Crystal structure and DFT studies of 4-(1-benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-6-phenylpyrimidin-2-amine

Abstract

The title compound (1) 4-(1-benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-6-phenylpyrimidin-2-amine (C₂₀H₁₈N₆) was synthesized and structurally characterized by elemental analysis, ¹H NMR, ¹³C NMR and single crystal X-ray diffraction. The compound crystallizes as a colourless needle shaped in the monoclinic system, space group C 2/c with cell constants: a = 18.6636(6) Å, b = 9.8655(4) Å, c = 19.5249(7) Å, α = γ = 90.0˚, β = 107.900(2)˚, V = 3421.0(2) ų, Z = 8. The molecular conformation is stabilized by an intra-molecular C–H…N hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked into one-dimensional infinite chains along c-axis by N—H···N hydrogen bond and C—H… π interactions involving the benzene ring attached to the triazole ring as an acceptor. These chains are alternately connected along a-axis by centro-symmetrically π­—π interactions [ring centroid (triazole) ring centroid (pyrimidine) distance = 3.721 (1) Å and ring centroid (pyrimidine)…ring centroid (benzene ring attached to pyrimidine ring) distance = 3.825 (1) Å] forming a two-dimensional supra molecular network. The molecular geometry was also optimized using density functional theory using (DFT/B3LYP) method with the 6-311G(d,p) basis set and compared with the experimental data. Mulliken population analyses on atomic charges and HOMO-LUMO energy levels of the title compound have been calculated. The charge energy distribution and site of chemical reactivity of molecules were obtained by mapping electron density iso-surface with electrostatic potential surfaces. The thermo dynamical properties of the title compound at different temperature have been calculated and corresponding relations between the properties and temperature have also been obtained.