Methyl isonicotinate 1-oxide

In the title compound, C7H7NO3, the benzene ring and the methyl ester group are nearly coplanar, forming a dihedral of 3.09 (9)°. The crystal structure is stabilized by intermolecular C—H⋯O hydrogen bonds, forming layers parallel to (101).

In the title compound, C 7 H 7 NO 3 , the benzene ring and the methyl ester group are nearly coplanar, forming a dihedral of 3.09 (9) . The crystal structure is stabilized by intermolecular C-HÁ Á ÁO hydrogen bonds, forming layers parallel to (101).

Comment
Carboxylate derivatives attracted more attention as pharmaceutical and phase transition dielectric materials for their application in micro-electronics and as memory storage devices (Fu et al., 2007;. With the purpose of obtaining phase transition crystals of carboxylate compounds, the interaction of methyl isonicotinate with hydrogen peroxide has been studied and we have elaborated a series of new materials including these organic molecules. In this paper, we describe the crystal structure of the title compound, Methyl isonicotinate 1-oxide. In the title compound ( Fig. 1), the benzene ring and the methyl ester group are nearly coplanar, the dihedral angle they form being 3.09 (9)°). The N1-O3 bond length of the nitrile group (1.292 (2)Å) is within the normal range. The crystal structure is stabilized by intermolecular C-H···O hydrogen bonds (Table 1) linking the molecules to form layers parallel to the (101) plane.

Experimental
Methyl isonicotinate 1-oxide (3 mmol, 0.46 g) was dissolved in methanol. The solvent was slowly evaporated in air affording colourless block-shaped crystals of the title compound suitable for X-ray analysis. Permittivity measurements show that there is no phase transition within the temperature range (from 100 K to 400 K), and the permittivity is 6.5 at 1 MHz at room temperature.

Refinement
All H atoms attached to C atoms were positioned geometrically and treated as riding, with C-H = 0.93 Å (aromatic), 0.96 Å (methyl) and U iso (H) = 1.2U eq (C) and 1.5U eq (C) for methyl H atoms. A rotating-group model was used for the methyl. Fig. 1

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.