阴离子自由基TCNQ-及其铜盐CuTCNQ非线性光学性质的理论.pdfVIP

2011 年第 69 卷 化 学 学 报 Vol. 69, 2011 第 12 期, 1387～1392 ACTA CHIMICA SINICA No. 12, 1387～1392 ·研究论文· － 阴离子自由基TCNQ 及其铜盐 CuTCNQ 非线性光学性质的理论研究 杜晓凤 孙世玲 刘海波 孙晓娜 仇永清* (东北师范大学化学学院 功能材料化学研究所 长春 130024) 摘要 采用量子化学方法计算分析了阴离子自由基 TCNQ－及其铜盐 CuTCNQ 单体、二聚体的非线性光学(NLO)性质. 结果表明, 将 Cu＋引入 TCNQ－分子, 极化率值减小, Cu＋的位置不同对分子NLO 系数的贡献不同; 二聚体分子的极化 率与其结合能相关, 同时分子的几何构型影响二阶NLO 系数. 由前线分子轨道组成得到, 电子在前线分子轨道间跃迁 产生的电荷转移程度决定分子三阶 NLO 系数的大小, 二聚体分子前线分子轨道在两共轭平面间的相互重叠对分子的 三阶 NLO 系数有一定贡献. 关键词 阴离子自由基TCNQ－; CuTCNQ; NLO 性质; 理论计算 Theoretical Study on Nonlinear Optical Properties of the Anion-radicals TCNQ－ and Their Copper-salts CuTCNQ Du, Xiaofeng Sun, Shiling Liu, Haibo Sun, Xiaona Qiu, Yongqing* (Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024) Abstract Quantum chemistry methods were applied to compute and analyze the nonlinear optical (NLO) － properties of the monomers and dimers for anion-radicals TCNQ and their copper-salts. It is found that, ＋ － ＋ the αs values decrease as a function of the introductive Cu into TCNQ and the various positions of Cu have different effects on NLO coefficients. The polarizabilities of the dimers are related to their binding en- ergies, the geometrical configurations for dimers influence the second-order NLO coefficients as well. From the frontier molecular orbit composition, the third-order NLO coefficients dependence of the charg