BF2-Complexes of Carbazole-Benzimidazole Conjugates: Synthesis, Structures, and Spectroscopic Properties

A series of carbazole-benzimidazole conjugates and corresponding BF2-complexes (BODIPYs) are synthesized and characterized. Carbazole-benzimidazole conjugates are synthesized by the condensation of 1-formyl carbazole and phenylene diamines in good yields. Various substituents are introduced into the benzimidazole moiety and subsequent reaction with BF3 center dot Et2O afforded the BF2-complexes in moderate to good yield. The structural and photophysical properties of the synthesized fluorophores are investigated with various spectroscopic techniques such as UV/Vis and fluorescence spectroscopy, cyclic voltammetry and X-ray crystallography.