Thermodynamic relationships on complex formation. Part VII. ΔHΔS interplay in the equilibria for the formation of amine complexes in aqueous solution

Complex Formation Equilibria between Ag(I) and Thioureas in Propan-2-ol

“…The actual results strengthen previous remarks on thermodynamics of complex formation between Ag(I) and thioureas in hydroxyl hard solvents and the tendency of the complexed central ion to bind further ligand [10][11][12][13][14][15]. The substratum to ligand affinities is contained within ranges of free energy changes which are related to the coordination levels of the substrata: the higher the coordination level of the reacting substrata, the narrower the amplitude of the free energy ranges.…”

“…The general sequence of the substratum to ligand affinity, enthalpy, and entropy changes (i) in the reactions of AgL ( = 1-3) substrata with the same ligands as dependent on the coordination level of the reacting substratum, (ii) in the reactions AgL ( ) −1 + L = AgL ( ) ( = 1-3) in dependence on the alkyl substitution at the same coordination level and (iii) the concurrent changes in the corresponding Δ ∘ and Δ ∘ are evident. Such parallelism in the Δ ∘ and Δ ∘ occurs very often in homologous series of reactions [10][11][12][13].…”

Thermodynamics of Dissolution of some Dicarboxylic Acids in Water/Ethane-1,2-Diol Mixtures

“…The isoequilibrium temperature in this solvent composition confirm that these reactions are of entropy-controlled type. The non-linear plots of ∆H • -∆S • correlation obtained for all other solvent compositions reflect an appreciable "shielding effect" [33] exerted by the solvent on the properties of each acid in the series, which results in differences of the specific properties of the different acids, thus in a homologous series of reactions with precise ∆H • -∆S • interplay, the mutual influence between the changes in the values of parameters is not necessarily compensative in nature.…”

Thermodynamic relationships in complex formation. IX. ΔH – ΔS and free energy relationships in mixed ligand complex formation reactions of Cd(II) in aqueous solution

“….). Because closely spread equilibrium isotherms are experimentally observed both for different series of reactions in the same solvent (8,(10)(11)(12)(13) or for the same series of reactions in different but similar solvents (water, methanol, ethanol) (14)(15)(16) it can be concluded that in the cases investigated the values of τ are mainly determined by the nature and the role of the solvent medium. (iv) The solvent molecules involved in the complex formation reactions appear to be the main factor that determines the relative position of the reactions in the respective trend.…”