Co-reporter:Yuzhong Wang, Hunter P. Hickox, Yaoming Xie, Pingrong Wei, Henry F. Schaefer III, and Gregory H. Robinson
Journal of the American Chemical Society November 15, 2017 Volume 139(Issue 45) pp:16109-16109
Publication Date(Web):November 1, 2017
DOI:10.1021/jacs.7b10325
Reaction of thiolate 1 with carbene-stabilized diiodo-bis-silylene (2) (in a 2:1 ratio) in THF unexpectedly gives both the first five-membered, sulfur-containing, zwitterionic silylene ring (3) via insertion of the “SiI2” unit of 2 into the olefinic C—H bond of the imidazole ring of 1 and four-membered cyclic silylene (4) via insertion of a silicon(I) atom of 2 into the Cphenyl—N bond of the carbene ligand. The parallel reaction in toluene only gives 3 as the major product. The nature of the bonding in isomeric 3 and 4 was probed by experimental and theoretical methods.
Co-reporter:Yuzhong Wang, Hunter P. Hickox, Yaoming Xie, Pingrong Wei, Soshawn A. Blair, Michael K. Johnson, Henry F. Schaefer III, and Gregory H. Robinson
Journal of the American Chemical Society May 24, 2017 Volume 139(Issue 20) pp:6859-6859
Publication Date(Web):May 8, 2017
DOI:10.1021/jacs.7b03794
Sulfurization of anionic N-heterocyclic dicarbene, [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (2), with elemental sulfur (in a 1:2 ratio) in Et2O at low temperature gives 3 by inserting two sulfur atoms into the Li–C (i.e., C2 and C4) bonds in polymeric 2. Further reaction of 3 with 2 equiv of elemental sulfur in THF affords 4• via unexpected C–H bond activation, which represents the first anionic dithiolene radical to be structurally characterized in the solid state. Alternatively, 4• may also be synthesized directly by reaction of 1 with sulfur (in a 1:4 ratio) in THF. Reaction of 4• with GeCl2·dioxane gives an anionic germanium(IV)–bis(dithiolene) complex (5). The nature of the bonding in 4• and 5 was probed by experimental and theoretical methods.
Co-reporter:Yuzhong Wang;Hunter P. Hickox;Pingrong Wei
Dalton Transactions 2017 vol. 46(Issue 17) pp:5508-5512
Publication Date(Web):2017/05/02
DOI:10.1039/C7DT00066A
While the 1 : 1 reaction of C4-trichlorosilyl-functionalized N-heterocyclic carbene (NHC) (2) with [(η5-C5H4Li)2Fe]3[TMEDA]2 (3) gives C4-sila[1]ferrocenophane-substituted NHC (4), C4-ferrocenylsilyl-bridged bis-NHC (6) is synthesized by combining 3 with C4-chlorodimethylsilyl-functionalized NHC (5) in a 1 : 2 ratio, (compound 5 is prepared by reaction of the anionic N-heterocyclic dicarbene (NHDC) [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (1) with Me2SiCl2). In addition, ligand 4- and 6-based GeCl2 complexes (7 and 8) are also synthesized. Compounds 4–8 have been characterized by 1H, 13C, and 29Si NMR spectroscopy and single crystal X-ray diffraction.
Co-reporter:Hunter P. Hickox, Yuzhong Wang, Yaoming Xie, Pingrong Wei, Henry F. Schaefer III, and Gregory H. Robinson
Journal of the American Chemical Society 2016 Volume 138(Issue 31) pp:9799-9802
Publication Date(Web):July 28, 2016
DOI:10.1021/jacs.6b06726
While reaction of carbene-stabilized disilicon L:Si═Si:L (L: = C{N(2,6-iPr2C6H3)CH}2) (8) with HCl·NC5H5 results in carbene-stabilized Si2Cl2 (2) and substituted 1H-imidazole (9), combination of the corresponding Fe(CO)4-modified disilicon carbene complex L:Si═Si[Fe(CO)4]:L (6) with pyridine hydrochloride gives a species containing two push–pull-stabilized parent monochlorosilylenes that are bridged by an Fe(CO)3 unit (7). The nature of 7 was further elucidated by spectroscopic, crystallographic, and computational methods. Spectroscopic data suggest that 7 exists as two diastereoisomers.
