Structural and Thermal Studies of a New Organic Monophosphate NH3(CH2)6NH3 HPO4.2H2OM. Belhouchet, M. Gargouri, T. Mhiri*, A. Daoud
Laboratoire de lĺEtat Solide, FacultÚ des sciences de Sfax, UniversitÚ de Sfax, 3018 Sfax, Tunisia
* Corresponding Author. E-mail: Belhouchet2002@yahoo.fr
Dedicated to Dr: H. Mhiri
Received : 04 October 2001; revised version accepted 29 January 2002
A new tridimensional organic monophosphate, NH3(CH2)6NH3 HPO4.2H2O was synthesized by slow evaporation at room temperature of the system NH2(CH2)6NH2 - H3PO4 - H2O. It crystallizes in the triclinic space group P with lattice parameters a = 10.187(2)┼, b = 11.084(3)┼, c = 12.627(2)┼, a = 110.70(2)░, b = 108.31(2)░, g = 96.14(2)░, V = 1227.4(5)┼3, Z = 4, R1 = 0.0372 and wR2 = 0.0866 for 701 observed reflexions. The crystal structure is characterized by the existence of [H2P2O8]4- clusters, resulting from the association of two [HPO4 ]2- tetrahedra related by one O-H...O hydrogen bond, linked with two water molecules forming an infinite zigzag centrosymetric chains, related themselves with two water molecules, building three dimensional anionic layers parallel to the (010) plane. Organic dications, encapsulated between two anionic layers, are linked to [HPO4 ]2- groups using N-H...O hydrogen bonds.
Keywords : Crystal structure; Organic phosphate; TG-DTA.