Justin R. Walensky

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Name: Walensky, Justin R.

Organization: University of Missouri , USA

Department: Department of Chemistry

Title: (PhD)

TOPICS

Inorganic Chemistry

Chemicals
References

Synthesis and fluorescence spectroscopy of tris(pyrenyl)pnictogen compounds

Co-reporter:Kira Behm;Jeremy B. Essner;Charles L. Barnes;Gary A. Baker

Dalton Transactions 2017 vol. 46(Issue 33) pp:10867-10875

Publication Date(Web):2017/08/22

DOI:10.1039/C7DT01953J

The synthesis, characterization, and fluorescence spectroscopy of E(C16H9)3 complexes (E = P, As, Sb, and Bi), as well as OP(C16H9)3, OAs(C16H9)3, and SP(C16H9)3, is reported. These compounds exhibit fluorescence quantum yields that span two orders of magnitude, from well below 1% to ca. 14%.

Formation of Methane versus Benzene in the Reactions of (C5Me5)2Th(CH3)2 with [CH3PPh3]X (X=Cl, Br, I) Yielding Thorium-Carbene or Thorium-Ylide Complexes

Co-reporter:Pokpong Rungthanaphatsophon;Adrien Bathelier;Dr. Ludovic Castro;Dr. Andrew C. Behrle;Dr. Charles L. Barnes;Dr. Laurent Maron;Dr. Justin R. Walensky

Angewandte Chemie International Edition 2017 Volume 56(Issue 42) pp:12925-12929

Publication Date(Web):2017/10/09

DOI:10.1002/anie.201706496

AbstractThe reaction of (C5Me5)2Th(CH3)2 with the phosphonium salts [CH3PPh3]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C5Me5)2Th[CHPPh3]X, rare terminal phosphorano-stabilized carbenes with thorium. These complexes feature the shortest thorium–carbon bonds (≈2.30 Å) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C5Me5)2Th[κ2-(C,C′)-(CH2)(CH2)PPh2]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH3PPh3]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene.

Formation of Methane versus Benzene in the Reactions of (C5Me5)2Th(CH3)2 with [CH3PPh3]X (X=Cl, Br, I) Yielding Thorium-Carbene or Thorium-Ylide Complexes

Co-reporter:Pokpong Rungthanaphatsophon;Adrien Bathelier;Dr. Ludovic Castro;Dr. Andrew C. Behrle;Dr. Charles L. Barnes;Dr. Laurent Maron;Dr. Justin R. Walensky

Angewandte Chemie 2017 Volume 129(Issue 42) pp:13105-13109

Publication Date(Web):2017/10/09

DOI:10.1002/ange.201706496

Insertion of tBuNC into thorium–phosphorus and thorium–arsenic bonds: phosphaazaallene and arsaazaallene moieties in f element chemistry

Co-reporter:Andrew C. Behrle and Justin R. Walensky

Dalton Transactions 2016 vol. 45(Issue 24) pp:10042-10049

Publication Date(Web):28 Apr 2016

DOI:10.1039/C6DT00776G

The reactivity of thorium–phosphido and thorium–arsenido bonds was probed using tert-butyl isocyanide, tBuNC. Reaction of (C5Me5)2Th[E(H)R]2, E = P, As; R = 2,4,6-iPr3C6H2, 2,4,6-Me3C6H2 with tBuNC affords the first phosphaazaallene and arsaazaallene moieties with an f-element.

Formation of a Bridging Phosphinidene Thorium Complex

Co-reporter:Andrew C. Behrle; Ludovic Castro; Laurent Maron

Journal of the American Chemical Society 2015 Volume 137(Issue 47) pp:14846-14849

Publication Date(Web):November 17, 2015

DOI:10.1021/jacs.5b09826

The synthesis and structural determination of the first thorium phosphinidene complex are reported. The reaction of 2 equiv of (C5Me5)2Th(CH3)2 with H2P(2,4,6-iPr3C6H2) at 95 °C produces [(C5Me5)2Th]2(μ2-P[(2,6-CH2CHCH3)2-4-iPrC6H2] as well as 4 equiv of methane, 2 equiv from deprotonation of the phosphine and 2 equiv from C–H bond activation of one methyl group of each of the isopropyl groups at the 2- and 6-positions. Transition state calculations indicate that the steps in the mechanism are P–H, C–H, C–H, and then P–H bond activation to form the phosphinidene.

