Rhodium– and iridium–perfluorobenzenethiolato complexes, [(C5Me5)Ir(SC6F5)2], [(C5Me5)Ir(SC6F4H-p)2] and [(C5Me5)2Rh2(µ-SC6F5)3][(C5Me5)Rh(SC6F5)3]: syntheses, crystal structures and solution behaviour

Abstract

Reaction of [(C₅Me₅)₂M₂(µ-Cl)₂Cl₂](M = Rh 1a or Ir 1b) with Pb(SR_F)₂ gave [(C₅Me₅)Ir(SR_F)₂]2b(R_F= C₆F₅ or C₆F₄H-p) containing five-co-ordinate Ir^III, or ionic [(C₅Me₅)₂Rh₂(µ-SR_F)₃][(C₅Me₅)Rh(SR_F)₃]3a(R_F= C₆F₅ or C₆F₄H-p) containing six-co-ordinate Rh^III in both the anion and cation. Complexes 2b and 3a(R_F= C₆F₅) were characterised by single-crystal X-ray determinations; the structures of 2b(R_F= C₆F₅ or C₆F₄H-p) are very similar, but in the former the SC₆F₅ ligands are related by a plane of symmetry. The NMR spectra of 2b in solution are consistent with the mirror-symmetric solid-state structure. However, those of the rhodium complexes 3a, while consistent with the ionic solid-state structures in methanol, show quite different features in less-polar solvents, indicating that they participate in the equilibrium [(C₅Me₅)₂Rh₂(µ-SR_F)₃][(C₅Me₅)Rh(SR_F)₃]⇌ 3[(C₅Me₅)Rh(SR_F)₂] where [(C₅Me₅)Rh(SR_F)₂] has a similar structure to that of 2b(R_F= C₆F₅). Complexes 1a and 1b reacted with Pb(SC₆H₄F-p)₂ to give salts formulated as the triply bridged [(C₅Me₅)₂M₂(µ-SC₆H₄F-p)₃]Cl·H₂O (M = Rh 4a cr Ir 4b), while 1b reacted with Ag(SCF₃) to afford the diiridium complexes [(C₅Me₅)₂Ir₂(µ-SCF₃)₂(SCF₃)₂]5b and [(C₅Me₅)₂Ir₂(µ-SCF₃)₃]Cl·H₂O 6b.