31P NMR studies. The red-violet compound originally formulated as a cationic π-CS2 complex, [RuCl(π-CS2)(PPh3)3]Cl, has been identified as a neutral molecule, RuCl2(S2CPPh3)(PPh3)2, which contains the unstable zwitterion S2CPPh3. In the absence of RuCl2(PPh3)3, there is no sign of a reaction between triphenylphosphine and carbon disulfide, although more basic trialkylphosphines form red adducts, S2CPR3. Despite the presence of an unstable ligand, RuCl2(S2CPPh3)(PPh3)2 is remarkably stable. It survives melting at 173–174 °C intact, is stable to air, and undergoes reversible electrochemical oxidation to form a monocation. When the reaction of RuCl2(PPh3)3 with carbon disulfide is conducted in the presence of methanol, crystals of orange [RuCl(S2CPPh3)(CS)(PPh3)2]Cl·2MeOH and yellow RuCl2(CS)(MeOH)(PPh3)2 also form. 31P NMR studies indicate that the unsymmetrical dinuclear complex (SC)(Ph3P)2Ru(μ-Cl)3Ru(PPh3)2Cl is the initial product of the reaction of RuCl2(PPh3)3 with carbon disulfide. A path connecting the isolated products is presented.
Co-reporter:Dr. Yang Zhang;Kamran B. Ghiassi;Qingming Deng;Nataliya A. Samoylova; Marilyn M. Olmstead; Alan L. Balch;Dr. Alexey A. Popov
Angewandte Chemie International Edition 2015 Volume 54( Issue 2) pp:495-499
Publication Date(Web):
DOI:10.1002/anie.201409094
Abstract
The synthesis and single-crystal X-ray structural characterization of the first endohedral metallofullerene to contain a heptagon in the carbon cage are reported. The carbon framework surrounding the planar LaSc2N unit in LaSc2N@Cs(hept)-C80 consists of one heptagon, 13 pentagons, and 28 hexagons. This cage is related to the most abundant Ih-C80 isomer by one Stone–Wales-like, heptagon/pentagon to hexagon/hexagon realignment. DFT computations predict that LaSc2N@Cs(hept)-C80 is more stable than LaSc2N@D5h-C80, and suggests that the low yield of the heptagon-containing endohedral fullerene may be caused by kinetic factors.
Co-reporter:Faye L. Bowles ; Marilyn M. Olmstead
Journal of the American Chemical Society 2014 Volume 136(Issue 9) pp:3338-3341
Publication Date(Web):February 17, 2014
DOI:10.1021/ja4120677
The reaction of {(η5-C5H5)Ru(CO)2}2 with C60 in toluene solution under thermal or photolytic conditions produces C60{η1-Ru(CO)2(η5-C5H5)}2, whose structure has been determined by single crystal X-ray diffraction. The two Ru(CO)2(η5-C5H5) units are bound at the opposite ends of a hexagon on the fullerene surface and are closely intertwined.
Co-reporter:Hongyun Fang, Hailin Cong, Mitsuaki Suzuki, Lipiao Bao, Bing Yu, Yunpeng Xie, Naomi Mizorogi, Marilyn M. Olmstead, Alan L. Balch, Shigeru Nagase, Takeshi Akasaka, and Xing Lu
Journal of the American Chemical Society 2014 Volume 136(Issue 29) pp:10534-10540
Publication Date(Web):July 7, 2014
DOI:10.1021/ja505858y
The endohedral fullerene once erroneously identified as Sc3@C82 was recently shown to be Sc3C2@Ih-C80, the first example of an open-shell cluster metallofullerene. We herein report that benzyl bromide (1) reacts with Sc3C2@ Ih-C80 via a regioselective radical addition that affords only one isomer of the adduct Sc3C2@Ih-C80(CH2C6H5) (2) in high yield. An X-ray crystallographic study of 2 demonstrated that the benzyl moiety is singly bonded to the fullerene cage, which eliminates the paramagnetism of the endohedral in agreement with the ESR results. Interestingly, X-ray results further reveal that the 3-fold disordered Sc3C2 cluster adopts two different configurations inside the cage. These configurations represent the so-called “planar” form and the computationally predicted, but not crystallographically characterized, “trifoliate” form. It is noteworthy that this is the first crystallographic observation of the “trifoliate” form for the Sc3C2 cluster. In contrast, crystallographic investigation of a Sc3C2@Ih-C80/Ni(OEP) cocrystal, in which the endohedral persists in an open-shell structure with paramagnetism, indicates that only the former form occurs in pristine Sc3C2@ Ih-C80. These results demonstrate that the cluster configuration in EMFs is highly sensitive to the electronic structure, which is tunable by exohedral modification. In addition, the electrochemical behavior of Sc3C2@Ih-C80 has been markedly changed by the radical addition, but the absorption spectra of the pristine and the derivative are both featureless. These results suggest that the unpaired electron of Sc3C2@Ih-C80 is buried in the Sc3C2 cluster and does not affect the electronic configuration of the cage.
Co-reporter:Amineh Aghabali, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2014 vol. 50(Issue 96) pp:15152-15155
Publication Date(Web):16 Oct 2014
DOI:10.1039/C4CC06995A
The reaction of Rh2(O2CCH3)4 with the functionalized fullerene N(CH2CH2)2NC60 can produce a linear, crystalline polymer or can trap free C60 or C70 molecules between similar chains.
Co-reporter:Kamran B. Ghiassi, Susanne Y. Chen, Peter Prinz, Armin de Meijere, Marilyn M. Olmstead, and Alan L. Balch
Crystal Growth & Design 2014 Volume 14(Issue 8) pp:4005-4010
Publication Date(Web):July 7, 2014
DOI:10.1021/cg500603c
The bowl-shaped hydrocarbon hexakis[(E)-3,3-dimethyl-1-butenyl]benzene (HB) has been cocrystallized with either C60 or C70 to form clamshell-like assemblies with the fullerenes residing within the concave surfaces of two HB molecules. The structures of these two crystals have been determined by single-crystal X-ray diffraction. The HB molecules exhibit back-to-back stacking and close contacts in both cocrystals. This trait is remarkably similar to the packing seen in cases in which fullerenes cocrystallize with MII(OEP), where OEP is the dianion of octaethylporphyrin and M is generally Ni or Co. The C60 structure features an ordered cage with a disordered solvent position, while the C70 structure exhibits two orientations of the cage, all other components being ordered.
Co-reporter:Sang Ho Lim, Jennifer C. Schmitt, Jason Shearer, Kellie R. England, Marilyn M. Olmstead and Alan L. Balch
Dalton Transactions 2014 vol. 43(Issue 36) pp:13756-13763
Publication Date(Web):29 Jul 2014
DOI:10.1039/C4DT01902D
The colorless, two-coordinate gold(I) complex, [(H2O)3Na][Au(SCSN3)2], has been synthesized through the [2 + 3] cyclic reaction of carbon disulfide and sodium azide in the presence of the labile complex (tht)AuCl. Metathesis of [(H2O)3Na][Au(SCSN3)2], with tetra(phenyl)arsonium chloride produced colorless needles of (Ph4As)[Au(SCSN3)2]. The structure of [(H2O)3Na][Au(SCSN3)2] involves linear gold coordination by two exocyclic sulfur atoms of the 1,2,3,4-thiatriazole-5-thiolate anions. These two-coordinate anions self-associate to form extended, zig-zag chains that are connected by aurophilic bonding with Au⋯Au distances of 3.2653(3) Å and 3.3090(3) Å. Remarkably, the individual S–Au–S units that are connected though aurophilic interactions are eclipsed. The structure of (Ph4As)[Au(SCSN3)2] also contains linear, two-coordinate gold ions with bonding to the 1,2,3,4-thiatriazole-5-thiolate anionic ligands through the exocyclic sulfur atoms. However, in this salt, the anions self-associate through Au⋯Au bonds (Au⋯Au distance of 3.2007(3) Å) to form simple dimers, which also have an eclipsed arrangement of the ligands. Electronic structure calculations strongly suggest that the staggered geometry for the [(Au(SCSN3))2]+ dimer is energetically favored relative to the eclipsed geometry. However, attractive π-stacking interactions appear to promote the observed eclipsed arrangement of the ligands.
Co-reporter:Kamran B. Ghiassi, Marilyn M. Olmstead and Alan L. Balch
Dalton Transactions 2014 vol. 43(Issue 20) pp:7346-7358
Publication Date(Web):29 Jan 2014
DOI:10.1039/C3DT53517G
Gadolinium-containing endohedral fullerenes represent a new class of effective relaxation agents for magnetic resonance imaging (MRI). The range of different structures possible for this class of molecules and their properties as MRI agents are reviewed here.
Co-reporter:Kamran B. Ghiassi, Faye L. Bowles, Susanne Y. Chen, Marilyn M. Olmstead, and Alan L. Balch
Crystal Growth & Design 2014 Volume 14(Issue 10) pp:5131-5136
Publication Date(Web):August 20, 2014
DOI:10.1021/cg500817w
Cocrystallization of diiodine and carbon disulfide with the two common fullerenes, C60 and C70, has been examined. The binary cocrystal, C70·I2, readily formed when a solution of diiodine in diethyl ether was layered over C70 dissolved in toluene, chlorobenzene, or 1,2-dichlorobenzene, but no binary cocrystal of diiodine and C60 could be obtained despite persistent efforts. The ternary cocrystal, C70·0.85I2·0.15CS2, which was grown from a carbon disulfide solution of C70 and a benzene solution of diiodine, is isostructural with C70·I2 but has 15% of the diiodine sites replaced with carbon disulfide. In contrast, C70·0.68I2·0.32CS2, which was obtained from diffusion of a cyclohexane solution of diiodine into a carbon disulfide solution of C70, is a unique ternary cocrystal that is not related to any binary cocrystal of C70 with diiodine or carbon disulfide. Crystals of 2C60·2.46CS2·0.54I2 were obtained from a saturated carbon disulfide solution of diiodine and C60. Black crystals of 2C60·2.46CS2·0.54I2 form in a different space group from those of the solvate 2C60·3CS2 but have a very similar structure. Remarkably, diiodine molecules fractionally replace carbon disulfide in only two of the three independent sites within this crystal.
Co-reporter:Sang Ho Lim, Marilyn M. Olmstead and Alan L. Balch
Chemical Science 2013 vol. 4(Issue 1) pp:311-318
Publication Date(Web):10 Sep 2012
DOI:10.1039/C2SC20820B
The solid state interconversions of four different crystalline compounds containing the Au2(dppe)2I2 unit (dppe is bis-(diphenylphosphino)ethane) have been observed and characterized through X-ray diffraction and emission spectroscopy. Treatment of AuI in acetone with solid dppe yields the crystalline polymorphs: α-Au2(μ-dppe)2I2·2OCMe2 (1) with orange emission and β-Au2(μ-dppe)2I2·2OCMe2 (2) with green emission. Both polymorphs contain dimeric molecules with three-coordinate gold(I) centers that are further apart in the orange emitting (1) (Au⋯Au distance, 3.6720(2) Å) than in the green emitting (2) (Au⋯Au distance, 3.3955(2) Å). The acetone molecules do not bond to the gold centers in either polymorph. Crystals of α-Au2(μ-dppe)2I2·2OCMe2 (1) and β-Au2(μ-dppe)2I2·2OCMe2 (2) undergo reversible, single-crystal to single-crystal transformations. Exposure of (2) to acetone vapor converts it into (1), while (1) is converted into (2) by exposure to air for a short time. Upon loss of acetone, α-Au2(μ-dppe)2I2·2OCMe2 (1) and β-Au2(μ-dppe)2I2·2OCMe2 (2) are converted into a microcrystalline powder (3) with a green emission. Remarkably, exposure of (3) to acetone vapor converts it into acetone-free Au2(μ-dppe)2(μ-I)2 (4), which displays orange emission. The X-ray crystal structure of Au2(μ-dppe)2(μ-I)2 (4) shows that each gold is in a highly distorted tetrahedral environment with bonds to two phosphorus and two iodine atoms. The transformations between these four types of crystals are notable because of the unusual role of vapors in promoting structural changes within solids that do not necessarily change composition. Thus, the reversible interconversion of α-Au2(μ-dppe)2I2·2OCMe2 (1) and β-Au2(μ-dppe)2I2·2OCMe2 (2) occurs as vapor-stimulated single-crystal-to-single-crystal transformation between polymorphs. Likewise, the irreversible transformation of microcrystalline (3) into Au2(μ-dppe)2(μ-I)2 (4) appears to be another case of a transformation of one polymorph into another.
Co-reporter:Kamran B. Ghiassi, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2013 vol. 49(Issue 91) pp:10721-10723
Publication Date(Web):04 Oct 2013
DOI:10.1039/C3CC46367B
Cocrystallization of C70 with bis(ethylenedithio)tetrathiafulvalene (ET) produces two different solvates, C70·ET·C6H6 and 2C70·2ET·CS2, which show distinctly different overlap between the fullerene and ET molecules.
