Step-Growth Polymerization of Terephthaldehyde Catalyzed by N-Heterocyclic Carbenes

The step growth polymerization of terephthaldehyde catalyzed by N-Heterocyclic Carbenes (NHC) was analyzed. The experiment was performed under an inert atmosphere using standard Schlenk technique and NHC-1 and NHC-2 were prepared by modifying the procedures. It was found that the conversion and molar masses of the poly-benzoin samples thus obtained were greatly influenced by the type of carbene employed. NHCs were featured as highly efficient organic catalyst for miscellaneous reactions of molecular chemistry. The isolated polybenzoins were also characterized by differential scanning calorimetry (DSC) not indicating any melting point, with all compounds being amorphous in nature with glass transition temperature value increasing with molar mass. NHC must be preferred to cyanide ions used, which can release cyanohydric acid in the presence of water.