SULFUR-COORDINATED THIOPHENE AND DIBENZOTHIOPHENE IN CP'(CO)2RE(THIOPHENE) COMPLEXES

A series of stable S-bound thiophene complexes Cp'(CO)2Re(Th), Cp' = C5H5 or C5Me5, Th = thiophene (T), 2-MeT, 3-MeT, 2,5-Me2T, Me4T, and dibenzothiophene (DBT), are prepared by the reaction of Cp'(CO)2Re(THF) with thiophenes. The first structural determination of a simple nonchelated S-coordinated thiophene complex Cp*(CO)2Re(T) is reported. Reactions of several of the Cp'(CO)2Re(Th) complexes [GRAPHICS] (Th = T, 2-MeT, and 3-MeT) with Fe2(CO)9 give thiophene-bridging dinuclear compounds Cp'(CO)2Re-(mu-2-eta-4(S)-Th)Fe(CO)3 thiophene is coordinated to the Re via the sulfur and to the Fe through the four carbons of the diene system. This reaction is the first to demonstrate that S coordination activates thiophene to undergo further reactions.