Di- and Trinuclear Mixed-Valence Copper Amidinate Complexes from Reduction of Iodine

Co-reporter:Andrew C. Lane; Charles L. Barnes; William E. Antholine; Denan Wang; Adam T. Fiedler

Inorganic Chemistry 2015 Volume 54(Issue 17) pp:8509-8517

Publication Date(Web):August 7, 2015

DOI:10.1021/acs.inorgchem.5b01161

Molecular examples of mixed-valence copper complexes through chemical oxidation are rare but invoked in the mechanism of substrate activation, especially oxygen, in copper-containing enzymes. To examine the cooperative chemistry between two metals in close proximity to each other we began studying the reactivity of a dinuclear Cu(I) amidinate complex. The reaction of [(2,6-Me2C6H3N)2C(H)]2Cu2, 1, with I2 in tetrahydrofuran (THF), CH3CN, and toluene affords three new mixed-valence copper complexes [(2,6-Me2C6H3N)2C(H)]2Cu2(μ2-I3)(THF)2, 2, [(2,6-Me2C6H3N)2C(H)]2Cu2(μ2-I) (NCMe)2, 3, and [(2,6-Me2C6H3N)2C(H)]3Cu3(μ3-I)2, 4, respectively. The first two compounds were characterized by UV–vis and electron paramagnetic resonance spectroscopies, and their molecular structure was determined by X-ray crystallography. Both di- and trinuclear mixed-valence intermediates were characterized for the reaction of compound 1 to compound 4, and the molecular structure of 4 was determined by X-ray crystallography. The electronic structure of each of these complexes was also investigated using density functional theory.

Stabilization of MIV = Ti, Zr, Hf, Ce, and Th using a selenium bis(phenolate) ligand

Co-reporter:Andrew C. Behrle, Jessica R. Levin, Jee Eon Kim, Jonathan M. Drewett, Charles L. Barnes, Eric J. Schelter and Justin R. Walensky

Dalton Transactions 2015 vol. 44(Issue 6) pp:2693-2702

Publication Date(Web):11 Sep 2014

DOI:10.1039/C4DT01798F

We report M(IV) M = Ti, Zr, Hf, Ce, and Th, complexes of a selenium bis(phenolate) ligand, 2,2′-selenobis(4,6-di-tert-butylphenol), (H2ArOSeO), 1. Reaction of Ti(NEt2)4 with two equivalents of 1 affords Ti(ArOSeO)2, 2. Salt metathesis of ZrCl4 and HfCl4 with two equivalents of Na2ArOSeO produces Zr(ArOSeO)2(THF), 3, and Hf(ArOSeO)2(THF), 4, respectively. Protonolysis of ThCl[N(SiMe3)2]3 with two equivalents of 1 yields Th(ArOSeO)2(THF)2, 5. Salt metathesis of Ce(OTf)3 and two equivalents of Na2ArOSeO produces [Na(THF)3][Ce(ArOSeO)2], which was oxidized in situ using 0.5 equivalents of I2 to yield the diamagnetic Ce(IV) product, Ce(ArOSeO)2(THF)2, 6. Addition of 2,2′-bipyridyl to 6 forms Ce(ArOSeO)2(bipy), 6a. Each diamagnetic complex was characterized using 1H, 13C, and 77Se NMR and IR spectroscopy and the structures of 2–6a were established with X-ray crystallography. Electrochemical measurements using cyclic voltammetry on complexes 2, 5, and 6 are also reported.

