Experimental and DFT computational studies on 5-benzyl-4-(3,4-dimethoxyphenethyl)-2H-1,2,4-triazol-3(4H)-one

Abstract
The triazole compound, 5-benzyl-4-(3,4-dimethoxyphenethyl)-2H-1,2,4-triazol-3(4H)-one, has been synthesized and characterized by 1H-NMR, 13C-NMR, IR, and X-ray single-crystal determination. The compound crystallizes in the monoclinic space group P21 with a = 11.8844(3) Å, b = 17.5087(4) Å, c = 17.3648(6) Å, β = 99.990(2)˚ and Z = 8. In addition to the molecular geometry from X-ray experiment, the molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) 1H- and 13C-NMR chemical shift values of the title compound in the ground state have been calculated using the density functional method (B3LYP) with 6-31G(d,p) basis set. The calculated results show that the optimized geometries can well reproduce the crystal structure and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental ones. Besides, molecular electrostatic potential (MEP), natural bond orbital (NBO), and frontier molecular orbitals (FMO) analysis of the title compound were performed by the B3LYP/6-31G(d,p) method.