The aggregation-induced emission enhancement properties of BF2 complex isatin-phenylhydrazone: Synthesis and fluorescence characteristics

Isatin-phenylhydrazone derivatives and their corresponding BF2 complexes were efficiently synthesised by a three-step reaction starting from isatin and phenylhydrazine hydrochloride. The fluorescence properties of the isatin-phenylhydrazone derivatives and derived BF2 complexes were investigated in different organic solvents, in the solid state and in mixed solvent solutions of THF and H2O. These fluorescent dyes exhibited low fluorescent intensity in solution but a high fluorescent intensity as aggregates and in their solid state due to the interesting aggregation-induced emission enhancement characteristics which were caused by the inhibition of intramolecular rotation in the single molecule state. Information supporting this inference was supported by single crystal X-ray analysis. (C) 2014 The Authors. Published by Elsevier Ltd.