Triphenylamine based benzimidazole and benzothiazole: Synthesis and applications in fluorescent chemosensors and laser dyes

Triphenylamine based fluorescent dyes TPA-benzimidazole and TPA-benzothiazole have been designed and synthesized. The TPA-benzimidazole chemosensor was tested for a number of metal ions and found to exhibit binding affinity for Fe3+ and Hg2+ in acetonitrile, and the fluorescence quenching was achieved through a PET process. The appearance of an isosbestic point in absorption titrations and Jobʹs plot analysis supported 1:1 stoichiometries for Fe3+ and Hg2+ ions. Laser experiments showed that under transversal pumping with a Q-switched Nd:YAG (355 nm) laser in toluene, TPA-benzothiazole exhibits efficient and stable amplified spontaneous emissions (ASE) at 436 nm.