SYNTHESIS AND CHARACTERIZATION OF )(2)[FE-6(HPO4)(2)(PO4)(6)(H2O)(2)]CENTER-DOT-H2O, A NEW IRON PHOSPHATE TEMPLATED BY PIPERAZINE

An organically templated iron phosphate, (C4H12N2)(2)[Fe-6 (HPO4)(2)(P O4)(6)(H2O)]. H2O, has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, thermogravimetr ic analysis, and Mossbauer spectroscopy. The compound crystallizes in the triclinic space group P (1) over bar (No, 2) with a = 9.1768(1), b = 12.7229(1), c = 16.4830(2) Angstrom, alpha = 68.530(1), beta = 83.2 85(1), gamma = 73.259(1)degrees, V = 1714.90(3) Angstrom(3), and Z = 2 , The structure consists of layers of FeO6 octahedra and phosphate tet rahedra, which are pillared through FeO5 trigonal bipyramids and phosp hate tetrahedra to form a three-dimensional framework structure, The f ramework contains infinite channels in which the charge compensating d iprotonated piperazinium cations reside. (C) 1998 Academic Press.