The first large-pore, mixed-valent titanium phosphate was hydrothermally synthesized by using elemental titanium as a starting material, and 1,3-diaminopropane as a template. The structure displays an open framework containing octahedrally coordinated Ti and Ti centers and tetrahedrally coordinated P centers; the diamine molecules are located within the zigzag channels (the picture shows a polyhedral representation of the structure).

The mixed-valence compound Ti III Ti IV (HPO 4 ) 4 ‚C 2 N 2 H 9 ‚H 2 O (1) is synthesized hydrothermally from titanium powder, phosphoric and boric acids, and ethylenediamine. The compound is structurally stable up to 650 °C. It loses the template and the water molecule above 250 °C, all titanium becomes Ti IV at 600 °C, and the result is the new compound Ti IV Ti IV (HPO 4 ) 4 (2). The structures of the two compounds were determined ab initio from powder diffraction data. Crystal data: Ti III Ti IV (HPO 4 ) 4 ‚C 2 N 2 H 9 ‚H 2 O, I4 1 , a ) 6.371(2), c ) 16.571(1) Å, V ) 672.5(1) Å 3 , Z ) 2; Ti IV Ti IV (HPO 4 ) 4, I4 1 /a, a ) 6.335(2), c ) 16.389(1) Å, V ) 657.7(1) Å 3 , Z ) 2. Both structures are of the open type, and the frameworks are nearly identical. Compound 2, τ-Ti(HPO 4 ) 2 , is the first three-dimensional titanium hydrogen phosphate. Results of magnetization, TGA, BET, X-ray thermodiffractometry, and density measurements are also presented.

Four new ethylenediamine-templated iron arsenates and fluoroarsenates have been hydrothermally synthesized from iron metal, hydrofluoric and arsenic acids, and ethylenediamine. Fe(H2AsO4)(HAsO4)2.enH2.H2O (1) is one-dimensional and contains chains, FeIIIFeIIF2(HAsO4)(AsO4).enH2.2H2O (2) is a layered fluoroarsenate, and Fe3(HAsO4)6.enH2.NH3.NH4 (3) and Fe2F2(AsO4)2(H2O).enH2 (4) are an arsenate and a fluoroarsenate, respectively, with three-dimensional open-framework type structures. Compounds 1, 3, and 4 contain Fe(III) only, while 2 is a mixed-valence compound of Fe(III) and Fe(II). The structures were determined from single-crystal X-ray diffraction. Crystal data: (1) P2(1), a = 4.762(1) A, b = 16.086(3) A, c = 8.698(2) A, beta = 90.65(3) degrees, Z = 2; (2) P-1, a = 5.289(1) A, b = 7.573 (1) A, c = 8.888(2) A, alpha = 67.32(3) degrees, beta = 82.77(3) degrees, gamma = 69.76(3) degrees, Z = 1; (3) C2/c, a = 18.384(3) A, b = 8.785(1) A, c = 16.052(2) A, beta = 111.11(1) degrees, Z = 4; (4) Pbca, a = 10.490(2) A, b = 10.090(2) A, c = 20.540(4) A, Z = 8. Strong hydrogen bonding exists between the chains and the layers in 1 and 2, and between the diprotonated ethylenediamine and the inorganic part of the structures of 1, 2, and 4. The ethylenediamine in 3 is not hydrogen bonded, and as a result it is disordered. The compounds are characterized also by thermogravimetric analysis, infrared spectroscopy, elemental analysis, and magnetic measurements.