Synthesis of Thorium(IV) and Uranium(IV) Salicylaldiminate Pseudo-Halide Complexes

Co-reporter:Ashley N. Dame;Mohan S. Bharara;Charles L. Barnes

European Journal of Inorganic Chemistry 2015 Volume 2015( Issue 18) pp:2996-3005

Publication Date(Web):

DOI:10.1002/ejic.201500378

Abstract

To explore the coordination chemistry of salicylaldiminate ligands as a non-cyclopentadienyl ligand framework, we report the synthesis of their Th^IV and U^IV complexes. Deprotonation of (NC₅H₄)N=C(H)(3,5-tBu₂C₆H₂)OH (1), (NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)OH (2), and (CH₃SC₆H₄)N=C(H)(3,5-tBu₂C₆H₂)OH (3) with sodium hydride and the subsequent addition of 0.5 equivalents of [UI₄(1,4-dioxane)₂] yielded [{(NC₅H₄)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂UI₂] (4), [{(NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂UI₂] (5), and [{(CH₃SC₆H₄)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,S)}₂UI₂] (6), respectively. The reaction of 3 equivalents of the sodium salt of 1 afforded [{(NC₅H₄)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₃U]I₃ (7). By using [ThCl₄(dme)₂], [{(NC₅H₄)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂ThCl₂] (8) and [{(NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂ThCl₂] (9) were isolated. The metathesis of both chloride ligands in 9 with NaN₃ led to a rare thorium azide product, [{(NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂Th(N₃)₂] (10). The reaction of 5 with AgOTf (OTf = O₃SCF₃) afforded [{(NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂U(OTf)₂] (11), and the subsequent reaction of 11 with 2 equivalents of NaN₃ provided [{(NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂U(N₃)₂] (12). The reaction of 5 with 2 equivalents of AgNO₃ produced [{(NC₉H₆)N=C(H)(3,5-tBu₂C₆H₂)O-κ³(O,N,N′)}₂U{NO₃-κ²(O,O)}₂] (13). Each complex was characterized by ¹H NMR and IR spectroscopy and, with the exception of 11, their structures were determined by X-ray crystallographic analysis.

Synthesis, Spectroscopy, and Electrochemistry of (α-Diimine)M(CO)3Br, M = Mn, Re, Complexes: Ligands Isoelectronic to Bipyridyl Show Differences in CO2 Reduction

Co-reporter:Matthew V. Vollmer, Charles W. Machan, Melissa L. Clark, William E. Antholine, Jay Agarwal, Henry F. Schaefer III, Clifford P. Kubiak, and Justin R. Walensky

Organometallics 2015 Volume 34(Issue 1) pp:3-12

Publication Date(Web):December 9, 2014

DOI:10.1021/om500838z

The synthesis and characterization of new Mn(I)- and Re(I)-centered organometallic complexes fashioned with 1,4-diazabutadiene (DAB) ligands is reported. Ten compounds of the type fac-(α-diimine)M(CO)3Br (M = Mn, Re) were obtained in moderate to excellent yield (35–80%) and high purity from the coordination of the five ligands with M(CO)5Br in refluxing ethanol. Despite the electronic similarity of DAB to 2,2′-bipyridyl, the complexes described herein were poor mediators of electrochemical CO2 conversion to CO, but provide insight into the role of redox-active ligands in catalysis. Additional characterization of the one-electron reduced rhenium compounds, relevant intermediates in CO2 reduction, by EPR and single-crystal X-ray analysis is described.

Trivalent Uranium Phenylchalcogenide Complexes: Exploring the Bonding and Reactivity with CS2 in the Tp*2UEPh Series (E = O, S, Se, Te)

Co-reporter:Ellen M. Matson, Andrew T. Breshears, John J. Kiernicki, Brian S. Newell, Phillip E. Fanwick, Matthew P. Shores, Justin R. Walensky, and Suzanne C. Bart

