取代基效应对环金属Rh(Ⅲ)配合物二阶非线性光学性质影响的DFT研究  

A DFT study of substituent effects on second-order nonlinear optical properties of cyclometalated Rh(Ⅲ)complexes

作　　者：王莹莹 孙丽婷 赵媛媛 仇永清[1] WANG Ying-ying;SUN Li-ting;ZHAO Yuan-yuan;QIU Yong-qing(Institute of Functional Material Chemistry,Faculty of Chemistry,Northeast Normal University,Changchun 130024,China)

机构地区：[1]东北师范大学化学学院功能材料化学研究所,吉林长春130024

出　　处：《分子科学学报》2023年第6期537-547,共11页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(21903012)。

摘　　要：本文采用密度泛函理论(DFT)方法对系列环金属Rh(Ⅲ)配合物的结构与二阶非线性光学性质进行了计算研究.结果显示,配体中取代基的改变对配合物的几何结构和Wiberg键级影响不大.当主配体上的—H被其他强的供/吸电子基团取代时,配合物的极化率增大.其中,对于配合物1-6,主配体或副配体中强供/强吸电子基团的引入均有效地提高了配合物的第一超极化率(βtot).而在配合物7-12中,配体中取代基的改变对配合物的βtot值也有所提高,但幅度不大.此外,计算所得的配合物动态超瑞利散射超极化率(βHRS)值与βtot值的变化规律一致.对配合物的电子结构与吸收光谱的分析表明,体系具有较大的βtot值与其吸收光谱的明显红移,较低的电子跃迁能,以及方向一致的电荷转移模式相关.Cyclometalated Rh(Ⅲ)complexes have exhibited high thermal stability and excellent luminescent characteri-stic,which motivates our interest in their nonlinear optical properties.Herein,twelve cyclometalated Rh(Ⅲ)com-plexes,named as complexes 1-12,were selected based on one synthesized compound and they involve different substituent groups,-H,-Ph,-Ph-NO_(2),-NO_(2) and NMe_(2),in the ligands.Density functional theory(DFT)method was employed in investigating the geometries,electronic,and optical properties of complexes.The ligands variation effect on electronic structures and second-order nonlinear optical properties were considered.The optimized structural parameters show a good agreement with the experimental data and it indicates that the variation of ligands has little effect on the the geometry of complexes.The calculated polarizability and first hyperpolarizability(β_(tot))have revealed that the ligands variation has a significant effect on the second-order nonlinear optical response of complexes.In gas and different solvent conditions,the β_(tot)values show good consistency,which indicates the environment has little effect on the nonlinear optical properties of complexes.Among complexes 1-6,when the main ligand includes strong electron-donating/withdrawing groups,the obtained β_(tot)values are increased by 77.6 and 36.9 times for complexes 5 and 6.Complexes 7-9 and complexes 10-12 involve same auxiliary ligand,respectively.The complexes with strong electron-donating group in main ligand,namely complexes 8 and 11,exhibit significantly increased second-order nonlinear optical response.Comparing the effect on nonlinear optical response induced by variation of main ligand and auxiliary ligand,it is obvious that the former is greater than the latter.In addition,the calculated dynamic hyper-Rayleigh scattering hyperpolarizability(β_(HRS))of the complexes are consistent with the obtained β_(tot)values,which indicates that the reliability of our estimation on the second-order nonlinear optical response of co

关 键 词：环金属Rh(Ⅲ)配合物 非线性光学性质 密度泛函理论 电荷转移 

分 类 号：O644[理学—物理化学]