Multifunctional, photochromic, acidichromic, electrochromic molecular switch: Novel aromatic poly(azomehine)s containing triphenylamine Group

Novel multifunctional polyazomethines containing triphenylamine structure in the main chain have been prepared via polycondensation of 4,4′-diformyltriphenylamine with aromatic diamines, which were characterized by elemental analysis, ¹H NMR, TG, DSC, and XRD techniques. The polymers with the decomposition temperatures of about 450 °C were heat resistant and amorphous. The UV-visible and PL spectra of polyazomethines were dependent on the diamines structures. The polyazomethines emit blue-green light at about 470 nm in pristine state and emit reddish orange at about 590 nm due to being doped with electrooxidation, acid or UV irradiation, respectively. The doped polyazomethines can go back pristine state under NH₃ vapor. The results suggest that the polyazomethines can be used as molecular switches, sensors or emitting dyes. The morphologies were investigated by AFM to be different appearance due to the natural structures of macromolecules and the convolution of self-assemblies during vaporization of solvent.