Synthesis, Structure and Quantum Mechanical Calculations of Methyl 2-（5-（（Quinolin-8-yloxy）-methyl）-1,3,4-oxadiazol-2-ylthio）-acetate

The title compound was synthesized by the base catalyzed reaction of 5-((quinolin-8-yloxy)methyl)-1,3,4-oxadiazole-2(3H)-thione with methyl chloroacetate.The structure was supported by the spectroscopic data and unambiguously confirmed by single-crystal X-ray diffraction studies.It crystallizes from a methanol solution in the triclinic space group P1with unit cell dimensions a=7.4509(9),b=10.2389(12),c=12.2299(15),α=74.771(2),β=77.956(2),γ=69.263(2)°,V=834.98(17)?3 and Z=2.In order to gain some valuable insights into the molecular structure,the quantum mechanical calculations were performed using both HF and time-dependent density functional theory at the B3LYP/6-31G(d,p)level.The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock(HF)and density functional theory(DFT)with the 6-31G(d)basis set.The calculated results show that the DFT and HF can well reproduce the structure of the title compound.The energetic behavior of the title compound was examined using the B3LYP method with the 6-31G(d)basis set.The harmonic vibrational frequencies calculated have been compared with the experimental FTIR and FT-Raman spectra.The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance(NMR)calculation procedure was also performed,and it was used for assigning the13C and1H NMR chemical shifts of the title compound.Moreover,molecular electrostatic potential and thermodynamic parameters of the title compound were investigated by theoretical calculations.