| Abstract
| - The Ge7(O,OH,F)19 cluster is found as a building block of three new germanate structures. The structures are constructed from new linkages of the clusters, which are made possible by the uniform distribution of seven potential linking Ge−O bonds within the cluster and the flexibility of the inter-cluster Ge−O−Ge bonds.
- Three new germanate solids, ASU-19, ASU-20-DAPe, and ASU-20-DACH, have beensynthesized under hydrothermal conditions using respectively 1,4-diaminobutane (DAB),1,5-diaminopentane (DAPe), and 1,4-diaminocyclohexane (DACH) as bases. The structuresof ASU-19 and ASU-20-DACH have been characterized by single-crystal X-ray diffraction: ASU-19, Ge14O29X4·[GeOX2]·[H2DAB]3·3.8H2O (X = F or OH), space group P1̄, a = 11.4191(5),b = 12.0525(6), c = 18.1847(8) Å, α = 90.704(1)°, β = 92.635(1)°, γ = 91.389(1)°, V = 2499.1(2)Å3; ASU-20-DACH: Ge7O14X3·[H2DACH]1.5·2H2O, space group C2/c, a = 15.9525(11), b =17.5476(12), c = 19.0027(13) Å, β = 109.446(1)°, and V = 5015.9(6) Å3. The structure ofASU-20-DAPe, Ge7O14X3·[H2DAPe]1.5·H2O, has been determined from X-ray powder diffraction data: space group C2/c, a = 16.3180(5), b = 16.6125(4), c = 17.8898(6) Å, β = 99.684(2)°, V = 4780.5(3) Å3. All three structures are based on the assembly of the same clusterGe7(O,OH,F)19. The two ASU-20 structures consist of a slab of four-connected clusters. InASU-19, the same layers are connected pairwise through a GeO2X2 spacer, generating aslab structure, with slab thickness ca. 20 Å. The existence of the same layer in the presenceof three different organic bases shows the adaptability of the structures to molecules differingin size, shape, and symmetry.
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