Molecular structure, NMR, UV-Visible, vibrational spectroscopic and HOMO, LUMO analysis of (E)-1-(2, 6-bis (4-methoxyphenyl)-3, 3-dimethylpiperidine-4-ylidene)-2-(3-(3, 5-dimethyl-1 H-pyrazol-1-yl) pyrazin-2-yl) hydrazine by DFT method

We have synthesized (E)-1-(2, 6-bis (4-methoxyphenyI)-3, 3-dimethylpiperidine-4-ylidene)-2-(3-(3, 5dimethy1-1H-pyrazol-1-yl) pyrazin-2-yl) hydrazine (PM6). It was characterized using FT-IR, FT-Raman, H-1 NMR, C-13 NMR techniques. To interpret the experimental data, ab initio computations of the vibrational frequencies were carried out using the Gaussian 09 program followed by the full optimizations done using Density Functional Theory (DFT) at B3LYP/6-311 G(d,p) level. The combined use of experiments and computations allowed a firm assignment of the majority of observed bands for the compound. The calculated stretching frequencies have been found to be in good agreement with the experimental frequencies. The electronic and charge transfer properties have been explained on the basis of highest occupied molecular orbitals (HOMOs), lowest unoccupied molecular orbitals (LUMOS) and density of states (DOS). The absorption spectra have been computed by using time dependent density functional theory (TD-DFT). H-1 and C-13 NMR spectra were recorded and H-1 and C-13 NMR chemical shifts of the molecule were calculated using the gauge independent atomic orbital (MO) method. From the optimized geometry of the molecule, molecular electrostatic potential (MEP) distribution, frontier molecular orbitals (FMOS) of the title compound have been calculated in the ground state theoretically. The theoretical results showed good agreement with the experimental values. (C) 2015 Elsevier B.V. All rights reserved.