Phenyl-bridged N,N,N'N'-Tetrasubstituted bis(2-amino-5-thiazolyl) diamine: Synthesis and applications in electrochromism and photocatalytic nitrobenzene reduction

Abstract

A novel type of triphenylamine derivatives, phenyl-bridged N,N,N′,N′-tetrasubstituted bis(2-amino-5-thiazolyl) diamine (4) and its cationic form (5) were synthesized via the Hantzsch reaction. The UV–Vis spectroscopy, cyclic voltammetry (CV) and density functional theory (DFT) calculation results showed that the diamine possesses excellent redox properties and a narrow optical energy gap (∼1.85 eV). As an electrochromic material, compound 4 exhibits a notable color change from colorless to blue. It maintains stable cycling performance for up to 175 cycles, even within a higher voltage range of −2.4 to 2.4 V. In addition, as a catalyst, compound 5 exhibits good substrate compatibility and an aniline conversion rate of up to 89 % during the photocatalytic reduction of nitrobenzene. These results would contribute to understand the synthesis of triphenylamine electrochromic materials and expand their applications in the field of photocatalysis.