FTIR study of conjugation in selected aromatic polyazomethines

A series of aromatic polyazomethines synthesized from reactions between selected aromatic diamines and either terephthalaldehyde or 4,4′-diformyltriphenylamine were characterized using infrared spectroscopy. In this report the influence of diamine structure on the CN stretching frequency and the conjugation of π-electrons in polymers are discussed. The results of infrared spectroscopy were confirmed by analyzing the 1H NMR spectra of the relevant compounds. Special attention was given to the conjugation in the polyimines and model compounds with ortho-substituted alkyl groups to the amine phenyl rings. For the model compounds geometry optimizations were calculated.