Molecular structure and vibrational spectra of 4-tert-butylpyridine by density functional theory and ab initio Hartree–Fock calculations

Abstract

The molecular geometry and vibrational frequencies of 4-tert-butylpyridine(4-tbpy) in the ground state have been calculated by using the Hartree–Fock and density functional methods (B3LYP and BLYP) with 6-31G (d) as the basis set. The optimized geometric bond lengths obtained by using B3LYP and bond angles obtained by BLYP show the best agreement with the experimental values. Comparison of the observed fundamental vibrational frequencies of 4-tbpy and calculated results by density functional B3LYP, BLYP and Hartree–Fock methods indicates that B3LYP is superior to the scaled Hartree–Fock and BLYP approach for molecular vibrational problems.