The First Templated Borogermanate (C2N2H10)2[(BO2.5)2(GeO2)3]: Linkage of Tetrahedra of Significantly Different Sizes

Abstract

Incorporation of boron into templated germanate frameworks has been achieved for the first time. Clusters of GeO4 three‐rings are connected by pairs of BO4 tetrahedra into a two‐dimensional framework structure with nine‐ring channels (see picture; GeO4: light gray; BO4: dark gray). The structure topology is very similar to that of (NH4)4[(GeO2)3(GeO1.5F3)2]⋅0.67 H2O, although very different types and sizes of polyhedra are present in the structures.

(C4N2H12)[(GeO2)3(BO1.5F)2], a layered borogermanate containing three- and nine-membered rings

“…One of the elements that has been incorporated is boron, although up to now only two borogermanates, prepared via molecular templating methods, have been reported. The ®rst is (C 2 H 10 N 2 ) 2 [(GeO 2 ) 3 (BO 2.5 ) 2 ], a layered structure containing nine-membered-ring channels templated by ethylenediamine (Dadachov et al, 2000), and the second is KBGe 2 O 6 , a chiral borogermanate with sevenmembered-ring channels (Lin et al, 2003). We report here another layered borogermanate containing nine-and threemembered-ring channels (templated by piperazine), viz.…”

GeB4O9⋅H2en: An Organically Templated Borogermanate with Large 12‐Ring Channels Built by B4O9 Polyanions and GeO4 Units: Host–Guest Symmetry and Charge Matching in Triangular‐Tetrahedral Frameworks

“…Structure relations : Interestingly, the structure of FJ‐18 has no Ge‐O‐Ge linkages; this is a rather unusual structural feature, even for microporous germanates containing framework heteroatoms, in which Ge–O polyhedra usually exist as isolated clusters or chainlike or layered anions, which are further linked by heteroatom polyhedra to form 3D framework structures. Some examples are several structures based on gallium and aluminum germanates10c–g with strictly alternate tetrahedral frameworks, but no borogermanate analogues have been found, which is attributed to the fact that the radius of B, in contrast to that of Al and Ga, is much small than that of Ge, and the cation‐to‐anion radius ratio for both B and Ge is somewhat outside the commonly observed range for tetrahedral oxygen environments 11a. Thus, polymerization of Ge polyhedra or B polyhedra is commonly observed in borogermanate systems.…”

A Borogermanate with Three‐Dimensional Open‐Framework Layers

“…We studied this system because: 1) compared to the silicates, the germanates have smaller Ge-O-Ge angles and b) germanium and boron are more diverse in their coordinations with oxygen and have generated many new borogermanates with porous structures. [8][9][10][11][12][13][14][15][16][17] Initially, we noticed that the structures of K 2 [Ge- [13] reported by Yang et al and the compound used for its synthesis, 4 ] 2À , is fully protonated and isolated, while that in the former is completely deprotonated and condensed with four GeO 4 groups at the formerly protonated oxygen atoms to form a three-dimensional (3D) open framework ( Figure 1). We were interested in eventual intermediates in which deprotonation of one, two, or three hydroxyl groups followed by condensation may lead to chain or layer compounds.…”