(C4N3H15)[(BO2)2(GeO2)4]: the first organically templated 3D borogermanate showing 1D 12-rings, large channels, and a novel zeolite-type framework topology constructed from Ge8O24 and B2O7 cluster units

The first organically templated 3D borogermanate with a novel zeolite-type topology, (C4N3H15)(BO2)2(GeO2)4] FJ-17, has been solvothermally synthesized and characterized by IR spectroscopy, powder X-ray diffraction (PXRD), TGA, and single-crystal X-ray diffraction. The compound crystallized in the monoclinic space group P2(1)/c with a = 6.967(1) A, b = 10.500(1) A, c = 20.501(1) A, beta = 90.500(3) degrees , V = 1499.68(8) A3, and Z = 4. The framework topology of this compound is the previously unknown topology with the vertex symbols 3.4.3.9.3.8(2) (vertex 1), 3.8.3.4.6(2).9(2) (vertex 2), 3.8(2).4.6(2).6(2).8 (vertex 3), 4.8.4.8.8(3).12 (vertex 4), 4.8.4.8.8(2).12 (vertex 5), and 3.8.4.6(2).6.8(2) (vertex 6). The structure is constructed from Ge8O24 and B2O7 clusters. The Ge8O24 cluster contains eight GeO4 tetrahedra that share vertices; the B2O7 unit is composed of two BO4 tetrahedra sharing a vertex. The cyclic Ge8O24 clusters connect to each other through vertices to form a 2D layer with 8,12-nets. The adjacent layers are further linked by the dimeric B2O7 cluster units, resulting in a 3D framework with 12- and 8-ring channels along the a and b axes, respectively. In addition, there is a unique B2GeO9 3-ring in the structure.