Hydrogen phosphates: Self initiated organocatalysts for the controlled ring-opening polymerization of cyclic esters

A series of arylhydrogenphosphates and aryldihydrogenphosphates was synthesized and characterized using spectroscopic methods and single crystal X-ray diffraction. These compounds were assessed as catalysts towards the ring-opening polymerization and proved to be potent organocatalysts for the ring-opening polymerization of cyclic esters. The bulk polymerizations were performed in the absence of external initiator. The polymerization proceeds in a controlled fashion which leads to well defined polyesters with narrow molecular weight distributions. In the post polymerization experiments, kinetics, mechanism and monomer concentration effects were investigated. The kinetic results have confirmed the pseudo-living character of the polymerizations and mechanistic studies suggest that the polymerization operates through a cationic mechanism.

Graphical abstractThe synthesis, characterization along with catalytic activity of arylhydrogenphosphates and aryldihydrogenphosphates towards the ring-opening polymerization of cyclic esters is reported.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis and complete characterization of arylhydrogenphosphates. ► Applications as catalysts in ring-opening polymerization. ► Polymerization using a cationic route.