− 71 − Radical Polymerization of Vinyl Monomers to Poly(vinyl)s having nBu3Sn end Groups with Biological Activity

Bu3Sn-endded poly(vinyl)s with biological activity were obtained by the radical polymerization of vinyl monomers using thianthrene cation radical/nBu3H. Thianthrene cation and stannyl radicals promoted the homopolymerization and copolymerization of styrene and ethyl vinyl ether having number average molecular weights of 2000-3100. Tributyltin hydride functions as a chain transfer agent. Such polymereization by cationic thianthrene and stannyl radicals could provide some clues for the biological reaction in living animals. Plausible polymerization mechanisms were suggested