Theoretical and experimental vibrational spectroscopic study of 3-piperidino-propylamine

FT-IR and Raman spectra and the vibrational spectral assignments of 3-piperidino-propylamine (3-pipa) have been reported in the region of 4000-400 cm−1 for the first time. The molecular geometry (bond lengths, bond angles and dihedral angles) and vibrational frequencies of 3-pipa have been calculated in the ground state by using the Hartree-Fock and density functional methods (BLYP and B3LYP) with the 6-31G(d) basis set. Comparison of the observed and the calculated wavenumbers of 3-pipa indicates that B3LYP is superior to the scaled BLYP and Hartree-Fock approach for predicting vibrational wavenumbers and the Hartree-Fock method seems very good at explaining NH2 and CH2 antisymmetric and symmetric vibrations in the region 3400-2800 cm−1.