Inorganic Chemistry 2014 Volume 53(Issue 24) pp:12977-12985

Publication Date(Web):November 21, 2014

DOI:10.1021/ic5020658

The trivalent uranium phenylchalcogenide series, Tp*2UEPh (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, E = O (1), S (2), Se (3), Te (4)), has been synthesized to investigate the nature of the U–E bond. All compounds have been characterized by 1H NMR, infrared and electronic absorption spectroscopies, and in the case of 4, X-ray crystallography. Compound 4 was also studied by SQUID magnetometry. Computational studies establish Mulliken spin densities for the uranium centers ranging from 3.005 to 3.027 (B3LYP), consistent for uranium–chalcogenide bonds that are primarily ionic in nature, with a small covalent contribution. The reactivity of 2–4 toward carbon disulfide was also investigated and showed reversible CS2 insertion into the U(III)–E bond, forming Tp*2U(κ2-S2CEPh) (E = S (5), Se (6), Te (7)). Compound 5 was characterized crystallographically.

Multinuclear Copper(I) and Silver(I) Amidinate Complexes: Synthesis, Luminescence, and CS2 Insertion Reactivity

Co-reporter:Andrew C. Lane, Matthew V. Vollmer, Charles H. Laber, Doris Y. Melgarejo, Gina M. Chiarella, John P. Fackler Jr., Xinzheng Yang, Gary A. Baker, and Justin R. Walensky

Inorganic Chemistry 2014 Volume 53(Issue 21) pp:11357-11366

Publication Date(Web):October 15, 2014

DOI:10.1021/ic501694d

Systematic Investigation of Thorium(IV)– and Uranium(IV)–Ligand Bonding in Dithiophosphonate, Thioselenophosphinate, and Diselenophosphonate Complexes

Co-reporter:Andrew C. Behrle, Charles L. Barnes, Nikolas Kaltsoyannis, and Justin R. Walensky

Inorganic Chemistry 2013 Volume 52(Issue 18) pp:10623-10631

Publication Date(Web):August 29, 2013

DOI:10.1021/ic401642a

Homoleptic soft-donor actinide complexes of the general form An[E2PROR′]4 were synthesized from salt metathesis between ThCl4(DME)2 or UI4(1,4-dioxane)2 and M[E2PROR′], M = Na, K, to yield 2 (An = Th, E = S, R = 4-MeOC6H4, R′ = Me), 3 (An = Th, E = S, R = 4-MeOC6H4, R′ = tBu), 4 (An = U, E = S, R = 4-MeOC6H4, R′ = Me), 5 (An = Th, E = Se, R = C6H5, R′ = Me), and 6 (An = U, E = Se, R = C6H5, R′ = Me). In addition thorium and uranium thioselenophosphinate complexes 7 and 8 were produced from the reaction of ThCl4(DME)2 and UI4(1,4-dioxane)2 and Na[SSePPh2], respectively. All compounds were characterized using elemental analysis, 1H and 31P NMR, and IR spectroscopy, and the U(IV) compounds were also examined with UV–vis spectroscopy. The 77Se NMR spectrum of 5 reveals the first reported resonance with a Th–Se bond. The solid-state structures of 2, 5, 7, and 8 were determined by X-ray crystallography. The actinide–ligand bonding was examined using density functional theory calculations in conjunction with quantum theory of atoms-in-molecules analysis and shows slightly increased covalency in actinide–selenium bonds than actinide–sulfur.

