Generation of stable carbocations in polydiphenylenesulfophthalide and ortho-substituted polytriarylcarbinols upon water desorption

Abstract

Formation of “green” color centers (CCs) with two absorption bands (ABs) in the visible spectrum at 480 and 610 nm upon evacuation and/or weak heating (~100 °C) of films of polytriarylcarbinol (PTAC) and polydiphenylenesulfophthalide (PDSP) due to loss of sorbed water was observed. Electronic spectra (ES) of solutions of compounds that simulate polymers, PTAC and PDSP polymers in sulfuric acid were obtained. Isolated CCs having ABs in electronic spectra (ES) at 462 and 595 nm were generated by “slight” treatment of a PTAC film with sulfuric acid. The ES of a series of model carbocations and energies of ionization of the model triphenylcarbinols by proton, oxonium ion and Li+ ion were calculated in B3LYP/6-311G(d,p) approximation. Experimental and theoretical results are showed that the CCs in question are carbocation nature. The paper discusses the ionization mechanism in polymers and some aspects of heterogeneous (in water) and homogeneous (in organic polar solvent) methods of PTAC preparation.