2,6-Diethylanilinium dihydrogen phosphate–phosphoric acid (1/1)

In the crystal structure of the title salt, C10H16N+·H2PO4 −·H3PO4, the H2PO4 − and H3PO4 components are connected into infinite chains extending along the b-axis direction by way of O—H⋯O links. These chains are also linked through O—H⋯O hydrogen bonds thus building up a supramolecular two-dimensional framework extending parallel to (001). The organic cations cross-link the anionic layers by way of multiple N—H⋯O interactions, leading to a cohesive network.

In the crystal structure of the title salt, C 10 H 16 N + ÁH 2 PO 4 À Á-H 3 PO 4 , the H 2 PO 4 À and H 3 PO 4 components are connected into infinite chains extending along the b-axis direction by way of O-HÁ Á ÁO links. These chains are also linked through O-HÁ Á ÁO hydrogen bonds thus building up a supramolecular two-dimensional framework extending parallel to (001). The organic cations cross-link the anionic layers by way of multiple N-HÁ Á ÁO interactions, leading to a cohesive network.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2632).

Comment
The H 3 PO 4 molecules play an important role for structure cohesion of adduct materials, by connecting the other components of crystal by a network of hydrogen bonds particularly strong (Desiraju, 1995;Blessing, 1986). Such hydrogen bonds are of interest because of their widespread biological occurrence. For example, hydrogen bonds between phosphate groups and histidyl, imidazolyl groups are involved in the active-site substrate-binding mechanism of ribonuclease (Richards et al., 1972) and in the regulation of the oxygen affinity of deoxyhemoglobin by 2,3-diphosphoglycerate (Perutz et al., 1972).
The influence of the hydrogen bond scheme on the building of supramolecular anionic packing for the title compound is discussed with regard to other adduct phosphates.
The asymmetric unit of (I) consists of two phosphoric entities (H 2 PO 4 and H 3 PO 4 ) and one 2,6-diethylanilinium organic cation ( Fig. 1). A view of the structure projected along the b direction ( Fig. 2 It is also useful to compare the geometrical parameters of phosphoric entities in the title compound and in the crystallized et al., 1969;Smith et al., 1955). This comparison does not show significant differences that could be generated by the organic molecule in the provided geometric properties of these species. The 2,6-diethylanilinium cations are pendant on both the faces of the two-dimensional inorganic sheet by establishing intermolecular N-H···O hydrogen bonds thanks to the NH 3 + group. Among the three hydrogen atoms of the ammonium group only one, establishes a hydrogen bond with the H 3 PO 4 molecule. The remaining ones are connected to oxygen atoms of H 2 PO 4 anions.
The geometrical hydrogen bonding scheme are given in Table 1