7,10,12顶点Fe(Ⅱ)碳硼烷夹心配合物NLO性质的DFT研究

DFT Study on Nonlinear Optical Properties of 7,10,12 Vertexes Ferradicarbollide Sandwich Complexes

采用密度泛函理论(DFT)CAM-B3LYP方法对系列7,10,12顶点Fe(Ⅱ)碳硼烷与1,2,4,5-Me4C6H2(dur1),1,2,3,4-Me4C5H(dur2)形成的夹心配合物的非线性光学(NLO)性质进行了计算分析.结果表明,Fe(Ⅱ)碳硼烷的顶点数和硝基的取代位置影响分子的几何构型,从而影响分子的NLO性质;Fe(Ⅱ)碳硼烷夹心配合物的偶极矩与极化率随碳硼烷的顶点数增加而增大;10顶点Fe(Ⅱ)碳硼烷分子的前线分子轨道能级差较小,其第一超极化率βtot值大于12及7顶点Fe(Ⅱ)碳硼烷分子;硝基与Fe(Ⅱ)处于对位时,其βtot值大于未取代分子;硝基与Fe(Ⅱ)处于邻位时,βtot值较未取代分子小;在此类Fe(Ⅱ)碳硼烷夹心配合物中,碳硼烷既可以作电子给体,也可以作电子受体.

The nonlinear optical （NLO） properties of a series of sandwich complexes which are coordinated by 7,10,12 vertexes ferradicarbaboranes and 1,2,4,5-Me4C6H2 （dUrl）, 1,2,3,4-Me4C5H （dur2） were investi- gated by density functional theory （DFT） CAM-B3LYP method. The results indicate that the vertexes of ferradicarbaboranes and the substitution position of nitryl both affect the molecular geometry and then affect the NLO properties of molecules. The dipole moment and the polarizability are both enhanced with the increase of the vertexes of ferradicarbaboranes. The HOMO-LUMO energy gaps of molecules with 10 vertexes ferradicarbaboranes are relatively smaller, so the first hyperpolarizabilities （βtot） values of them are larger than the molecules with 12 and 7 vertexes ferradicarbaboranes. When replacing of the atom H of Fe（Ⅱ） para position by nitro, the βtot values of molecules are larger than the nonsubstitution molecules; however, the atom H of Fe（Ⅱ） ortho position is substituted by nitro, the βtot values of molecules are smaller than the nonsubstitution molecules. In the studied molecules, the carboranes can act as either electronic donor or acceptor.