Dithioethers as ligands in pentamethylcyclopentadienylrhodium(III) and iridium(III) complexes. Crystal structures of [{(η5-C5Me5)Rh}2(μ-Cl)2{μ-(MeS)2CH2}](BF4)2·H2O and [(η5-C5Me5)IrCl2{η1-(PhS)2CH2}]

Reactions of complexes [{(η5-C5Me5)MCl2}2] (M=Rh, Ir) with the ligand (MeS)2CH2 in CH2Cl2 solution led to the neutral dinuclear complexes of the general formula [{(η5-C5Me5)MCl2}2{μ-(MeS)2CH2}] [M=Rh (1), Ir (2)]. Compound 1 reacts in CH2Cl2 solution with silver tetrafluoroborate in 1:2 molar ratio to yield the dinuclear cationic complex [{(η5-C5Me5)Rh}2(μ-Cl)2{μ-(MeS)2CH2}](BF4)2·H2O (3). Compound 2 reacts with silver salts in analogous conditions to give the mononuclear cationic complex [(η5-C5Me5)IrCl{η2-(MeS)2CH2}]BF4 (4). Reactions of the starting complexes [{(η5-C5Me5)MCl2}2] with the ligand (PhS)2CH2 afforded the mononuclear complexes [(η5-C5Me5)MCl2(η1-(PhS)2CH2)] [M=Rh (5), Ir (6)]. All the complexes have been characterised by analytical and spectroscopic means, and the fluxional behaviour of 4, in solution, has been studied. The crystal structures of complexes 3 and 6 have been established by X-ray crystallography. Complex 3 crystallised in space group P21/n, a=11.848(2), b=12.693(2), c=21.608(4) Å, β=95.18(2)° and Z=4. The complex cation consists of two (η5-C5Me5)Rh moieties connected by two chloride atoms and one dithioether group. The two rhodium atoms are separated by 3.6093(10) Å. Complex 6 crystallised in space group P21/c, a=8.366(1), b=16.011(3), c=17.911(2) Å, β=100.28(1)° and Z=4. The iridium atom has a distorted octahedral co-ordination with a η5-C5Me5 group occupying the centre of three octahedral sites, two chloride atoms and a sulphur of a monodentate bis(phenylthio)methane ligand.