Thiophene C–S bond cleavage by rhodium and iridium. An unprecedented bridging mode of the open C4H4S fragment

Abstract

The complexes [{(triphos)M}₂(µ-η³,η⁴-SC₄H₄)](Y)₂(M = Ir, Y = BPh₄; M = Rh, Y = PF₆) are obtained by reaction of thiophene with either [(triphos)Ir(η⁴-C₆H₆)]BPh₄ in Me₂SO at 80 °C or [(triphos)RhCl(C₂H₄)]+ TIPF₆ in THF at room temperature; a single-crystal X-ray diffraction analysis of the iridium complex shows that an open C₄H₄S moiety sits astride two metal centres; the bridge-bonding mode implies the sharing of four electron pairs with the metals.