title: Affinity capillary electrophoresis and density functional theory applied to binding constant determination and structure elucidation of hexaarylbenzene-based receptor complex with ammonium cation.
abstract: Affinity capillary electrophoresis (ACE) and quantum mechanical density functional theory (DFT) calculations have been employed for the investigation of noncovalent interactions between hexaarylbenzene-based receptor (R) and ammonium cation NH(4)(+). Firstly, by means of ACE, the binding constant of the NH(4)R(+) complex in methanol was estimated from the dependence of the effective electrophoretic mobility of the receptor R (in advance corrected by our earlier developed procedure to a reference temperature of 25°C) on the concentration of ammonium ion in the background electrolyte using non-linear regression analysis. The logarithmic form of the apparent binding (stability) constant of NH(4)R(+) complex in the methanolic background electrolyte (25 mM Tris, 50 mM chloroacetate, pH(MeOH) 7.8) was evaluated as log K(NH(4)R) = 4.03 ± 0.15. Secondly, the structural characteristics of NH(4)R(+) complex were determined by DFT calculations.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, vvi, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Sille
authors.initials: S
authors.lastname: Ehala
authors.forename: Petr
authors.initials: P
authors.lastname: Toman
authors.forename: Emanuel
authors.initials: E
authors.lastname: Makrlík
authors.forename: Rajendra
authors.initials: R
authors.lastname: Rathore
authors.forename: Václav
authors.initials: V
authors.lastname: Kašička
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002846:Chromatography, Affinity / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006860:Hydrogen Bonding; D000432:Methanol; D008958:Models, Molecular; D008968:Molecular Conformation; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013696:Temperature
chemical_list: D001555:Benzene Derivatives; D002412:Cations; D000644:Quaternary Ammonium Compounds; D000432:Methanol