Complexation of Alkali Metal Cations by a Tertiary Amide Calix[4]Arene Derivative in Strongly Cation Solvating Solvents

Croatica Chemica Acta

Tranfić Bakić, Marina¹  Cindro, Nikola²  Cvetnić, Marija²  Bregović, Nikola²  Tomišić, Vladislav²  Leko, Katarina²  Požar, Josip² 

[1] Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia;Division of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia

关键词: tertiary amide calix[4]arene derivative;    microcalorimetry;    solvation effect;    alkali metal cation complexation;   

DOI  :  10.5562/cca3200

学科分类：化学（综合）

来源: Croatica Chemica Acta

【 摘 要 】

The complexation of alkali-metal cations with calix[4]arene tertiary amide derivative (L) was studied in N-methylformamide (NMF), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) by means of microcalorimetric and UV spectrophotometric titrations. The Gibbs energies, enthalpies, and entropies for transfer of reactants and products from N-methylformamide to other solvents were determined. Favorable enthalpic contribution to overall stability was found to be the most important for all complexation reactions, especially in the case of NaL+ formation, resulting in an affinity peak of L for this cation. The complexation entropy changes were always unfavorable. The ligand dissolution was endothermic in all solvents, accompanied by positive solution entropy. The highest complex stability constants were determined in NMF, whereas in DMSO the affinity of L towards alkali metal cations was the lowest. An interesting interplay between the transfer enthalpies and entropies of the reactants and complexes was revealed and discussed in detail.

【 授权许可】

CC BY