Understanding of the Kinetic Stability of <i>cis‐</i> Isomer of Azobenzenes through Kinetic and Computational Studies
Dhiraj Das, Manish K. Yadav, Labhini Singla, Atul Kumar, Maheswararao Karanam, Sagarika Dev, Angshuman Roy Choudhury
Abstract
Abstract A library of halogen‐substituted azobenzenes (ABs) have been synthesized and structurally characterized by single crystal X‐ray diffraction technique. Azobenzenes studied herein display fast photo switching properties. Kinetics of cis‐ → trans‐ isomerization has been studied using UV‐VIS spectroscopy and the rate constant for this transformation were determined. Optimization of probable conformers of the cis‐ isomer and the corresponding transition state (TS) were carried out to determine the energy of activation. The Time‐Dependent Density Functional Theory (TD‐DFT) calculations were also performed to gain insight into the photo‐isomerization. Our results indicate that the fluorinated compounds display better kinetic stability of the cis‐ isomer compared to the corresponding chloro and bromo analogues.