Effect of the change of heteroatom on phenyl capped benzazole: Photophysical and electrochemical properties from the structural viewpoint

Phenyl capped benzazoles were synthesized and characterized through crystal structures optical and electrochemical study. By changing the heteroatom (N, O, S and Se) of central acceptor benzazole unit, the emission color was varied from blue to green. Importantly these oligomers showed good emission quantum yields in solid state also. The non-planarity and absence of strong intermolecular interactions in the solid state may be the reason for high quantum yield in solid state. Except phenyl capped benzotriazole (1), all compounds showed reversible reduction peak in cyclic voltammetry experiments which reflects the considerable n-type nature.280