Electrochemistry of ferrocenylphosphines FcCH₂PR₂ (Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄); R=Ph, CH₂OH and CH₂CH₂CN), and some phosphine oxide, phosphine sulfide, phosphonium and metal complex derivatives

Abstract

Electrochemical studies of the free ferrocenylphosphine ligands FcCH₂PR₂ (Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄); R=Ph, CH₂OH and CH₂CH₂CN) and some phosphine oxide, phosphine sulfide, phosphonium and metal derivatives are described. The free ligands exhibit complex voltammetric responses due to participation of the phosphorus lone pair in the redox reactions. Uncomplicated ferrocene-based redox chemistry is observed for PV derivatives and when the ligands are coordinated in complexes cis-PtCl₂[FcCH₂P(CH₂OH)₂], PdCl₂[FcCH₂P(CH₂OH)₂], [Au{FcCH₂P(CH₂OH)₂}₂]Cl, RuCl₂(η⁶-C₁₀H₁₄)[FcCH₂P(CH₂OH)₂] and RuCl₂(η⁶-C₁₀H₁₄)(FcCH₂PPh₂). The reaction pathways of the free ligands after one-electron oxidation have been examined in detail using voltammetry, NMR spectroscopy and electrospray mass spectrometry. Direct evidence for formation of a P---P bonded product is presented.