The unexpected and important role of alcohol stabilizer in thermal cis-trans isomerization of push-pull dyes in chloroform solution

The study demonstrates the influence of ethanol as a stabilizer in unstable chloroform on the thermal cis-trans isomerization kinetics of photochromic compounds based on azobenzene (Az, alko-Az) and azopyridine (AzPy, alko-AzPy) derivatives. The effect of ethanol presence was studied in the context of intermolecular H-bonds between molecules of azodyes, and azodye-solvent.

The data includes:

• ¹H NMR for four azodyes denoted as Az, AzPy, alko-Az, alko AzPy in CDCl₃ and after adding ethanol stabilizer in the content 1 - 28% (v/v).