Lindqvist型钼酸盐修饰的碳纳米管二阶非线性光学性质的理论研究

利用密度泛函理论(DFT)方法研究了Mo₆O₁₉]^2-修饰的单壁碳纳米管的非线性光学(NLO)性质. 结果表明, Mo₆O₁₉]^2-修饰的单壁碳纳米管作为特殊的有机-无机杂化体系, 具有显著的二阶非线性光学响应. 通过调整Mo₆O₁₉]^2-与纳米管之间的角度, 体系的稳定性显示出规律性的变化趋势, 且二阶NLO响应发生了变化. 对静场二阶极化率(β_vec)有主要贡献的电子跃迁特征表明, Mo₆O₁₉]^2-与碳纳米管之间角度的改变影响了分子内的给受体特征. 当角度达到30°时, 化合物显示出最大的β_vec值, 此时杂多阴离子簇为电子受体, 而碳纳米管为电子给体. 此外, 在碳纳米管的端位连接电子给体(如氨基)可有效地增大β_vec值.

Theoretical Study of Second-order Nonlinear Optical Properties of Hexamolybdates-substituted Carbon Nanotubes

The nonlinear optical(NLO) properties of Mo 6O 19]2-decorated single wall carbon nanotubes(SWCNT) were investigated by density functional theory(DFT).These special organic-inorganic hybrids possess a large second-order NLO response.It is noteworthy that the second-order NLO behavior can be switched by the variable angle between Mo 6O 19]2-and CNT and the stability of systems shows the regular trends.The characteristic of the charge-transfer transition corresponding to the dominant contributions to the static second-order polarizibility(β vec) values indicates that the variable anchoring angles of Mo 6O 19]2-can influence the intramolecular donor or acceptor character.When the anchoring angle of Mo 6O 19]2-becomes 30°,the complex exhibits the largest β vec value;besides,the polyoxometalate(POM) cluster acts as the acceptor and the CNT as the donor.Furthermore,the incorporation of an electron donor(the amido group) leads to a larger β vec value at the end of the CNT segment.