Di- and trithiocarbamato complexes of osmium(III) and the crystal and molecular structure of [Os2(SeS2CNMe2)2(S2CNMe2)3]PF6

Synthesis, Crystal Structures, and Reactivity of Osmium(II) and -(IV) Complexes Containing a Dithioimidodiphosphinate Ligand

Reduction of trans-[OsL2(O)2] (1) (L-=[N(i-Pr2PS)2]-) with hydrazine hydrate afforded a dinitrogen complex 2, possibly "[OsL2(N2)(solv)]" (solv=H2O or THF), which reacted with RCN, R'NC, and SO2 to give trans-[OsL2(RCN)2] (R=Ph (3), 4-tolyl (4), 4-t-BuC6H4 (5)), trans-[OsL2(R'NC)2] (R'=2,6-Me2C6H3 (xyl) (6), t-Bu (7)), and [Os(L)2(SO2)(H2O)] (8) complexes, respectively. Protonation of compounds 2, 3, and 6 with HBF4 led to formation of dicationic trans-[Os(LH)2(N2)(H2O)][BF4]2 (9), trans-[Os(LH)2(PhCN)2][BF4]2 (10), and trans-[Os(LH)2(xylNC)2][BF4]2 (11), respectively. Treatment of 1 with phenylhydrazine and SnCl2 afforded trans-[OsL2(N2Ph)2] (12) and trans-[OsL2Cl2] (13), respectively. Air oxidation of compound 2 in hexane/MeOH gave the dimethoxy complex trans-[OsL2(OMe)2] (14), which in CH2Cl2 solution was readily air oxidized to 1. Compound 1 is capable of catalyzing aerobic oxidation of PPh3, possibly via an Os(IV) intermediate. The formal potentials for the Os-L complexes have been determined by cyclic voltammetry. The solid-state structures of compounds 4, 6, cis-8, 13, and 14 have been established by X-ray crystallography.

Multiple nitrene insertions into metal-sulfur bonds of dithiocarbamate complexes: synthesis of sulfido-amido and zwitterionic tetraamido complexes

The iodine(III) reagent, PhI[double bond, length as m-dash]NTs, acts as a source of the nitrene fragment NTs, which undergoes facile insertion into the metal-sulfur bonds of a range of dithiocarbamate complexes. Addition of two equivalents of PhI=NTs to [M(S(2)CNR2)2] affords sulfido-amido complexes [M{SC(NR2)SNTs}2](M=Ni, Cu), which insert two further nitrene fragments to afford zwitterionic tetraamido complexes [M{TsNSC(NR2)SNTs}2](M=Co, Ni, Cu). Crystallographic studies have been carried out on both types of complex allowing possible resonance hydrids of the new ligand types to be assessed.