Theoretical study on the electronic spectrum and the origin of remarkably large third-order nonlinear optical properties of organoimide derivatives of hexamolybdates.
Theoretical study on the electronic spectrum and the origin of remarkably large third-order nonlinear optical properties of organoimide derivatives of hexamolybdates.
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DOI：
10.1021/jp062820p
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发表时间：
2006-10
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影响因子：
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通讯作者：
Guochun Yang;W. Guan;Likai Yan;Zhongmin Su;Lin Xu;E. Wang
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文献类型：
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作者：
Guochun Yang;W. Guan;Likai Yan;Zhongmin Su;Lin Xu;E. Wang
本文首次结合Van Leeuwen-Baerends （LB94）交换相关电位、统计平均轨道电位（SAOP）和梯度调节连接电位（GRAC），利用时间依赖密度泛函理论计算了六酸盐有机亚胺衍生物的电子能谱。与LB94和SAOP相比，GRAC得到的激发能与实验结果吻合得更好。跃迁性质分析表明，对角线和正交取代导数之间存在显著差异。利用时变密度泛函理论结合态和法计算了静态和动态三阶极化率。结果表明，这些衍生物具有显著的大分子三阶极化率，特别是体系8具有-17882.6 × 10(-36) esu。这个值大约是C（60）分子的250倍。在[Mo(6)O(19)]（2-）中加入有机亚胺段可以显著提高nu值。这种变化可以追溯到[Mo(6)O(19)]（2-）和[Mo(6)O(19)]（2-）衍生物之间不同的电子跃迁特性。对于我们所研究的体系，增加共轭长度和对角取代是提高三阶极化率的有效方法。因此，从大值、小色散和高透明度的角度来看，六聚酸盐的有机亚胺衍生物可能构成一类新的有前途的非线性光学材料。
Electronic spectrum of organoimide derivatives of hexamolybdates have first been calculated within the time-dependent density-functional theory in conjunction with Van Leeuwen-Baerends (LB94) exchange correlation potential, statistical average of orbital potentials (SAOP), and gradient-regulated connection potential (GRAC), respectively. The GRAC yields much better agreement with experiments for the excitation energies comparing with both LB94 and SAOP. The analysis of transition nature indicates that there is a significant difference between the diagonal and the orthogonal substituted derivatives. The static and dynamic third-order polarizabilities are calculated using time-dependent density-functional theory combined with the sum-over-states method. The results show that these derivatives possess remarkable large molecular third-order polarizabilities, especially for system 8 with -17882.6 x 10(-36) esu. This value is about 250 times that for the C(60) molecule. Adding the organoimide segment to the [Mo(6)O(19)](2-) can substantially increase the nu value. This variation can be traced to the different electronic transition characteristics between the derivatives of [Mo(6)O(19)](2-) and [Mo(6)O(19)](2-). For our studied systems, increasing the conjugation length and diagonal substituted are efficient ways to enhance the third-order polarizability. Thus, the organoimide derivatives of hexamolybdates may comprise a new promising class of nonlinear optical materials from the standpoint of large values, small dispersion behavior, and high transparency.