Chin. J. Org. Chem. ›› 2017, Vol. 37 ›› Issue (3): 704-710.DOI: 10.6023/cjoc201607013 Previous Articles     Next Articles



吴云英a, 苟高章c, 伍贤学a, 杨丽君a, 傅文甫b   

  1. a 玉溪师范学院资源环境学院化学系 玉溪 653100;
    b 中国科学院理化技术研究所 北京 100190;
    c 红河学院理学院 理学院化学系 蒙自 661199
  • 收稿日期:2016-07-08 修回日期:2016-09-30 发布日期:2016-11-17
  • 通讯作者: 傅文甫,
  • 基金资助:


Synthesis and Spectroscopic Properties of N,O-Chelated Pyridine-BF2 Complexes

Wu Yunyinga, Gou Gaozhangc, Wu Xianxuea, Yang Lijuna, Fu Wenfub   

  1. a College of Resources and Environment, School of Yuxi Normal University, Yuxi 653100;
    b Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190;
    c College of Science, School of Honghe University, Mengzi 661199
  • Received:2016-07-08 Revised:2016-09-30 Published:2016-11-17
  • Contact: 10.6023/cjoc201607013
  • Supported by:

    Project supported by the Youth Project of Science and Technology Department of Yunnan Province (No. 2014FD050) and the General Program of Yunnan Provincial Education Department (No. 2015Y455).

The six novel N,O-chelated pyridine-BF2 complexes (2a~2f) were successfully obtained by a facile two-step synthesis from 2-amino-pyridine derivatives. All compounds synthesized were fully characterized by 1H NMR, 13C NMR, 19F NMR, IR, ESI-MS and X-ray diffraction analysis. It was found that complexes 2b, 2c, 2e and 2f, in which electron-donating groups were substituted on p-positions of the phenyl ring (or 6-positions of the pyridine ring) exhibit a structured absorption at 360~420 nm (λabs=368, 400, 365, 418 nm) with a large extinction coefficient, such as 28760, 51980, 25250, 40750 L·mol-1·cm-1, respectively. In sharp contrast, the complexes 2a and 2d with a relatively neutral group (H for 2a) or an electron-withdrawing group (COOMe for 2d) on the p-position of the phenyl ring gave the absorption (λabs) blue shifted to 340 and 337 nm. Meanwhile, the intramolecular charge transfer (ICT) could be detected for complexes 2b, 2c, 2e and 2f, whose emission bands bathochromic shift significantly and emission intensities decreased with increasing the solvent polarities. Additionally, similar to most boron-dipyrromethene derivatives (BODIPYs) and their derivatives, this pyridine-BF2 complex exhibited faint photoluminescence in the solid state. In order to better illustrate intramolecular charge transfer in 2b, 2c, 2e and 2f, theoretical calculations were carried out. Therefore, these experimental facts and theoretical calculations support our proposed ICT mechanism in the novel boron fluoride complexes 2b, 2c, 2e and 2f, and reveal that substituent groups have a significant in-fluence on optical properties. The investigations of novel pyridine-BF2 complexes will provide favorable foundation and theo-retical support for the further development of ICT-based fluorescent dyes and their applications.

Key words: N,O-chelated, pyridine, fluorine-boron compound, ICT, spectroscopic properties