Synthesis and spectroscopic properties of some new difluoroboron bis-β-diketonate derivatives.
Six new bis-β-diketones (RCOCH2CO-C7H7N-COCH2COR) were synthesized from 3,5-diacetyl-2,6-dimethylpyridine via Claisen condensation with the corresponding esters, and then reacted with boron trifluoride etherate to afford difluoroboron bis-β-diketonate derivatives. Their spectroscopic properties were investigated by UV-vis, FTIR, (1)H NMR and fluorescence spectroscopic techniques. It was found that these boron complexes exhibited violet or blue fluorescence emission at 422-445nm and possessed high extinction coefficients. The results indicate that the extending π-conjugation can increase the fluorescence intensity and quantum yield for these boron complexes. Especially, the compound 2b displayed the stronger fluorescence intensity and the highest fluorescence quantum yield (Φu=0.94) in these boron compounds. However, compounds 2c and 2d had the lower fluorescence intensity and quantum yield as a result of the heavy atom effect of the chlorine atom in the molecules.
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China.
Yan
Y
Pi
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China. Electronic address: dunjiawang@163.com.
Dun-Jia
DJ
Wang
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China.
Hua
H
Liu
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China.
Yan-Jun
YJ
Hu
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China.
Xian-Hong
XH
Wei
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University, Huangshi 435002, China.
Jing
J
Zheng
D001880:Boranes / Q000138:chemical synthesis / Q000737:chemistry; D001896:Boron Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D054879:Halogenation; D009682:Magnetic Resonance Spectroscopy; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
D001880:Boranes; D001896:Boron Compounds; C101707:boron trifluoride etherate
Bis-β-diketone; Difluoroboron complexes; Fluorescence; Quantum yield; Spectroscopic properties