Co-reporter:Faye L. Bowles, Marilyn M. Olmstead, Christine M. Beavers and Alan L. Balch
Chemical Communications 2013 vol. 49(Issue 53) pp:5921-5923
Publication Date(Web):26 Apr 2013
DOI:10.1039/C3CC41773E
Cocrystallization of Hg{Co(CO)4}2 with C60 produces Hg{Co(CO)4}2·C60·toluene in which the geometry of the Hg{Co(CO)4}2 molecule is rearranged to fit between the remarkably well ordered fullerenes.
Co-reporter:Sang Ho Lim, Jennifer C. Schmitt, Jason Shearer, Jianhua Jia, Marilyn M. Olmstead, James C. Fettinger, and Alan L. Balch
Inorganic Chemistry 2013 Volume 52(Issue 2) pp:823-831
Publication Date(Web):January 9, 2013
DOI:10.1021/ic301954n
Four crystalline dimers of the type, AuI2(μ-PnP)2I2, where PnP is PPh2(CH2)nPPh2 with n = 3, 4, 5, and 6 have been prepared and characterized by single-crystal X-ray diffraction and by 31P NMR and infrared spectroscopy. AuI2(μ-P3P)2I2 and AuI2(μ-P6P)2I2 are centrosymmetric dimers with the planar AuIP2I units oriented in antiparallel fashion. Remarkably, noncentrosymmetric AuI2(μ-P5P)2I2 has its planar AuIP2I units oriented in parallel manner. AuI2(μ-P4P)2(μ-I)2 is unique, since it contains four-coordinate gold centers that are bridged by both iodide and diphosphine ligands. All four compounds are luminescent as solids at room temperature. B3LYP, B2PLYP, and spectroscopically oriented configuration interaction (SORCI) calculations have been conducted to give insight into the electronic and geometric structures of the ground and first excited triplet states of the three trigonal-planar complexes. The emission energies for the trigonal planar complexes are more strongly correlated with changes in the Au–I bond length rather than changes in the P–Au–P angle.
Co-reporter:Hua Yang, Zhimin Wang, Hongxiao Jin, Bo Hong, Ziyang Liu, Christine M. Beavers, Marilyn M. Olmstead, and Alan L. Balch
Inorganic Chemistry 2013 Volume 52(Issue 3) pp:1275-1284
Publication Date(Web):January 23, 2013
DOI:10.1021/ic301794r
Sm@C2v(3)-C80 has been separated from the carbon soot produced by electrical arc vaporization of graphite rods doped with Sm2O3 and purified. Its structure has been determined by single crystal X-ray diffraction using cocrystals obtained from either NiII(octaethylporphyrin) (NiII(OEP)) to form Sm@C2v(3)-C80·NiII(OEP)·1.68(toluene)·0.32(benzene) or bis(ethylenedithio)-tetrathiafulvalene (ET) to produce Sm@C2v(3)-C80·ET·0.5(toluene). Thus, this study offers the first opportunity to compare a common endohedral fullerene in two different cocrystals. Both cocrystals provide consistent information on the basic structure of Sm@C2v(3)-C80 but show that the distribution of samarium ion sites inside the carbon cage depends upon whether NiII(OEP) or ET is present. The samarium ion is disordered in both structures, but the prominent sites lie slightly off the 2-fold symmetry axis of the cage. Computational studies at the B3LYP level indicate that Sm@C2v(3)-C80 is more stable than any of the other six isomers of Sm@C80 that obey the isolated pentagon rule (IPR). The surface electrostatic potential of the interacting components in the cocrystals has been examined to identify factors responsible for the ordering of the fullerene cages. The regions of the NiII(OEP) or ET molecules that are closest to the fullerene display negative potential, while the corresponding regions of the endohedral fullerene show positive potential in a consistent fashion in both cocrystals.
Co-reporter:Faye L. Bowles, Brandon Q. Mercado, Kamran B. Ghiassi, Susanne Y. Chen, Marilyn M. Olmstead, Hua Yang, Ziyang Liu, and Alan L. Balch
Crystal Growth & Design 2013 Volume 13(Issue 10) pp:4591-4598
Publication Date(Web):August 26, 2013
DOI:10.1021/cg401138g
The structures of three crystalline solvates, D5h(1)-C90·CS2, D5h-C70·3CS2, and 2(D5h-C70)·3CS2, of nanotubular fullerenes have been determined by single crystal X-ray diffraction. Despite the marked tendency for fullerenes to disorder, the carbon cages in all three structures are fully ordered at 100(2) K for D5h(1)-C90·CS2 and 90 K for the other two crystals. Moreover, the carbon disulfide molecules are also ordered, except for the case of D5h(1)-C90·CS2, where there is a minor disorder in the solvate location. The molecular packing in D5h(1)-C90·CS2 reflects the nanotubular nature of the fullerene component with channels of alternating fullerenes and carbon disulfide molecules running along the crystallographic b axis. The molecular packing arrangements for D5h-C70·3CS2 and 2(D5h-C70)·3CS2 do not show such channels. In D5h-C70·3CS2, the carbon disulfide molecules form chains that snake between the fullerenes and along the crystallographic a axis. In 2(D5h-C70)·3CS2, there are two crystallographically distinct fullerene cages, which are segregated into individual layers. Within each layer, the fullerenes show hexagonal close packing and the carbon disulfide molecules form chains that snake between the fullerene layers in a zigzag fashion. The presence of diiodine in solution was essential for the formation of crystals of D5h-C70·3CS2 and 2(D5h-C70)·3CS2 that were suitable for structure determination, although no diiodine was incorporated in these crystals.
Co-reporter:Brandon Q. Mercado, Manuel N. Chaur, Luis Echegoyen, Jafar Attar Gharamaleki, Marilyn M. Olmstead, Alan L. Balch
Polyhedron 2013 58() pp: 129-133
Publication Date(Web):
DOI:10.1016/j.poly.2012.08.035
Co-reporter:Tong-Xin Liu ; Tao Wei ; San-E Zhu ; Guan-Wu Wang ; Mingzhi Jiao ; Shangfeng Yang ; Faye L. Bowles ; Marilyn M. Olmstead
Journal of the American Chemical Society 2012 Volume 134(Issue 29) pp:11956-11959
Publication Date(Web):July 12, 2012
DOI:10.1021/ja305446v
The reaction of an organic azide with an endohedral metallofullerene has been investigated for the first time. Isomeric [5,6]- and [6,6]-azafulleroids can be obtained from the thermal reaction of Sc3N@Ih-C80 with 4-isopropoxyphenyl azide, while photoirradiation leads exclusively to the [6,6]-azafulleroid. An unprecedented thermal interconversion between the two isomeric azafulleroids has also been discovered.
Co-reporter:Mark A. Malwitz ; Sang Ho Lim ; Rochelle L. White-Morris ; David M. Pham ; Marilyn M. Olmstead
Journal of the American Chemical Society 2012 Volume 134(Issue 26) pp:10885-10893
Publication Date(Web):April 17, 2012
DOI:10.1021/ja302025m
The remarkable, vapor-induced transformation of the yellow polymorphs of [(C6H11NC)2AuI](AsF6) and [(C6H11NC)2AuI](PF6) into the colorless forms are reported along with related studies of the crystallization of these polymorphs. Although the interconversion of these polymorphs is produced by vapor exposure, molecules of the vapor are not incorporated into the crystals. Thus, our observations may have broad implications regarding the formation and persistence of other crystal polymorphs where issues of stability and reproducibility of formation exist. Crystallographic studies show that the colorless polymorphs, which display blue luminescence, are isostructural and consist of linear chains of gold(I) cations that self-associate through aurophilic interactions. Significantly, the yellow polymorph of [(C6H11NC)2AuI](AsF6) is not isostructural with the yellow polymorph of [(C6H11NC)2AuI](PF6). Both yellow polymorphs exhibit green emission and have the gold cations arranged into somewhat bent chains with significantly closer Au···Au separations than are seen in the colorless counterparts. Luminescence differences in these polymorphs clearly enhance the ability to detect and monitor their phase stability.
Co-reporter:Hua Yang ; Meilan Yu ; Hongxiao Jin ; Ziyang Liu ; Mingguang Yao ; Bingbing Liu ; Marilyn M. Olmstead
Journal of the American Chemical Society 2012 Volume 134(Issue 11) pp:5331-5338
Publication Date(Web):February 14, 2012
DOI:10.1021/ja211785u
Three isomers with the composition Sm@C84 were isolated from carbon soot obtained by electric arc vaporization of carbon rods doped with Sm2O3. These isomers were labeled Sm@C84(I), Sm@C84(II), and Sm@C84(III) in order of their elution times during chromatography on a Buckyprep column with toluene as the eluent. Analysis of the structures by single-crystal X-ray diffraction on cocrystals formed with NiII(octaethylporphyrin) reveals the identities of two of the isomers: Sm@C84(I) is Sm@C2(13)-C84, and Sm@C84(III) is Sm@ D3d(19)-C84. Sm@C84(II) can be identified as Sm@C2(11)-C84 on the basis of the similarity of its UV/vis/NIR spectrum with that of Yb@C2(11)-C84, whose carbon cage has been characterized by 13C NMR spectroscopy. Comparison of the three Sm@C84 isomers identified in this project with two prior reports of the preparation and isolation of isomers of Sm@C84 indicate that five different Sm@C84 isomers have been found and that the source of samarium used for the generation of fullerene soot is important in determining which of these isomers form.
Co-reporter:Mitsuaki Suzuki, Zdenek Slanina, Naomi Mizorogi, Xing Lu, Shigeru Nagase, Marilyn M. Olmstead, Alan L. Balch, and Takeshi Akasaka
Journal of the American Chemical Society 2012 Volume 134(Issue 45) pp:18772-18778
Publication Date(Web):October 22, 2012
DOI:10.1021/ja308706d
Single crystals of three soluble Yb@C82 isomers, namely, Yb@C2(5)-C82, Yb@Cs(6)-C82, and Yb@C2v(9)-C82, cocrystallized with NiII(octaethylporphyrin), allowed accurate crystallographic elucidation of their molecular structures in terms of both cage symmetry and metal location. Multiple metal positions were found in all these isomers, but the major metal sites were found in some specific regions within these cages. Specifically, the Yb2+ ion prefers to reside close to a hexagonal ring in Yb@C2(5)-C82 and Yb@C2v(9)-C82 but a [5,6,6]-junction carbon atom in Yb@Cs(6)-C82. Theoretical calculations at the B3LYP level revealed that these metal positions all correspond to energy minima from the electrostatic potential maps and give rise to the most stable configurations of these Yb@C82 isomers. Furthermore, it is noteworthy that this is the first report on X-ray crystallographic studies of such metallofullerenes with the popular C2v(9)-C82 encapsulating a divalent metal ion, described as M2+@[C2v(9)-C82]2–.
Co-reporter:Hongxiao Jin ; Hua Yang ; Meilan Yu ; Ziyang Liu ; Christine M. Beavers ; Marilyn M. Olmstead
Journal of the American Chemical Society 2012 Volume 134(Issue 26) pp:10933-10941
Publication Date(Web):April 26, 2012
DOI:10.1021/ja302859r
Two isomers of Sm@C92 and four isomers of Sm@C94 were isolated from carbon soot obtained by electric arc vaporization of carbon rods doped with Sm2O3. Analysis of the structures by single-crystal X-ray diffraction on cocrystals formed with NiII(octaethylporphyrin) reveals the identities of two of the Sm@C92 isomers: Sm@C92(I), which is the more abundant isomer, is Sm@C1(42)-C92, and Sm@C92(II) is Sm@Cs(24)-C92. The structure of the most abundant form of the four isomers of Sm@C94, Sm@C94(I), is Sm@C3v(134)-C94, which utilizes the same cage isomer as the previously known Ca@C3v(134)-C94 and Tm@C3v(134)-C94. All of the structurally characterized isomers obey the isolated pentagon rule. While the four Sm@C90 and five isomers of Sm@C84 belong to common isomerization maps that allow these isomers to be interconverted through Stone–Wales transformations, Sm@C1(42)-C92 and Sm@Cs(24)-C92 are not related to each other by any set of Stone–Wales transformations. UV–vis–NIR spectroscopy and computational studies indicate that Sm@C1(42)-C92 is more stable than Sm@Cs(24)-C92 but possesses a smaller HOMO–LUMO gap. While the electronic structures of these endohedrals can be formally described as Sm2+@C2n2–, the net charge transferred to the cage is less than two due to some back-donation of electrons from π orbitals of the cage to the metal ion.