Co-reporter:Yuzhong Wang, Hunter P. Hickox, Yaoming Xie, Pingrong Wei, Dongtao Cui, Melody R. Walter, Henry F. Schaefer III and Gregory H. Robinson
Chemical Communications 2016 vol. 52(Issue 33) pp:5746-5748
Publication Date(Web):05 Apr 2016
DOI:10.1039/C6CC01759B
Reaction of carbene-stabilized diphosphorus, L:P–P:L (5) (L: = :C{N(2,6-Pri2C6H3)CH}2) with pyridine hydrochloride yields [L:(H)P–P:L]Cl (6), a salt containing the HP2+ cation—the elusive phosphorus analogue of the well known diazonium cation, HN2+. In addition to reporting the synthesis and structure, the nature of (6) was further probed by DFT computations. Interestingly, carbenes may be employed to deprotonate (6), affording the starting material (5).
Co-reporter:Yuzhong Wang, Yaoming Xie, Pingrong Wei, Henry F. Schaefer and Gregory H. Robinson
Dalton Transactions 2016 vol. 45(Issue 14) pp:5941-5944
Publication Date(Web):25 Nov 2015
DOI:10.1039/C5DT03894D
Reaction of the anionic N-heterocyclic dicarbene (NHDC), [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (1), with SiCl4 gives the trichlorosilyl-substituted (at the C4 carbon) N-heterocyclic carbene complex (7). Abnormal carbene–SiCl4 complex (8) may be conveniently synthesized by combining 7 with HCl·NEt3. In addition, 7 may react with CH2Cl2 in warm hexane, giving the abnormal carbene-complexed SiCl3+ cation (9). The nature of the bonding in 9 was probed with complementary DFT computations.
Co-reporter:Yuzhong Wang; Mingwei Chen; Yaoming Xie; Pingrong Wei; Henry F. SchaeferIII
Journal of the American Chemical Society 2015 Volume 137(Issue 26) pp:8396-8399
Publication Date(Web):June 29, 2015
DOI:10.1021/jacs.5b05202
The first carbene-stabilized silicon–carbon mixed oxide, (SiO2)2CO2 (4), was synthesized by CO2 oxidation of either carbene-stabilized disilicon, L:Si═Si:L (L: = :C{N(2,6-Pri2C6H3)CH}2) (1), or carbene-stabilized Si2O3 (2) (which can be obtained via N2O oxidation of 1). The structure and bonding of 4 was probed by both experimental and computational methods.
Co-reporter:Hunter P. Hickox;Dr. Yuzhong Wang;Dr. Yaoming Xie;Dr. Mingwei Chen;Dr. Pingrong Wei;Dr. Henry F. Schaefer III ;Dr. Gregory H. Robinson
Angewandte Chemie 2015 Volume 127( Issue 35) pp:10405-10408
Publication Date(Web):
DOI:10.1002/ange.201503069
Abstract
Reaction of carbene-stabilized disilicon (1) with Fe(CO)5 gives the 1:1 adduct L:SiSi[Fe(CO)4]:L (L:=C{N(2,6-Pri2C6H3)CH}2) (2) at room temperature. At raised temperature, however, 2 may react with another equivalent of Fe(CO)5 to give L:Si[μ-Fe2(CO)6](μ-CO)Si:L (3) through insertion of both CO and Fe2(CO)6 into the Si2 core, which represents the first experimental realization of transition metal-carbonyl-mediated cleavage of a SiSi double bond. The structures and bonding of both 2 and 3 have been investigated by spectroscopic, crystallographic, and computational methods.
