8-羟基喹啉锌及其衍生物的电子结构和荧光性质的理论研究

Theoretical studies on electronic structures and fluorescence properties of 8-hydroxyquinoline zinc and its derivatives

采用M06泛函对8-羟基喹啉锌及其衍生物分子的基态和离子结构进行了全优化计算.在基态结构基础上,用TD-M06计算其吸收光谱及第一单重激发态(S1)的垂直跃迁能.采用TD-M062X方法对8-羟基喹啉锌及其衍生物的激发态进行构型优化并得到其发射光谱.结果表明:电子供体增强了分子空穴注入能力,却降低了其电子注入能力,供电子基个数越多或供电子基的供电子能力越强,空穴注入能力的增强和电子注入能力的减弱越明显;吸电子基增强分子的电子注入能力,却减弱了其空穴注入能力,吸电子基个数越多或吸电子基的吸电子能力越强,空穴注入的减弱和电子注入能力的增强越明显;相对于8-羟基喹啉锌配合物,引入吸电子基使最大吸收光谱红移,吸电子程度越弱,红移程度越大.2位引入一个氨基时,吸收光谱蓝移,而在2,5位分别引入2个氨基时,吸收光谱红移.

The ground-state and ion geometries of 8-hydroxyquinoline-zinc and its derivatives were optimized using DFT/M06 method. On the basis of the ground states,the absorption spectra and the lowest single excited energies were calculated by time-dependent DFT （TD-DFT） with M06 functional. The time-dependent DFT （TD-DFT） with M062X method was carried out to obtain the $1 states and the emission spectra of 8-hydroxyquinoline zinc and its derivatives. The results indicate that the introduction of electron donors enhances the hole-injecting ability of the complexes but decreases their electron-iniecting ability. The introduction of electron-withdrawing group increases the electron- injecting ability of the complexes but lows down their hole-injecting ability. The more the electron donors （electron-withdrawing group） or the stronger of the electron providing ability （electron withdrawing ability）,the greater degree the hole-injecting ability of the complexes （electron-injecting ability） enhances. Compared to 8-hydroxyquinoline zinc, the introduction of electron-withdrawing group makes the absorption spectra of the complexes red shift. And more, the weaker of the electron withdrawing ability,the greater degree of the red shift. Introducing one amino group on the 2 point makes the absorption spectra of the complexes blue shift,while introducing two amino groups on the 2 and 5 point makes the absorption spectra of the complexes red shift.