Molecular Structure, Vibrational Spectroscopic, First Order Hyperpolarizability and Homo–Lumo Studies of 1-Aminopiperidine Using Ab Initio Hf and DFT Calculations

Abstract

The molecular vibrations Of 1-Aminopiperidine has been investigated at room temperature by Fourier transform infrared FT-IR and  FT-Raman spectroscopies. The spectra of the molecule have been recorded in the regions 4000-400 cm-1 and 3500-50 cm-1 respectively. Theoretical information on the optimized geometry, harmonic vibrational frequencies, infrared and Raman intensities were obtained by means of ab initio Hartree–Fock (HF) and Density functional theory (DFT) using 6-311+G(d,p) basis set. The vibrational frequencies which were determined experimentally from the spectral data are compared with those obtained theoretically from ab initio and DFT calculations. A close agreement achieved between the observed and calculated frequencies by re?nement of the scale factors. The HOMO-LUMO and Thermodynamic properties like entropy, heat capacity, zero point energy have been calculated for the molecule.