Determination of the oxidation potentials of organic benzene derivatives: theory and experiment

• Published in: Chemical physics letters Vol. 368; no. 5; pp. 601 - 608
• Main Authors: Han, Young-Kyu, Jung, Jaehoon, Cho, Jeong-Ju, Kim, Hyeong-Jin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 24.01.2003; Elsevier Science
• Subjects: Atomic and molecular physics; Chemical thermodynamics; Chemistry; Exact sciences and technology; General and physical chemistry; General. Theory; Ionization potentials, electron affinities, molecular core binding energy; Molecular properties and interactions with photons; Physics; Properties of molecules and molecular ions; Solvation; Ionization; Oxidation potential; Theoretical study; Density functional method; Benzenic compound; Ionization potential; Thermodynamic properties; Free energy; Organic compounds
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/S0009-2614(02)01857-2

We have calculated the IP, Δ G e, and E ox values for 10 mono-substituted benzene molecules and compared them with experimental values obtained by linear sweep voltammetry. The E ox values were evaluated using the density functional method and thermodynamic cycles. The relative oxidation potentials are in close agreement with experimental values, while the UB3LYP/6-31+G(d) approach shows the absolute E ox values to be lower by about 0.9 V. Consideration of bulk solvent effects is important to fully describe the experimental variation in E ox. The HOMO, NBO, and Wiberg bond index were analyzed to investigate the changes when moving from neutral to cationic molecules.