Co-reporter:Hunter P. Hickox;Dr. Yuzhong Wang;Dr. Yaoming Xie;Dr. Mingwei Chen;Dr. Pingrong Wei;Dr. Henry F. Schaefer III ;Dr. Gregory H. Robinson
Angewandte Chemie International Edition 2015 Volume 54( Issue 35) pp:10267-10270
Publication Date(Web):
DOI:10.1002/anie.201503069
Abstract
Reaction of carbene-stabilized disilicon (1) with Fe(CO)5 gives the 1:1 adduct L:SiSi[Fe(CO)4]:L (L:=C{N(2,6-Pri2C6H3)CH}2) (2) at room temperature. At raised temperature, however, 2 may react with another equivalent of Fe(CO)5 to give L:Si[μ-Fe2(CO)6](μ-CO)Si:L (3) through insertion of both CO and Fe2(CO)6 into the Si2 core, which represents the first experimental realization of transition metal-carbonyl-mediated cleavage of a SiSi double bond. The structures and bonding of both 2 and 3 have been investigated by spectroscopic, crystallographic, and computational methods.
Co-reporter:Yuzhong Wang and Gregory H. Robinson
Inorganic Chemistry 2014 Volume 53(Issue 22) pp:11815-11832
Publication Date(Web):October 24, 2014
DOI:10.1021/ic502231m
This Award Article targets the evolving, yet surprisingly fruitful, chemistry of N-heterocyclic carbenes with low-oxidation-state main-group elements. Specifically, the chemistry of carbene-stabilized diatomic allotropes, diborenes, gallium octahedra, beryllium borohydride, and a host of related compounds will be presented. Providing a valuable historical perspective, the foundational work concerning the organometallic chemistry of gallium with sterically demanding m-terphenyl ligands from this laboratory will also be discussed.
Co-reporter:Mingwei Chen, Yuzhong Wang, Robert J. Gilliard, Jr., Pingrong Wei, Nichole A. Schwartz and Gregory H. Robinson
Dalton Transactions 2014 vol. 43(Issue 38) pp:14211-14214
Publication Date(Web):17 Jun 2014
DOI:10.1039/C4DT00933A
Low temperature reaction of N-heterocyclic carbene:BEt3 with nBuLi (in THF) initially gives the C4-lithiated N-heterocyclic carbene:BEt3 complex (4), which isomerizes to the C2-lithiated abnormal N-heterocyclic carbene:BEt3 complex (2) in refluxing THF. While reaction of 2 with GaCl3 gives a 4-functionalized N-heterocyclic carbene:GaCl3 adduct (6), reaction of 4 with GaCl3 affords the first abnormal carbene–gallium chloride complexes (5).
Co-reporter:Dr. Mingwei Chen;Dr. Yuzhong Wang;Dr. Yaoming Xie;Dr. Pingrong Wei;Robert J. Gilliard Jr.;Nichole A. Schwartz;Dr. Henry F. Schaefer III;Dr. Paul von R. Schleyer ;Dr. Gregory H. Robinson
Chemistry - A European Journal 2014 Volume 20( Issue 30) pp:9208-9211
Publication Date(Web):
DOI:10.1002/chem.201403095
Abstract
Reaction of N-heterocyclic-carbene (NHC)-stabilized disilicon (1) with CuCl gave a carbene-stabilized disilicon–copper(I) chloride complex (2). The nature of the structure and bonding in 2 has been investigated by crystallographic, spectroscopic, and computational methods. The dynamic complexation behavior of 2 was experimentally explored by variable-temperature NMR analysis.
