Aggregation-induced and crystallization-enhanced emissions with time-dependence of a new Schiff-base family based on benzimidazole

A new Schiff-base family containing [4-(1H-benzimidazole-2-yl)-phenyl]-bis-(4-ethoxy-phenyl)-amine has been synthesized through a condensation reaction. All the derivatives possess properties of aggregation-induced and crystallization-enhanced emission (AIE and CEE), which show time-dependent characteristics at a concentration of 10 μM and are studied in detail by scanning electron microscope (SEM) and transmission electron microscope (TEM). Different aggregation forms and the growth of crystals of the compounds, could be responsible for the notably different degrees of fluorescence enhancement.