Synthesis and spectroscopic properties of novel fluorescent compounds containing bis-pyrazole ring.

A series of pyrazoline derivatives containing pyrazole group were synthesized and characterized by means of (1)H NMR, FT-IR, MS and elemental analysis, and their UV-vis absorption behavior and fluorescent properties were also measured. Moreover, the influence of metal ions on spectral properties of synthetic products was examined with compound A₅ as an example. It has been found that all synthetic pyrazoline derivatives show two remarkable absorption peaks at about 260 and 360 nm and the maximum emission peak at 445-467 nm. Especially, the joined of Co(2+) can quench the fluorescence of compound A₅ obviously.