Formation of mono(dithiolene)-thiocarboxamido complexes in reactions of thio(dithiocarbamato)-Mo/W complexes and dimethyl acetylenedicarboxylate

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Patrick J. Lim, Damian A. Slizys, Edward R. T. Tiekink, Charles G. Young

2005 Inorganic Chemistry Vol. 44 Issue 1 Article Cited by 14 Quartile

Abstract

Reactions of Tp*MS(S2CNEt2) with dimethyl acetylenedicarboxylate in dichloromethane produce olive green/black Tp*M{S2C2(CO2Me)2}(SCNEt 2-κ2S,C) (M = Mo (1), W (2); Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate). The seven-coordinate complexes exhibit pseudo-octahedral (1) and distorted pentagonal bipyramidal (2) coordination spheres comprised of tridentate fac-Tp*, bidentate dithiolene, and thiocarboxamido-κ2S,C ligands. In the solid state, molecules of 1 exhibit pseudo-Cs symmetry, with the thiocarboxamide NEt2 group in a cleft in the Tp* ligand. Molecules of 2 have C1 symmetry in the solid state; here, the thiocarboxamide unit is orientated along one of the W-S(dithiolene) bonds with its NEt2 group projecting away from the Tp* ligand. Both complexes possess effective Cs symmetry in solution. Reaction of Tp*Mol(CO)3 with AgS2CNEt2 affords olive green Tp*Mo(S2CNEt2)(CO)2 (3), which reacts with propylene sulfide in a new synthesis for Tp*MoS(S 2CNEt2), the starting material for 1. Complex 3 exhibits a distorted pentagonal bipyramidal structure, the axial sites being defined by a Tp* nitrogen atom and a carbonyl ligand, the pentagonal plane by the remaining nitrogen and carbonyl donors and the two sulfur atoms of the bidentate dithiocarbamate ligand.

Affiliations

School of Chemistry, University of Melbourne, Australia; Victorian College of Pharmacy, Monash University, Clayton, Vic. 3168, Australia; Department of Chemistry, University of Adelaide, Adelaide 5005, SA, Australia; Department of Chemistry, University of San Carlos, Cebu City 6000, Philippines; Department of Chemistry, National University of Singapore, Singapore 117543, Singapore