theoretical investigation of structural and electronic properties of azophenol molecular switches and its derivatives

The quantum chemical calculations have been utilized for obtaining the equilibrium geometries and transition states of four azophenol molecular photoswitches. the transition structures were obtained for two mechanism (rotation and inversion). for all studied molecules, the trans isomers are more stable than the cis configurations both in the vacuum and ethanol solvent. the cis-to-trans thermal isomerization pathways were studied using relaxed potential energy surface scan. the transition structures were obtained and the barrier energies were predicted for rotation and inversion mechanisms. the rotation pathway was found to be preferred. the order of the calculated energy barriers are in very good agreement with the experimental relaxation times.