Bis(adamantan-1-aminium) hydrogen phosphate fumaric acid sesquisolvate

The asymmetric unit of the title compound, 2C₁₀H₁₈N⁺·HPO₄²⁻·1.5C₄H₄O₄, contains two adamantan-1-aminium cations, one hydrogen phosphate anion, and one and a half mol­ecules of fumaric acid, one of which exhibits crystallographic inversion symmetry. Each HPO₄²⁻ anion is hydrogen bonded, via all of its O atoms, to four NH₃⁺ groups of the adamantan-1-aminium cations, forming chains along [100]. These chains are, in turn, inter­connected via a set of O—H...O hydrogen bonds involving the fumaric acid solvent mol­ecules, forming layers parallel to (001). Weak C—H...O inter­actions lead to a consolidation of the three-dimensional set-up.

Tris(5-amino-1H-1,2,4-triazol-4-ium) dihydrogenphosphate hydrogen­phosphate trihydrate

In the crystal structure of the title molecular salt, 3C₂H₅N₄⁺·HPO₄²⁻·H₂PO₄⁻·3H₂O, the phosphate-based framework is built upon layers parallel to (010) made up from the H₂PO₄⁻ and HPO₄²⁻ anions and water mol­ecules, which are inter­connected through O—H...O hydrogen bonds. The organic cations are located between the phosphate–water layers and are connected to them via N—H...O hydrogen bonds. The bond-length features are consistent with an imino resonance form for the exocyclic amino group, as is commonly found for a C—N single bond involving sp²-hybridized C and N atoms.