A new 2,2′:6′,2′′-terpyridine-based ligand and its complexes: structures, photophysical properties and DFT calculations to evaluate the halogen effect on the TPA
作者:Fei-Xia Zhou、Zheng Zheng、Hong-Ping Zhou、Wei-Zai Ke、Jian-Qing Wang、Zhi-Peng Yu、Feng Jin、Jia-Xiang Yang、Jie-Ying Wu、Yu-Peng Tian
DOI:10.1039/c2ce25467k
日期:——
A novel 2,2':6',2â²â²-terpyridine-based ligand (L) and eight complexes have been synthesized and fully characterized. Six of these complexes ([CdLBr2]2·CHCl3 (2), ZnLI2 (3), [CdLI2]2·CH2Cl2 (4), ZnL(SCN)2·CHCl3 (5), [ZnL2]2(ClO4)4·7H2O (7) and [CdL2](ClO4)2·CH3OH (8)) were determined by single crystal X-ray diffraction analysis. Various weak interactions, including hydrogen bonds (CâHâ¯N, CâHâ¯X), CâHâ¯Ï and ÏâÏ interactions played significant roles in the final supramolecular structures. Linear and nonlinear optical properties of the ligand and eight complexes are described. Experimental results reveal that two-photon absorption (TPA) cross-sections of these complexes are extraordinarily larger than that of the ligand, with maximum values of 97, 661, 787, 218, 133, 613, 230, 384 and 241 GM for L and complexes 1â8 in DMF, respectively. Density functional theory (DFT) calculations were performed on 1â6 and revealed that the halogen affects the accepting capability of surrounding metals due to different electron inductive effects, in the order Br > SCN > I. Thus, this in turn affects the TPA cross-section values. The results indicate that the TPA cross-sections vary in the order Br > SCN > I, which is consistent with the experimental results.
我们合成了一种新型 2,2':6',2â²â²-三吡啶配体(L)和八种配合物,并对其进行了全面表征。通过单晶 X 射线衍射分析确定了其中六个配合物([CdLBr2]2Â-CHCl3 (2)、ZnLI2 (3)、[CdLI2]2Â-CH2Cl2 (4)、ZnL(SCN)2Â-CHCl3 (5)、[ZnL2]2(ClO4)4Â-7H2O (7) 和 [CdL2](ClO4)2Â-CH3OH (8))。各种弱相互作用,包括氢键(CâHâ¯N、CâHâ¯X)、CâHâ¯和ÏâÏ相互作用在最终的超分子结构中发挥了重要作用。本文描述了配体和八种配合物的线性和非线性光学特性。实验结果表明,这些配合物的双光子吸收(TPA)截面比配体的大得多,在 DMF 中,L 和配合物 1â8 的最大值分别为 97、661、787、218、133、613、230、384 和 241 GM。对 1â6 进行的密度泛函理论(DFT)计算表明,由于电子感应效应不同,卤素会影响周围金属的接受能力,其顺序为 Br > SCN > I。结果表明,TPA 横截面的变化顺序为 Br > SCN > I,这与实验结果一致。