Dithioethers as ligands in pentamethylcyclopentadienylrhodium(III) and iridium(III) complexes. Crystal structures of [{(η 5-C 5Me 5)Rh} 2(μ-Cl) 2{μ-(MeS) 2CH 2}](BF 4) 2·H 2O and [(η 5-C 5Me 5)IrCl 2{η 1-(PhS) 2CH 2}

Abstract

Reactions of complexes [{(η 5-C 5Me 5)MCl 2} 2] (M=Rh, Ir) with the ligand (MeS) 2CH 2 in CH 2Cl 2 solution led to the neutral dinuclear complexes of the general formula [{(η 5-C 5Me 5)MCl 2} 2{μ-(MeS) 2CH 2}] [M=Rh ( 1), Ir ( 2)]. Compound 1 reacts in CH 2Cl 2 solution with silver tetrafluoroborate in 1:2 molar ratio to yield the dinuclear cationic complex [{(η 5-C 5Me 5)Rh} 2(μ-Cl) 2{μ-(MeS) 2CH 2}](BF 4) 2·H 2O ( 3). Compound 2 reacts with silver salts in analogous conditions to give the mononuclear cationic complex [(η 5-C 5Me 5)IrCl{η 2-(MeS) 2CH 2}]BF 4 ( 4). Reactions of the starting complexes [{(η 5-C 5Me 5)MCl 2} 2] with the ligand (PhS) 2CH 2 afforded the mononuclear complexes [(η 5-C 5Me 5)MCl 2(η 1-(PhS) 2CH 2)] [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 P2 1/ 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 (η 5-C 5Me 5)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 P2 1/ 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 η 5-C 5Me 5 group occupying the centre of three octahedral sites, two chloride atoms and a sulphur of a monodentate bis(phenylthio)methane ligand.