摘要
采用密度泛函理论(DFT)方法对系列具有D-A-D(D')型结构的邻位碳硼烷三元体系的电子结构、第一超极化率和电子光谱等性质进行研究.结果表明,碳硼烷具有独特的缺电子特征,可以作为有效的吸电子基团,与其桥联不同的供电子取代基Ar,形成三元体系的电荷转移方向是由Ar基团到碳硼烷.随着Ar基团供电子能力的增强,体系相应的第一超极化率值增大,其中分子7(Ar=N,N-二甲基苯)的βtot值(39197 a.u.)约为分子1(Ar=间三氟甲基苯,640 a.u.)的61倍.分子的电子光谱随Ar基团供电能力的增强发生红移,并采用二级能级公式对分子的第一超极化率规律给予了解释.
Density functional theory（ DFT） calculations were carried out to investigate the electronic structures,the first hyperpolarizabilities and UV-Vis spectra for a series of o-carborane triads bearing D-A-D（ D＇） features. The results suggest that carborane can be used as an effective electron-withdrawing group due to its electron-deficient structure. For different electron-donating groups,the electron transition is mainly from the Ar group to the carborane moiety. With the enhancement of electron-donating ability of the Ar,the corresponding first hyperpolarizabilities can significantly increase. The βtotvalue of molecule 7（ Ar = N,N-dimethyl benzene,39197 a.u.） is almost 61 times as large as that of molecule 1（ Ar = m-trifluoromethyl benzene,640 a.u.）. In addition,the absorption spectra of molecules exhibit a remarkably red shift as the electron-donating ability of Ar increased. The two-level model was used to give a reasonable explanation for the first hyperpolarizabilities. Therefore,the second-order nonlinear optical responses of o-carborane triads can be effectively modified by changing the electron-donating capability of bridged Ar substituents.
作者
吴娟
王洪强
刘晓云
史志圆
仇永清
WU Juan;WANG Hongqiang;LIU Xiaoyun;SHI Zhiyuan;QIU Yongqing(Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第7期1490-1496,共7页
Chemical Journal of Chinese Universities
基金
吉林省教育厅"十二五"科学技术研究规划项目(批准号:吉教科合字[2016]第494号)资助~~
