POLYMERIZATION OF METHACRYLIC ESTERS USING METAL ALKOXIDES CONTAININGLANTHANOIDS

Polymerization of methyl methacrylate (MMA) was promoted by the cluste rs of lithium isopropoxide containing lanthanoid(III) isopropoxides [L a(O i-Pr)(3) (1) and Ce(O i-Pr)(3) (2)], prepared from the correspondi ng lanthanoid(III) chlorides according to the Kagan's method. The init iators provided an isotactic poly(MMA) in a good yield, although lithi um isopropoxide afforded no polymer in toluene at 0 degrees C. While l ithium isopropoxide also gave no polymer in tetrahydrofuran at O degre es C, syndiotactic poly(MMA) was obtained even at -40 degrees C using the cerium triisopropoxide (2) in 91% yield. The polymerization was co nfirmed to be initiated through Meerwein-Ponndorf-Verley (MPV) reducti on.