Transition metal–carbon bonds. Part XV. A crotyl–butadiene–rhodium(III) complex and related complexes

Abstract

Butadiene reacts with rhodium trichloride in methanol to give a crotyl, butadiene-bridged, chloro-bridged complex, [C₄H₇RhCl₂(C₄H₆)RhCl₂C₄H₇]. The complex reacts with pyridine to give [RhCl₂(1-methylallyl)(py)₂] and with cyclopentadienylthallium to give [RhCl(1-methylallyl)(C₅H₅)], both with evolution of butadiene. The complex [C₄H₇RhCl₂(C₄H₆)RhCl₂(C₄H₇)] is also formed by the oxidative addition of 1-methyallyl chloride to [RhCl(C₄H₆)₂] or by treating [Rh₂Cl₂(C₂H₄)₄] successively with 1-methylallyl chloride then with butadiene; this method was also used to synthesise the corresponding allyl and 2-methylallyl complexes, [Rh₂Cl₄(all)₂(C₄H₆)](all = allyl or 2-methylallyl). An allyl alcohol complex [Rh₂Cl₄(Allyl)₂(C₃H₅OH)₂] has also been prepared. N.m.r. and infrared data are given.