New Challenge for Classics: Neutral Zinc Complexes Stabilised by 2,2’-Bipyridine and 1,10-Phenanthroline and Their Application in the Ring-Opening Polymerisation of Lactide

The zinc acetato and triflato complexes of 2,2’-bipyridine and 1,10-phenanthroline were prepared and completely characterised. The whole series (including the already described dichlorido complexes and the ligands themselves) were screened for their catalytic activity in the solvent free ring-opening polymerisation of D,L-lactide. The acetato and triflato complexes were found to be active initiators and polylactides could be obtained in almost quantitative yields or with high molecular weights, up to 145,000 g/mol