Extraction and DFT study on the complexation of K+ with a hexaarylbenzene - based polyaromatic receptor

0356372 - ÚMCH 2011 RIV SI eng J - Journal Article
Makrlík, E. - Toman, Petr - Vaňura, P. - Rathore, R.
Extraction and DFT study on the complexation of K+ with a hexaarylbenzene - based polyaromatic receptor.
Acta Chimica Slovenica. Roč. 57, č. 4 (2010), s. 948-952. ISSN 1318-0207. E-ISSN 1580-3155
R&D Projects: GA ČR(CZ) GAP205/10/2280
Institutional research plan: CEZ:AV0Z40500505
Keywords : hexaarylbenzene-based polyaromatic receptor * potassium cation * complexation
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.011, year: 2010
http://acta.chem-soc.si/57/57-4-948.pdf

From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium between K+ (aq) + 1•Cs+(nb) and 1•K+ (nb) + Cs+(aq) taking part in the two–phase water–nitrobenzene system (1 = hexaarylbenzene – based polyaromatic receptor; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (K+, 1•Cs+) = –1.0. Further, the stability constant of the hexaarylbenzene–based polyaromatic receptor • K+ complex in nitrobenzene saturated with water was calculated: log βnb (1•K+) = 5.1. By using quantum chemical DFT calculations, the most probable structure of the 1•K+ complex was solved. In this complex, the cation K+ synergistically interacts with the polar ethereal oxygen fence and with the central hydrophobic benzene bottom via cation–π interaction. The calculated binding energy of the resulting complex 1•K+ is –282.8 kJ/mol, confirming the relatively high stability of the considered cationic complex species.
Permanent Link: http://hdl.handle.net/11104/0006335