Статья
2021

Relationship between Atomic Structure and Electrochemistry. 2. Influence of pH and Ligand Field on the Gibbs Free Energy of Oxidation \(\Delta G_{{0,{\text{Ox}}}}^{^\circ }\)

J. A. Díaz-Ponce J. A. Díaz-Ponce , A. Campero A. Campero
Российский электрохимический журнал
https://doi.org/10.1134/S1023193520120058
Abstract / Full Text
Díaz-Ponce, J.A., Campero, A. Relationship between Atomic Structure and Electrochemistry. 2. Influence of pH and Ligand Field on the Gibbs Free Energy of Oxidation \(\Delta G_{{0,{\text{Ox}}}}^{^\circ }\) . Russ J Electrochem 57, 412–418 (2021). https://doi.org/10.1134/S1023193520120058

In this work it is found that the HOMO–LUMO gap, formed after the electron is added to bond the ligand and the transition metal, determines the stability and the power of reduction of the metal complex. In order to establish this relationship, we have used the values of the Gibbs energy of oxidation in water at pH 0 for different ligands in which the same number of electrons are transferred. We have also used diagrams of molecular orbitals for metal complexes of Ta, Re, Pt and Au. This relationship is based on the higher probability of electronic transition between orbitals with a lower HOMO–LUMO gap.

Author information

  • Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa. Col. Vicentina, Apdo. Post. 55-534, D.F., C.P. 09340, México, México

    J. A. Díaz-Ponce

  • Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa. Col. Vicentina, Apdo. Post. 55-534, D.F., C.P. 09340, México, México

    A. Campero

References
  1. Huheey, J.E., Keiter, E.A., and Keiter, R.L., Inorganic Chemistry, Principles of Structure and Reactivity, 4th ed., New York: Harper Collins College Publishers, 1993, pp. 184, 206, 411, 578–579.
  2. Hinze, J., Whitehead, M.A., and Jaffé, H.H., Electronegativity: II: bond and orbital electronegativities, J. Am. Chem. Soc., 1963, vol. 85, no. 2, p. 148; Parr, R.G., Donnelly, R.A., Levy, M., and Palke, W.E., Electronegativity: the density functional viewpoint, J. Chem. Phys., 1978, vol. 68, no. 8, p. 3801; Geerlings, P., de Proft, F., and Langenaeker, W., Conceptual density functional theory, Chem. Rev., 2003, vol. 103, no. 5, p. 1793; Galván, M., Vela, A., and Vázquez, J.L., Chemical reactivity in spin polarized density functional theory, J. Phys. Chem., 1988, vol. 82, no. 22, p. 6470.
  3. Campero, A. and Díaz Ponce, J.A., Relationship between the atomic structure and electrochemistry. 1. Electric force, standard reduction potential E°, and standard reaction Gibbs free energy ΔG°, ACS Omega 2020, vol. 5, no. 21, p. 12046; Campero, A. and Díaz Ponce, J.A., Averaged scale in electronegativity joined to physicochemical perturbations. Consequences of periodicity, ACS Omega 2020, vol. 5, no. 40, p. 25520.
  4. Gschneider, K.A., Jr. and Eyring, L.R., Handbook on the Physics and Chemistry of Rare Earths, vol. 1: Metals, Amsterdam: North-Holland, 1978; Bard, A., Parsons, J.R., and Jordan, J., Standard Potentials in Aqueous Solutions, Basel: Marcel Dekker, 1985.
  5. Atkins, P., Overton, T., and Rourke, J., Shriver and Atkins Inorganic Chemistry, 5th ed., New York: Oxford Univ. Press, 2010; Rayner-Canham, G., Descriptive Inorganic Chemistry, 2nd ed., New York: Freeman and Co, 2000.
  6. Pearson, R., Hard and soft scids and bases, J. Am. Chem. Soc., 1963, vol. 85, no. 22, p. 3533; Geerlings, P., de Proft, F., and Langenaeker, W., Conceptual density functional theory, Chem. Rev., 2003, vol 103, no. 5, p. 1793.
  7. Cotton, F.A. and Wilkinson, G., Advanced Inorganic Chemistry, 4th ed., New York: John Wiley & Sons, 1980; Correa, H.P.S., Cavalcante, I.P., and Martínez, L., Refinement of monoclinic ReO2 structure for XRD by Rietveld method, Braz. J. Phys., 2004, vol. 34, no. 3B, p. 1208.
  8. Parr, R.G. and Pearson, R.G., Absolute hardness: companion parameter to the absolute electronegativity, J. Am. Chem. Soc., 1983, vol. 105, no. 26, p. 7512.
  9. Zuckerman, J.J., Crystal field splitting diagrams, J. Chem. Educ., 1965, vol. 42, no. 6, p. 315.
  10. Atkins, P.W., Fisicoquímica, 3th ed., Washington: Fondo Educativo Interamericano, 1983.
  11. Requena, A. and Zúñiga, J.Z., Espectroscopía, Madrid: Pearson Educación, 2004.
  12. Bruice, P.Y., Química Orgánica, 5th ed., Madrid: Pearson Educación, 2008.