Co-reporter:Ning Chen ; Christine M. Beavers ; Marc Mulet-Gas ; Antonio Rodríguez-Fortea ; Elias J. Munoz ; Yu-Yang Li ; Marilyn M. Olmstead ; Alan L. Balch ; Josep M. Poblet ;Luis Echegoyen
Journal of the American Chemical Society 2012 Volume 134(Issue 18) pp:7851-7860
Publication Date(Web):April 21, 2012
DOI:10.1021/ja300765z
A non isolated pentagon rule metallic sulfide clusterfullerene, Sc2S@Cs(10528)-C72, has been isolated from a raw mixture of Sc2S@C2n (n = 35–50) obtained by arc-discharging graphite rods packed with Sc2O3 and graphite powder under an atmosphere of SO2 and helium. Multistage HPLC methods were utilized to isolate and purify the Sc2S@C72. The purified Sc2S@Cs(10528)-C72 was characterized by mass spectrometry, UV–vis–NIR absorption spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction. The crystallographic analysis unambiguously elucidated that the C72 fullerene cage violates the isolated pentagon rule, and the cage symmetry was assigned to Cs(10528)-C72. The electrochemical behavior of Sc2S@Cs(10528)-C72 shows a major difference from those of Sc2S@Cs(6)-C82 and Sc2S@C3v(8)-C82 as well as the other metallic clusterfullerenes. Computational studies show that the Sc2S cluster transfers four electrons to the C72 cage and Cs(10528)-C72 is the most stable cage isomer for both empty C724– and Sc2S@C72, among the many possibilities. The structural differences between the reported fullerenes with C72 cages are discussed, and it is concluded that both the transfer of four electrons to the cage and the geometrical requirements of the encaged Sc2S cluster play important roles in the stabilization of the Cs(10528)-C72 cage.
Co-reporter:Sang Ho Lim, Marilyn M. Olmstead, James C. Fettinger, and Alan L. Balch
Inorganic Chemistry 2012 Volume 51(Issue 3) pp:1925-1932
Publication Date(Web):January 18, 2012
DOI:10.1021/ic2022165
Solutions containing the components Au+, dpae (dpae is 1,2 bis-(diphenylarsino)ethane), and X– (X is Cl, Br, or I) can produce two different types of crystals with the composition Au2(μ-dpae)X2: colorless blocks and colorless needles. Crystallographic studies of these crystals show that they are polymorphs with different structural motifs. In the α-polymorphs, which are isostructural, individual molecules of Au2(μ-dpae)X2 form discrete dimers through two identical Au···Au contacts. In the β-polymorphs, which each have unique crystallographic parameters, the Au2(μ-dpae)X2 molecules assemble into polymeric chains through aurophilic interactions. The Au···Au contacts in the α-polymorph (3.1163(2), 3.1064(3), and 3.0842(2) Å for Cl, Br, I, respectively) are somewhat shorter than those in the β-polymorph (3.1668(3), 3.1042(8), and 3.1046(2) for Cl, Br, I respectively). The systematic study we now report shows an increase in the strength of this aurophilic interaction for the α-form in the series X = Cl < Br < I, which is in good agreement with theoretical studies by Pyykkö and his co-workers.
Co-reporter:Steven Stevenson, Coralie B. Rose, Juliya S. Maslenikova, Jimmy R. Villarreal, Mary A. Mackey, Brandon Q. Mercado, Kelly Chen, Marilyn M. Olmstead, and Alan L. Balch
Inorganic Chemistry 2012 Volume 51(Issue 24) pp:13096-13102
Publication Date(Web):December 6, 2012
DOI:10.1021/ic300888e
The successful preparation and isolation of the mixed-metal endohedral fullerene, LaSc2N@Ih-C80, and its structural characterization by single-crystal X-ray diffraction are reported. Results from chemically adjusting plasma temperature, energy, and reactivity (CAPTEAR) experiments indicate that a 10 wt % addition of Cu(NO3)2·2.5H2O to a mixture of La2O3 and Sc2O3 decreases the amount of C60 and C70 found in soot extracts by an order of magnitude. By combining a stoichiometric 2-fold excess of La to Sc atoms in the plasma reactor, an extract containing a greater abundance of LaSc2N@Ih-C80 relative to Sc3N@Ih-C80 was obtained. Alternatively, the stir and filter approach (SAFA method) can be used to remove the empty cage fullerenes from a carbon soot sample prepared without using Cu(NO3)2·2.5H2O. LaSc2N@Ih-C80 has been characterized by UV/vis absorption spectroscopy and by single-crystal X-ray diffraction. Ordered crystals with nearly identical orientations of the endohedral relative to the porphyrin have been obtained by cocrystallization of LaSc2N@Ih-C80 with either NiII(OEP) or H2(OEP). The LaSc2N unit is planar, although earlier computations suggested that it would be pyramidal.
Co-reporter:Hua Yang;Hongxiao Jin;Yuliang Che;Bo Hong;Dr. Ziyang Liu;Dr. Jafar Attar Gharamaleki;Dr. Marilyn M. Olmstead;Dr. Alan L. Balch
Chemistry - A European Journal 2012 Volume 18( Issue 10) pp:2792-2796
Publication Date(Web):
DOI:10.1002/chem.201103852
Co-reporter:Hua Yang, Hongxiao Jin, Bo Hong, Ziyang Liu, Christine M. Beavers, Hongyu Zhen, Zhimin Wang, Brandon Q. Mercado, Marilyn M. Olmstead, and Alan L. Balch
Journal of the American Chemical Society 2011 Volume 133(Issue 42) pp:16911-16919
Publication Date(Web):September 14, 2011
DOI:10.1021/ja206244w
The carbon soot obtained by electric arc vaporization of carbon rods doped with Sm2O3 contains a series of monometallic endohedral fullerenes, Sm@C2n, along with smaller quantities of the dimetallic endohedrals Sm2@C2n with n = 44, 45, 46, and the previously described Sm2@D3d(822)-C104. The compounds Sm2@C2n with n = 44, 45, 46 were purified by high pressure liquid chromatography on several different columns. For endohedral fullerenes that contain two metal atoms, there are two structural possibilities: a normal dimetallofullerene, M2@C2n, or a metal carbide, M2(μ-C2)@C2n–2. For structural analysis, the individual Sm2@C2n endohedral fullerenes were cocrystallized with Ni(octaethylporphyrin), and the products were examined by single-crystal X-ray diffraction. These data identified the three new endohedrals as normal dimetallofullerenes and not as carbides: Sm2@D2(35)-C88, Sm2@C1(21)-C90, and Sm2@D3(85)-C92. All four of the known Sm2@C2n endohedral fullerenes have cages that obey the isolated pentagon rule (IPR). As the cage size expands in this series, so do the distances between the variously disordered samarium atoms. Since the UV/vis/NIR spectra of Sm2@D2(35)-C88 and Sm2@C1(21)-C90 are very similar to those of Gd2C90 and Gd2C92, we conclude that Gd2C90 and Gd2C92 are the carbides Gd2(μ-C2)@D2(35)-C88 and Gd2(μ-C2)@C1(21)-C90, respectively.
Co-reporter:Fang-Fang Li ; Julio R. Pinzón ; Brandon Q. Mercado ; Marilyn M. Olmstead ; Alan L. Balch ;Luis Echegoyen
Journal of the American Chemical Society 2011 Volume 133(Issue 5) pp:1563-1571
Publication Date(Web):January 10, 2011
DOI:10.1021/ja1097176
The [2 + 2] cycloaddition reaction of Sc3N@Ih-C80 with benzyne was successfully conducted for the first time. The reaction affords both the [5,6]- and [6,6]-monoadducts with a four-membered ring attached to the cage surface on 5,6- and 6,6-ring fusions, respectively. The compounds were characterized by MALDI-TOF, NMR, UV−vis−NIR spectroscopy and single-crystal X-ray structure determination. The electrochemical behavior of both monoadducts was investigated. The [5,6]-regioisomer displays reversible cathodic behavior similar to that observed for the fulleropyrrolidines with a 5,6-addition pattern. Surprisingly, the [6,6]-regioisomer also exhibits reversible cathodic behavior. The interconversion reaction of the isomers was also explored, and the results showed that both monoadducts are thermally very stable.
Co-reporter:Hua Yang ; Hongxiao Jin ; Hongyu Zhen ; Zhimin Wang ; Ziyang Liu ; Christine M. Beavers ; Brandon Q. Mercado ; Marilyn M. Olmstead
Journal of the American Chemical Society 2011 Volume 133(Issue 16) pp:6299-6306
Publication Date(Web):March 31, 2011
DOI:10.1021/ja111465n
Four isomers with the composition SmC90 were obtained from carbon soot produced by electric arc vaporization of carbon rods doped with Sm2O3. These were labeled Sm@C90(I), Sm@C90(II), Sm@C90(III), and Sm@C90(IV) in order of their elution times during chromatography on a Buckyprep column with toluene as the eluent. Analysis of the structures by single-crystal X-ray diffraction on cocrystals formed with Ni(octaethylporphyrin) reveals the identities of the individual isomers as follows: I, Sm@C2(40)-C90; II, Sm@C2(42)-C90; III, Sm@C2v(46)-C90 and IV, Sm@C2(45)-C90. This is the most extensive series of isomers of any endohedral fullerene to have their individual structures determined by single-crystal X-ray diffraction. The cage structures of these four isomers can be related pairwise to one another in a formal sense through sequential Stone−Wales transformations.
Co-reporter:Christine M. Beavers ; Hongxiao Jin ; Hua Yang ; Zhimin Wang ; Xinqing Wang ; Hongliang Ge ; Ziyang Liu ; Brandon Q. Mercado ; Marilyn M. Olmstead
Journal of the American Chemical Society 2011 Volume 133(Issue 39) pp:15338-15341
Publication Date(Web):August 24, 2011
DOI:10.1021/ja207090e
An extensive series of soluble dilanthanum endohedral fullerenes that extends from La2C90 to La2C138 has been discovered. The most abundant of these, the nanotubular La2@D5(450)-C100, has been isolated in pure form and characterized by single-crystal X-ray diffraction.
Co-reporter:Brandon Q. Mercado ; Ning Chen ; Antonio Rodríguez-Fortea ; Mary A. Mackey ; Steven Stevenson ; Luis Echegoyen ; Josep M. Poblet ; Marilyn M. Olmstead
Journal of the American Chemical Society 2011 Volume 133(Issue 17) pp:6752-6760
Publication Date(Web):April 7, 2011
DOI:10.1021/ja200289w
Single-crystal X-ray diffraction studies of Sc2(μ2-S)@Cs(6)-C82·NiII(OEP)·2C6H6 and Sc2(μ2-S)@C3v(8)-C82·NiII(OEP)·2C6H6 reveal that both contain fully ordered fullerene cages. The crystallographic data for Sc2(μ2-S)@Cs(6)-C82·NiII(OEP)·2C6H6 show two remarkable features: the presence of two slightly different cage sites and a fully ordered molecule Sc2(μ2-S)@Cs(6)-C82 in one of these sites. The Sc−S−Sc angles in Sc2(μ2-S)@Cs(6)-C82 (113.84(3)°) and Sc2(μ2-S)@C3v(8)-C82 differ (97.34(13)°). This is the first case where the nature and structure of the fullerene cage isomer exerts a demonstrable effect on the geometry of the cluster contained within. Computational studies have shown that, among the nine isomers that follow the isolated pentagon rule for C82, the cage stability changes markedly between 0 and 250 K, but the Cs(6)-C82 cage is preferred at temperatures ≥250 °C when using the energies obtained with the free encapsulated model (FEM). However, the C3v(8)-C82 cage is preferred at temperatures ≥250 °C using the energies obtained by rigid rotor−harmonic oscillator (RRHO) approximation. These results corroborate the fact that both cages are observed and likely to trap the Sc2(μ2-S) cluster, whereas earlier FEM and RRHO calculations predicted only the Cs(6)-C82 cage is likely to trap the Sc2(μ2-O) cluster. We also compare the recently published electrochemistry of the sulfide-containing Sc2(μ2-S)@Cs(6)-C82 to that of corresponding oxide-containing Sc2(μ2-O)@Cs(6)-C82.
Co-reporter:Hua Yang, Brandon Q. Mercado, Hongxiao Jin, Zhimin Wang, An Jiang, Ziyang Liu, Christine M. Beavers, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2011 vol. 47(Issue 7) pp:2068-2070
Publication Date(Web):07 Dec 2010
DOI:10.1039/C0CC03017A
Fullerenes are generally considered as highly symmetric, yet fullerene isomers with only C1 symmetry, such as C1(30)–C90 and C1(32)–C90 whose structures are reported here, become increasingly numerous as fullerene size increases.
