A combined extraction and DFT study on the complexation of K+ with valinomycin

0332179 - ÚMCH 2010 RIV AT eng J - Journal Article
Makrlík, E. - Dybal, Jiří - Vaňura, P.
A combined extraction and DFT study on the complexation of K+ with valinomycin.
Monatshefte fur Chemie. Roč. 140, č. 11 (2009), s. 1289-1292. ISSN 0026-9247. E-ISSN 1434-4475
R&D Projects: GA AV ČR 1ET400500402
Institutional research plan: CEZ:AV0Z40500505
Keywords : antibiotics * macrocycles * stability constant
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 1.312, year: 2009

The extraction constant corresponding to the equilibrium K+(aq) + 1.Cs+(nb) equil. 1.K+(nb) + Cs+(aq) taking place in the two-phase water-nitrobenzene system was evaluated as -0.9 +/- 0.1. By using DFT calculations, the most probable structure of the 1.K+ complex species was derived, with the valinomycin part stabilized by strong bond interactions of K+ with six ester carbonyl oxygen atoms. The calculated stabilization energy of the considered cationic complex species 1.K+ is -376.1 kJ/mol, confirming the very high stability of the complex.
Permanent Link: http://hdl.handle.net/11104/0005538