N-(2-Pyridylmethanimidamido)pyridine-2-carboximidamide

In the title molecule, C12H12N6, the dihedral angles between the pyridine rings and the central dimethanimine–hydrazine group are 0.30 (3) and 13.94 (3)°. Two intramolecular N—H⋯N hydrogen bonds stabilize the planar conformation of one pyridine ring with respect to its hydrazine-residue neighbour, whereas the other pyridine ring and an N-bonded H atom are rotated out of the plane and link the molecules into intermolecular N—H⋯N chains propagating in [010].

In the title molecule, C 12 H 12 N 6 , the dihedral angles between the pyridine rings and the central dimethanimine-hydrazine group are 0.30 (3) and 13.94 (3) . Two intramolecular N-HÁ Á ÁN hydrogen bonds stabilize the planar conformation of one pyridine ring with respect to its hydrazine-residue neighbour, whereas the other pyridine ring and an N-bonded H atom are rotated out of the plane and link the molecules into intermolecular N-HÁ Á ÁN chains propagating in [010].

Comment
The study of seignette-electrics materials has received much attention. Some materials have predominant dielectric-ferroelectric performance. The study of phase transition and related dielectric-ferroelectric property about PyHX (X=ICl 4 , ClO 4 , IO 4 , ReO 4 etc) (Asaji et al. (2007); Wasicki et al. (1997)) has received much attention. As one part of our continuing studies on finding for dielectric-ferroelectric materials, especially which contain N-H···N hydrogen bonds, we synthesized the title compound C 12 H 12 N 6 (I). It has no phase-transition in dielectric measurement during 93 K to 425 K (m.p 458 K).

Experimental
Picolinonitrile 5.2 g (100 mmol) and hydrazine hydrate 2.94 g (85%, 100 mmol) in flask and water (75 ml) was added, then the reagent react at 50°C for 24 h (Shintou et al.(2005)). The reaction solution was extracted by dichloromethane, and the solvate was removed under reduced pressure and the product was obtained as yellow solid. The crystals suitable for structure determination were grown by slow evaporation in dichloromethane and methanol (1: 1) at room temperature.

Refinement
Positional parameters of all the H atoms were calculated geometrically and were allowed to ride on the C atoms to which they are bonded,with C-H = 0.93Å , N-H = 0.75-0.86 Å; with U iso (H) = 1.2U eq (C), and with U iso (H) = 1.2-1.5U eq (N).

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