Pyridine-based polymers and derivatives: Synthesis and applications

Pyridine (C5H5N) is an aromatic molecule in which all of the pi electrons are shared by a ring, forming a continuous circle of electrons. This chapter offers an in-depth overview of different synthesis procedures for pyridine-based polymers, their applications, and also focuses on methodology and significant outcomes. The chapter also presents the importance and thorough insight into pyridine-based polymers along with their synthesis and applications in various fields. Pyridine and its derivative polymeric products are significant chemical compounds having a wide range of uses including both medical as well as nonmedical aspects. Pyridine was found as a by-product of the distillation of bones in a dry environment in the mid-nineteenth century. Crystalline samples of trigonelline (N-methyl pyridinium-3-carboxylic acid; 1) were isolated from the plant Trigonella foenum graecum, which was the first case to isolate a pyridine derivative from live tissue. They can be synthesized taking both metals and nonmetals in conjugation with the pyridine molecule. Polyimide, polyamide, polyarylate, and their copolymers are the most common types of these polymers synthesized in conjugation with pyridine. The inclusion of pyridine is a significant synthetic approach in medicine-related areas for the excellent therapeutic qualities of pyridine-based polymeric medicines which have prompted the medicinal chemists to develop a greater number of new chemotherapy-based medications. Pyridine-based polymers are becoming increasingly important in the aspect of modern medicine also. Polymers based on pyridine have been demonstrated to be potential options for polymer light-emitting devices as well. They are quite resistant to oxidation and are also reported to have superior electron transport characteristics. Many efforts have been made for improving the processing properties of these pyridine-based polymers. These efforts in several fields include the introduction of elastic segments into the polymeric chain, incorporating large groups to decrease crystallization, replacing symmetrical aromatic rings with unsymmetrical ones to reduce crystallinity.