RESUMO
The coordination chemistry of a series of pro-ligands ([L¹]-[L6]) with cobalt and zinc derivatives has been studied. All complexes have been characterized by multinuclear NMR, elemental analysis, and by single-crystal X-ray diffraction studies. Polymerization of rac-lactide takes place at 130 °C in the presence of cobalt and zinc complexes to yield polymers under solvent free conditions with controlled molecular masses and narrow polydispersities.
Assuntos
Cobalto/química , Complexos de Coordenação/química , Dioxanos/química , Zinco/química , Complexos de Coordenação/síntese química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Polimerização , Polímeros/químicaRESUMO
Grafting of [Ln(BH(4))(3)(THF)(3)] (Ln = La, Nd) onto silica affords materials containing well-identified bis(borohydride) surface species. The neodymium-decorated silica converts the beta-butyrolactone monomer into highly isotactic poly(beta-hydroxybutyrate). Under similar conditions, the molecular precursor gives rise to an atactic polymer.
