Preparation and photolysis of polyamides having coumarin dimer component

Abstract

AbstractThe ring‐opening polyaddition reaction of anti and syn head‐to‐head Coumarin dimers with diamines and the photocleavage behavior of the resulting polyamides were investigated. Anti head‐to‐head Coumarin dimer successfully reacted with aliphatic and aromatic diamines in an aprotic polar solvent to give corresponding high molecular weight polyamides. The polyamides showed good film forming ability and exhibited solubility behavior typical of polyelectrolytes. Furthermore, these polyamides were found to undergo exclusively asymmetric photocleavage on the cyclobutane rings in the polymer main chain to give a fumaramide unit with elimination of 2,2′‐dihydroxystilbene. On the other hand, syn head‐to‐head Coumarin dimer gave only low molecular weight polyamides. These polymerization and photocleavage behaviors were elucidated in comparison with those of model reactions.