Synthesis and characterization of a new p-phenylenediammonium dihydrogenmonophosphate [p-NH3C6H4NH3][H2PO4

Abstract

Chemical preparation, crystal structure and NMR spectroscopy of a new organic cation p-phenylenediammonium monophosphate [p-NH3C6H4NH3][H2PO4]2 are presented. This new compound crystallizes in the orthorhombic system, with the space group Pnma and the following parameters: a=7.970 (2)Å; b=22.770 (7)Å; c=7.000 (7)Å, V=1270.3 (11)Å3, Z=4 and Dx=1.590gcm−3. The crystal structure has been determined and refined to R=0.043 and R(w)=0.057 using 2623 independent reflections. The structural arrangement can be described as inorganic layers of (H8P4O16)4− units, parallel to (a, c) planes. The organic groups (p-H3NC6H4NH3)2+are anchored between the phosphoric layers to form a three-dimensional infinite network. This compound is also investigated by IR and solid-state 1H, 13C and 31P MAS NMR spectroscopies. The ab initio method is used in the calculation of chemical shifts.