Combined Theoretical and Experimental Study of the Complexation of a Hexaarylbenzene-Based Receptor with the Potassium Cation

摘要

In this study, non-covalent binding interactions of the hexaarylbenzene-based receptor (R) with the potassium cation have been investigated. Employing quantum mechanical density functional theory calculations, the most probable structure of the KR~+ complex species was predicted. In this complex, the K~+ cation synergistically interacts with the polar ethereal oxygen fence and with the central hydrophobic benzene bottom via cation–π interaction. The strength of the KR~+ complex was evaluated experimentally by affinity capillary electrophoresis. From the dependence of the effective electrophoretic mobility of the receptor R on the concentration of the potassium ion in the background electrolyte, the thermodynamic binding (stability, association) constant (KKR) of the KR~+ complex in methanol was evaluated as log_(10) K_(KR) = 3.20 ± 0.22.