The synthesis, characterization and theoretical study on nicotinic acid [1-(2,3-dihydroxyphenyl)methylidene]hydrazide.

Abstract In this study, we reported a combined experimental and theoretical study on nicotinic acid [1-(2,3-dihydroxyphenyl)methylidene]hydrazide (C 13 H 11 N 3 O 3 ) molecule. The title compound was prepared and characterized by 1 H and 13 C FT-NMR, FT-IR and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 2 1 /c with a  = 6.2681(3) A, b  = 16.5309(7) A, c  = 12.4197(6) A, α  = 90°, β  = 111.603(4)°, γ  = 90° and Z  = 4. In addition, the molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO), continuous set of gauge transformations (CSGT), individual gauges for atoms in molecules (IGAIM) 1 H and 13 C NMR chemical shift values, natural bond orbital (NBO), nonlinear optical (NLO) and HOMO–LUMO analyses, molecular electrostatic potentials (MEPs) and thermodynamic properties of the title compound in the ground state were investigated by using Hartree–Fock (HF) and density functional theory (DFT/B3LYP) methods with 6-311++G(d,p). Besides, the hardness and electronegativity parameters were obtained from HOMO and LUMO energies. Obtained results indicate that there is a good agreement between the experimental and theoretical data.