Lanthanides benzimidinates: initiators or real catalysts for the epsilon-caprolactone polymerization

摘要

Lanthanides (samarium and ytterbium) tris and monobenzimidinates are efficient for the polymerization of epsilon-caprolactone, the systems remaining active after consumption of the monomer. Nevertheless it is not a living polymerization because the benzimidinates are recovered. Evidence for support of the proposed catalytic obtained by NMR studies. References: 13