Co-reporter:Mariham Y. Abraham ; Yuzhong Wang ; Yaoming Xie ; Robert J. Gilliard ; Jr.; Pingrong Wei ; Brian J. Vaccaro ; Michael K. Johnson ; Henry F. Schaefer ; III; Paul v. R. Schleyer
Journal of the American Chemical Society 2013 Volume 135(Issue 7) pp:2486-2488
Publication Date(Web):January 30, 2013
DOI:10.1021/ja400219d
Oxidation of carbene-stabilized diarsenic, L:As–As:L [L: = :C{N(2,6-iPr2C6H3)CH}2] (1), with gallium chloride in a 1:4 ratio in toluene affords the dicationic diarsene complex [L:As═As:L]2+([GaCl4]−)2 (22+[GaCl4]2), while oxidation of 1 with GaCl3 in a 1:2 ratio in Et2O yields the monocationic diarsenic radical complex [L:AsAs:L]•+[GaCl4]− (2•+[GaCl4]). Strikingly, complex 2•+ is the first arsenic radical to be structurally characterized in the solid state. The nature of the bonding in these complexes was probed computationally and spectroscopically.
Co-reporter:Yuzhong Wang ; Yaoming Xie ; Pingrong Wei ; Henry F. Schaefer ; III; Paul von R. Schleyer
Journal of the American Chemical Society 2013 Volume 135(Issue 51) pp:19139-19142
Publication Date(Web):December 3, 2013
DOI:10.1021/ja411667f
In contrast to stable phosphorus oxides such as P4O6 and P4O10 that possess iconic adamantane-like cage structures, highly reactive phosphorus oxides such as PO, PO2, and P2Ox (x = 1–5) only have been studied in the gas phase or by matrix isolation techniques. Elusive diphosphorus tetroxide, the long sought phosphorus analogue of N2O4, is particularly noteworthy. Computations predict that the oxo-bridged O2POPO form of P2O4 is energetically more favored than the P–P bonded O2P–PO2 isomer. Herein, we report the experimental realization of diphosphorus tetroxide—in its energetically disfavored O2P–PO2 form—via carbene-stabilization. The synthesis of the title compound involves the splitting of molecular oxygen by carbene-stabilized diphosphorus.
Co-reporter:Yuzhong Wang, Mariham Y. Abraham, Robert J. Gilliard Jr., Daniel R. Sexton, Pingrong Wei, and Gregory H. Robinson
Organometallics 2013 Volume 32(Issue 22) pp:6639-6642
Publication Date(Web):July 12, 2013
DOI:10.1021/om400539z
The reaction of the N-heterocyclic dicarbene (NHDC) [:C{[N(2,6-Pri2C6H3)]2CHCLi(THF)}]n with iodomethane, in a hexane/THF mixture, affords the ylidic N-heterocyclic olefin NHC═CH2 (1; NHC = :C{N(2,6-Pri2C6H3)CH}2) in high yield. The reaction of 1 with BBr3 in hexane gives the neutral compound NHC–CH2:BBr3 (2), which in THF unexpectedly converts to the borenium salt [NHC–CH2:B{O(CH2)4Br}2]+[Br]− (3) through ring opening of THF.
Co-reporter:Robert J. Gilliard ; Jr.; Mariham Y. Abraham ; Yuzhong Wang ; Pingrong Wei ; Yaoming Xie ; Brandon Quillian ; Henry F. Schaefer ; III; Paul v. R. Schleyer
Journal of the American Chemical Society 2012 Volume 134(Issue 24) pp:9953-9955
Publication Date(Web):June 6, 2012
DOI:10.1021/ja304514f
The reaction of N-heterocyclic carbene, L:, with BeCl2 quantitatively yields L:BeCl21 (L: = :C{N(2,6-Pri2C6H3)CH}2). The carbene-stabilized beryllium borohydride monomer L:Be(BH4)22 is prepared by the reaction of 1 with LiBH4. Compound 3, prepared by the reaction of 2 with Na2[Fe(CO)4]·dioxane, represents an unusual “dual reduction” of the imidazole ring (i.e., hydroboration of the C═C backbone and hydrogenation of the C2 carbene center).
