Ab Initio Study of Vibrational Spectra of p-tert-Butylcalix[4]aryl Ester Complexed with Alkali Metal Cation

infrared(IR) absorption spectra were calculated for the ethyl ester of p-tert-butylcalix[4]arene (1) in the cone conformer and its alkali-metal-ion complex. The vibrational spectra were obtained by restricted Hartree-Fock (RHF) calculations with the 6-31G basis set. The characteristic vibrational frequencies of various C-O and C