Structure and second-order NLO property of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7)  

作　　者：QIU YongQingt CHEN Hui SUN ShiLing FAN HongLing SU ZhongMin 

机构地区：[1]Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, China

出　　处：《Chinese Science Bulletin》2007年第17期2326-2330,共5页

基　　金：Supported by the Foundation of Jilin Provincial Excellent Youth (Grant No. 20050107);Youth Science Foundation of Northeast Normal University (Grant No. 111494117)

摘　　要：Density functional theory (DFT) B3LYP at 6-31G* level is employed to optimize the structures of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7) and combined with finite field (FF) formalism to calculate the second-order NLO properties. The results indicate that the structures of n-vertex bis-substituted carborane (n=5, 6, 7) are changed due to bridged donor and acceptor moieties. The distances between two C atoms are becoming longer. And the stability and dipole moment are in- fluenced by changing substituted positions of C atoms. The isomers with the substituents connecting with C atoms of lower coordination number have better stability and larger values of polarizability. One-dimensional structure of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7) is in favor of intramolecular charge-transfer. Meanwhile, the isomer with a larger change of dipole moment has larger value of second-order NLO properties during the charge-transfer process.Density functional theory （DFT） B3LYP at 6-31G^＊ level is employed to optimize the structures of the molecules bridged through n-vertex bis-substituted carborane （n=5, 6, 7） and combined with finite field （FF） formalism to calculate the second-order NLO properties. The results indicate that the structures of n-vertex bis-substituted carborane （n=-5, 6, 7） are changed due to bridged donor and acceptor moieties. The distances between two C atoms are becoming longer. And the stability and dipole moment are in- fluenced by changing substituted positions of C atoms. The isomers with the substituents connecting with C atoms of lower coordination number have better stability and larger values of polarizability. One-dimensional structure of the molecules bridged through n-vertex bis-substituted carborane （n=5, 6, 7） is in favor of intramolecular charge-transfer. Meanwhile, the isomer with a larger change of dipole moment has larger value of second-order NLO properties during the charge-transfer process.

关 键 词：碳硼烷 分子桥联 稳定性 密度泛函理论 

分 类 号：O627[理学—有机化学]