Chemiluminescence properties of luminol related o-hydroxybenzimidazole analogues: Experimental and DFT based approach to photophysical properties

Novel luminol-isoluminol derivatives containing o-hydroxyphenyl benzimidazole unit were synthesized from aromatic aldehydes and diaminophthalates followed by heating under reflux with hydrazine hydrate. The chemiluminescent properties were studied in hydrogen peroxide, potassium hexacyanoferrate(III) and sodium hydroxide solution. The chemiluminescence properties were compared with the standard luminol and isoluminol systems it was observed that the chemiluminescence properties of the novel derivatives were superior to luminol and isoluminol. Density Functional Theory computations have been used in order to have a greater understanding of the structural, molecular, electronic and photophysical properties. The experimental absorption and emission wavelength values were in good agreement with the computed vertical excitation and emission values.