Synthesis and Crystal Structure of a New Adduct 4-Benzyl Piperidinium Dihydrogenphosphate Phosphoric Acid [C₁₂H₁₆NH₂]₂ (H₂PO₄)₂ H₃PO₄

A new adduct 4-benzyl piperidinium dihydrogenphosphate monophosphoric acid [C ₁₂ H ₁₆ NH ₂ ] ₂ (H ₂ PO ₄ ) ₂ H ₃ PO ₄ , has been prepared and analyzed by X-ray diffraction. This adduct compound cristallizes in the monoclinic system, with the acentric space group P2 ₁ and the following unit-cell parameters: a = 13.103(3), b = 8.737(4), c = 13.620(3) Å, β = 92.38(2)°, Z = 2, and V = 1557.8(7) Å[3]. The crystal structure has been solved and refined to R = 0.059 and R_(w) = 0.069 using 3306 independent reflections. Its structure can be described as inorganic layers of H ₃ PO ₄ and H ₂ PO ₄ ⁻ entities separated by organic molecules. In this atomic arrangement, H-bonds between the different species play an important role in the tridimensionnel network cohesion. Solid-state¹³C and ³¹ P MAS NMR spectroscopies are in agreement with the X-ray structure. Ab initio calculations allow the attribution of phosphorus and carbon signals to the independent crystallographic sites and to the various atoms of the organic groups.

Keywords:

• Hydrogen bonds
• IR spectroscopy
• layered compounds
• NMR spectroscopy
• X-ray diffraction