Lithium ionophore VIII as an extraordinarily effective receptor for the strontium cation: Experimental and theoretical study

0427713 - ÚOCHB 2015 RIV NL eng J - Journal Article
Makrlík, E. - Novák, Vít - Vaňura, P. - Bouř, Petr
Lithium ionophore VIII as an extraordinarily effective receptor for the strontium cation: Experimental and theoretical study.
Journal of Molecular Structure. Roč. 1061, Mar 5 (2014), s. 110-113. ISSN 0022-2860. E-ISSN 1872-8014
Institutional support: RVO:61388963
Keywords : strontium cation * lithium ionophore VIII * complexation * extraction and stability constants * DFT calculations * structures
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 1.602, year: 2014

From extraction experiments and gamma-activity measurements, the extraction constant corresponding to the equilibrium Sr2+(aq) + 2A(-)(aq) + 1(nb) = 1 center dot Sr2+(nb) + 2A(-)(nb) taking place in the two-phase water-nitrobenzene system (A(-) = picrate, 1 = lithium ionophore VIII; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as logK(ex) (1 center dot Sr2+, 2A(-)) = 7.8 +/- 0.1. Further, the extremely high stability constant of the 1-Sr2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 degrees C: log beta(nb) (1 center dot Sr2+) = 16.9 +/- 0.1. Finally, by using OFT calculations, the most probable structure of the cationic complex species 1.Sr2+ was derived. In the resulting complex, the "central" cation Sr' is bound by six very strong bond interactions to the corresponding six oxygen atoms of the parent ligand 1; the interaction energy of this complex was found to be -959.9 kJ/mol.
Permanent Link: http://hdl.handle.net/11104/0233289