2-Amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium chloride

In the crystal structure of the title compound, C4H8N3O+·Cl−, N—H⋯Cl hydrogen bonds link the components into chains along [010]. In addition, weak C—H⋯Cl hydrogen bonds link the chains into a two-dimensional network perpendicular to (001).

In the crystal structure of the title compound, C 4 H 8 N 3 O + ÁCl À , N-HÁ Á ÁCl hydrogen bonds link the components into chains along [010]. In addition, weak C-HÁ Á ÁCl hydrogen bonds link the chains into a two-dimensional network perpendicular to (001).
The molecular structure of (I) is shown in Fig. 1. During the reaction a proton was transferred to the ring N atom of the  (Tabatabaee et al., 2007).
In the crystal, intermolecular N-H···Cl hydrogen bonds link the components into one-dimensional chains along [010].
In addition, weak intermolecular C-H···Cl hydrogen bonds link one-dimensional-chains into a two-dimensional network perpendicular to (001) (Fig. 2). When compared with the crystal structure of 1,2,4-triazolium chloride (Bujak & Zaleski 2002), the N-H···Cl interactions are weaker in the present structure while C-H···Cl interactions are similar. For the weak intermolecular hydrogen bonds the C-H···Cl angles are in the range of those previously reported (Freytag & Jones, 2000;Taylor & Kennard, 1982).
The resulting solid residue was filtered and the colorless crystals of the title compound were obtained after few days at 277K from mother liquor.

Refinement
H atoms bonded to C atoms were included in calculated positions with C-H = 0.96 and 0.97Å and with U iso (H) = 1.5U eq (C). H atoms bonded to N atom were included with N-H 0.86 amd 0.89Å and with U iso (H) = 1.5U eq (N). DIAMOND (Brandenburg, 1999); software used to prepare material for publication: publCIF (Westrip, 2010).

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. The H atoms were all located in a difference map, but those attached to carbon atoms and the nitrogen atom in amino group were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C-H in the range 0.93-0.98, N-H in the range 0.86-0.89 N-H to 0.86 O-H = 0.82 Å) and U iso (H) (in the range 1.2 times U eq of the parent atom). The distance between hydrogen atom H3 and N2 was left unrestrained.