2-Phenylimidazolium chloride monohydrate

In the title hydrated molecular salt, C9H9N2 +·Cl−·H2O, the dihedral angle between the five- and six-membered rings in the cation is 18.00 (2)°. O—H⋯Cl, N—H⋯O and N—H⋯Cl hrdrogen-bonding interactions are present in the crystal structure.


Comment
The 2-phenylimidazolium nitrate structure has been reported as a hemihydrate (Zhang et al., 2007) and as a hydrate (Xia et al., 2009). Here we report the synthesis and structure of the chloride hydrate, namely, C 9 H 11 ClN 2 O.
The asymmetric unit of the title compound contains one 2-phenylimidazolium cation, one chloride anion and one water molecule ( Fig. 1). There are O-H···Cl, N-H···O and N-H···Cl H-bonding interactions in the structure (Table I).

Refinement
All H atoms on C and N atoms were positioned geometrically (N-H = 0.86 Å and C-H = 0.93 Å) and refined as riding, with U iso (H)=1.2U eq (carrier). The water H-atom was located in a difference Fourier map, and was refined freely. Fig. 1. The structure of the title compound showing the atomic numbering scheme and displacement ellipsoids at the 30% probability level.

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.