Crystal structure and Hirshfeld surface analysis of 5-methyl-1,2,4-triazolo[1,5-a]pyrimidine

Abstract

The nine-membered ring system of the title compound, C6H6N4, is essentially planar. In the crystal, molecules are linked via C—HTrz...NTrz and C—HPyrm...NTrz (Trz = triazole and Pyrm = pyrimidine) hydrogen bonds together with weaker C—HPyrm...NPyrm hydrogen bonds to form layers parallel to (\overline{1}02). The layers are further connected by π–π-stacking interactions between the nine-membered ring system [centroid–centroid = 3.7910 (8) Å], forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...N/N...H (40.1%), H...H (35.3%), H...C/C...H (9.5%), N...C/C...N (9.0%), N...N (3.1%) and C...C (3.0%) interactions and that hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. No significant C—H...π interactions are observed.

Keywords

• crystal structure
• triazole
• pyrimidine
• hydrogen bond
• π...π-stacking
• Hirshfeld surface analysis