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.