THIOPHENE C-S BOND-CLEAVAGE BY RHODIUM AND IRIDIUM - AN UNPRECEDENTEDBRIDGING MODE OF THE OPEN C4H4S FRAGMENT

The complexes [{(triphos)M}(2)(mu-eta(3),eta(4)-SC4H4)](Y)(2) (M = Ir, Y = BPh(4); M = Rh, Y = PF6) are obtained by reaction of thiophene wi th either [(triphos)Ir(eta(4)-C6H6)]BPh(4) in Me(2)SO at 80 degrees C or [(triphos)RhCl(C2H4)] + TlPF6 in THF at room temperature; a single- crystal X-ray diffraction analysis of the iridium complex shows that a n open C4H4S moiety sits astride two metal centres; the bridge-bonding mode implies the sharing of four electron pairs with the metals.