Synthesis of Novel Zn Metal Complexes Based on 2-Substituted-8-hydroxyquinoline with Fluorine Groups and Their Optical Properties

KeyWord:8-hydroxyquinoline  fluorobenzene  zinc complexes  fluorescence

Abstract:

      Two new 8-hydroxyquinoline derivatives:(E)-2-£Û2-(2-fluorophenyl)ethenyl£Ý-8-hydroxyquinoline(4a),(E)-2-£Û2-(pentafluorophenyl)ethenyl£Ý-8-hydroxyquinoline(4b)and their corresponding zinc complexes(5a,5b)were designed,synthesized and identified by 1H NMR,IR,MS spectra and elemental analyses.The aggregation behaviors of Zn(AcO)2 and the ligands:4a£¬4b in solution were investigated by UV-Vis spectra.The luminescence properties of the complexes:5a£¬5b were investigated by fluorescence spectra in DMF solution at room temperature.The results showed that the ¦Ëmax of 4a and 4b were 505 nm(blue and green)and 517 nm(green),and the ¦Ëmax of 5a and 5b were 559 nm(dark green)and 599 nm(yellow).The ¦Ëmax of the complexes:5a and 5b exhibited a red shift compared to that of the corresponding ligands:4a and 4b,which can be attributed to the increasing conjugated degree of the complexes,and the ¦Ëmax of ligands and complexes exhibited evident red shift in the presence of increasing numbers of fluorine.The comparative study of the luminescent properties of 5a and 5b showed that the emission ¦Ëmax can be tuned by introducing different fluorine numbers.