N-(Naphthalen-1-ylmethylidene)-4H-1,2,4-triazol-4-amine

In the title molecule, C13H10N4, the dihedral angle between the triazole ring and the naphthalene ring system is is 56.1 (2)°. In the crystal, molecules are connected by weak C—H⋯N hydrogen bonds into chains along [100]. A short intramolecular C—H⋯N contact is also observed.

In the title molecule, C 13 H 10 N 4 , the dihedral angle between the triazole ring and the naphthalene ring system is is 56.1 (2) . In the crystal, molecules are connected by weak C-HÁ Á ÁN hydrogen bonds into chains along [100]. A short intramolecular C-HÁ Á ÁN contact is also observed.
The molecular structure of the title compound is shown in Fig. 1. The dihedral angle between the triazole and naphthalene ring system is is 56.1 (2)°. The C-N and C═N bond lengths agree with standard values (Allen et al., (1987) and show the obvious effects of electron delocalization. In the crystal, molecules are connected by weak C-H···N hydrogen bonds into chains along [100] (Fig. 2).

Experimental
A mixture of 1-naphthaldehyde (10 mmol) and 4-amino-4H-1,2,4-triazole (10 mmol) in ethanol (20 mL) was refluxed on a steam-bath for 30 min. The colour of the solution changed to reddish-orange and was kept under ice-cold conditions to obtain a white solid product. Single crystals were formed in the mother liquor after ten days.

Refinement
H atoms were positioned geometrically (C-H = 0.93 Å) and allowed to ride on their parent atoms, with U iso (H) = 1.2 U eq (C).

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. 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 R-factors(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.