Synthesis, photochromic, thermochromic, piezochromic and solvatochromic properties of new bis-imidazole derived from substituted chlorobenzaldehyds

Purpose ‐ To evaluate the photo, thermo, piezo and solvatochromism of new bis-imidazole derived from three isomers of chlorobenzaldehyde. Design/methodology/approach ‐ The synthesis of the three new bis-imidazoles was accomplished using modified procedure of the previously reported method, by dissolving the imidazol derivative and cooling in ice bath, and adding potassium ferricyanide drop wise. The compounds were used evaluate the effects of the position of the substitutions on the aromatic ring, on the photo, thermo and piezochromic properties. Findings ‐ New bis-imidazole derived from 2-chloro, 3-chloro and 4-chloro phenyl have been synthesised and their photochromic properties upon irradiation with ultraviolet light were studies in different solvents. The photochromic properties and performance were affected remarkably upon changing the solvent. Also, the thermochromic properties upon heating in different solvents were studied. The dimers showed piezochromism on grinding. Practical implications ‐ The method reported for the synthesis is simple. The new compounds showed photochromic, thermochromic, piezochromic, and solvatochromic making them potential candidates for many applications such as sensors, optical data storage and heat sensitive materials. Originality/value ‐ The method for preparation was modified and improved. The materials prepared were new compounds.