First Diphosphinoamine Ligand Bearing a Polymerizable Side Chain: Complexation with Copper(I)

A diphosphinoamine ligand with a polymerizable side chain, (PPh2)2N CH2 C6H4 CH1⁄4CH2 (vbzpnp or 1), was synthesized. The ligand could be polymerized by anionic polymerization with n-butyllithium as the initiator. Polyvbzpnp was soluble in tetrahydrofuran and chloroform but was insoluble in methanol and was characterized with NMR, IR, and gel permeation chromatography. The numberaverage and weight-average molecular weights were 40,050 and 55,690, respectively, and the polydispersity index was 1.39. [Cu(CH3CN)4]ClO4 formed a bischelated complex with the monomer and produced [Cu(1)2]ClO4 (2), and CuCl formed a tetramer, Cu4(1)2Cl4 (3). All the compounds (1, 2, and 3) were characterized with single-crystalstructure determination, NMR, and IR spectroscopy. The addition of [Cu(CH3CN)4]ClO4 to polyvbzpnp resulted in an insoluble crosslinked polymer, which was characterized with solid-state P {H} magic-angle-spinning NMR. The copolymerization of styrene and 1 produced a styrene–vbzpnp copolymer that was found to be soluble in common organic solvents.