Light-Controlled Switchable Ring Opening Polymerization

• DOI: 10.1021/acs.macromol.9b00984
• Publication Date: 2019-07-18T19:19:52Z
• Authors: Min Li; Pan Zhang; Changle Chen
• Keywords: Azobenzene; Reactivity

Light is a fascinating source of external stimulus for the regulation polymerization processes. In this contribution, some salicylaldimine Zn(II) complexes bearing azobenzene moieties were prepared and characterized. Isomerization between trans cis forms these achieved by exposure to light; both isomers are active in ring-opening polymerizations ε-caprolactone (CL), rac-lactide, trimethylene carbonate, β-oxetanone, δ-valerolactone, cyclopentadecanolide, 5-methyl-5-propyl-1,3-dioxan-2-one but exhibit different kinetic profiles. A 6-fold reactivity difference was realized CL upon irradiation with light. The light-induced isomerization also led discrimination monomers copolymerization reactions. Reversible photoswitching two catalytically states provides strategy control processes, as well compositions polymers produced.