| Abstrakt: |
The laws of the combined action of σ- and π-ligands on the electronic structure and thermodynamic parameters of Cu+ acidoaquachlorocomplexes were investigated using the method of quantum chemical modeling. It was found that anhydrous chloride complexes with molecules of unsaturated organic acids (acrylic, maleic, fumaric) have the best energy characteristics. They achieve the maximum binding energies of the central atom with the chloride ion (151 ± 2 kJ/mol) and the organic ligand (130 ± 1 kJ/mol), which are practically independent of the nature of the acid. The addition of water molecules to [Cu+(L)(Cl-)] is energetically beneficial in all cases. The value of ΔEr depends on the nature of the organic acid, its form of existence (molecules, anions), and the number of water molecules. Therefore, it varies in a wide range of values (10-60 kJ/mol). Hydration promotes the transition from σ- bonding by the central atom of anionic forms of organic ligands to π-bonding. Stable π-complexes [Cu+(L)(Cl-)(H2O)] exist with all forms of the studied acids. At the same time, the transition from the molecular form of organic acids to the anionic one totally worsens both the energetics of σ-bonds of Сu+ with chlorine anions and water molecules, as well as the energetics of π-bonds. The antagonism of the combined action of σ-ligands in [Cu+(L)(Cl-)(H2O)] was quantified by the change in the effective charge of the central atom. It was shown that in complexes with the molecular form of the studied unsaturated acids, chlorine anions reduce the electron donation of water molecules by 86 %, and water molecules reduce the electron donation of Cl- by 35 %. [ABSTRACT FROM AUTHOR] |