Co-reporter:Dr. Guan-Wu Wang;Tong-Xin Liu;Mingzhi Jiao;Nan Wang;San-E Zhu;Chuanbao Chen;Dr. Shangfeng Yang;Faye L. Bowles;Dr. Christine M. Beavers;Dr. Marilyn M. Olmstead;Bron Q. Mercado;Dr. Alan L. Balch
Angewandte Chemie International Edition 2011 Volume 50( Issue 20) pp:4658-4662
Publication Date(Web):
DOI:10.1002/anie.201100510
Co-reporter:Brandon Q. Mercado ; Melissa A. Stuart ; Mary A. Mackey ; Jane E. Pickens ; Bridget S. Confait ; Steven Stevenson ; Michael L. Easterling ; Ramón Valencia ; Antonio Rodríguez-Fortea ; Josep M. Poblet ; Marilyn M. Olmstead
Journal of the American Chemical Society 2010 Volume 132(Issue 34) pp:12098-12105
Publication Date(Web):August 10, 2010
DOI:10.1021/ja104902e
The new endohedral fullerene, Sc2(μ2-O)@Cs(6)-C82, has been isolated from the carbon soot obtained by electric arc generation of fullerenes utilizing graphite rods doped with 90% Sc2O3 and 10% Cu (w/w). Sc2(μ2-O)@Cs(6)-C82 has been characterized by single crystal X-ray diffraction, mass spectrometry, and UV/vis spectroscopy. Computational studies have shown that, among the nine isomers that follow the isolated pentagon rule (IPR) for C82, cage 6 with Cs symmetry is the most favorable to encapsulate the cluster at T > 1200 K. Sc2(μ2-O)@Cs(6)-C82 is the first example in which the relevance of the thermal and entropic contributions to the stability of the fullerene isomer has been clearly confirmed through the characterization of the X-ray crystal structure.
Co-reporter:Zhimin Wang, Hua Yang, An Jiang, Ziyang Liu, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2010 vol. 46(Issue 29) pp:5262-5264
Publication Date(Web):10 Jun 2010
DOI:10.1039/C0CC00697A
We report an analysis of the similar structures of Cs(16)-C86 and C2(17)-C86 from a single crystal X-ray diffraction study of Cs(16)/C2(17)-C86·(nickel octaethylporphyrin)·2toluene.
Co-reporter:Brandon Q. Mercado, Marilyn M. Olmstead, Christine M. Beavers, Michael L. Easterling, Steven Stevenson, Mary A. Mackey, Curtis E. Coumbe, Joshua D. Phillips, J. Paige Phillips, Josep M. Poblet and Alan L. Balch
Chemical Communications 2010 vol. 46(Issue 2) pp:279-281
Publication Date(Web):09 Nov 2009
DOI:10.1039/B918731F
The tetrahedral array of four scandium atoms with oxygen atoms capping three of the four faces found in Sc4(μ3-O)3@Ih-C80 is the largest cluster isolated to date inside a fullerene cage.
Co-reporter:Monika Wysocka-Żołopa, Krzysztof Winkler, Adrienne A. Thorn, Christopher J. Chancellor, Alan L. Balch
Electrochimica Acta 2010 Volume 55(Issue 6) pp:2010-2021
Publication Date(Web):15 February 2010
DOI:10.1016/j.electacta.2009.11.024
Redox-active films have been generated via electrochemical reduction in a solution containing palladium(II) acetate and [C60]fullerene, or derivatives of C60. The C60 derivatives include piperazine (piperazine-C60), pyrrolidine (CH3-pyr-C60), and a pyrrolidine salt, [(CH3)2-pyr-C60]+ attached to the fullerene unit. In these films, fullerene moieties are covalently bonded to palladium atoms to form a polymeric network. The polymer yields involving the piperazine and pyrrolidine derivatives of C60 are significantly lower than the yield of the C60/Pd film. The CH3-pyr-C60/Pd and [(CH3)2-pyr-C60]+/Pd films are electrochemically active in the negative potential region due to the reduction of the fullerene moiety. Reduction of the CH3-pyr-C60/Pd film is accompanied by the transport of supporting electrolyte cations from the solution into the film. In the first reduction step of the [(CH3)2-pyr-C60]+/Pd film, both cations and anions of the supporting electrolyte are involved. The piperazine-C60/Pd film exhibits electrochemical activity at both negative and positive potentials. In the negative potential region, reduction of the fullerene cage takes place. Oxidation of the piperazine moiety is responsible for the observed current in the positive potential range. Here, the oxidation process of this polymer is significantly influenced by the presence of metallic palladium particles in the film.
Co-reporter:Thelma Y. Garcia, Marilyn M. Olmstead, James C. Fettinger and Alan L. Balch
CrystEngComm 2010 vol. 12(Issue 3) pp:866-871
Publication Date(Web):05 Nov 2009
DOI:10.1039/B911180H
X-Ray diffraction studies are reported for six forms of ClInIII(OEP) (OEP is the dianion of octaethylporphyrin): ClInIII(OEP), ClInIII(OEP)·1.5 benzene, ClInIII(OEP)·1.5 pyridine, ClInIII(OEP)·0.5p-dioxane·benzene, ClInIII(OEP)·1.5 chlorobenzene, ClInIII(OEP)·C60·benzene. All crystals involve a square pyramidal coordination geometry about the indium ion with the chloride ion occupying the axial position and the four nitrogen atoms of the porphyrin defining the equatorial plane. In five of the structures the ethyl groups adopt an arrangement where they protrude outward on the opposite side of the porphyrin from the axial chloride so that they can encapsulate a guest. Pairs of ClInIII(OEP) molecules have been found to encapsulate molecules of benzene, pyridine, p-dioxane and chlorobenzene in a novel clamshell-like arrangement.
Co-reporter:Hua Yang;ChristineM. Beavers Dr.;Zhimin Wang;An Jiang;Ziyang Liu Dr.;Hongxiao Jin Dr.;BronQ. Mercado;MarilynM. Olmstead Dr.;AlanL. Balch Dr.
Angewandte Chemie International Edition 2010 Volume 49( Issue 5) pp:886-890
Publication Date(Web):
DOI:10.1002/anie.200906023
Co-reporter:Christine M. Beavers ; Manuel N. Chaur ; Marilyn M. Olmstead ; Luis Echegoyen
Journal of the American Chemical Society 2009 Volume 131(Issue 32) pp:11519-11524
Publication Date(Web):July 14, 2009
DOI:10.1021/ja903741r
An isomerically pure sample of Gd3N@C78 has been extracted from the carbon soot formed in the electric-arc generation of fullerenes using hollow graphite rods packed with Gd2O3 and graphite powder under an atmosphere of helium and dinitrogen. Purification has been achieved by chromatographic methods and the product has been characterized by mass spectrometry, UV/vis absorption spectroscopy, and cyclic voltammetry. Although a number of endohedral fullerenes have been found to utilize the D3h(5)-C78 cage, comparison of the spectroscopic and electrochemical properties of the previously characterized Sc3N@D3h(5)-C78 with those of Gd3N@C78 reveals significant differences that indicate that these two endohedrals do not possess the same cage structure. A single crystal X-ray diffraction study indicates that the fullerene cage does not follow the isolated pentagon rule (IPR) but has two equivalent sites where two pentagons abut. The endohedral has been identified as Gd3N@C2(22010)-C78. Two of the gadolinium atoms of the planar Gd3N unit are located within the pentalene folds formed by the adjacent pentagons. The third gadolinium atom resides at the center of a hexagonal face of the fullerene.
Co-reporter:Thelma Y. Garcia, James C. Fettinger, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2009 (Issue 46) pp:7143-7145
Publication Date(Web):29 Oct 2009
DOI:10.1039/B915083H
Cocrystallization of Co2(CO)8 with C60 traps the cobalt carbonyl molecule as the D3d isomer that otherwise is not available for crystallographic analysis.
Co-reporter:Christopher J. Chancellor ; Marilyn M. Olmstead
Inorganic Chemistry 2009 Volume 48(Issue 4) pp:1339-1345
Publication Date(Web):January 9, 2009
DOI:10.1021/ic8012427
Three new crystalline compounds of Ag(I) with fullerene-containing ligands, the piperidine adduct [C60(N(CH2CH2)2N)] and the fullero[60]pyrrolidine [C60(CH2N(CH3)CH2)], have been prepared and characterized by X-ray crystallography. The polymeric structure of {[C60(N(CH2CH2)2N)][Ag(O2CCF3)]2}·CS2 consists of linear chains composed of two distinct molecules of the functionalized fullerene, with four Ag(I) ions attached to the four nitrogen atoms and four bridging trifluoroacetate ions. Two of the four Ag(I) ions form η2-bonds to carbon atoms in different regions of the fullerene cage, and there is one close Ag−Ag contact (3.1657(7) Å) as well. These chains are further cross-linked by bridging trifluoroacetate ions. The structure of {[C60(CH2N(CH3)CH2)]Ag(NO3)}·0.25CH3OH involves two similar polymeric chains in which Ag(I) ions bind to the nitrogen atom of one N-methyl-3,4-fullero[60]pyrrolidine ligand and to a carbon atom of another N-methyl-3,4-fullero[60]pyrrolidine in η1-fashion for one chain and in distorted η2-fashion in the other. Additionally, each Ag(I) ion is bonded to two oxygen atoms from two bridging nitrate ions. On the other hand, [C60(N(CH2CH2)2N)]2Ag(NO3)·0.5CH3OH·CH2Cl2 is a simple coordination complex with two very large ligands attached to Ag(I). Coordination of Ag(I) to C60 produces much smaller alterations to the fullerene geometry than does coordination of Pt0(PPh3)2 or IrI(CO)Cl(PPh3)2 groups.
Co-reporter:Daniel Rios, Marilyn M. Olmstead and Alan L. Balch
Inorganic Chemistry 2009 Volume 48(Issue 12) pp:5279-5287
Publication Date(Web):April 28, 2009
DOI:10.1021/ic900243v
The metalloligand [Au{C(NHMe)(NHCH2CH2NH2)}2]Cl, 1, has been prepared by the reaction of ethylenediamine with [Au(CNMe)2]Cl. Compound 1 crystallized as a luminescent dimer with a Au···Au separation of 3.0224(4) Å. It reacted in solution with silver hexafluorophosphate to form the coordination polymer, {[Au{μ-C(NHMe)(NHCH2CH2NH2)}2Ag(NCMe)](PF6)2}n, 2. The structure of 2 involves a chain of alternating gold(I) and silver(I) ions with a Au···Ag distance of 2.9694(4)Å. The reaction of the metalloligand, 1, with silver tetrafluoroborate yielded three products: the green luminescent coordination polymer, {[Au{μ-C(NHMe)(NHCH2CH2NH2)}2Ag-(NCMe)](BF4)2}n, 3, which is analogous to 2; the non-luminescent binuclear complex, [Au{μ-C(NHMe)(NHCH2CH2NH2)}2Ag](BF4)2, 4; and the blue luminescent complex, [{μ-C(NHMe)NHCH2CH2NH(MeHN)C}Au2{μ-C(NHMe)(NHCH2CH2NH2)}2Ag](BF4)3-·3(MeCN), 5. Compound 5 involves a bent Au···Ag···Au cation with two different Au···Ag distances (2.9165(8) Å and 3.1743(8) Å). This cation self-associates through a Au···Au interaction of 3.0275(5) Å, which allows the formation of an extended zigzag chain of cations in 5.
Co-reporter:Yuliang Che, Hua Yang, Zhimin Wang, Hongxiao Jin, Ziyang Liu, Chunxin Lu, Tianming Zuo, Harry C. Dorn, Christine M. Beavers, Marilyn M. Olmstead and Alan L. Balch
Inorganic Chemistry 2009 Volume 48(Issue 13) pp:6004-6010
Publication Date(Web):June 9, 2009
DOI:10.1021/ic900322d
The structures of two newly synthesized endohedral fullerenes, Tm@C3v-C94 and Ca@C3v-C94, have been determined by single crystal X-ray diffraction on samples cocrystallized with NiII(octaethylporphyrin). Both compounds exhibit the same cage geometry and conform to the isolated pentagon rule (IPR). The metal ions within these rather large cages are localized near one end and along the C3 axis. While the calcium ion is situated over a C−C bond at a 6:6 ring junction, the thulium ion is positioned above a six-membered ring of the fullerene.
Co-reporter:Ramón Valencia, Antonio Rodríguez-Fortea, Steven Stevenson, Alan L. Balch and Josep M. Poblet
Inorganic Chemistry 2009 Volume 48(Issue 13) pp:5957-5961
Publication Date(Web):June 11, 2009
DOI:10.1021/ic900686a
Density functional theory computations for Sc4(μ3-O)2@Ih-C80 and Sc4(μ3-O)3@Ih-C80 (which is more stable than the alternative Sc4(μ3-O)2@Ih-C80O) reveal that the electronic structures of these two Sc-oxide endohedral metallofulerenes are different. Sc4(μ3-O)2@Ih-C80 involves a mixed valence cluster with the highest occupied molecular orbital (HOMO) localized on the metal cluster while in Sc4(μ3-O)3@Ih-C80 the HOMO is localized on the carbon cage and the electronic structure resembles that of Sc3N@Ih-C80.
