SYNTHESIS AND CHARACTERIZATION OF A LARGE-PORE, OPEN-FRAMEWORK GALLIUM PHOSPHATE, [NH3(CH2)4NH3]2[Ga4(HPO4)2(PO4)3(OH)3].yH2O (y approx equal to 5.4), AND ITS VANADIUM-GALLIUM PHOSPHATE ANALOGUE, [NH3(CH2)4NH3]2[Ga4-xVx(HPO4)2(PO4)3(OH)3].yH2O (x app

摘要

A new 3-D gallium phosphate, [NH3(CH2)4 NH3]2[Ga4(HPO4)2(PO4)3(OH)3].yH2O (y approx equal to 5.4), has been synthesized under hydrothermal conditions at 433 K in the presence of 1,4-diaminobutane and its structure determined using RT single-crystal XRD data (Mr=1084.03, tetragonal, space group I41/a, a=15.261(1), c=28.898(2) angstroms; V=6730.4 angstroms3, Z=8, R=4.09% and Rw=4.45% for 3093 observed data (I>3(sigma(I))). The structure consists of chains of GaO6 octahedra and PO4 tetrahedra cross-linked by additional PO4 tetrahedra to generate a 3-D framework containing large tunnels in which 1,4-diaminobutane dications and water molecules reside. The tunnels are bounded by 20-ring windows of alternating Ga- and P-based polyhedra. The framework is closely related to that of a 1,3-diaminopropane encapsulating iron (III) phosphate, [NH3(CH2)3 NH3]2[Fe4(HPO4)2(PO4)3(OH)3].yH2O (y approx equal to 9), Further syntheses in the presence of V2O5 show that up to 12% of the Ga(III) can be replaced by V(III) with retention of the large-pore framework structure. 36 refs.