Solvent effects on complexation of molybdenum(VI) with nitrilotriacetic acid in different aqueous solutions of methanol

Solvent effects on complexation of thallium(I) with guanosine 5′‐monophosphate in methanol–water mixtures

“…However, in our previous studies similar results were obtained for other complex species but again in methanol-water mixtures. 2,7,8 In accordance with our previous experiments and this work the stability of the complexes, which is mainly determined by the metal ion affinity of the purine moiety, increases with increasing the amounts of methanol. This rule seems true not only for the complexes formed by nucleic acid bases but also amino acid (penicillamine) and amino polycarboxilic acid (nitrilotriacetic acid) complex species apparently follow the same policy.…”

“…The interaction of solvents of different dielectric constants with biological molecules is of importance for understanding the chemistry of in vivo processes like enzyme interactions, the assembly of lipids in biomembrans, surfactant aggregation, etc. 9 In three recent publications, 2,7,8 we have reported that the dielectric constant alone (as believed for many years) cannot serve as a quantitative measurement of the solvent polarity. This property is often inadequate, since the dielectric constant description considers a solvent as a non-structured continuum, not composed of individual solvent molecules with their own solvent-solvent interactions, and does not take into account specific solute-solvent interactions.…”

“…This effect is well established for most metal ion complexes of biologically ligands. 2,7,8 Hence, the knowledge of physio-chemical properties of the solvent in order to understand the intermolecular interactions between solute-solvent and also solvent-solvent molecules is required for a proper bench-work.…”

“…This rule seems true not only for the complexes formed by nucleic acid bases but also amino acid (penicillamine) and amino polycarboxilic acid (nitrilotriacetic acid) complex species apparently follow the same policy. 7,8 This could be explained by, upon addition of larger amounts of methanol to the aqueous solution, the activity of water is decreased to the point where poor solvation results for those metal ion sites not occupied by the ligand. Consequently, the poorer solvation leads to an increased affinity of the metal ion sites for other ligating ligands.…”

Determination of Solvatochromic Regression Coefficients for the Molybdenum(VI) Complex with Ethylenediamine‐N,N′‐diacetic Acid by Using Kamlet‐Abboud‐Taft Equation

“…31 In our research KAT parameters are in the order of β＞π*＞α, which is similar to the literature. 29 According to our knowledge there is no report in the literature about the solvatochromic parameters for the dissociation constants of EDDA. We found the order for lg K 1 is β＞α＞π*, but the order for lg K 2 is β＞π*＞α, which is similar to the order for complex formation of EDDA with molybdenum(VI).…”