JOURNAL of the Tunisian Chemical Society

A new organic phosphate C₆H₁₆N₂HPO₄.2H₂O (2,6DMPHP) is prepared by interaction of H₃PO₄ with the organic molecule 2,6-dimethylpiperazin. This compound crystallizes in the monoclinic system P2₁/c, Z=8 with the parameters: a=1.3.271(3), b=11.855(4), c=15.748(4)Å, β=105.22(3)°, ρ_c=1.379, ρ_m=1.367g/cm³, µ=0.243mm^-1. The structural matrix is made up of a three dimensional network of O(W)—H...O, O(P)—H...O and N—H...O hydrogen bonds. The thermal decomposition of 2,6DMPHP shows two large endothermic effects at 127 and 152°C, corresponding to the elimination of water molecules and a set of endotherms, from 170 to 300°C, probably due to the evolution of ammonia from the structure. The overall DDH of the dehydration, deduced from the DSC thermogram, is 82.61 kJ/mol. The IR study, based on theoretical analyses and on in the literature data, allows interpretation of the IR spectrum.

L. Baouab, A. Jouini

Pages 1053-1062