In Pursuit of Homoleptic Actinide Alkyl Complexes

Co-reporter:Lani A. Seaman, Justin R. Walensky, Guang Wu, and Trevor W. Hayton

Inorganic Chemistry 2013 Volume 52(Issue 7) pp:3556-3564

Publication Date(Web):June 20, 2012

DOI:10.1021/ic300867m

This Forum Article describes the pursuit of isolable homoleptic actinide alkyl complexes, starting with the pioneering work of Gilman during the Manhattan project. The initial reports in this area suggested that homoleptic uranium alkyls were too unstable to be isolated, but Wilkinson demonstrated that tractable uranium alkyls could be generated by purposeful “ate” complex formation, which serves to saturate the uranium coordination sphere and provide the complexes with greater kinetic stability. More recently, we reported the solid-state molecular structures of several homoleptic uranium alkyl complexes, including [Li(THF)4][U(CH2tBu)5], [Li(TMEDA)]2[UMe6], [K(THF)]3[K(THF)2][U(CH2Ph)6]2, and [Li(THF)4][U(CH2SiMe3)6], by employing Wilkinson’s strategy. Herein, we describe our attempts to extend this chemistry to thorium. The treatment of ThCl4(DME)2 with 5 equiv of LiCH2tBu or LiCH2SiMe3 at −25 °C in THF affords [Th(CH2tBu)5] (1) and [Li(DME)2][Th(CH2SiMe3)5 (2), respectively, in moderate yields. Similarly, the treatment of ThCl4(DME)2 with 6 equiv of K(CH2Ph) produces [K(THF)]2[Th(CH2Ph)6] (3), in good yield. Complexes 1–3 have been fully characterized, while the structures of 1 and 3 were confirmed by X-ray crystallography. Additionally, the electronic properties of 1 and 3 were explored by density functional theory.

Bringing Redox Reactivity to a Redox Inactive Metal Center EI (E = C, Si) Bond Cleavage with a Thorium Bis(-diimine) Complex

Co-reporter:Agnes Mrutu;Charles L. Barnes;Suzanne C. Bart

European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 22-23) pp:4050-4055

Publication Date(Web):

DOI:10.1002/ejic.201300390

Abstract

As the reactivity of transition-metal complexes with redox-active ligands has gained significant attention in recent years, we have begun expanding to the actinides. Here, we report the synthesis, characterization, and reactivity of (^MesDAB^Me)₂Th(THF) {1, ^MesDAB^Me = [MesNC(Me)=C(Me)NMes]^2–, Mes = 2,4,6-trimethylphenyl, THF = tetrahydrofuran}, which cleaves the C–I bond in CH₃I with subsequent Th–I and C–C bond formation to produce (^MesDAB^Me)(^MesDAB)ThI {2, ^MesDAB = [MesN=C(Me)C(Me)₂NMes]^–}. When 2 is crystallized in acetonitrile, the solvated adduct (^MesDAB^Me)(^MesDAB)ThI(NCCH₃) (2-MeCN) is isolated. The reaction of 2 equiv. of 1 with Me₃SiI produces (^MesDAB^Me)₂ThI (3) and Me₃SiSiMe₃. In 3, one ^MesDAB^Me ligand is now monoanionic and provides an electron to cleave the Si–I bond. This represents a rare example of the reactivity of thorium with a redox-active ligand.

Molecular structure and spectroscopy of divalent first row transition metals, Mn–Zn, with salicylaldiminate ligands

Co-reporter:Agnes Mrutu, Andrew C. Lane, Jonathan M. Drewett, Steven D. Yourstone, Charles L. Barnes, Christopher M. Halsey, Jason W. Cooley, Justin R. Walensky

Polyhedron 2013 Volume 54() pp:300-308

Publication Date(Web):30 April 2013

DOI:10.1016/j.poly.2013.02.011

The synthesis and spectroscopy of divalent first row transition metals bearing two monoanionic salicylaldiminate ligands is reported. The reaction of MnCl2, FeCl2, CoBr2, 1,2-(Ph2PCH2CH2PPh2)NiCl2, and CuCl2 with 2 equiv. of the alkali metal salt of [OC6H2tBu2C(H)N(C6H3Me2)]1− produces the corresponding M[OC6H2tBu2C(H)N(C6H3Me2)]2, M = Mn, Fe, Co, Ni, and Cu. Reaction of ZnEt2 with 2 equiv. of the protonated ligand affords Zn[OC6H2tBu2C(H)N(C6H3Me2)]2. The molecular structure of each complex has been analyzed using IR spectroscopy and X-ray crystallography while UV–Vis, CW-EPR, solution magnetic susceptibilities, and DFT calculations were also used to probe their electronic structure.The synthesis, structure, and spectroscopy of first row transition metal, Mn–Zn, complexes with two salicylaldiminate ligands are reported. The complexes exhibit non-covalent interactions which add stability to the tetrahedral geometry about the metal center instead of square planar which is observed if these interactions are absent.

