Synthesis, crystal structure and characterization of [C9H11N4] H2PO4

Chemical preparation crystal structure and spectroscopic investigations are given for a new organic-cation dihydrogenomonophosphate (C9H11N4) H2PO4 in the solid state. This compound crystallizes in the monoclinic space group P 21 with the following unit cell parameters: a = 9.640 (5) Ǻ. b = 4.582 (5) Ǻ. c = 14.094 (5) Ǻ, β = 106.979 (5)°, Z = 2, V = 595.4 (7) Å3. Crystal structure was solved with a final R = 0.054 for 2077 independent reflections. The atomic arrangement can be described as inorganic layers of H2PO4- anions between which are located the organic groups. Solid-state 13C and 31P MAS-NMR spectroscopies are in agreement with the X-ray structure. Ab initio calculations allow the attribution of the phosphorous and carbon signals to the independent crystallographic sites and to the various atoms of the organic groups.