Gibbs energies of protonation and complexation of platinum and vanadate metal ions with naringenin and phenolic acids: Theoretical calculations associated with experimental values
| Autor: | Hisham S. M. Abd-Rabboh, Mohammad Y. Alfaifi, Ahmed E. Fazary, Kamel A. Saleh, Khaled F. Fawy, Ayed S. Al-Shihri, Serag Eldin I. Elbehairi |
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| Rok vydání: | 2016 |
| Předmět: |
Metal ions in aqueous solution
Inorganic chemistry Solvation Vanadium chemistry.chemical_element Protonation 02 engineering and technology 010402 general chemistry 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Ferulic acid chemistry.chemical_compound Deprotonation 020401 chemical engineering chemistry Computational chemistry Vanillic acid Caffeic acid General Materials Science 0204 chemical engineering Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Chemical Thermodynamics. 100:7-21 |
| ISSN: | 0021-9614 |
| Popis: | The Experimental thermodynamic equilibrium (pKa values) and stability (log β) constants of vanadium and platinum binary and mixed ligand complexes involving naringenin, ferulic acid, p-coumaric acid, caffeic acid, vanillic acid, sinapic acid, and gallic acid were determined at 310.15 K in 0.16 mol·dm−3 KCl aqueous solutions using pH-potentiometric technique and by means of two estimation models (HYPERQUAD 2008 and Bjerrum–Calvin). The theoretical calculations of overall protonation and stability constants of the metal complex species in solution were predicted as the free energy change associated with the ligand protonation, and metal ion–ligand complex formation equilibria (species solvation/de-solvation) using ab initio and density function theory (DFT) calculations. The usage of the experimental potentiometry technique and theoretical predictions provides a complete picture of the microscopic equilibria of the studied systems (vanadium/platinum–naringenin–phenolic acid). Specifically, this theoretically DFT predications would be useful to determine the most real protonation constants of the studied bioligands in which the binding sites changes due to the ligand protonation/deprotonation equilibria. Also, the complexing capacities of vanadium and platinum towards naringenin, ferulic acid, p-coumaric acid, caffeic acid, vanillic acid, sinapic acid, and gallic acid in solutions were evaluated and discussed. From the determined experimental stability constants of different metal complex species, the concentration distribution diagrams of the various metal ion complex species in solution was estimated using HySS 2009 software. |
| Databáze: | OpenAIRE |
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