Synthesis of Terminal Uranium(IV) Disulfido and Diselenido Compounds by Activation of Elemental Sulfur and Selenium

Co-reporter:Ellen M. Matson;Mitchell D. Goshert;John J. Kiernicki;Brian S. Newell;Phillip E. Fanwick; Matthew P. Shores; Justin R. Walensky; Suzanne C. Bart

Chemistry - A European Journal 2013 Volume 19( Issue 48) pp:16176-16180

Publication Date(Web):

DOI:10.1002/chem.201303095

Synthesis of a Phosphorano-Stabilized U(IV)-Carbene via One-Electron Oxidation of a U(III)-Ylide Adduct

Co-reporter:Skye Fortier ; Justin R. Walensky ; Guang Wu ;Trevor W. Hayton

Journal of the American Chemical Society 2011 Volume 133(Issue 18) pp:6894-6897

Publication Date(Web):April 13, 2011

DOI:10.1021/ja2001133

Addition of the Wittig reagent Ph3P═CH2 to the U(III) tris(amide) U(NR2)3 (R = SiMe3) generates a mixture of products from which the U(IV) complex U═CHPPh3(NR2)3 (2) can be obtained. Complex 2 features a short U═C bond and represents a rare example of a uranium carbene. In solution, 2 exists in equilibrium with the U(IV) metallacycle U(CH2SiMe2NR)(NR2)2 and free Ph3P═CH2. Measurement of this equilibrium as a function of temperature provides ΔHrxn = 11 kcal/mol and ΔSrxn = 31 eu. Additionally, the electronic structure of the U═C bond was investigated using DFT analysis.

Dithio- and Diselenophosphinate Thorium(IV) and Uranium(IV) Complexes: Molecular and Electronic Structures, Spectroscopy, and Transmetalation Reactivity

Co-reporter:Andrew C. Behrle; Andrew Kerridge

Inorganic Chemistry () pp:

Publication Date(Web):December 4, 2015

DOI:10.1021/acs.inorgchem.5b01342

We report a comparison of the molecular and electronic structures of dithio- and diselenophosphinate, (E2PR2)1– (E = S, Se; R = iPr, tBu), with thorium(IV) and uranium(IV) complexes. For the thorium dithiophosphinate complexes, reaction of ThCl4(DME)2 with 4 equiv of KS2PR2 (R = iPr, tBu) produced the homoleptic complexes, Th(S2PiPr2)4 (1S-Th-iPr) and Th(S2PtBu2)4 (2S-Th-tBu). The diselenophosphinate complexes were synthesized in a similar manner using KSe2PR2 to produce Th(Se2PiPr2)4 (1Se-Th-iPr) and Th(Se2PtBu2)4 (2Se-Th-tBu). U(S2PiPr2)4, 1S-U-iPr, could be made directly from UCl4 and 4 equiv of KS2PiPr2. With (Se2PiPr2)1–, using UCl4 and 3 or 4 equiv of KSe2PiPr2 yielded the monochloride product U(Se2PiPr2)3Cl (3Se-UiPr-Cl), but using UI4(1,4-dioxane)2 produced the homoleptic U(Se2PiPr2)4 (1Se-U-iPr). Similarly, the reaction of UCl4 with 4 equiv of KS2PtBu2 yielded U(S2PtBu2)4 (2S-U-tBu), whereas the reaction with KSe2PtBu2 resulted in the formation of U(Se2PtBu2)3Cl (4Se-UtBu-Cl). Using UI4(1,4-dioxane)2 and 4 equiv of KSe2PtBu2 with UCl4 in acetonitrile yielded U(Se2PtBu2)4 (2Se-U-tBu). Transmetalation reactions were investigated with complex 2Se-U-tBu and various CuX (X = Br, I) salts to yield U(Se2PtBu2)3X (6Se-UtBu-Br and 7Se-UtBu-I) and 0.25 equiv of [Cu(Se2PtBu2)]4 (8Se-Cu-tBu). Additionally, 2Se-U-tBu underwent transmetalation reactions with Hg2F2 and ZnCl2 to yield U(Se2PtBu2)3F (6) and U(Se2PtBu2)3Cl (4Se-UtBu-Cl), respectively. The molecular structures were analyzed using 1H, 13C, 31P, and 77Se NMR and IR spectroscopy and structurally characterized using X-ray crystallography. Using the QTAIM approach, the electronic structure of all homoleptic complexes was probed, showing slightly more covalent bonding character in actinide–selenium bonds over actinide–sulfur bonds.

