Synthesis and Properties of Polyquinolines and Polyanthrazolines Containing Pyrrole Units in the Main Chain

Abstract

A series of eight new polyquinolines and polyanthrazolines with pyrrole isomeric units in main chain were synthesized and characterized. The new polymers showed high glass transition temperatures (Tg = 242−339 °C) and excellent thermal stability (T5% = 398−536 °C in air, TGA). Compared to the series of polyanthrazolines, the series of polyquinolines exhibited higher thermal stability, better solubility in common organic solvents, and lower maximum absorption wavelengths (λamax). Polyanthrazolines with 2,5-pyrrole linkage showed an unusually high λamax (565 nm) and small band gap (2.02 eV). All polymers in solution had low photoluminescence quantum yields between 10-2% and 10-5% and excited-state lifetimes of 0.28−1.29 ns. The effects of molecular structure, especially pyrrole linkage structures, on the electronic structure, thermodynamics, and some of the optical properties of the polymers were explored. A model of hydrogen bonds in the main chain of the polymers was suggested to explain the difference in...