A MO theoretical study of organic dyes I. Effect of chemical softness on the electronic spectra
A MO theoretical study of organic dyes I. Effect of chemical softness on the electronic spectra
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有机染料的MO理论研究Ⅰ.化学柔软性对电子能谱的影响
DOI：
10.1246/bcsj.66.1876
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发表时间：
1993
影响因子：
4
通讯作者：
K. Nishimoto
中科院分区：
文献类型：
--
作者：
K. Nishimoto
为了用简单的半经验MO方法获得有机染料的π电子谱的合理结果，考虑了π共轭体系的化学柔软性，提出了一种新的二中心电子斥力积分（新伽马）近似。新的伽马值成功应用于线性多烯、简单花青和简单部花青电子光谱的 PPP 计算。计算结果与实验数据吻合良好。相反，基于传统 PPP 参数的计算给出了电荷共振系统（例如花青和部花青）的电子光谱的吸收最大值的更短波长。此外，由于电子跃迁能量的一电子部分和二电子部分之间的不平衡，它们给部花青带来了非常奇怪的电子光谱偏移（见文本）。
In order to obtain reasonable results for the π-electronic spectra of organic dyes with simple semi-empirical MO methods, a new approximation for the two-center electron repulsion integral (new gamma) is proposed which takes the chemical softness of the π-conjugated system into account. New gamma was successfully applied to PPP calculations of the electronic spectra of linear polyenes, simple cyanines, and simple merocyanines. The calculated results agree satisfactorily with the experimental data. On the contrary, a calculation based on the conventional PPP parameters gives shorter wavelengths for the absorption maxima of the electronic spectra of charge-resonance systems, such as cyanines and merocyanines. Furthermore, they give very strange electronic spectral shifts for merocyanines (see text), due to an inbalance between the one- and two-electron parts of the electronic transition energy.
DOI：
10.1073/pnas.82.20.6723
发表时间：
1985-01-01
影响因子：
11.1
作者：
YANG, WT;PARR, RG
通讯作者：
PARR, RG