| Abstract
| - A family of open-framework zinc phosphates has been synthesized in the presence of a tetramine, triethylenetetramine. The solids were characterized using powder and single-crystal X-ray diffraction, thermogravimetric analysis, and elemental analysis using EDAX. The compounds form one-, two-, and three-dimensional architectures encompassing the amine molecules. The figure shows a 16-member channel observed in a zinc phosphate, [C6N4H22]0.5[Zn3(PO4)2(HPO4)], possessing three-dimensional architecture.
- Five new open-framework zinc phosphates, encompassing the entire hierarchy of open-framework structures,have been synthesized hydrothermally in the presence of triethylenetetramine. The structures include one-dimensional ladders, two-dimensional layers, and three-dimensional structures as well as a zinc phosphate wherethe amine acts as a ligand. [C6N4H22]0.5[Zn(HPO4)2] (I): monoclinic, space group P21/c (no. 14), a = 5.2677(1)Å, b = 13.3025(1) Å, c = 14.7833(1) Å, β = 96.049°, Z = 4. [C6N4H22]0.5[Zn2(HPO4)3] (II): triclinic, spacegroup P1̄ (no. 2), a = 7.515(1) Å, b = 8.2553(1) Å, c = 12.911(1) Å, α = 98.654(1)°, β = 101.274(1)°, γ =115.791(1)°, Z = 2. [C6N4H22]0.5[Zn2P2O8] (III): triclinic, space group P1̄ (no. 2), a = 8.064(1) Å, b = 8.457(1)Å, c = 9.023(1) Å, α = 111.9(1)°, β = 108.0(1)°, γ = 103.6(1)°, Z = 2. [C6N4H22]0.5[Zn3(PO4)2(HPO4)] (IV): triclinic, space group P1̄ (no. 2), a = 5.218(1) Å, b = 8.780(1) Å, c = 16.081(1) Å, α = 89.3(1)°, β = 83.5(1)°,γ = 74.3(1)°, Z = 2. [C6N4H20]0.5[Zn4P4O16] (V): monoclinic, space group P21/c (no. 14), a = 9.219(1) Å,b = 15.239(1) Å, c = 10.227(1) Å, β = 105.2(1), Z = 4. The structure of I is composed of ZnO4 and HPO4tetrahedra, which are edge-shared to form four-membered rings, which, in turn, form a one-dimensional chain(ladder). In II, these ladders are fused into a layer. The structures of III and IV comprise networks of ZnO4 andPO4 tetrahedra forming three-dimensional architectures. In V, the amine molecule coordinates to the Zn and actsas a pillar supporting the zinc phosphate layers, which possess infinite Zn−O−Zn linkages. The 16-memberedone-dimensional channel in IV and the ZnO3N pillar, along with infinite Zn−O−Zn linkages in V, are novelfeatures. The structure of the open-framework zinc phosphates is found to depend sensitively on the relativeconcentrations of the amine and phosphoric acid, with high concentrations of the latter favoring structures withlower dimensions.
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