Precise PPP molecular orbital calculations of excitation energies of polycyclic aromatic hydrocarbons. Part 1. On the correlation between the chemical softness and the absolute hardness
Precise PPP molecular orbital calculations of excitation energies of polycyclic aromatic hydrocarbons. Part 1. On the correlation between the chemical softness and the absolute hardness
复制标题
多环芳烃激发能的精确PPP分子轨道计算。
DOI：
10.1039/p29950001443
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
K. Nishimoto
中科院分区：
文献类型：
--
作者：
K. Hiruta;S. Tokita;K. Nishimoto
考虑到多环芳烃π共轭体系的特点，新的双中心电子排斥积分NEW-γ考虑了π共轭体系的化学软性，适用于多环芳烃P带激发能的Pariser-Parr-Pople分子轨道(PPP MO)计算。利用化学柔软度与绝对硬度的相关关系，建立了化学柔软度参数k的计算方法。与传统的Nishimoto·Matagaγ(N·M-γ)函数相比，计算的38个多环芳烃的激发能有很大的提高，并与实测值有很好的相关性。这是第一个使用NEW-γ精确计算各种PAN的激发能的PPP MO的例子。
By considering the character of π-conjugated systems of polycyclic aromatic hydrocarbons (PAHs), it has become apparent that a new two centre electron repulsion integral, new-γ, which takes the chemical softness of a π-conjugated system into account is useful for the Pariser–Parr–Pople molecular orbital (PPP MO) calculations of the excitation energy of the p-band of PAHs. Employing the correlation between the chemical softness and the absolute hardness, the method to evaluate the chemical softness parameter k was established. The calculated excitation energies for 38 PAHs were greatly improved compared with the calculated ones using the conventional Nishimoto·Mataga γ(N·M-γ) function, and were well correlated with the observed ones. This is the first example of precise PPP MO calculations of excitation energies of various PANS using new-γ.