CF3和CH3取代吡啶吡唑硼配合物的结构和吸收光谱的理论研究

Theoretical study on molecular structures and electronic structures of pyridyl and pyrazole boron complexes by CF_3 and CH_3 substituted

采用密度泛函理论DFT/B3LYP在6-31G水平上研究了CH3和CF3取代吡啶吡唑硼配合物的几何和电子结构,在基态平衡构型的基础上通过含时密度泛函理论TD-DFT计算了其光谱性质.结果表明:氟代甲基吡啶甲基吡唑硼配合物(2b′)的配位键略强于甲基吡啶氟代甲基吡唑硼配合物(2b);二者的中心B原子对分子的结构不但起支撑稳定作用,还可以作为电子桥传输电子;当取代基交换位置时,苯环和吡唑环都可以作为空穴传输基团,电子传输基团仍为吡啶环,配合物的主要跃迁都属于配体内部的π→π*跃迁类型.

The theoretical study on molecular and electronic structures of pyridyl and pyrazole boron complexes by CH3 and CF3 substituted using DFT/B3LYP at 6-31G level. In addition, time dependent density functional theory （TD-DFT） method is applied to investigate the properties of absorption spectra and electronic transition mechanism based on the ground state geometries. The results show that the chemical bond formed between nitrogen on the pyridyl ring and boron can be attributed to coordination effect and the coordinate bond. The calculated absorption wavelength is in good agreement with the experimental one. It can be detected that the main transitions correspond to the intraligand π→π^＊ character.