N-(1H-1,2,4-Triazol-5-yl)pyridine-2-carboxamide

In the structure of the title compound, C8H7N5O, the pyridine ring and the imidazole ring are nearly coplanar, making a dihedral angle of 2.97 (15)°. An intramolecular N—H⋯O hydrogen bond occurs. In the crystal molecules are connected by intermolecular hydrogen bonds and π–π stacking interactions between neighboring imidazole rings [centroid–centroid distance = 3.5842 (5) Å and off-set angle = 21.77°], leading to the formation of a two-dimensional supramolecular sheet.

In the structure of the title compound, C 8 H 7 N 5 O, the pyridine ring and the imidazole ring are nearly coplanar, making a dihedral angle of 2.97 (15) . An intramolecular N-HÁ Á ÁO hydrogen bond occurs. In the crystal molecules are connected by intermolecular hydrogen bonds andstacking interactions between neighboring imidazole rings [centroidcentroid distance = 3.5842 (5) Å and off-set angle = 21.77 ], leading to the formation of a two-dimensional supramolecular sheet.
N- 2,pyridine-2-carboxamide J. Miao, M. Jia, X. Liu, W. Xiong and Z. Chen Comment 1,2,4-Triazoles derivatives represent an interesting class of heterocycles. They present various potential applications in bioinorganic chemistry (Bohm & Karow, 1981;Bahel, et al., 1984). The preparation of the title compound has been reported previously (Browne & Polya, 1968), but its crystal structure has not yet been reported. Thus we report here the structure ( Fig. 1) of the title compound obtained using an alternative method.
The pyridine ring and the imidazole ring are nearly co-planar with a dihedral angle of 2.97 (15)°. An intramolecular N-H···O hydrogen bond is present in the molecule. Adjacent molecules are connected alternatively by intermolecular N-H···N and N-H···O hydrogen bonds into one dimensional supramolecular chains (Fig. 2). The neighboring imidazole rings from adjacent one dimensional chains are parallel to each other with a perpendicular distance of 3.3285 (1) Å, a centroid-to-centroid distance of 3.5842 (5) Å and an off-set angle of 21.774° (calculated as the angle formed by the line through the two centroids of the two imidazole rings and the normal of the imidazole plane). This indicates the presence of a π-π stacking interaction between the neighboring imidazole rings from adjacent one dimensional chains, which leads to the construction of a two dimensional supramolecular sheet (Fig. 2).

Refinement
H atoms on the N atoms were located in an electron density map and and allowed to ride on the N atoms with U iso (H) = 1.5U eq (N). H atoms on the carbon atoms were placed at calculated positions (C-H = 0.93 Å) and were included in the refinement in the riding model approximation, with U iso (H) = 1.2U eq (C). Fig. 1. The molecular structure of the title compound with the atom-numbering scheme and 30% displacement ellipsoids.

Figures
supplementary materials sup-2 N- (1H-1,2,4 Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.