Co-reporter:Yuzhong Wang, Mariham Y. Abraham, Robert J. Gilliard Jr., Pingrong Wei, Jared C. Smith, and Gregory H. Robinson
Organometallics 2012 Volume 31(Issue 3) pp:791-793
Publication Date(Web):January 18, 2012
DOI:10.1021/om201259d
The anionic N-heterocyclic dicarbenes (NHDCs) I are demonstrated to be a convenient platform from which abnormal NHC (aNHC)–borane complexes V–VII may be prepared. The anionic NHDC binuclear complex II and the aNHC mononuclear adduct VII can be interconverted through lithiation and protonation, respectively, of the C2 carbon atom of the imidazole ring.
Co-reporter:Dr. Yuzhong Wang;Dr. Yaoming Xie;Mariham Y. Abraham;Robert J. Gilliard Jr.;Dr. Pingrong Wei;Dr. Charles F. Campana;Dr. Henry F. Schaefer III;Dr. Paul von R. Schleyer;Dr. Gregory H. Robinson
Angewandte Chemie International Edition 2012 Volume 51( Issue 40) pp:10173-10176
Publication Date(Web):
DOI:10.1002/anie.201204712
Co-reporter:Dr. Yuzhong Wang;Dr. Yaoming Xie;Mariham Y. Abraham;Robert J. Gilliard Jr.;Dr. Pingrong Wei;Dr. Charles F. Campana;Dr. Henry F. Schaefer III;Dr. Paul von R. Schleyer;Dr. Gregory H. Robinson
Angewandte Chemie 2012 Volume 124( Issue 40) pp:10320-10323
Publication Date(Web):
DOI:10.1002/ange.201204712
Co-reporter:Yuzhong Wang, Hunter P. Hickox, Pingrong Wei and Gregory H. Robinson
Dalton Transactions 2017 - vol. 46(Issue 17) pp:NaN5512-5512
Publication Date(Web):2017/02/23
DOI:10.1039/C7DT00066A
While the 1:1 reaction of C4-trichlorosilyl-functionalized N-heterocyclic carbene (NHC) (2) with [(η5-C5H4Li)2Fe]3[TMEDA]2 (3) gives C4-sila[1]ferrocenophane-substituted NHC (4), C4-ferrocenylsilyl-bridged bis-NHC (6) is synthesized by combining 3 with C4-chlorodimethylsilyl-functionalized NHC (5) in a 1:2 ratio, (compound 5 is prepared by reaction of the anionic N-heterocyclic dicarbene (NHDC) [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (1) with Me2SiCl2). In addition, ligand 4- and 6-based GeCl2 complexes (7 and 8) are also synthesized. Compounds 4–8 have been characterized by 1H, 13C, and 29Si NMR spectroscopy and single crystal X-ray diffraction.
Co-reporter:Yuzhong Wang, Hunter P. Hickox, Yaoming Xie, Pingrong Wei, Dongtao Cui, Melody R. Walter, Henry F. Schaefer III and Gregory H. Robinson
Chemical Communications 2016 - vol. 52(Issue 33) pp:NaN5748-5748
Publication Date(Web):2016/04/05
DOI:10.1039/C6CC01759B
Reaction of carbene-stabilized diphosphorus, L:P–P:L (5) (L: = :C{N(2,6-Pri2C6H3)CH}2) with pyridine hydrochloride yields [L:(H)P–P:L]Cl (6), a salt containing the HP2+ cation—the elusive phosphorus analogue of the well known diazonium cation, HN2+. In addition to reporting the synthesis and structure, the nature of (6) was further probed by DFT computations. Interestingly, carbenes may be employed to deprotonate (6), affording the starting material (5).
