LAUSR

Abstract Tridentate 2,6-bis(imino)phenol (L1−L4) and 2,6-bis(amino)phenol (L5−L8) ligands and their corresponding zinc chloride complexes (1–8) have been synthesized and well characterized by FT-IR, 1H and 13C NMR, elemental analysis and single-crystal X-ray diffraction analysis. It was found that zinc complexes (1–4) with 2,6-bis(imino)phenol ligands were inactive for the ring-opening polymerization (ROP) of e-caprolactone (e-CL) even if they were activated by methyllithium. Zinc complexes (5–8) with 2,6-bis(amino)phenol ligands were proved to be highly efficient initiators for the ROP of e-CL in combination with 4 equiv. of methyllithium. The ROP of e-CL in the absence or presence of benzyl alcohol, including the influence of monomer ratio, reaction temperature and the substituents in the ligands, were investigated. The structure and thermal properties of obtained polymers were analyzed by NMR and MALDI-TOF mass spectra, DSC and TGA, respectively.