Co-reporter:Krzysztof Winkler ; Monika Wysocka-Żołopa ; Katarzyna Rećko ; Ludwik Dobrzyński ; Jess C. Vickery
Inorganic Chemistry 2009 Volume 48(Issue 4) pp:1551-1558
Publication Date(Web):January 16, 2009
DOI:10.1021/ic801922a
The trinuclear complex, Au3(MeN═COMe)3, which displays a number of remarkable properties including solvoluminescence, has been found to undergo electrochemical oxidation with the deposition of long, thin needles on the electrode surface. The electro-deposition process has been studied by cyclic voltammetry, chronoamperometry, and quartz crystal microbalance techniques. The composition of the electrically conducting needles has been determined to be [Au3(MeN═COMe)3](ClO4)0.34 by two complementary methods. The related complex Au3(PhCH2N═COMe)3 underwent oxidation at a significantly more positive potential and did not produce a deposit on the electrode surface.
Co-reporter:Emily M. Gussenhoven, Martyn Jevric, Marilyn M. Olmstead, James C. Fettinger, Mark Mascal and Alan L. Balch
Crystal Growth & Design 2009 Volume 9(Issue 4) pp:1786-1792
Publication Date(Web):February 25, 2009
DOI:10.1021/cg800906x
The molecular packing arrangements for the unsolvated compounds, PtCl2(ATQ-CH2NH2) (1a) and PdCl2(ATQ-CH2NH2) (2) (ATQ = azatriquinane), and two solvates of the platinum complex, 6{PtCl2(ATQ-CH2NH2)}·2(CH3CN) (1b) and 3{PtCl2(ATQ-CH2NH2)}·2(CH2Cl2) (1c), are reported. These planar, d8 complexes have a wedgelike shape due to the presence of the bulky azatriquinane unit coordinated directly to the metal. All of the crystals exhibit hydrogen bonding between the N−H groups of one molecule and the chloride ligands on another. Despite the similar sizes and shapes of the complexes, the unsolvated compounds, PtCl2(ATQ-CH2NH2) (1a) and PdCl2(ATQ-CH2NH2) (2), pack in entirely different fashions, with metallophilic interactions between pairs of cofacial complexes in the palladium complex. The platinum complex lacks the metallophillic interactions. The structure of 6{PtCl2(ATQ-CH2NH2)}·2(CH3CN) (1b) is noteworthy for two features. First, these crystals contain an ordered cyclic assembly of 10 molecules of the complex with all the Pt−Cl groups directed toward the inside of the ring. The formation of this supramolecular macrocyclic array is facilitated by extensive hydrogen bonding between the NH groups of one molecule and the chloride ligands of another. Second, these crystals also contain a poorly organized region where one PtCl2(ATQ-CH2NH2) molecule is disordered over several orientations. 3{PtCl2(ATQ-CH2NH2)}·2(CH2Cl2) (1c) crystallizes with three molecules of the platinum complex in a crescent-shaped array that shows some similarity with the cyclic structure found in 6{PtCl2(ATQ-CH2NH2)}·2(CH3CN) (1b).
Co-reporter:AlanL. Balch
Angewandte Chemie International Edition 2009 Volume 48( Issue 15) pp:2641-2644
Publication Date(Web):
DOI:10.1002/anie.200805602
Co-reporter:BronQ. Mercado;An Jiang;Hua Yang;Zhimin Wang;Hongxiao Jin;Ziyang Liu Dr.;MarilynM. Olmstead Dr.;AlanL. Balch Dr.
Angewandte Chemie International Edition 2009 Volume 48( Issue 48) pp:9114-9116
Publication Date(Web):
DOI:10.1002/anie.200904662
Co-reporter:AlanL. Balch
Angewandte Chemie 2009 Volume 121( Issue 15) pp:2679-2682
Publication Date(Web):
DOI:10.1002/ange.200805602
Co-reporter:Krzysztof Winkler, Monika Wysocka-Żołopa, Marta M. Oleksicka, Katarzyna Rećko, Ludwik Dobrzyński, Jay R. Stork, Emily M. Gussenhoven, Marilyn M. Olmstead, Alan L. Balch
Electrochimica Acta 2008 Volume 53(Issue 24) pp:7288-7297
Publication Date(Web):15 October 2008
DOI:10.1016/j.electacta.2008.04.011
The electrochemical properties of the ions [Ir(CO)2X2]− (X = Cl, Br, and I) have been studied in dichloromethane solutions using cyclic voltammetry, chronoamperometry, electrochemical quartz crystal microbalance (EQCM), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and infrared spectroscopy. For the chloro and bromo salts, the anion [Ir(CO)2X2]− is oxidized initially to form [Ir(CO)2X2]+. The standard rate constants for the two-electron oxidations of [Ir(CO)2X2]− are 7.8(±0.6) × 10−3 and 9.2(±0.9) × 10−4 cm s−1 for the redox couples, [Ir(CO)2Cl2]−/+ and [Ir(CO)2Br2]−/+, respectively. The processes following electrolysis lead to the formation of two types of crystalline deposits on the electrode surface: needles and plates. The relative amounts of these solid phases that form depend mainly on the concentration of iridium complex in solution and on the time window of experiment. The strong intermetallic Ir–Ir interaction is responsible for the formation of the one-dimensional iridium complex chain. The crystal structures of the needle phases formed from [Ir(CO)2Cl2]− and [Ir(CO)2Br2]− are the same and belong to the space group Cmcm (no. 63). The stoichiometry of the one-dimensional crystals depends on the constitution of the supporting electrolyte: (TAA)0.6[Ir(CO)2Cl2] and (TAA)0.7[Ir(CO)2Br2] (TAA is tetra(alkyl)ammonium cation) salts are formed on the electrode surface. The formation of large three-dimensional crystal is responsible for the accumulation of electroactive materials on the electrode surface. The irreversible oxidation of [Ir(CO)2I2]− leads only to the formation of large, plate-like crystals on the electrode surface, no needles are formed.
Co-reporter:Steven Stevenson ; Christopher J. Chancellor ; Hon Man Lee ; Marilyn M. Olmstead
Inorganic Chemistry 2008 Volume 47(Issue 5) pp:1420-1427
Publication Date(Web):February 5, 2008
DOI:10.1021/ic701824q
Structural characterizations of three new mixed-metal endohedrals, GdSc2N@Ih-C80, Gd2ScN@Ih-C80, and TbSc2@Ih-C80, have been obtained by single-crystal X-ray diffraction on GdSc2N@Ih-C80·NiII(OEP)·2C6H6, Gd2ScN@Ih-C80·NiII(OEP)·2C6H6, and TbSc2N@Ih-C80·NiII(OEP)·2C6H6. All three have Ih-C80 cages and planar MM′2N units. The central nitride ion is positioned further from the larger Gd3+ or Tb3+ ions and closer to the smaller Sc3+ ions. The MM′2N units show a remarkable degree of orientational order in these and related compounds in which the endohedral fullerene is cocrystallized with a metalloporphyrin. The MM′2N units are oriented perpendicularly to the porphyrin plane and aligned along one of the N−Ni−N axes of the porphyrin. The smaller Sc3+ ions show a marked preference to lie near the porphyrin plane. The larger Gd3+ or Tb3+ ions assume positions further from the plane of the porphyrin. The roles of dipole forces and electrostatic forces in ordering these cocrystals of endohedral fullerenes and metalloporphyrins are considered.
Co-reporter:Daniel Rios ; David M. Pham ; James C. Fettinger ; Marilyn M. Olmstead
Inorganic Chemistry 2008 Volume 47(Issue 8) pp:3442-3451
Publication Date(Web):March 18, 2008
DOI:10.1021/ic702481v
Depending upon the crystallization conditions, [Au{C(NHMe)2}2](AsF6) forms colorless crystals that display a blue or green luminescence. The difference involves the type of solvate molecule that is incorporated into the crystal and the structure of the chains of cations that are formed upon crystallization. The crystallographically determined structures of blue-glowing [Au{C(NHMe)2}2](AsF6)·0.5(benzene), blue-glowing [Au{C(NHMe)2}2](AsF6)·0.5(acetone), green-glowing [Au{C(NHMe)2}2](AsF6)·0.5(chlorobenzene), and blue-glowing, solvate-free [Au{C(NHMe)2}2](EF6), E = P, As, Sb are reported. All pack with the cations forming extended columns, which may be linear or bent, but all show significant aurophilic interactions. The blue-glowing crystals have ordered stacks of cations with some variation in structural arrangement whereas the green-glowing crystals have disorder in their stacking pattern. Although there is extensive hydrogen bonding between the cations and anions in all structures, in the solvated crystals, the solvate molecules occupy channels but make no hydrogen-bonded contacts. The emission spectra of these new salts taken at 298 and 77 K are reported.
Co-reporter:Emily M. Gussenhoven ; Marilyn M. Olmstead ; James C. Fettinger
Inorganic Chemistry 2008 Volume 47(Issue 11) pp:4570-4578
Publication Date(Web):May 1, 2008
DOI:10.1021/ic702243z
Four polymorphs of IrI(CO)2(OC(CH3)CHC(CH3)N(p-tol)) have been characterized by single crystal X-ray crystallography. While all contain the same molecular unit with no significant structural variations within the molecules, all show different degrees of metallophilic interactions between the planar molecules. Three of these (the amber, the pale yellow, and the orange forms) are stable at room temperature, while the fourth, the L. T. orange form, is only obtained by cooling the orange polymorph. At 77 K, the amber, pale yellow, and L. T. orange polymorphs show intense luminescence. The variations in the luminescence among the polymorphs are considered in the context of the structural differences between them and the nature of the metallophilic interactions between the iridium centers. These results demonstrate how subtle variations in molecular organization can affect the physical properties of planar d8 transition metal compounds, which are an important class of lumiphores.
Co-reporter:Thelma Y. Garcia ; Marilyn M. Olmstead ; James C. Fettinger
Inorganic Chemistry 2008 Volume 47(Issue 23) pp:11417-11422
Publication Date(Web):October 24, 2008
DOI:10.1021/ic801605b
Splitting of the oxygen-bridged dimer {InIII(OEPO)}2 [where (OEPO)3− is the trianion of octaethyloxophlorin] by potential axial ligands has been examined and compared to results obtained previously for the cleavage of {FeIII(OEPO)}2. Treatment of {InIII(OEPO)}2 with an excess of imidazole (im) produced the crystalline complex {(im)2InIII(OEPO···im)}2·(im)2InIII(OEPO)·2Cl2C6H4. This solid contains two different (im)2InIII(OEPO) units that are bridged through hydrogen bonding by an uncoordinated imidazole. Treatment of {InIII(OEPO)}2 with an excess of pyridine (py) produced (py)2InIII(OEPO), which is isostructural with (py)2FeIII(OEPO). Although {FeIII(OEPO)}2 reacted with xylyl isocyanide (xylylNC) to form the novel free-radical complex (2,6-xylylNC)2FeII(OEPO•) [where (OEPO•)2− is the radical dianion of octaethyloxophlorin], {InIII(OEPO)}2 was unreactive toward xylyl isocyanide.
Co-reporter:Tianming Zuo, Marilyn M. Olmstead, Christine M. Beavers, Alan L. Balch, Guangbin Wang, Gordon T. Yee, Chunying Shu, Liaosa Xu, Bevan Elliott, Luis Echegoyen, James C. Duchamp and Harry C. Dorn
Inorganic Chemistry 2008 Volume 47(Issue 12) pp:5234-5244
Publication Date(Web):April 30, 2008
DOI:10.1021/ic800227x
We report an efficient method for the preparation and purification of the Ih and the D5h isomers of Tm3N@C80. Following preparation in a Krätschmer−Huffman electric-arc generator, the Tm3N@C80 isomers were obtained by a chemical separation process followed by a one-stage isomer selective chromatographic high-performance liquid chromatography (HPLC) separation (pyrenyl, 5PYE column). The HPLC chromatographic retention behavior on a pentabromobenzyl (5PBB) column suggests a charge transfer of ∼6 electrons; [M3N]6+@C806− and the chromatographic retention mechanisms of the Ih and the D5h isomers of Tm3N@C80 on both 5PBB and 5PYE columns are discussed. Single-crystal X-ray diffraction data demonstrate that the Tm3N cluster has a planar structure but represents a tight fit for trapping the Tm3N cluster inside the Ih- and the D5h-C80 cages. Specifically, the Tm atoms punch out the cage carbon atoms adjacent to them. The “punched out” effect can be demonstrated by cage radii and pyramidal angles at cage carbon atoms near the Tm atoms. The magnetic susceptibility (χT) for Tm3N@ Ih-C80 was found to exhibit Curie−Weiss behavior with C = 23.4 emu·K/mol, which is consistent with the calculated value for three uncoupled Tm3+ ions by considering the spin and orbital contributions with no quenching of the orbital angular momentum (L = 5, S = 1, and J = 6; Ccalcd = 23.3 emu·K/mol). The electrochemical measurements demonstrate that both the Ih and the D5h isomers of Tm3N@C80 have a large electrochemical gap.
