Synthesis and electrochromic, acidochromic properties of Schiff bases containing triphenylamine and thiophene units.

A series of Schiff bases (SBs) were designed and prepared from 2-thiophenecarboxaldehyde and different triphenylamine (TPA) derivatives. The structures of the compounds were characterized by Fourier transform infrared (FT-IR), hydrogen nuclear magnetic resonance ( 1 H NMR). The optical and electrochemical properties were tested by ultraviolet–visible (UV–vis) spectroscopy and cyclic voltammetry (CV) techniques. The SBs exhibited stable and reversible electrochromic properties. Furthermore, multiple reversible colors states were also observed with the change of pH. Consequently, the SBs can be used as electrochromic and acidochromic materials. [ABSTRACT FROM AUTHOR]