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Updated: Jul 9, 2025

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation
Published on: October 10, 2018
Study of the electronic effect and quantitative spectra predictions of o-methoxyaniline-terminated monoazonaphthols:
Guoxun Zhu1, Yan Lin2, Wenxian Zhou3
1Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Institute of Analysis, Guangdong Academy of Sciences, China National Analytical Centre Guangzhou 510070 P. R. China 1539888623@qq.com lzq@fenxi.com.cn.
Abstract:
A combined experimental and density functional theory (DFT) study on the UV-Vis spectra of o-methoxyaniline-terminated mono azo dyes was conducted. By applying time-dependent-DFT calculations, details of excitation processes were determined and visualization by hole-electron analysis was undertaken. Fragment-divided analysis revealed the contributions of different parts of the structures for the UV-Vis spectra, that richer/poorer electron density on aromatic rings lead to greater/less maximum absorption wavelengths (λmax) and larger/smaller half peak width (W1/2). Combining theoretical prediction with experimental verification, we answered the question of how the electronegativities of substituents affected the electron densities and how it affected the spectra. In addition, a linear model connecting the λmax and W1/2 to the chemical shifts obtained by NMR spectroscopy was constructed, which laid the foundation for construction of a spectral library.
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