Co-reporter:Christopher J. Chancellor, Adrienne A. Thorn, Christine M. Beavers, Marilyn M. Olmstead and Alan L. Balch
Crystal Growth & Design 2008 Volume 8(Issue 3) pp:976
Publication Date(Web):February 13, 2008
DOI:10.1021/cg070643r
The structures of three crystalline salts—[C60(N(CH2CH2)2NH)+][Rh(CO)2Cl2−]·2CS2, [C60(CH2NH(CH3)CH2)+][Rh(CO)2Cl2−]·CS2, and [C60(CH2N(CH3)(CH2CH3)CH2)+](I−)·CH3CH2I—have been determined. Each packs in a bilayered arrangement such that the cationic heads of the fullerene units and the corresponding anions form distinct polar regions, whereas the fullerene cage and the solvate molecules (carbon disulfide or ethyl iodide) are located in distinct hydrophobic regions.
Co-reporter:Luis Echegoyen, Christopher J. Chancellor, Claudia M. Cardona, Bevan Elliott, José Rivera, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2006 (Issue 25) pp:2653-2655
Publication Date(Web):18 May 2006
DOI:10.1039/B604011J
Crystallographic data for the pyrrolidine adduct Y3N@C80C4H9N·2.5CS2 reveals a slightly pyramidalized Y3N unit with idealized mirror symmetry that straddles the site of addition but does not directly interact with the addend.
Co-reporter:Ngon T. Tran, Jay R. Stork, David Pham, Marilyn M. Olmstead, James C. Fettinger and Alan L. Balch
Chemical Communications 2006 (Issue 10) pp:1130-1132
Publication Date(Web):25 Jan 2006
DOI:10.1039/B513700D
Trimeric green [(i-PrNC)12RhI3]Cl3·4.5H2O, monomeric [(C6H11NC)4RhI](BPh4) and [(i-PrNC)4RhI](BPh4) (both yellow), and red, dimeric [(C6H11NC)8RhI2]Cl2·0.5C6H6·2H2O have been crystallized.
Co-reporter:Elena P. Krinichnaya, Alexander P. Moravsky, Oleg Efimov, Janusz W. Sobczak, Krzysztof Winkler, Wlodzimierz Kutner and Alan L. Balch
Journal of Materials Chemistry A 2005 vol. 15(Issue 14) pp:1468-1476
Publication Date(Web):09 Feb 2005
DOI:10.1039/B416357E
Electropolymerization of C60 in the presence of dioxygen, in a mixture of acetonitrile and toluene (1 : 4, v : v) containing tetra(alkyl)ammonium perchlorate, was investigated by multi-scan cyclic voltammetry and piezoelectric microgravimetry with the use of an electrochemical quartz crystal microbalance. The fullerene was readily electropolymerized if the O2 to C60 concentration ratio in solution exceeded 1 : 10 and the applied potential reached values where electro-reduction of dioxygen to superoxide, O2˙−, and C60 to C602− occurred. The redox activity of the polymer was determined by cyclic voltammetry for solutions with different tetra-(alkyl)ammonium perchlorates used as supporting electrolytes. The film conductivity was higher the smaller the size of the cation in the supporting electrolyte. The C60 electropolymerization in the presence of dioxygen was suppressed when a spin trapping agent, N-tert-butyl-α-(4-nitrophenyl)nitrone that could intercept superoxide, was present. The fullerene was also electropolymerized in the presence of small amounts of the epoxide, C60O, in the absence of dioxygen. We postulate that the C60 electropolymerization in the presence of O2 proceeds via the initial nucleophilic attack of superoxide on C60 to form a C60O2˙− radical anion, which then interacts with another molecule of C60 to produce C60O and C60O˙−. Under further electro-reduction, these intermediates serve to initiate polymerization of C60 through the formation of C60O2−, as determined earlier in studies of the electropolymerization of C60O itself.
Co-reporter:David M. Pham, Daniel Rios, Marilyn M. Olmstead, Alan L. Balch
Inorganica Chimica Acta 2005 Volume 358(Issue 14) pp:4261-4269
Publication Date(Web):15 November 2005
DOI:10.1016/j.ica.2005.06.033
The salts – yellow [Cr(NH3)6][Ag(CN)2]3 · 2H2O, red [Co(NH3)6][Ag(CN)2]3 · 2H2O, red [Co(NH3)6][Au(CN)2]3 · 2H2O, pale yellow [Ru(NH3)6][Ag(CN)2]3 · 2H2O, yellow K[Cr(NH3)6]2[Au(CN)2]7 · 4H2O, and colorless [(μ2-NH2)2Pt2(NH3)10][Au(CN)2]6 · 5.5{OS(CH3)2} · 0.5H2O – have been prepared by evaporation of aqueous solutions of potassium dicyanoargenate or potassium dicyanoaurate and salts of the appropriate cations. Hydrogen bonding between the cations and the cyano groups of the anions facilitates the formation of structures with strong metallophilic interactions between the anions. Thus, the [Au(CN)2]− or [Ag(CN)2]− ions self-associate into linear trimers in the isostructural set of crystals, [Cr(NH3)6][Ag(CN)2]3 · 2H2O (Ag⋯Ag distance; 3.1610(4) Å), [Co(NH3)6][Ag(CN)2]3 · 2H2O (Ag⋯Ag distance; 3.1557(2) Å), [Co(NH3)6][Au(CN)2]3 · 2H2O (Au⋯Au distance; 3.0939(4) Å), and [Ru(NH3)6][Ag(CN)2]3 · 2H2O (Ag⋯Ag distance; 3.1584(5) Å). Crystalline [(μ2-NH2)2Pt2(NH3)10][Au(CN)2]6 · 5.5{OS(CH3)2} · 0.5H2O also contains nearly linear trimers of the dicyanoaurate ion. Yellow crystals of K[Cr(NH3)6]2[Au(CN)2]7 · 4H2O contain a centrosymmetric, bent chain of seven dicyanoaurate ions with Au⋯Au separations of 3.1806(3), 3.2584(4), and 3.1294(4) Å.Aggregation of [Ag(CN)2]− and Au(CN)2]− in salts with metal amine cations (e.g. [Co(NH3)6][Ag(CN)2]3 · 2H2O) has been examined crystallographically.
Co-reporter:Steven Stevenson, J. Paige Phillips, Jon E. Reid, Marilyn M. Olmstead, Sankar Prasad Rath and Alan L. Balch
Chemical Communications 2004 (Issue 24) pp:2814-2815
Publication Date(Web):16 Nov 2004
DOI:10.1039/B412338G
The X-ray crystal structure of Gd3N@C80•NiII(OEP)•1.5(benzene) shows that the Gd3N unit within the Ih C80 cage is pyramidal, whereas Sc3N@C80, Sc3N@C78, Sc3N@C68, Lu3N@C80 and Sc2ErN@C80 have planar M3N units.
Co-reporter:Matthias Stender, Marilyn M. Olmstead, Alan L. Balch, Daniel Rios and Saeed Attar
Dalton Transactions 2003 (Issue 22) pp:4282-4287
Publication Date(Web):23 Sep 2003
DOI:10.1039/B310085E
The colorless salts [C5H10NH2][AuI(CN)2], [C4H8NH2][AuI(CN)2], [Ph2NNH3][AuI(CN)2]·H2O and [(n-C3H7)4N][AuI(CN)2]·H2O have been prepared by evaporation of aqueous solutions of potassium dicyanoaurate and the chloride salt of the appropriate cation. Hydrogen bonding between the cations and the cyano groups of the anions facilitates the formation of structures with strong aurophilic interactions between the anions. Thus, the [Au(CN)2]− ions self-associate in the three salts [C5H10NH2][AuI(CN)2]
(Au⋯Au 3.0969(3)
Å), [C4H8NH2][AuI(CN)2]
(Au1⋯Au2 3.0795(4)
Å), [Ph2NNH3][AuI(CN)2]·H2O (Au⋯Au 3.0866(4)
Å), while in [(n-C3H7)4N][AuI(CN)2]·H2O, which lacks N–H units, the gold ions are widely dispersed. The crystals of [C5H10NH2][AuI(CN)2], [C4H8NH2][AuI(CN)2] and [Ph2NNH3][AuI(CN)2]·H2O each show strong blue luminescence at room temperature, while [(n-C3H7)4N][AuI(CN)2]·H2O is non-luminescent.
Co-reporter:Marilyn M. Olmstead, Ana de Bettencourt-Dias, Hon Man Lee, David Pham and Alan L. Balch
Dalton Transactions 2003 (Issue 16) pp:3227-3232
Publication Date(Web):10 Jul 2003
DOI:10.1039/B306714A
Crystals of C60·PtII(OEP)·2(C6H6), TCNQ·CuII(OEP), TCNQ·H2(OEP), TCNQ·2CuII(OEP), TCNQ·2ZnII(OEP) and TNFM·CoII(OEP) [OEP is the dianion of octaethylporphyrin, TCNQ is 7,7,8,8-tetracyanoquinodimethane, TNFM is (2,4,7-trinitrofluorenylidene)malonitrile] have been obtained by diffusion of a solution of the porphyrin as donor into a solution of the respective acceptor molecule. The structure of C60·PtII(OEP)·2(C6H6) consists of an ordered C60 cage nestled against the platinum porphyrin which makes close face-to-face contact with another PtII(OEP) molecule. In contrast, there are no close face-to-face contacts between porphyrins in the crystal structures of TCNQ·CuII(OEP), TCNQ·H2(OEP), and TNFM·CoII(OEP). These compounds consist of classical donor–acceptor stacks of interleaved porphyrin and TCNQ or TNFM molecules with separations of ca. 3.3 Å between adjacent molecules. However with TCNQ·2CuII(OEP) and TCNQ·2ZnII(OEP) the structures involve TCNQ (A) and MII(OEP)
(D) molecules that crystallize in stacks with a DDA(DDA)nDDA arrangement. Within these stacks there are pairwise contacts between MII(OEP) molecules and these pairs are compared to those found in C60·PtII(OEP)·2(C6H6) and related fullerene-containing crystals.
Co-reporter:Ana de Bettencourt-Dias, Krzysztof Winkler, W.Ronald Fawcett, Alan L. Balch
Journal of Electroanalytical Chemistry 2003 Volume 549() pp:109-117
Publication Date(Web):5 June 2003
DOI:10.1016/S0022-0728(03)00265-1
A study of simple redox solutes, ferrocene, N,N,N′,N′-tetramethyl-1,4-phenylenediamine, decamethylferrocene, bis(i-propylcyclopentadienyl)iron(II), [Ru(phen)3](ClO4)2, [Fe(bpy)3](ClO4)2, [Co(bpy)3](ClO4)2, and iodine has been performed at electrodes modified with polymeric fullerene films. Fullerene-modified electrodes were prepared by electropolymerization of C60 initiated by a trace amount of dioxygen or by simultaneous electroreduction of fullerene and a palladium(II) acetate trimer. These two films affect the electrochemical behavior of reversible redox systems differently. For the film formed from C60 and O2, a significant decrease of electrochemical activity is observed upon repeated potential cycling. The electrochemical activity of the film is stabilized by the redox solute added to the growth solution due to the catalytic oxidation of the fullerene film by the oxidized form of the redox system. Positively charged species can also be incorporated into the structure of the film during the electropolymerization process. The electrochemical behavior of redox-active solutes themselves becomes less reversible as the Pd/C60 film growth proceeds. This film incorporates also ferricinium ion, N,N,N′,N′-tetramethyl-1,4-phenylenediamine cation, decamethylferricinium ion, and to a smaller degree [Co(bpy)3]n+.
Co-reporter:Marilyn M. Olmstead Dr.;Hon Man Lee Dr.;James C. Duchamp Dr.;Steven Stevenson Dr.;Daniela Marciu Dr.;Harry C. Dorn Dr. Dr.
Angewandte Chemie International Edition 2003 Volume 42(Issue 8) pp:
Publication Date(Web):21 FEB 2003
DOI:10.1002/anie.200390237
Breaking the rule: The structure of Sc3N@C68⋅[NiII(OEP)]⋅2 C6H6 has been determined by single-crystal X-ray diffraction. The fullerene cage exists as an isomer with D3 symmetry (see picture), as initially predicted by density functional calculations. The scandium atoms are located over the centers of three pentalene units within the three-cornered carbon cage, which cannot obey the isolated pentagon rule. OEP=Octaethylporphyrinate.
