Zwitterionic Complexes of Group 4 Metal Chlorides Containing a Bis(imino)phenoxide Scaffold: Synthesis, Characterization and Polymerization Studies. Issue 16 (7th October 2016) - Chakraborty, Debashis
Abstract: Chlorides of group 4 metals containing the bis(imino)phenoxide ligand scaffold were synthesized from a direct reaction between the respective ligand and metal chlorides MCl4 (M=Ti, Zr and Hf). These complexes were thoroughly characterized using various spectroscopic methods and single crystal X‐ray diffraction studies. They are potent catalysts for the polymerization of rac ‐lactide ( rac ‐LA), L ‐lactide ( L– LA), ϵ ‐caprolactone ( ϵ ‐CL), epoxides such as, rac ‐cyclohexene oxide ( rac ‐CHO), rac ‐propylene oxide ( rac ‐PO), rac ‐styrene oxide ( rac ‐SO) and ethylene, resulting in polymers with high number average molecular weights ( M n ) and narrow molecular weight distributions (MWDs). The kinetic and mechanistic studies associated with the polymerization of lactide, ϵ ‐CL and CHO has been investigated in details. Abstract : Zwitterionic complexes of group 4 metals containing the bis(imino) phenoxide ligand scaffold were synthesized and their activity towards the ROP of lactide, ϵ ‐CL, ethylene and homopolymerization of epoxides were investigated.