The interaction of thin polyaniline films with various H-phosphonates: Spectroscopy and quantum chemical calculations

The conducting form of polyaniline (PANI) is formed by doping of non-conducting PANI base usually by protonic acids. An alternative way of doping, consisting in an interaction via hydrogen bonding, has been previously proven for H-phosphonates. In this study, PANI base films are exposed to various H-phosphonates, changes in the structure of the films are analyzed by ultraviolet-visible, infrared, and Raman spectroscopies and spectroscopic data are compared with quantum chemical calculations. According to our results, the interaction of the PANI base films with H-phosphonates is realized by hydrogen bonding between the imine nitrogen of PANI and the hydroxy group of the H-phosphonate tautomeric form, i.e., phosphite. This is in the contrast to the PANI powders doped with H-phosphonates where both interacting phosphite and non-interacting H-phosphonate forms were observed. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46728.