Electronic structure investigations of 1-amino-2,6-dimethylpiperidine by NMR spectral studies by ab initio and DFT calculations

In this work, a combined experimental and theoretical study on molecular structure, vibrational spectra of 1-amino-2,6-dimethylpiperidine (ADP) has been reported. The FTIR and FT-Raman spectrum have been recorded in the region 4000-400 cm(-1) and 3500-50 cm-1, respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of ADP have been calculated by using ab initio/HF and density functional theory/B3LYP methods with 6-31+G(d,p) basis set. A detailed interpretation of the FTIR, FT-Raman, NMR spectra of ADP has also been reported. Natural bond orbital analysis has been carried out to explain the charge transfer or delocalization of charge due to the intramolecular interactions. Energy of the highest occupied molecular (HOMO) orbital and lowest unoccupied (LUMO) molecular orbital have been predicted.