LnNa8[OC(CH3)3]10(OH) alkoxide clusters: Highly active single-component catalysts for the homopolymerization and copolymerization of ε-caprolactone and trimethylene carbonate

Heterometal alkoxide clusters of lanthanide and sodium, LnNa8[OC(CH3)3]10(OH) [where Ln = Nd (1) or Yb (2)], which were synthesized by the metathesis reaction of LnCl3 with NaOC(CH3)3 and NaOH in a 1 : 10 : 1 molar ratio in high yields and fully characterized including X‐ray analysis for 2, were found to be highly active catalysts in the ring‐opening polymerization of ε‐caprolactone and trimethylene carbonate and their copolymerization. All of the polymers obtained showed a unimodal molecular weight distribution, indicating that 1 and 2 could really be used as single‐component catalysts. The dependence of catalytic activity on the lanthanide metals was observed: Yb < Nd. A coordination–insertion mechanism for the ring‐opening polymerization is proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009