Solid-state polymerization of monomers possessing two diphenylbutadiyne moieties with amido groups to form ladder polymers

Abstract

Two series of monomers possessing two diphenylbutadiyne moieties connected by a methylene chain via amido groups, i.e., alkanedi{3-[4-(3-nitrophenyl)butadynyl]anilide} (N-n) and alkanedi{3-[4-(3-alkanoylaminophenyl)butadiynyl]anilide} (mA-n), were synthesized, and their solid-state polymerization behaviors and the polymer structures were investigated by various spectroscopic measurements and powder X-Ray diffractions. Although polymerization of N-n only proceeds in one of two diphenylbutadiyne moieties in a monomer to give single-chain polydiacetylenes, mA-n polymerized at both diphenylbutadiyne moieties to give double-chain polydiacetylenes. All the results suggest that two arrays of intermolecular hydrogen bonding formed between two diphenylbutadiyne moieties for N-n are not sufficient to fix the structure, and atomic movements during polymerization influence the polymerizable stack of the other remaining diphenylbutadiyne to disorder into non-polymerizable one. Meanwhile, mA-n can form four arrays of intermolecular hydrogen bonding on both sides of each diphenylbutadiyne moiety to fix it, and polydiactylene-based ladder polymers were successfully prepared from mA-n.