Uranium(III) and thorium(IV) alkyl complexes as potential starting materials

Co-reporter:Andrew C. Behrle, Alexander J. Myers, Pokpong Rungthanaphatsophon, Wayne W. Lukens, Charles L. Barnes and Justin R. Walensky

Chemical Communications 2016 - vol. 52(Issue 100) pp:NaN14375-14375

Publication Date(Web):2016/11/16

DOI:10.1039/C6CC08105C

The synthesis and characterisation of a rare U(III) alkyl complex, U[η4-Me2NC(H)C6H5]3, using the dimethylbenzylamine (DMBA) ligand has been accomplished. While attempting to prepare the U(IV) compound, reduction to the U(III) complex occurred. In the analogous Th(IV) system, C–H bond activation of a methyl group of one dimethylamine was observed yielding Th[η4-Me2NC(H)C6H5]2[η5-(CH2)MeNC(H)C6H5] with a dianionic DMBA ligand. The utility of these complexes as starting materials has been analyzed using a bulky dithiocarboxylate ligand to yield tetravalent actinide species.

Copper(I) clusters with bulky dithiocarboxylate, thiolate, and selenolate ligands

Co-reporter:Pokpong Rungthanaphatsophon, Charles L. Barnes and Justin R. Walensky

Dalton Transactions 2016 - vol. 45(Issue 36) pp:NaN14276-14276

Publication Date(Web):2016/08/18

DOI:10.1039/C6DT02709A

The coordination chemistry of copper has interest due to its use in biological systems as well as for photochemical and medicinal properties. We report the coordination chemistry of copper(I) complexes using terphenyl-based dithiocarboxylate, thiolate, and selenolate ligands. The number of metal ions of the resulting complexes can be tuned by varying the steric properties of the terphenyl ligands, changing the starting material, as well as adding PEt3. In addition, the steric crowding of the terphenyl ligand leads to varying reactivity. For example, while the reaction of carbon disulfide with [Cu(2,6-(Ph)2C6H3)]2 results in an insertion into the copper–carbon bond, no reaction occurs with [Cu(2,4,6-(Mes)2C6H3)], Mes = 2,4,6-Me3C6H2, or [Et3PCu(2,4,6-(Mes)2C6H2)2C6H3]. The synthesis and characterization of new copper(I) complexes using NMR and IR spectroscopy, as well as X-ray crystallography is described.

Stabilization of MIV = Ti, Zr, Hf, Ce, and Th using a selenium bis(phenolate) ligand

Co-reporter:Andrew C. Behrle, Jessica R. Levin, Jee Eon Kim, Jonathan M. Drewett, Charles L. Barnes, Eric J. Schelter and Justin R. Walensky

Dalton Transactions 2015 - vol. 44(Issue 6) pp:NaN2702-2702

Publication Date(Web):2014/09/11

DOI:10.1039/C4DT01798F

Insertion of tBuNC into thorium–phosphorus and thorium–arsenic bonds: phosphaazaallene and arsaazaallene moieties in f element chemistry

Co-reporter:Andrew C. Behrle and Justin R. Walensky

Dalton Transactions 2016 - vol. 45(Issue 24) pp:NaN10049-10049

Publication Date(Web):2016/04/28

DOI:10.1039/C6DT00776G