Glaser coupling for the synthesis of transformable polymacrocyclic polymers

Abstract

Following the success in the synthetic methodology of macrocyclic polymers, effective construction of the precise structures of polymacrocyclic polymers with macrocyclic repeating units has been new pursuits in the fields of materials science and polymer chemistry. A polymacrocyclic polymer (PCP) with about 25 repeating macrocyclic units is synthesized in this work, via Glaser coupling of a macrocyclic monomer with a transformable truxillic ester junction and two end alkynyl groups. PCP is analyzed by FTIR, ¹H NMR and GPC. The Glaser coupling of the macrocyclic monomer is highly efficient. Gelling of PCP in the solid state due to the polymerization of conjugated diacetylene groups is also very quick. However, the gelling possibility of the polymer with linear PEG branches can be significantly suppressed. The polymacrocyclic polymer can be transformed into a linear polymer if the truxillic ester junction in PCP is cleaved under UV below 260 nm. Glaser coupling in conjunction with transformable photochemistry shows robustness in effectively constructing novel topological macromolecular structures.