Microwave-assisted synthesis and photochromic properties of new azo-imidazoles

A convenient, one-pot three-component synthesis of new photochromic azo-imidazoles (1a-1h) from the corresponding azo dyes (2a-2h), benzil and ammonium acetate under microwave irradiation were described and their photochromic properties were investigated. The structures of the new azo-imidazoles were confirmed by UV-Vis, FT-IR and NMR spectroscopies and elemental analysis. The properties and photochromic structural behavior relationship (PSBR) of these compounds have been analyzed. All the compounds exhibit good photochromic behavior upon irradiation with alternative UV and visible light.