Novel Disubstituted Phenylene‐Linked Bis‐imidazole Derivatives: Facile Synthesis and Optical Properties

Six novel disubstituted phenylene-linked bis-imidazole derivatives, 3a–3f, were prepared by a one-pot, microwave-assisted method under solvent-free conditions, in yields ranging from 61.6 to 85.6%. The new compounds were characterized by 1H- and 13C-NMR, UV/VIS, and fluorescence spectroscopy, and mass spectrometry, as well as by elemental analyses. The influence of substituents and solvents on the optical properties of 3a–3f was investigated. It was found that there is little influence on absorption and excitation spectra in contrast to emission spectra. Compounds 3a–3f exhibit strong fluorescence in solution, their fluorescence quantum yields ranging from 0.27 to 0.96.