Synthesis and two-photon absorption properties of novel 2-substituted-4,5-diphenyl-1H-imidazoles

Novel 2-substituted-4,5-diphenyl-1H-imidazoles (M1-M4) have been synthesized via the solvent-free Debus-Radziszewski reaction. They emit up-converted fluorescence, and the two-photon absorption cross-sections are 585, 31, 34, and 1193 GM in DMF, respectively.