Chromium and Molybdenum Pentacarbonyl Complexes of Phosphinocarbodithioates: Synthesis, Molecular Structure and Behaviour in RAFT Polymerisation

Molybdenum and chromium pentacarbonyldiphenylphosphinocarbodithioate complexes have been prepared in a one-pot reaction from the corresponding metallocarbonyldiphenylphosphine. The complexes have been characterised by IR, H-1, P-31 and C-13 NMR spectroscopies and by mass spectrometry. The solid-state structures of [Cr(CO)(5){PPh2CS2CH(Ph)CH3}] (1) and [Mo(CO)(5){PPh2CS2CH(Ph)CH3}] (2) are reported. Compounds 1 and 2 are isostructural and crystallise in the triclinic P (1) over bar space group. These new organometallic compounds are highly efficient reversible chain-transfer agents for reversible addition-fragmentation chain-transfer (RAFT) polymerisation of styrene (St) and n-butyl acrylate (nBA), with controlled number-average molar mass values and narrow dispersities (< 1.2). The controlled character of the polymerisation was further exemplified by the synthesis of St and nBA diblock copolymers.