Department of Physics, Gulbarga University, Jnana Ganga, Gulbarga 585106, Karnataka, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 Apr;75(4):1203-10. doi: 10.1016/j.saa.2009.12.007. Epub 2009 Dec 6.
The both, ground-state (mu(g)) and the excited-state (mu(e)) dipole moments of three 1,4-disubstituted anthraquinones, namely 1,4-diaminoanthracene-9,10-dione (1,4-DAAQ), 1-amino-4-hydroxyanthracene-9,10-dione (1,4-AHAQ), and 1,4-dihydroxyanthracene-9,10-dione (1,4-DHAQ) were estimated in binary solvent mixtures (methylcyclohexane-ethyl acetate and ethyl acetate-acetonitrile). The dipole moments (mu(g) and mu(e)) were estimated from Lippert-Mataga, Bakhshiev, Kawski-Chamma-Viallet, McRae, and Suppan equations by using the variation of Stokes shift with the solvent's relative permittivity and refractive index. The ground-state dipole moments were also calculated theoretically by Gaussian 03 software using B3LYP/6-31 G* level of theory. Further, the change in dipole moment values Deltamu were also calculated by using the variation of Stokes shift with the molecular-microscopic empirical solvent polarity parameter (E(T)(N)). The excited-state dipole moments observed are larger than their ground-state counterparts, indicating a substantial redistribution of the pi-electron densities in a more polar excited state for all the molecules investigated.
三种 1,4-取代蒽醌的基态（μ(g)）和激发态（μ(e)）偶极矩，即 1,4-二氨基蒽醌-9,10-二酮（1,4-DAAQ）、1-氨基-4-羟基蒽醌-9,10-二酮（1,4-AHAQ）和 1,4-二羟基蒽醌-9,10-二酮（1,4-DHAQ），在二元溶剂混合物（甲基环己烷-乙酸乙酯和乙酸乙酯-乙腈）中进行了估算。偶极矩（μ(g)和μ(e)）是通过 Lippert-Mataga、Bakhshiev、Kawski-Chamma-Viallet、McRae 和 Suppan 方程，利用斯托克斯位移随溶剂相对介电常数和折射率的变化来估算的。基态偶极矩也通过 Gaussian 03 软件使用 B3LYP/6-31 G*理论水平进行了理论计算。此外，还通过斯托克斯位移随分子微观经验溶剂极性参数（E(T)(N)）的变化来计算偶极矩值的变化Δμ。观察到的激发态偶极矩大于其基态偶极矩，表明在所有研究的分子中，在更极性的激发态下，π电子密度发生了实质性的重新分布。
