The conformations and energies of tri alkylated calix[4]aryl ester (1) and its alkyl ammonium complexes have been simulated by molecular mechanics, AM1 semi empirical and ab initio quantum mechanics calculations. We performed molecular dynamics calcul...
The conformations and energies of tri alkylated calix[4]aryl ester (1) and its alkyl ammonium complexes have been simulated by molecular mechanics, AM1 semi empirical and ab initio quantum mechanics calculations. We performed molecular dynamics calculations to simulate the behavior of these complexes primarily focusing on the six representative conformations (cone, 1, 2, and 3 partial cone, 1,2 alternate and 1,3 alternate) of host molecule 1. When we peformed ab initio and AM1 semi empirical quantum mechanics and molecular mechanics calculations, the cone conformation was generally found to be most stable for all the employed calculation methods. The primary binding site of host 1 for the recognition of alkyl ammonium guests was the upper rim of calix[4]arene part. The complexation energy calculations revealed that the alkyl ammonium cations without alkyl group showed the better complexation efficiencies when combined with tri alkylated calix[4]aryl ester (1).