Structural, vibrational, electronic and NMR spectral analysis of 3-chloro-6-methoxypyridazine by DFT calculations

In this work, the FT-Raman and FT-Infrared spectra of 3-chloro-6-methoxypyridazine sample were measured to elucidate the spectroscopic properties of title molecule in the spectral range of 3500-50 cm(-1) and 4000-400 cm(-1), respectively. The molecular geometry and vibrational frequencies of 3-chloro-6-methoxypyridazine in the ground state were calculated using the DFT/B3LYP/6-31 G(d),6-311G(d,p) level. The recorded FT-IR and FT-Raman spectral measurements favor the calculated structural parameters which are further supported by spectral simulation. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The UV-Visible absorption spectrum of the compound that dissolved in methanol was recorded in the range of 800-200 nm. The formation of hydrogen bond and the most possible interaction are explained using natural bond orbital (NBO) analysis. The isotropic chemical shift computed by C-13 and H-1 NMR analysis also shows good agreement with experimental observations. In addition, the molecular electrostatic potential (MEP) and frontier molecular orbitals (FMOs) analysis of the title compound were investigated using theoretical calculations. (C) 2013 Elsevier B.V. All rights reserved.