Co-reporter:Yuzhong Wang, Yaoming Xie, Pingrong Wei, Henry F. Schaefer and Gregory H. Robinson
Dalton Transactions 2016 - vol. 45(Issue 14) pp:NaN5944-5944
Publication Date(Web):2015/11/25
DOI:10.1039/C5DT03894D
Reaction of the anionic N-heterocyclic dicarbene (NHDC), [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (1), with SiCl4 gives the trichlorosilyl-substituted (at the C4 carbon) N-heterocyclic carbene complex (7). Abnormal carbene–SiCl4 complex (8) may be conveniently synthesized by combining 7 with HCl·NEt3. In addition, 7 may react with CH2Cl2 in warm hexane, giving the abnormal carbene-complexed SiCl3+ cation (9). The nature of the bonding in 9 was probed with complementary DFT computations.
Co-reporter:Mingwei Chen, Yuzhong Wang, Robert J. Gilliard, Jr., Pingrong Wei, Nichole A. Schwartz and Gregory H. Robinson
Dalton Transactions 2014 - vol. 43(Issue 38) pp:NaN14214-14214
Publication Date(Web):2014/06/17
DOI:10.1039/C4DT00933A
Low temperature reaction of N-heterocyclic carbene:BEt3 with nBuLi (in THF) initially gives the C4-lithiated N-heterocyclic carbene:BEt3 complex (4), which isomerizes to the C2-lithiated abnormal N-heterocyclic carbene:BEt3 complex (2) in refluxing THF. While reaction of 2 with GaCl3 gives a 4-functionalized N-heterocyclic carbene:GaCl3 adduct (6), reaction of 4 with GaCl3 affords the first abnormal carbene–gallium chloride complexes (5).
.jpg)
![Plumbylene, bis(5'-phenyl[1,1':3',1''-terphenyl]-2'-yl)-](http://img.cochemist.com/ccimg/878600/878549-64-5.png)
![Plumbylene, bis(5'-phenyl[1,1':3',1''-terphenyl]-2'-yl)-](http://img.cochemist.com/ccimg/878600/878549-64-5_b.png)
![Lithium, [4,4''-bis(1,1-dimethylethyl)[1,1':3',1''-terphenyl]-2'-yl]-](http://img.cochemist.com/ccimg/349600/349551-30-0.png)
![Lithium, [4,4''-bis(1,1-dimethylethyl)[1,1':3',1''-terphenyl]-2'-yl]-](http://img.cochemist.com/ccimg/349600/349551-30-0_b.png)
![Lithium, [1,1':3',1''-terphenyl]-2'-yl-](http://img.cochemist.com/ccimg/214500/214491-82-4.png)
![Lithium, [1,1':3',1''-terphenyl]-2'-yl-](http://img.cochemist.com/ccimg/214500/214491-82-4_b.png)
![Magnesium, bromotricyclo[3.3.1.13,7]dec-1-yl-](http://img.cochemist.com/ccimg/57700/57680-77-0.png)
![Magnesium, bromotricyclo[3.3.1.13,7]dec-1-yl-](http://img.cochemist.com/ccimg/57700/57680-77-0_b.png)
![1-BROMO-2-[2-(2-BROMOPHENYL)ETHENYL]BENZENE](http://img.cochemist.com/ccimg/56700/56667-11-9.png)
![1-BROMO-2-[2-(2-BROMOPHENYL)ETHENYL]BENZENE](http://img.cochemist.com/ccimg/56700/56667-11-9_b.png)
![Oxirane, 2,2-dimethyl-3-[(2E)-3-methyl-2,4-pentadienyl]-](http://img.cochemist.com/ccimg/29000/28977-57-3.png)
![Oxirane, 2,2-dimethyl-3-[(2E)-3-methyl-2,4-pentadienyl]-](http://img.cochemist.com/ccimg/29000/28977-57-3_b.png)
![Lithium, (2,2'',4,4'',6,6''-hexamethyl[1,1':3',1''-terphenyl]-2'-yl)-](http://img.cochemist.com/ccimg/164400/164356-88-1.png)
![Lithium, (2,2'',4,4'',6,6''-hexamethyl[1,1':3',1''-terphenyl]-2'-yl)-](http://img.cochemist.com/ccimg/164400/164356-88-1_b.png)
