https://www.selleckchem.com/pr....oducts/fluorescein-5
Employing a 13 C-labeled model, the individual steps of the oxidation sequence could be observed directly by NMR, and the activation energy for the rotation could be estimated to be approximately 2.8 kcal/mol. Reaction rates were solvent dependent, with polar solvents exerting a stabilizing effect on the zwitterion. The observed effects confirmed the central relevance of the rotation step in the change from the aromatic to the quinoid state and allowed a more detailed examination of the oxidation behavior of to