Co-reporter:Akari Hayashi, Ana de Bettencourt-Dias, Krzysztof Winkler and Alan L. Balch
Journal of Materials Chemistry A 2002 vol. 12(Issue 7) pp:2116-2122
Publication Date(Web):25 Mar 2002
DOI:10.1039/B200037G
Electroreduction of a toluene–acetonitrile (4∶1 v/v) solution of C60 and cis-Pt(py)2Cl2 in the presence of 0.10 M tetra(n-butyl)ammonium perchlorate as supporting electrolyte produces a black, redox active film that coats the electrode surface. This film retains its redox activity when transferred to an acetonitrile solution that contains only the supporting electrolyte, 0.10 M tetra(n-butyl)ammonium perchlorate. The film has been characterized by infrared spectroscopy, laser desorption mass spectrometry, and XPS spectroscopy. The formation of this film is dependent on the platinum complex used as precursor and on the potential range utilized during film growth. No film growth is observed when Pt(bipy)Cl2, Pt(py)2I2, cis-Pt(PPh3)2Cl2 or trans-Pt(py)2Cl2
are used as precursors, but {Pt(μ-Cl)Cl(C2H4)}2 is a useful precursor which allows film growth at less negative potentials. Chemically prepared C60Pt1 is also electrochemically active when precipitated on a platinum electrode. The formation of an electroactive film from the electroreduction of C70 and cis-Pt(py)2Cl2 is also reported.
Co-reporter:Marilyn M. Olmstead, Hon Man Lee, Steve Stevenson, Harry C. Dorn and Alan L. Balch
Chemical Communications 2002 (Issue 22) pp:2688-2689
Publication Date(Web):21 Oct 2002
DOI:10.1039/B209270K
The X-ray crystal structure of (Isomer 2 of Er2@C82)·NiII(OEP)·2(benzene) shows that the fullerene cage in Isomer 2 of Er2@C82 is the C3v isomer (82∶8) and that the erbium ions are distributed over 23 interior sites with occupancies ranging from 0.25 to 0.03.
Co-reporter:Hon Man Lee, Marilyn M. Olmstead, Tomohiro Suetsuna, Hidekazu Shimotani, Nita Dragoe, R. James Cross, Koichi Kitazawa and Alan L. Balch
Chemical Communications 2002 (Issue 13) pp:1352-1353
Publication Date(Web):23 May 2002
DOI:10.1039/B202925C
A sample of C60 containing ca. 9% Kr@C60 has been used to form crystalline (0.09Kr@C60/0.91C60)·{NiII(OEP)}·2C6H6 whose X-ray crystal structure reveals that the Kr atom is centered within the carbon cage and does not produce a detectable change in the size of the fullerene.
Co-reporter:Steve Stevenson Dr.;Hon Man Lee Dr.;Marilyn M. Olmstead Dr.;Carrie Kozikowski Dr.;Paige Stevenson Dr. Dr.
Chemistry - A European Journal 2002 Volume 8(Issue 19) pp:
Publication Date(Web):26 SEP 2002
DOI:10.1002/1521-3765(20021004)8:19<4333::AID-CHEM4333>3.0.CO;2-B
The cover picture shows a drawing of the solid-state structure of the new endohedral fullerene, Lu3N@C80, in crystalline Lu3N@C80⋅5(o-xylene). The fullerene cage is shown in yellow, the ordered o-xylene molecules in orange, and the atoms of the Lu3N unit connected in purple with black dashed lines outlining the positions of the Lu atoms. In this structure the fullerene cages are fully ordered, but the positions of the lutetium atoms are disordered with four different orientations existing inside the C80 cage. However, the Lu3N unit is nearly planar at each site. Only the major Lu3N site is illustrated in the cover drawing. Crystals of Lu3N@C80⋅5(o-xylene) and Sc3N@C80⋅5(o-xylene) are isomorphous, and despite the difference in ionic radii of Lu3+ (0.848 Å) and Sc3+ (0.68 Å), the dimensions of the C80 cage and of the Lu3N and Sc3N units within it are similar in these crystals. For details see the article by Balch et al. on p. 4528 ff.
Co-reporter:Steve Stevenson Dr.;Hon Man Lee Dr.;Marilyn M. Olmstead Dr.;Carrie Kozikowski Dr.;Paige Stevenson Dr. Dr.
Chemistry - A European Journal 2002 Volume 8(Issue 19) pp:
Publication Date(Web):26 SEP 2002
DOI:10.1002/1521-3765(20021004)8:19<4528::AID-CHEM4528>3.0.CO;2-8
The trimetallic nitride template (TNT) approach has been successfully utilized to prepare the new endohedral Lu3N@C80. Well-ordered crystals of Lu3N@C80⋅5 (o-xylene) and Sc3N@C80⋅5 (o-xylene) form upon cooling of o-xylene solutions of these endohedrals and they are isomorphous. Although the positions of the fullerene cage (which is fully ordered and located at a crystallographic center of symmetry) and the o-xylene molecules are nearly identical in these two structures, the positioning of the metal ions in the two crystals differ in significant ways. However, the expected difference in sizes of lutetium and scandium does not affect the dimensions of the C80 cage. Nevertheless, the positions of the metal atoms do produce a slight outward dislocation of the immediately adjacent carbon atoms.
Co-reporter:Marilyn M. Olmstead Dr.;Ana de Bettencourt-Dias Dr.;James C. Duchamp Dr.;Steven Stevenson Dr.;Daniela Marciu Dr.;Harry C. Dorn Dr. Dr.
Angewandte Chemie 2001 Volume 113(Issue 7) pp:
Publication Date(Web):27 MAR 2001
DOI:10.1002/1521-3757(20010401)113:7<1263::AID-ANGE1263>3.0.CO;2-G
Co-reporter:Feilong Jiang, Marilyn M. Olmstead and Alan L. Balch
Dalton Transactions 2000 (Issue 22) pp:4098-4103
Publication Date(Web):25 Oct 2000
DOI:10.1039/B005684G
Three salts of the cation [Au{C(OMe)NMeH}2]+, formed by protonation of the solvoluminescent gold(I) trimer [Au3(MeNCOMe)3], have been prepared and spectroscopically and structurally characterized. Each crystallizes as a unique form with varying aurophilic interactions between the linear, two-coordinate cations. Thus, the chloroform solvate, [Au{C(OMe)NMeH}2][C7Cl2NO3]·CHCl3, (where [C7Cl2NO3]− is an anion obtained by hydrolysis of 2,3-dichloro-4,5-dicyano-1,4-benzoquinone, DDQ), contains the cation as an isolated monomer, while unsolvated [Au{C(OMe)NMeH}2][C7Cl2NO3] contains pairs of cations that are linked by a single Au⋯Au interaction with a 3.1955(3) Å separation between the gold centers. In [Au{C(OMe)NMeH}2][O2CCF3] the cations associate to form infinite, nearly linear (Au⋯Au⋯Au angle, 172.209(7)°) chains that have the gold centers only 3.27797(15) Å apart. The luminescent behavior of [Au{C(OMe)NMeH}2][O2CCF3] is reported.
Co-reporter:Pamela Lord;Marilyn M. Olmstead
Angewandte Chemie 1999 Volume 111(Issue 18) pp:
Publication Date(Web):15 SEP 1999
DOI:10.1002/(SICI)1521-3757(19990917)111:18<2930::AID-ANGE2930>3.0.CO;2-4
Die Metallierung von Octaethylbilindion (H3OEB) mit Palladium(II)-acetat liefert den neuartigen vierkernigen Komplex [Pd4(OEB)2], in dem eine (Pd)2+-Einheit mit zwei helicalen Pd(OEB)-Einheiten eine Sandwichverbindung bildet (siehe Abbildung). Bei der Umsetzung von [Pd4(OEB)2] mit Pyridin/Ethanol entsteht der helicale Komplex [Pd(OEB)] mit ungepaarten Elektronen.
Co-reporter:Marilyn M. Olmstead;Kalyani Maitra
Angewandte Chemie 1999 Volume 111(Issue 1‐2) pp:
Publication Date(Web):12 MAR 1999
DOI:10.1002/(SICI)1521-3757(19990115)111:1/2<243::AID-ANGE243>3.0.CO;2-Z
Cokristallisation eines Fullerens mit einer ionischen Komponente wurde erstmals festgestellt: Dunkelrote, nahezu schwarze Kristalle von C60{Ag(NO3)}5 (siehe Ausschnitt aus der Struktur im Kristall) bilden sich, wenn man Lösungen von C60 in Benzol und von AgNO3 in Ethanol mischt. Die Silbernitratkomponente bildet ein Zeolith-artiges Netz, in dessen Hohlräumen Fullerenmoleküle fixiert sind. Trotz der Wasserlöslichkeit von AgNO3 ist C60{Ag(NO3)}5 in Wasser einige Stunden stabil.
Co-reporter:Pamela Lord;Marilyn M. Olmstead
Angewandte Chemie International Edition 1999 Volume 38(Issue 18) pp:
Publication Date(Web):15 SEP 1999
DOI:10.1002/(SICI)1521-3773(19990917)38:18<2761::AID-ANIE2761>3.0.CO;2-Y
Metalation of octaethylbilindione (H3OEB) with palladium(II) acetate produces the novel tetranuclear complex [Pd4(OEB)2] in which a (PdI2)2+ unit is sandwiched between two helical Pd(OEB) units (see picture). Treatment of [Pd4(OEB)2] with pyridine/ethanol gives the odd-electron helical complex [Pd(OEB)].
Co-reporter:Marilyn M. Olmstead;Kalyani Maitra
Angewandte Chemie International Edition 1999 Volume 38(Issue 1‐2) pp:
Publication Date(Web):18 JAN 1999
DOI:10.1002/(SICI)1521-3773(19990115)38:1/2<231::AID-ANIE231>3.0.CO;2-5
Cocrystallization of a fullerene and an ionic component has been observed for the first time. Dark red, nearly black crystals of C60{Ag(NO3)}5 (a section of the crystal structure is shown) form when solutions of C60 in benzene and Ag(NO3) in ethanol are mixed. The silver nitrate portion forms a zeolite-like network, in which rounded cavities are formed that are occupied by the fullerene molecules. Despite the good solubility of silver nitrate, C60{Ag(NO3)}5 is stable when immersed in water for several hours.
Co-reporter:Marilyn M. Olmstead;Pin-pin Wei
Chemistry - A European Journal 1999 Volume 5(Issue 11) pp:
Publication Date(Web):29 OCT 1999
DOI:10.1002/(SICI)1521-3765(19991105)5:11<3136::AID-CHEM3136>3.0.CO;2-#
Deeply colored, air-stable molecular crystals, [Pd6Cl12]⋅1.5 (naphthalene), [Pd6Cl12]⋅(1-methylanthracene), and [Pd6Cl12]⋅0.5 (1,2:5,6-dibenzanthracene)⋅0.5 (benzene) (shown here) consisting of planar polynuclear aromatic hydrocarbon (PAH) molecules and cubic clusters of [Pd6Cl12] are readily formed from solutions of bis(benzonitrile)palladium(II) dichloride and the approriate PAH in benzene.
Co-reporter:Jess C. Vickery;Dr. Marilyn M. Olmstead;Dr. Ella Y. Fung; Dr. Alan L. Balch
Angewandte Chemie 1997 Volume 109(Issue 11) pp:
Publication Date(Web):31 JAN 2006
DOI:10.1002/ange.19971091109
Co-reporter: Dr. Alan L. Balch;Dr. Leijun Hao;Dr. Marilyn M. Olmstead
Angewandte Chemie 1996 Volume 108(Issue 2) pp:
Publication Date(Web):31 JAN 2006
DOI:10.1002/ange.19961080220
Co-reporter: Dr. Lechoslaw Latos-Grażyński;Ewa Pacholska;Dr. Piotr J. Chmielewski;Dr. Marilyn M. Olmstead; Dr. Alan L. Balch
Angewandte Chemie 1995 Volume 107(Issue 20) pp:
Publication Date(Web):13 JAN 2006
DOI:10.1002/ange.19951072032
Co-reporter:Hua Yang ; Hongxiao Jin ; Xinqing Wang ; Ziyang Liu ; Meilan Yu ; Fukun Zhao ; Brandon Q. Mercado ; Marilyn M. Olmstead
Journal of the American Chemical Society () pp:
Publication Date(Web):August 3, 2012
DOI:10.1021/ja304867j
Three isomers of Sm@C82 that are soluble in organic solvents were obtained from the carbon soot produced by vaporization of hollow carbon rods doped with Sm2O3/graphite powder in an electric arc. These isomers were numbered as Sm@C82(I), Sm@C82(II), and Sm@C82(III) in order of their elution times from HPLC chromatography on a Buckyprep column with toluene as the eluent. The identities of isomers, Sm@C82(I) as Sm@Cs(6)-C82, Sm@C82(II) as Sm@C3v(7)-C82, and Sm@C82(III) as Sm@C2(5)-C82, were determined by single-crystal X-ray diffraction on cocrystals formed with Ni(octaethylporphyrin). For endohedral fullerenes like La@C82, which have three electrons transferred to the cage to produce the M3+@(C82)3– electronic distribution, generally only two soluble isomers (e.g., La@C2v(9)-C82 (major) and La@Cs(6)-C82 (minor)) are observed. In contrast, with samarium, which generates the M2+@(C82)2– electronic distribution, five soluble isomers of Sm@C82 have been detected, three in this study, the other two in two related prior studies. The structures of the four Sm@C82 isomers that are currently established are Sm@C2(5)-C82, Sm@Cs(6)-C82, Sm@C3v(7)-C82, and Sm@C2v(9)-C82. All of these isomers obey the isolated pentagon rule (IPR) and are sequentially interconvertable through Stone–Wales transformations.
