Synthesis of non-symmetrically sulphonated phosphine sulphonate based Pd(ii) catalyst salts for olefin polymerisation reactions

Abstract

Direct sulphonation of 2-(diphenylphosphino)benzenesulphonic acid was extensively studied. The non-symmetrically functionalised reaction products obtained, related to the widely applied water soluble phosphine ligands m,m,m-TPPTS and m,m-TPPDS, display chelating κ²-(P,O)-coordination to Pd(II) metal centres. Phase transfer reaction of rac-o,m-TPPDS as the potassium salt with 18-crown-6 and complexation to Pd(II) gives the novel anionic catalyst precursor [K(18-crown-6)]₂[κ²(P,O){rac-o,m-TPPDS}PdMeCl] suitable for olefin polymerisation reactions. Ethene homo- and co-polymerisation reactions with polar functionalised olefins were investigated with this anionic phosphine sulphonate Pd(II)-based pre-catalyst salt.