Zhang Xiang-Biao, Feng Ji-Kang, Ren Ai-Min
State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, JiLin University, Changchun 130023, People's Republic of China.
J Phys Chem A. 2007 Feb 22;111(7):1328-38. doi: 10.1021/jp0669097. Epub 2007 Jan 26.
The molecular equilibrium structures, electronic structures, and one- and two-photon absorption (TPA) properties of C2v (Zn(II), Fe(II) and Cu(I)) dipolar and D2d (Zn(II) and Cu(I)) and D3 (Zn(II)) octupolar metal complexes featuring different functionalized bipyridyl ligands have been studied by the ZINDO-SOS method. The calculated results show that one- and two-photon absorption properties of metal complexes are strongly influenced by the nature of the ligands (donor end groups and pi linkers) and metal ions as well as by the symmetry of the complexes. The length of the pi-conjugated backbone, the Lewis acidity of the metal ions, and the increase of ligand-to-metal ratio result in a substantial enhancement of the TPA cross sections of metal complexes. Substitution of C=N and N=N for C=C plays an important role in altering the maximum TPA wavelengths and the maximum TPA cross sections of metal complexes. Of them, the C=N substituted metal complexes have relatively large TPA cross sections. Replacing styryl with thienylvinyl makes the one-photon absorption wavelength red shift and at the same time leads to a great decrease of the maximum TPA cross sections of metal complexes. The possible reason is discussed. In the range 500-1250 nm, octupolar metal complexes exhibit intense TPAs and therefore are promising candidates for TPA materials.
采用ZINDO - SOS方法研究了具有不同功能化联吡啶配体的C2v（Zn(II)、Fe(II)和Cu(I)）偶极以及D2d（Zn(II)和Cu(I)）和D3（Zn(II)）八极金属配合物的分子平衡结构、电子结构以及单光子和双光子吸收（TPA）性质。计算结果表明，金属配合物的单光子和双光子吸收性质受配体性质（供体端基和π连接体）、金属离子以及配合物对称性的强烈影响。π共轭主链的长度、金属离子的路易斯酸度以及配体与金属比例的增加导致金属配合物的TPA截面显著增强。用C=N和N=N取代C=C在改变金属配合物的最大TPA波长和最大TPA截面方面起着重要作用。其中，C=N取代的金属配合物具有相对较大的TPA截面。用噻吩乙烯基取代苯乙烯基使单光子吸收波长红移，同时导致金属配合物的最大TPA截面大幅降低。讨论了可能的原因。在500 - 1,250 nm范围内，八极金属配合物表现出强烈的TPA，因此是TPA材料的有前途的候选者。
