The polarographic behaviour of complexes formed between the bis(π-cyclopentadienyl)vanadium(IV) group and some O-alkyl dithiocarbonates and OO′-dialkyl dithiophosphates has been investigated in acetone. Each complex exhibits two well defined one-electron reduction waves, and in most cases further reduction waves. The wave at most positive potentials is associated with the reversible process [(cp)2VIVL]+ + e ⇋ [(cp)2VIIIL]0 (where L is an alkyl dithiocarbonate or dialkyl dithiophosphate). For L = methyl dithiocarbonate and dialkyl dithiophosphate, the neutral vanadium(III) complexes are prone to dissociation. Mercury is oxidized in the presence of released ligand providing an example of [graphic omitted] mechanisms.