Meta-Substituted Asymmetric Azobenzenes: Insights into Structure–Property Relationship

This article presents a comprehensive investigation into the functionalization of methoxyphenylazobenzene using electron-directing groups located at the meta position relative to the azo group. Spectroscopic analysis of meta-functionalized azobenzenes reveals that the incorporation of electron-withdrawing units significantly influences the absorption spectra of both E and Z isomers, while electron-donating functionalities lead to more subtle changes. The thermal relaxation process from Z to E result in almost twice as prolonged for electron-withdrawing functionalized azobenzenes compared to their electron-rich counterparts. Computational analysis contributes a theoretical understanding of the electronic structure and properties of meta-substituted azobenzenes. This combined approach, integrating experimental and computational techniques, yields significant insights into the structure-property relationship of meta-substituted asymmetrical phenolazobenzenes.