Theoretical study on conformational features and cation-binding properties of a diquinone calix[4]arene

摘要

Theoretical studies of a diquinone calix[4]arene and its interactions with the cations Li~+, Na~+, K~+and Ag~+have been performed. Conformational features and cation-binding properties were evaluated with the restricted hybrid Becke threeparameter exchange functional method using the 6-31G(d) basis set and its relativistic effective core potentials. To model the effect of medium, the polarisable continuum model was also used. Four typical conformations of the parent diquinone calix[4]arene were studied. The calculated results show that the most stable conformers are 1,3-alternate and partial cone in the gas phase and in CH_2Cl_2 solution, respectively. The optimised geometric structures were used to perform natural bond orbital analysis. The two main types of driving force metal – ligand and cation – p interactions are investigated. The calculated binding energy for cations (Li~+, Na~+, K~+ and Ag~+) is discussed. The calculated results indicate that cone complexes are the most stable.