MOLECULAR STRUCTURE, FTIR, FT-RAMAN, NBO ANALYSIS, FIRST ORDER HYPERPOLARIZABILITIES, THERMODYNAMIC FUNCTIONS AND NMR CHEMICAL SHIELDING ANISOTROPY (CSA) PARAMETERS OF METHYL 2-CHLORONICOTINATE BY AB INITIO DFT CALCULATIONS.

In this work, FT-IR and FT-Raman spectra are recorded on the solid phase of methyl 2-chloronicotinate in the regions 4000–400 cm-1 and 3500–100 cm-1 respectively. The geometrical parameters, vibrational assignments, HOMO–LUMO energies and NBO calculations are obtained for the monomer and dimer of methyl 2-chloronicotinate from DFT (B3LYP) with 6-311++G (d, p) basis set calculations. Second order perturbation energies and electron density (ED) transfer from filled lone pairs of Lewis base to unfilled Lewis acid sites of methyl 2-chloronicotinate are discussed on the basis of NBO analysis. give the evidence for the formation of dimer entities in the title molecule. The theoretically calculated harmonic frequencies are scaled by common scale factor. The observed and the calculated frequencies are found to be in good agreement. The thermodynamic functions were obtained for the range of temperature 100–1000 K. The polarizability, first hyperpolarizability, anisotropy polarizability invariant has been computed using quantum chemical calculations. The chemical parameters were calculated from the HOMO and LUMO values. The NMR chemical shielding anisotropy (CSA) parameters were also computed for the title molecule.