Interaction of the thallium cation with 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6: experimental and theoretical study

0393887 - ÚMCH 2014 RIV NL eng J - Článek v odborném periodiku
Makrlík, E. - Dybal, Jiří - Vaňura, P.
Interaction of the thallium cation with 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6: experimental and theoretical study.
Journal of Molecular Structure. Roč. 1042, 24 June (2013), s. 73-77. ISSN 0022-2860. E-ISSN 1872-8014
Grant CEP: GA ČR GA203/09/1478
Institucionální podpora: RVO:61389013
Klíčová slova: thallium cation * substituted calix[4]arene-crown-6 * compound
Kód oboru RIV: CD - Makromolekulární chemie
Impakt faktor: 1.599, rok: 2013

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Tl+ (aq) + 1.Cs+ (nb) reversible arrow 1.Tl+ (nb) + Cs+ (aq) taking place in the two–phase water–nitrobenzene system (1 = 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (Tl+, 1.Cs+) = −2.1 ± 0.1. Further, the stability constant of the 1.Tl+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb(1.Tl+) = 11.6 ± 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structures A and B of the cationic complex species 1.Tl+, which are obviously in a dynamic equilibrium, were indicated. In both of these structures of the resulting 1.Tl+ complex, the “central” cation Tl+ is bound by eight strong bond interactions to six oxygen atoms from the 18-crown-6 moiety and to two carbons of the respective two benzene rings of the parent ligand 1 via cation-π interaction.
Trvalý link: http://hdl.handle.net/11104/0222245