2-Ureido-1,3-thiazol-3-ium dihydrogen phosphate

The title compound, C4H6N3OS+·H2PO4 −, (I), was obtained as a result of hydrolysis of [(1,3-thiazol-2-ylamino)carbonyl]phosphoramidic acid, (II), in water. X-ray analysis has shown that the N—P bond in (II) breaks, leading to the formation of the substituted carbamide (I). This compound exists as an internal salt. The unit cell consists of a urea cation and an anion of H2PO4 −. Protonation of the N atom of the heterocyclic ring was confirmed by the location of the H atom in a difference Fourier map. The molecules of substituted urea are connected by O⋯O hydrogen bonds into unlimited planes. In turn, those planes are connected to each other via N—H⋯O hydrogen bonds with molecules of phosphoric acid, forming a three-dimensional polymer.

The title compound, C 4 H 6 N 3 OS + ÁH 2 PO 4 À , (I), was obtained as a result of hydrolysis of [(1,3-thiazol-2-ylamino)carbonyl]phosphoramidic acid, (II), in water. X-ray analysis has shown that the N-P bond in (II) breaks, leading to the formation of the substituted carbamide (I). This compound exists as an internal salt. The unit cell consists of a urea cation and an anion of H 2 PO 4 À . Protonation of the N atom of the heterocyclic ring was confirmed by the location of the H atom in a difference Fourier map. The molecules of substituted urea are connected by OÁ Á ÁO hydrogen bonds into unlimited planes. In turn, those planes are connected to each other via N-HÁ Á ÁO hydrogen bonds with molecules of phosphoric acid, forming a three-dimensional polymer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2693).   Fig.2). The interaction of nonbonded S and O atoms can be described as attractive (Angyan, et al., 1987). In the molecule the S O nonbonded distances are significantly shorter (2.653 Å) than the sum of the corresponding van der Waals radii (3.25 Å).

Refinement
H2,H3A and H4A atoms were included in the refinement in the riding motion approximation but with refined isotropic thermal parameter. Other hydrogen atoms were refine isotropically. Fig. 1. View of N-1,3-

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.