Cleavage of the sulphur–sulphur bond in alkyl and aryl disulphides by dicarbonylbis(η-cyclopentadienyl)titanium(II) and bis(η-cyclopentadienyl)vanadium(II): synthesis and properties of alkylthio- and aryl-thio-derivatives of titanium(IV), titanium(III), vanadium(IV), and vanadium(III)

Abstract

A new synthesis of the complexes [Ti(cp)₂(SR)₂], (II), via oxidative addition of alkyl and aryl disulphides to [Ti(cp)₂(CO)₂], (I), is reported (cp =η-cyclopentadienyl). Reactions of (II) with (I) give binuclear titanium(III) complexes, [(cp)₂Ti(µ-SR)₂Ti(cp)₂], (III), and this type of reaction is proposed as a general synthetic route to such complexes. Complexes (III) show reduced paramagnetism, in agreement with titanium(III)–titanium(III) interaction, and unusual affinity for carbon monoxide. The oxidative addition of disulphides to [V(cp)₂], (VI) affords, depending on the reactions conditions, [V(cp)₂(SR)₂], (VIII), or [V(cp)₂SR], (VII). The latter complexes can reversibly co-ordinate carbon monoxide.