有机化学 ›› 2017, Vol. 37 ›› Issue (3): 704-710.DOI: 10.6023/cjoc201607013 上一篇    下一篇

研究论文

新型N,O-配位吡啶氟硼化合物的合成及其光谱性质

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,E-mail:wuyy@yxnu.net E-mail:wuyy@yxnu.net
  • 基金资助:

    云南省科技厅青年(No.2014FD050)和云南省教育厅(No.2015Y455)资助项目.

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 E-mail:wuyy@yxnu.net
  • 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).

以2-氨基吡啶衍生物为原料,通过简单而高效的两步反应合成了6个新型N,O-配位吡啶氟硼化合物2a~2f,其结构经1H(13C、19F)NMR,ESI-MS,IR和X单晶衍射分析表征,并对其光谱性质进行实验和理论计算研究.结果表明,苯环(或吡啶环)上含给电子基的化合物2b,2c,2e,2f的最大吸收峰位于360~420 nm(λabs=368,400,365,418 nm),且具有较大的摩尔吸光系数(ε=28760,51980,25250,40750 L·mol-1·cm-1).明显不同的是,苯环对位无取代基的化合物2a和含吸电子基的化合物2d的最大吸收峰分别为340和337 nm.同时,化合物2b,2c,2e,2f具有一定的溶剂效应,随着溶剂极性的增加,发射光谱红移且荧光强度降低,说明这些化合物中存在着一定的分子内电荷转移(ICT)效应.此外,实验结果和理论计算验证了化合物2b,2c,2e,2f中存在ICT,并揭示了取代基对化合物的光谱性质具有显著影响.希望通过这些研究可为进一步发展ICT-型荧光染料及其应用打下良好基础.

关键词: N,O-配位, 吡啶, 氟硼化合物, 分子内电荷转移, 光谱性质

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