Prediction of Remarkably Large Second-Order Nonlinear Optical Properties of Organoimido-Substituted Hexamolybdates
Prediction of Remarkably Large Second-Order Nonlinear Optical Properties of Organoimido-Substituted Hexamolybdates
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DOI：
10.1021/jp808707q
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发表时间：
2009-04-16
影响因子：
2.9
通讯作者：
Su, Zhong-Min
中科院分区：
文献类型：
--
作者：
Janjua, Muhammad Ramzan Saeed Ashraf;Liu, Chun-Guan;Su, Zhong-Min
利用时变密度泛函响应理论研究了六钼酸盐有机胺衍生物的偶极极化率、偶极矩、态密度和二阶非线性光学性质。这类有机-无机杂化化合物具有显著的分子二阶NLO响应，特别是[Mo6O17(NC16H12NO2)(FeNC10H9)](2-)(7)和[Mo6O17(NC16H12NO2)(NC6H2(NH2)(3))](2-)(6)，其静态二阶极化率（beta(vee)）分别为15766.27 × 10(-30) esu和6299.59 × 10(-30) esu。因此，这些系统有可能成为优良的二阶非线性光学材料。对beta（vec）值的主要贡献分析表明，沿z轴从聚阴离子向有机段（D-A）的电荷转移（CT）在NLO响应中起关键作用；在所有研究的体系中，聚阴离子作为供体(D)，而有机咪胺作为受体(a)。在有机胺段苯基环末端加入电子受体（-NO2），计算出的β (vec)值增加。此外，在聚阴离子外侧取代氨基（-NH2）或二铁基（-FeC10H9），同时在有机亚胺段苯基环末端取代电子受体（-NO2），对增强光学非线性更为重要。轨道分析表明，引入二茂铁给体后，聚阴离子与有机亚胺段之间的CT度增加。本研究为有机酰亚胺取代六酸酯的显著的NLO性质提供了重要的见解。
The dipole polarizabilities, dipole moments, density of states, and second-order nonlinear optical (NLO) properties of organoimido derivatives of hexamolybdates have been investigated by using time-dependent density functional response theory. This class of organic-inorganic hybrid compounds possesses remarkably large and eye-catching molecular second-order NLO response, especially [Mo6O17(NC16H12NO2)(FeNC10H9)](2-) (7) and [Mo6O17(NC16H12NO2)(NC6H2(NH2)(3))](2-) (6) with static second-order polarizability (beta(vee)) computed to be 15766.27 x 10(-30) esu and 6299.59 x 10(-30) esu, respectively. Thus, these systems have the possibility to be excellent second-order nonlinear optical materials. Analysis of the major contributions to the beta(vec) value suggests that the charge transfer (CT) from polyanion to organic segment (D-A) along the z-axis plays the key role in NLO response; the polyanion acts as a donor (D) whereas organoimido acts as an acceptor (A) in all the studied systems. The computed beta(vec) values increase by incorporation of an electron acceptor (-NO2) at the end of the phenyl ring of the organoimido segment. Furthermore, substitution of amino (-NH2) or ferrocenyl (-FeC10H9) at the outer side of polyanion and an electron acceptor (-NO2) at the end of the phenyl ring in organoimido segment simultaneously is more important to enhance the optical nonlinearity. Orbital analysis shows that the degree of CT between the polyanion and organoimido segments was increased when ferrocenyl donor was introduced. The present investigation provides important insight into the remarkably large NLO properties of organoimido-substituted hexamolybdates.