Dimeric rhodium(III), iridium(III) and ruthenium(II) thiosalicylate complexes

Reactions of the chloride-bridged dimers [LMC1(mu -Cl)](2) (M = Rh, Ir; L = Cp* = eta (5)-C5Me5; M = Ru, L = eta (6)-p-cymene) with two mole equivalents of thiosalicylic acid (HSC6H4CO2H, H(2)tsal) and excess base gives the dimeric rhodium(III), iridium(III) and ruthenium(II) thiosalicylate complexes [LM(tsal)](2). Reaction of the complex [Cp*RhCl2(PPh3)] with one equivalent of H(2)tsal and triethylamine in dichloromethane gives a mixture of the dimer [Cp*Rh(tsal)l, and the phosphine complex [Cp*Rh(tsal)(PPh3)]; upon recrystallisation, pure dimer is obtained. A single-crystal X-ray diffraction study on the rhodium and ruthenium dimers reveals the expected thiolate-bridged M-2(mu -S)(2) unit. Electrospray mass spectrometry (ESMS) is a useful technique in studying the chemistry of the thiosalicylate complexes, all complexes giving strong [M + H](+) ions. With added thiosalicylic acid, cations of the type [(LM)(2)(Htsal)(3)](+) were detected in the mass spectra. (C) 2001 Elsevier Science B.V. All rights reserved.