title: Molecular structure, vibrational spectra, natural bond orbital and thermodynamic analysis of 3,6-dichloro-4-methylpyridazine and 3,6-dichloropyridazine-4-carboxylic acid by dft approach.
abstract: Vibrational spectral analysis of the molecules 3,6-dichloro-4-methylpyridazine (DMP) and 3,6-dichloropyridazine-4-carboxylic acid (DPC) was carried out using FT-IR and FT-Raman spectroscopic techniques. The molecular structure and vibrational spectra of DMP and DPC were obtained by the density functional theory (DFT) method, using B3LYP functional, with 6-311++G(d,p) basis set. A detailed interpretation of the Infrared and Raman spectra of the two molecules were reported based on potential energy distribution (PED). The theoretically predicted FTIR and FT-Raman spectra of the titled molecules have been simulated and were compared with the experimental spectra. Determination of electric dipole moment (μ) and hyperpolarizability β0 helps to study the non-linear optical (NLO) behavior of DMP and DPC. Stability of the molecules arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. (13)C and (1)H NMR spectra were recorded and (13)C and (1)H NMR chemical shifts of the molecules were calculated using the gauge independent atomic orbital (GIAO) method. UV-visible spectrum of the compounds was also recorded in the region 200-1100 nm and electronic properties, HOMO (Highest Occupied Molecular Orbitals) and LUMO (Lowest Unoccupied Molecular Orbitals) energies were measured by time-dependent TD-DFT approach. Charge density distribution and site of chemical reactivity of the molecule have been studied by mapping electron density isosurface with molecular electrostatic potential (MESP).
authors.affiliation: Department of Physics, Sri Sarada College for Women (Autonomous), Salem 636 016, India. Electronic address: n.prabavathi@yahoo.co.in.
authors.forename: N
authors.initials: N
authors.lastname: Prabavathi
authors.affiliation: Department of Physics, Sri Sarada College for Women (Autonomous), Salem 636 016, India.
authors.forename: N
authors.initials: N
authors.lastname: Senthil Nayaki
authors.affiliation: Department of Physics, Kakatiya University, Warangal, Telangana 506009, India.
authors.forename: B
authors.initials: B
authors.lastname: Venkatram Reddy
mesh_terms: D004583:Electrons; D019277:Entropy; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011724:Pyridazines / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013816:Thermodynamics; D014732:Vibration
chemical_list: D011724:Pyridazines
keywords: 3,6-Dichloro-4-methylpyridazine; 3,6-Dichloropyridazine-4-carboxylic acid; DFT; HOMO–LUMO; NMR; Natural bond orbitals