Synthesis and Characterization of a large-pore, open-framework gallium phosphate, [NH3(CH2)4NH3]2[Ga4(HPO4)2(PO4)3(OH)3] • yH2O (y ∼ 5.4), and its vanadium-gallium phosphate analogue, [NH3(CH2)4NH3]2[Ga4-xVx(HPO4)2(PO4)3(OH)3] • yH2O (x ∼ 0.4, y ∼ 6)

A new three-dimensional gallium phosphate, [NH3(CH2)(4) NH3](2)[Ga-4(HPO4)(2)(PO4)(3)(OH)(3)] . gamma H2O (gamma similar to 5.4), has been synthesized under hydrothermal conditions at 433 K in the presence of 1,4-diaminobutane and its structure determined using room-temperature single-crystal X-ray diffraction data (M-r = 1084.03, tetragonal, space group 14(1)/a, a = 15.261(1), c = 28.898(2) Angstrom; V= 6730.4 Angstrom(3), Z = 8, R = 4.09% and R-w = 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 three-dimensional framework containing large tunnels in which 1,4-diaminobutane dications and water molecules reside. The tunnels are bounded by 20-ring windows of alternating gallium- and phosphorus-based polyhedra. The framework is closely related to that of a 1,3-diaminopropane encapsulating iron (III) phosphate, [NH3(CH2)(3) NH3](2)[Fe-4(HPO4)(2)(PO4)(3)(OH)(3)] . gamma H2O (gamma similar 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. (C) 1999 Academic Press.