Co-reporter:Sang Ho Lim ; Marilyn M. Olmstead
Journal of the American Chemical Society () pp:
Publication Date(Web):May 26, 2011
DOI:10.1021/ja2026807
Solutions containing the components Au+, dppe (dppe is bis(diphenylphosphino)ethane), and Br– in a 1:1:1 ratio can produce three different types of crystals: type A, orange luminescent solvates of the dimer Au2(dppe)2Br2 (Au2(μ-dppe)2Br2·2(OSMe2), Au2(μ-dppe)2Br2·2(OCMe2), Au2(μ-dppe)2Br2·2(CH2Cl2), Au2(μ-dppe)2Br2·2(HC(O)NMe2)); type B, green luminescent solvates of the same dimer (Au2(μ-dppe)2Br2·(NCMe) and Au2(μ-dppe)2Br2·0.5(C4H10O)); and type C, orange luminescent solvates of a polymer ({Au(μ-dppe)Br}n·0.5(C4H10O) and {Au(μ-dppe)Br}n·(CH2Cl2)). Some crystals of types A are solvoluminescent. Exposure of type A crystals of Au2(μ-dppe)2Br2·2(OCMe2) or Au2(μ-dppe)2Br2·2(CH2Cl2) to air or vacuum results in the loss of the orange luminescence and the formation of new green luminescent crystals. Subsequent exposure of these crystals to acetone or dichloromethane vapor results in the reformation of crystals of type A. The dimeric complexes in crystals of types A and B are all centrosymmetric and share a common ring conformation. Within these dimers, the coordination geometry of each gold center is planar with a P2Br donor set. In other respects, the Au2(μ-dppe)2Br2 molecule is remarkably flexible and behaves as a molecular accordion, whose dimensions depend upon the solvate content of a particular crystalline phase. In particular, the dimer Au2(μ-dppe)2Br2 is able to accommodate Au···Au separations that range from 3.8479(3) to 3.0943(2) Å, and these variations along with alterations in the Au–Br distances and in the P–Au–P angles are the likely causes of the differences in the luminescence properties of these crystals.
Co-reporter:Sang Ho Lim, Jennifer C. Schmitt, Jason Shearer, Kellie R. England, Marilyn M. Olmstead and Alan L. Balch
Dalton Transactions 2014 - vol. 43(Issue 36) pp:NaN13763-13763
Publication Date(Web):2014/07/29
DOI:10.1039/C4DT01902D
The colorless, two-coordinate gold(I) complex, [(H2O)3Na][Au(SCSN3)2], has been synthesized through the [2 + 3] cyclic reaction of carbon disulfide and sodium azide in the presence of the labile complex (tht)AuCl. Metathesis of [(H2O)3Na][Au(SCSN3)2], with tetra(phenyl)arsonium chloride produced colorless needles of (Ph4As)[Au(SCSN3)2]. The structure of [(H2O)3Na][Au(SCSN3)2] involves linear gold coordination by two exocyclic sulfur atoms of the 1,2,3,4-thiatriazole-5-thiolate anions. These two-coordinate anions self-associate to form extended, zig-zag chains that are connected by aurophilic bonding with Au⋯Au distances of 3.2653(3) Å and 3.3090(3) Å. Remarkably, the individual S–Au–S units that are connected though aurophilic interactions are eclipsed. The structure of (Ph4As)[Au(SCSN3)2] also contains linear, two-coordinate gold ions with bonding to the 1,2,3,4-thiatriazole-5-thiolate anionic ligands through the exocyclic sulfur atoms. However, in this salt, the anions self-associate through Au⋯Au bonds (Au⋯Au distance of 3.2007(3) Å) to form simple dimers, which also have an eclipsed arrangement of the ligands. Electronic structure calculations strongly suggest that the staggered geometry for the [(Au(SCSN3))2]+ dimer is energetically favored relative to the eclipsed geometry. However, attractive π-stacking interactions appear to promote the observed eclipsed arrangement of the ligands.
Co-reporter:Kamran B. Ghiassi, Marilyn M. Olmstead and Alan L. Balch
Dalton Transactions 2014 - vol. 43(Issue 20) pp:NaN7358-7358
Publication Date(Web):2014/01/29
DOI:10.1039/C3DT53517G
Gadolinium-containing endohedral fullerenes represent a new class of effective relaxation agents for magnetic resonance imaging (MRI). The range of different structures possible for this class of molecules and their properties as MRI agents are reviewed here.
Co-reporter:Brandon Q. Mercado, Marilyn M. Olmstead, Christine M. Beavers, Michael L. Easterling, Steven Stevenson, Mary A. Mackey, Curtis E. Coumbe, Joshua D. Phillips, J. Paige Phillips, Josep M. Poblet and Alan L. Balch
Chemical Communications 2010 - vol. 46(Issue 2) pp:NaN281-281
Publication Date(Web):2009/11/09
DOI:10.1039/B918731F
The tetrahedral array of four scandium atoms with oxygen atoms capping three of the four faces found in Sc4(μ3-O)3@Ih-C80 is the largest cluster isolated to date inside a fullerene cage.
Co-reporter:Thelma Y. Garcia, James C. Fettinger, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2009(Issue 46) pp:NaN7145-7145
Publication Date(Web):2009/10/29
DOI:10.1039/B915083H
Cocrystallization of Co2(CO)8 with C60 traps the cobalt carbonyl molecule as the D3d isomer that otherwise is not available for crystallographic analysis.
Co-reporter:Hua Yang, Brandon Q. Mercado, Hongxiao Jin, Zhimin Wang, An Jiang, Ziyang Liu, Christine M. Beavers, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2011 - vol. 47(Issue 7) pp:NaN2070-2070
Publication Date(Web):2010/12/07
DOI:10.1039/C0CC03017A
Fullerenes are generally considered as highly symmetric, yet fullerene isomers with only C1 symmetry, such as C1(30)–C90 and C1(32)–C90 whose structures are reported here, become increasingly numerous as fullerene size increases.
Co-reporter:Faye L. Bowles, Marilyn M. Olmstead, Christine M. Beavers and Alan L. Balch
Chemical Communications 2013 - vol. 49(Issue 53) pp:NaN5923-5923
Publication Date(Web):2013/04/26
DOI:10.1039/C3CC41773E
Cocrystallization of Hg{Co(CO)4}2 with C60 produces Hg{Co(CO)4}2·C60·toluene in which the geometry of the Hg{Co(CO)4}2 molecule is rearranged to fit between the remarkably well ordered fullerenes.
Co-reporter:Amineh Aghabali, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2014 - vol. 50(Issue 96) pp:NaN15155-15155
Publication Date(Web):2014/10/16
DOI:10.1039/C4CC06995A
The reaction of Rh2(O2CCH3)4 with the functionalized fullerene N(CH2CH2)2NC60 can produce a linear, crystalline polymer or can trap free C60 or C70 molecules between similar chains.
Co-reporter:Amineh Aghabali, Sharon Jun, Marilyn M. Olmstead and Alan L. Balch
Dalton Transactions 2017 - vol. 46(Issue 11) pp:NaN3715-3715
Publication Date(Web):2017/02/23
DOI:10.1039/C7DT00026J
The reaction of the piperazine mono-adduct, N(CH2CH2)2NC60, with diiodine produced well ordered, black crystals of (I2N(CH2CH2)2NI2)C60·2.884(C6H6)·0.116I2, which contains two nearly linear N–I–I units. Reaction of N(CH2CH2)2NC60 with iodine monochloride produced two materials: the dihalogen adduct, (ClIN(CH2CH2)2NICl)C60·2.3(CS2)·0.7(CH2Cl2), when crystallization occurred rapidly from carbon disulfide/dichloromethane solution or the salt, [(N(CH2CH2)2NH)C60+][ICl2−]·CS2, when crystallization happened more slowly from toluene/dichloromethane solution where hydrolysis of the iodine monochloride by adventitious water presumably occurred.
Co-reporter:Kamran B. Ghiassi, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2013 - vol. 49(Issue 91) pp:NaN10723-10723
Publication Date(Web):2013/10/04
DOI:10.1039/C3CC46367B
Cocrystallization of C70 with bis(ethylenedithio)tetrathiafulvalene (ET) produces two different solvates, C70·ET·C6H6 and 2C70·2ET·CS2, which show distinctly different overlap between the fullerene and ET molecules.
Co-reporter:Zhimin Wang, Hua Yang, An Jiang, Ziyang Liu, Marilyn M. Olmstead and Alan L. Balch
Chemical Communications 2010 - vol. 46(Issue 29) pp:NaN5264-5264
Publication Date(Web):2010/06/10
DOI:10.1039/C0CC00697A
We report an analysis of the similar structures of Cs(16)-C86 and C2(17)-C86 from a single crystal X-ray diffraction study of Cs(16)/C2(17)-C86·(nickel octaethylporphyrin)·2toluene.
Co-reporter:Sang Ho Lim, Marilyn M. Olmstead and Alan L. Balch
Chemical Science (2010-Present) 2013 - vol. 4(Issue 1) pp:NaN318-318
Publication Date(Web):2012/09/10
DOI:10.1039/C2SC20820B
The solid state interconversions of four different crystalline compounds containing the Au2(dppe)2I2 unit (dppe is bis-(diphenylphosphino)ethane) have been observed and characterized through X-ray diffraction and emission spectroscopy. Treatment of AuI in acetone with solid dppe yields the crystalline polymorphs: α-Au2(μ-dppe)2I2·2OCMe2 (1) with orange emission and β-Au2(μ-dppe)2I2·2OCMe2 (2) with green emission. Both polymorphs contain dimeric molecules with three-coordinate gold(I) centers that are further apart in the orange emitting (1) (Au⋯Au distance, 3.6720(2) Å) than in the green emitting (2) (Au⋯Au distance, 3.3955(2) Å). The acetone molecules do not bond to the gold centers in either polymorph. Crystals of α-Au2(μ-dppe)2I2·2OCMe2 (1) and β-Au2(μ-dppe)2I2·2OCMe2 (2) undergo reversible, single-crystal to single-crystal transformations. Exposure of (2) to acetone vapor converts it into (1), while (1) is converted into (2) by exposure to air for a short time. Upon loss of acetone, α-Au2(μ-dppe)2I2·2OCMe2 (1) and β-Au2(μ-dppe)2I2·2OCMe2 (2) are converted into a microcrystalline powder (3) with a green emission. Remarkably, exposure of (3) to acetone vapor converts it into acetone-free Au2(μ-dppe)2(μ-I)2 (4), which displays orange emission. The X-ray crystal structure of Au2(μ-dppe)2(μ-I)2 (4) shows that each gold is in a highly distorted tetrahedral environment with bonds to two phosphorus and two iodine atoms. The transformations between these four types of crystals are notable because of the unusual role of vapors in promoting structural changes within solids that do not necessarily change composition. Thus, the reversible interconversion of α-Au2(μ-dppe)2I2·2OCMe2 (1) and β-Au2(μ-dppe)2I2·2OCMe2 (2) occurs as vapor-stimulated single-crystal-to-single-crystal transformation between polymorphs. Likewise, the irreversible transformation of microcrystalline (3) into Au2(μ-dppe)2(μ-I)2 (4) appears to be another case of a transformation of one polymorph into another.
![Nickel, [2,7,12,17-tetraethyl-3,8,13,18-tetramethyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/461900/14055-19-7.png)
![Nickel, [2,7,12,17-tetraethyl-3,8,13,18-tetramethyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/461900/14055-19-7_b.png)
![Cobalt, [2,7,12,17-tetraethyl-3,8,13,18-tetramethyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/928300/14055-17-5.png)
![Cobalt, [2,7,12,17-tetraethyl-3,8,13,18-tetramethyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/928300/14055-17-5_b.png)
![Nickel, [2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/2500/24803-99-4.png)
![Nickel, [2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/2500/24803-99-4_b.png)
![Ferrate(2-), [7,12-diethenyl-3,8,13,17-tetramethyl-21H,23H-porphine-2,18-dipropanoato(4-)-κN21,κN22,κN23,κN24]-, hydrogen (1:2), (SP-4-2)-](/data/chemimg/522800/14875-96-8.png)
![Ferrate(2-), [7,12-diethenyl-3,8,13,17-tetramethyl-21H,23H-porphine-2,18-dipropanoato(4-)-κN21,κN22,κN23,κN24]-, hydrogen (1:2), (SP-4-2)-](/data/chemimg/522800/14875-96-8_b.png)
