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 C=N stretching frequency and the conjugation of pi-electrons in polymers are discussed. The results of infrared spectroscopy were confirmed by analyzing the H-1 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. (c) 2013 Elsevier B.V. All rights reserved.