Salicylaldimine Copper(II) complex catalyst: Pioneer for ring opening Polymerization of Lactide
AbstractSalicylaldimine copper complex has been synthesized and its reactivity for the ring opening polymerization (ROP) of lactide has been studied. This monomeric copper complex was prepared by the reaction of copper(II) solution with one molar equivalent of salicylaldimine Schiff base ligand in methanol under nitrogen atmosphere. This copper complex has been characterized by different spectroscopic methods, which showed square planar geometry. The molecular structure of the salicylaldimine Schiff base has been determined by X ray diffraction studies. The complex was tested as the initiator for the ring opening polymerization of lactide, with variation in diamine group in ligand. The rate of polymerization is dependent on the diamine group in the following order: ethylene propylene phenyl. The salicylaldimine copper complex allows controlled ring opening polymerization as indicated by the linear relationship between the percentage conversion and the number average molecular weight. On the basis of literature reports, a mechanism for ROP of lactide has been proposed. Graphical AbstractThis article describes the synthesis and characterization of salicylaldimine copper(II) complexes, and their catalytic activity towards ring opening polymerization of L lactide.
Journal of Chemical Sciences