Reactions of half-sandwich rhodium(III) and iridium(III) compounds with pyridinethiolate ligands: Mono-, di-, and tri-nuclear complexes

Neutral trinuclear metallomacrocycles, [Cp* RhCl(mu-4-PyS)](3) (3) and [Cp* IrCl(mu-4-PyS)](3) (4) [Cp* = pentamethylcyclopentadienyl, 4-PyS = 4-pyridinethiolate], have been synthesized by self-assembly reactions of [Cp* RhCl2](2) (1) and [Cp* IrCl2](2) (2) with lithium 4-pyridinethiolate, respectively. In situ reaction of complex 3 with three equivalent of lithium 4-pyridinethiolate resulted in [Cp* Rh(mu-4-PyS)(4-PyS)](3) (5) containing both skeleton and pendent 4-PyS groups. Chelating coordination of 2-pyridinethiolate broke down the triangular skeleton to give mononuclear metalloligands Cp* Rh(2-PyS)(4-PyS) (6) and Cp* Ir(2-PyS)(4-PyS) (7) [2-PyS = 2-pyridinethiolate], which could also be synthesized from Cp* RhCl(2-PyS) (10) and Cp* IrCl(2-PyS) (11) with lithium 4-pyridinethiolate. The coordination reactions of 6 with complexes 1 and 2 gave dinuclear complexes [Cp* Rh(2-PyS)(mu-4-PyS)][Cp* RhCl2] (8) and [Cp* Rh(2-PyS)( mu-4-PyS)][Cp* IrCl2] (9), respectively. Molecular structures of 3, 4, 6 and 11 were determined by X-ray crystallographic analysis. All the complexes have been well characterized by elemental analysis, NMR and IR spectra. (C) 2009 Elsevier B.V. All rights reserved.