噻吩基卟啉衍生物的单光子和双光子吸收性质的理论研究

本文理论上研究了两个系列的噻吩基卟啉衍生物,这种衍生物在可见光区具有大的双光子吸收截面。用密度泛函理论和ZINDO-SOS方法,计算了分子的几何构型、电子结构,单光子和双光子吸收性质。结果显示噻吩单元的数目影响分子的单光子和双光子吸收性质。具有两个或三个噻吩基团的噻吩基卟啉衍生物在较大范围内具有可用于实际应用中的双光子吸收响应,这一性质有利于这类分子在光限幅中的应用。插入乙炔基有利于扩大共轭范围,增加分子的双光子吸收截面。同时,乙炔基团的加入导致了单光子和双光子波长的红移。从高透明性和相对大的非线性光学响应考虑,噻吩基卟啉衍生物是一类有应用前景的双光子吸收材料。     

Theoretical studies on the one- and two-photon absorption properties of azulenylporphyrins and azulene-fused porphyrins

The electronic structures, one-photon absorption (OPA) and two-photon absorption (TPA) properties of the azulenylporphyrins and azulene-fused porphyrins have been comparatively studied by using DFT/B3LYP/6-31G(d) and the ZINDO/SDCI method. With the number of azulenyl groups increasing, the OPA wavelengths of all molecules are red-shifted in 400--600~nm and the two-photon absorption cross section is gradually enlarged. The azulene-fused structures facilitate an expanding conjugated area and increasing TPA cross section. The origin of TPA properties of studied compounds is studied with a two-level model. In summary, the azulene-fused porphyrins exhibit strong two-photon absorption.     

具有大的双光子吸收截面的四羧酸二萘嵌苯衍生物的理论研究

用密度泛涵方法和ZINDO方法,从理论上研究了一系列四羧酸二萘嵌苯的衍生物(PTCDS)。对其平衡几何、电子结构和单双光子吸收性质进行了详细的计算研究。结果表明,此系列衍生物的双光子吸收截面主要由其主体结构(二萘嵌苯)决定。△EH-Lgap (HOMO与LUMO间的能隙)的减小,HOMO轨道能量的增大,分子主轴两端取代基给电子强度的增强,共轭长度的增大,分子刚性的增强都有利于此系列化合物双光子吸收截面的增大。并设计了比文献[22]报道的分子C有更大的双光子吸收截面的两个分子D1,D2。