Molecular structure, vibrational spectral assignments (FT-IR and FT-Raman), UV-Vis, NMR, NBO, HOMO-LUMO and NLO properties of 3t-penty1-2r,6c-diphenylpiperidin-4-one picrate based on DFT calculations

The FT-IR and FT-Raman spectra were recorded for title compound 3 t-penty1-2r,6c-diphenylpiperidin-4-one picrate (3-PDPPP) and the data were compared with the theoretical values. The stability of the molecule due to hyper-conjugative interaction and charge delocalization was studied by NBO analysis. The UV Vis spectral data calculated by using the DFT method were correlated with the experimental values. The calculated HOMO and LUMO energies revealed that charge transfer occurs within the molecule and Mulliken charges were also obtained. Molecular electrostatic potential (MEP) analyses were performed to predict the reactive sites of the molecule. The calculated first hyperpolarizabilty is high suggesting an extended ?v-electron delocalization over the picryl ring and piperidone moiety which is also responsible for the nonlinear optical property of the molecule. The H-1 and C-13 NMR chemical shifts of the molecule were calculated by the Gauge independent atomic orbital (GIAO) method and compared with the experimental results. The thermodynamic properties of the compound at different temperatures have been determined and correlations between heat capacity, entropy, enthalpy and temperature have been done. 2015 Elsevier B.V. All rights reserved.