Density-functional theory studies on standard electrode potentials of half reaction for l-adrenaline and adrenalinequinone

DFT (B3LY/6-31G(d) and B3PW91/6-31G(d)) calculations are performed for l-adrenaline and adrenalinequinone. The calculated IR spectrum of l-adrenaline is used for the assignment of IR frequencies that are observed in the experimental IR spectrum. Cyclic voltammetry with a platinum electrode of l-adrenaline solutions in phosphate buffers at pH 1 shows that standard electrode potential of half reaction for l-adrenaline and adrenalinequinone is 0.803 V. Standard electrode potential of half reaction for l-adrenaline and adrenalinequinone is calculated using the energies of solvation and the sum of electronic and thermal free energies of l-adrenaline and adrenalinequinone.

Cyclic voltammetry with a platinum electrode of l-adrenaline solutions in phosphate buffers at pH 1 shows that standard electrode potential of half reaction for l-adrenaline and adrenalinequinone is 0.803 V. The predicted standard electrode potentials of 0.57 V at B3LYP/6-31G(d) level and 0.67 V at B3PW91/6-31G(d) level for l-adrenaline and adrenalinequinone are in better agreement with experimental data. This method is a very useful to predict unknown standard potential of compounds.Figure optionsDownload as PowerPoint slide