Complexes of the platinum metals. Part VI. Dithiocarbamato- and O-alkyl dithiocarbonato-derivatives of ruthenium, osmium, and iridium

Abstract

New dithiocarbamato- and O-alkyl dithiocarbonato-derivatives, [M(S–S)₂(PPh₃)₂], [M(S–S)₂(CO)(PPh₃)], [MH(S–S)(CO)(PPh₃)₂](M = Ru or Os; S–S = R₂NCS₂^– or ROCS₂^–; R = Me or Et), [OsCl(S₂CNR₂)(CO)(PPh₃)₂], and [IrH₂(S–S)(PPh₃)₂], have been prepared by treating the appropriate chloro- orcarboxylato-complexes with sodium salts of the ligand. In several instances, hydride ligands, present in the parent complex, are also replaced by S–S groups. Tetramethylthiuram disulphide reacts with [IrCl(CO)(PPh₃)₂], [RuH₂(PPh₃)₄], and [RuH₂(CO)(PPh₃)₃] or [RuHCl(CO)(PPh₃)₃] to afford the complexes [Ir(S₂CNMe₂)₂(CO)(PPh₃)]Cl, [Ru(S₂-CNMe₂)₂(PPh₃)₂], and [Ru(S₂CNMe₂)₂(CO)(PPh₃)] respectively. Structural and stereochemical assignments based on n.m.r. and i.r. spectroscopic data for the R₂NCS₂^– and ROCS₂^– complexes confirm the expected substantial barrier to rotation about the S₂C–NR₂ bond in the former, but reveal no evidence of a comparable barrier to rotation about the S₂C–OR bond in the latter.