Naslov
Solvation Effect on Complexation of Alkali Metal Cations by a Calix[4]arene Ketone Derivative

Autori
Požar, Josip ; Nikšić-Franjić, Ivana ; Cvetnić, Marija ; Leko, Katarina ; Cindro, Nikola ; Pičuljan, Katarina ; Borilović, Ivana ; Frkanec, Leo ; Tomišić, Vladislav

Izvornik
The journal of physical chemistry. B, Condensed matter, materials, surfaces, interfaces & biophysical (1520-6106) 121 (2017), 36; 8539-8550

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
calix[4]arene ketone derivative ; solvation effect ; alkali metal cation complexation

Sažetak
The medium effect on the complexation of alkali metal cations with a calix[4]arene ketone derivative (L) was systematically examined in methanol, ethanol, N-methylformamide, N, N- dimethylformamide, dimethyl sulfoxide, and acetonitrile. In all solvents the binding of Na+ cation by L was rather efficient, whereas the complexation of other alkali metal cations was observed only in methanol and acetonitrile. Complexation reactions were enthalpically controlled, while ligand dissolution was endothermic in all cases. A notable influence of the solvent on NaL+ complex stability could be mainly attributed to the differences in complexation entropies. The higher NaL+ stability in comparison to complexes with other alkali metal cations in acetonitrile was predominantly due to a more favorable complexation enthalpy. The 1H NMR investigations revealed a relatively low affinity of the calixarene sodium complex for inclusion of the solvent molecule in the calixarene hydrophobic cavity, with the exception of acetonitrile. Differences in complex stabilities in the explored solvents, apart from N, N-dimethylformamide and acetonitrile, could be mostly explained by taking into account solely the cation and complex solvation. A considerable solvent effect on the complexation equilibria was proven to be due to an interesting interplay between the transfer enthalpies and entropies of the reactants and the complexes formed.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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