Oбернено-фазне ВЕРХ-дослідження комплексоутворення 5,17-біс-(N-тoлілiмiнoмeтил)-25,27-дипропоксикалікс[4]aрену з ароматичними карбоновими кислотами

• Datum: 2015
• Hauptverfasser: Kalchenko, O. I., Solovyov, A. V., Kalchenko, V. I.
• Format: Artikel
• Sprache: English
• Veröffentlicht: National University of Pharmacy 2015
• Schlagworte: калікс[4]арен; обернено-фазна високоефективна рідинна хроматографія; ароматичні карбонові кислоти; молекулярне моделювання; комплексоутворення типу Гість-Господар; УДК 547.03 547.562
• Online Zugang: https://ophcj.nuph.edu.ua/article/view/ophcj.15.856
• Назва журналу: Journal of Organic and Pharmaceutical Chemistry

The Host-Guest complexation of 5,17-bis-(N-tolyliminomethyl)-25,27-dipropoxycalix[4]arene with a number of aromatic carboxylic acids has been studied by reversed-phase high-performance liquid chromatography. The mobile phase was acetonitrile-water (80/20, v/v) with addition of 0.1% formic acid. The column was LiChrosorb RP 18, the UV detector operated at λ = 254 nm and at 26°C. The main chromatographic characteristics (retention time t[sub]R[/sub] and capacity factor k’) of the aromatic carboxylic acids have been determined. The lipophilicity values of log P of carboxylic acids, as well as the binding constants K[sub]A[/sub] (387-941 M[sup]-1[/sup]) and Gibbs free energies ∆G (-14.74 – -16.94 kJ/mol) of the calixarene complexes with aromatic carboxylic acids have been calculated. The molecular modelling (Hyper Chem, version 8.0) of the calixarene complexes has revealed the presence of hydrogen bonds between carboxylic groups of the acids and nitrogen atoms of imino groups at the upper rim or oxygen atoms of hydroxyl groups at the lower rim of the calixarene macrocycle. The infl uence of log P lipophilicity of acids on K[sub]A[/sub] values of the calixarene complexes has been assessed. The linear dependence of the binding constants on the acid lipophilicity indicates a signifi cant role of solvophobic interactions on the complexation process. The relationship between supramolecular (K[sub]A[/sub]) and physicochemical (molecular weight, log P, pKa) characteristics of acids has been found. The binding constants K[sub]A[/sub] of the complexes increase with increase of their molecular weight and log P values.