Investigation of the structure-property relationship of aminophenyl-based polyazomethine synthesized via ultrasonication method

A wide range of small-molecular materials and polymers are mostly synthesized via Suzuki, Stille and Wittig-type reactions. However, these processes utilize expensive metal catalysts, require inert and drastic reaction conditions, employ toxic solvents, long reaction time and need substantial product purification. An interesting alternative to traditional conjugated polymers is the use of poly(azomethine)s, or Schiff bases (–CH=N-), which have been successfully synthesized and employed in various applications. Herein, we synthesized two aminophenyl-based poly(azomethine)s, namely poly(4–2-APIMP) and poly(4-NBB-1, 2-D), under ultrasonic conditions (45 kHz, 550 W and 80 °C). A high yield was obtained in a shorter reaction time compared to silent conditions. The resulting polymers were fairly soluble in polar aprotic solvents. The structure-property correlations of the monomers and polymers were analyzed using FT-IR NMR, UV-Vis, XRD, and SEM techniques. Finally, DFT calculations was carried out using Gaussian 09 with a hybrid B3LYP correlation functional and a 6–311 G(d,p) basis set level to provide insight into the electronic properties. Results of experimental and theoretical studies showed that the structural properties of materials could be tuneable based on desired applications.