series of pyridine and polypyridine-zinc complexes were synthesized, and their application in ε-caprolactone and l-lactide polymerization was studied. In ε-caprolactone polymerization, zinc complexes bearing 1,10-phenanthroline derivatives exhibited a higher polymerization rate than did diethyl zinc (2–10 times). In l-lactide polymerization, zinc complexes bearing 1,10-phenanthroline derivatives exhibited