Spectroscopy, photophysical and photochemical properties of bisimidazole derivatives

Novel bisimidazole derivatives were synthesized and their physico-chemical properties were determined. Different bisimidazole derivatives exhibit solvatochromism, halochromism and photochromism in solution.We have conducted an investigation of the spectroscopy, photophysical and photochemical properties of all derivatives. The photochemical properties of 1, 3 and their derivatives, were studied by irradiating acetonitrile solutions with medium-pressure xenon lamp and their photochemical quantum yields, ranging from 0.0011 to 0.0024, together with the corresponding fluorescence quantum yields, ranging from 0.52 to 0.90, and life-times, ranging from 1.03 to 1.42 ns, were determined. The photophysics of these bisimidazole derivatives was studied in details. The photochemistry of the two prototype derivatives was studied in solutions, showing an interesting general photochemical reaction between these derivatives and molecular oxygen.