Germanates of 1D Chains, 2D Layers, and 3D Frameworks Built from Ge–O Clusters by Using Metal‐Complex Templates: Host–Guest Symmetry and Chirality Transfer

Abstract

The self-assembly of Ge-O polyhedra by metal-complex templates leads to initial examples of open germanate structures under mild solvothermal conditions. These materials are constructed from Ge-O cluster building blocks (Ge7X19 (X = O, OH, or F) or Ni@Ge14O24(OH)3) and span the full range of dimensionalities from 1D chains of Ge7O13(OH)2F3 x Cl x 2 [Ni(dien)2] (FJ-6) to 2D layers of Ge7O14F3 x 0.5 [In(dien)2] x 0.5 H3dien x 2 H2O (1) and 3D frameworks of Ni@ Ge14O24(OH)3 x 2 [Ni(L)3] (FJ-1 a/FJ-1 b) (dien = diethylenetriamine, L = ethylenediamine (en) or 1,2-diaminopropane (enMe)). The Ge7X19 cluster in FJ-6 and 1 is formed by condensation of four GeX4 tetrahedra, two GeX5 trigonal bipyramids, and one GeX6 octahedron with a mu3-O atom at the center of the cluster, whereas the Ni@ Ge14O24(OH)3 cluster in FJ-1 a/FJ-1 b is formed by condensation of nine peripheral GeO4 tetrahedra and five interior GeO3Ni units with one mu5-Ni atom at the center of the cluster. FJ-6 is characterized by a pair of racemic Ge7O14(OH)2F3 cluster chains and represents only one example of 1D germanates; 1 exhibits unique germanate layers with uniform 10-membered-ring apertures encapsulating an unknown indium complex, and the framework structure of FJ-1 a/FJ-1 b with large 24-membered-ring channels is the first example of porous materials that contain metal-metal bonds (Ge2+-Ni+). These initial examples of germanates from metal-complex templates provide a useful model system for understanding the mechanisms of host-guest interactions, which may further facilitate the design and development of new porous materials "on demand". It is shown that the symmetry and configuration of the guest metal complex can be imprinted onto the host inorganic framework through hydrogen bonding between host and guest.

Three low-dimensional open-germanates based on the 44 net

“…9 Germanium is able to form multiple coordination polyhedra with oxygen, which tend to assemble into large composite building units of polyhedral clusters. The growing number of structures built from Ge 7 X 19 (Ge 7 ), [10][11][12][13][14][15][16][17][18][19][20][21][22] Ge 9 X 26-27 (Ge 9 ), [23][24][25][26] Ge 10 X 28 (Ge 10 ) 5,[27][28][29][30][31][32][33][34] clusters (where X = O, OH or F) or combinations of these clusters 18,[35][36][37] illustrate the role of composite building units in scale chemistry 38 to construct very open structures. For example, SU-M 28 is built from Ge 10 clusters which lie along the gyroidal surface and form mesoporous 30-ring channels.…”

“…The Ge 7 cluster contains one GeO 6 octahedron, two GeO 5 trigonal bipyramids and four GeO 4 tetrahedra (Fig. 1) and has been utilized to construct numerous 3D, [10][11][12][13] 2D [15][16][17][18][19] and 1D [20][21][22] structures. Each polyhedron has one vertex available that either connect to another neighboring polyhedron or form a terminal OH or F bond.…”

“…22 ASU-16 is built of Ge 7 clusters and has a 3D framework with 24-ring channels that vary in diameter with temperature. 10 ASU-20, 16 Ge 7 O 14 F 3 ?0.5[In(dien) 2 ]?0.5H 3 dien?2H 2 O, 19 SU-22, 17 SU-23 17 and (C 8 H 24 N 4 )[NbOGe 6 O 13 (OH) 2 F] 15 are all built from Ge 7 clusters and have layered structures with the same 4 4 3.6.3.6 kagome ´net. 18 ASU-19 has also a 2D structure but here pairs of layers join to form a slab-like structure.…”

A family of germanates constructed from Ge7 clusters co-templated by metal complexes and organic/inorganic species

“…Our previous studies have shown that a chiral metal complex can transfer its chirality to the inorganic framework through the H bonding of the host framework and guest molecules. 10 The compounds synthesized by using metal complexes as SDAs are usually found in metal phosphates, 11,12 13 ICMM-2, 14 FJ-1, 15 FJ-6, 16 and JLG-4. 18 with 11-ring channels, has been reported.…”

A Germanate Compound Constructed from Dissymmetric Ge7 Chains and Metal Complexes

“…Yu and co‐workers have shown that a chiral metal complex cation can transfer its chirality to the inorganic framework through host‐guest hydrogen bonding interactions 12. To date, several open‐framework germanates have been synthesized by using metal complexes as the SDA's, including FJ‐6,6 JU‐82,3d ICMM‐2,13 |[In(dien) 2 ] 0.5 (H 3 dien) 0.5 (H 2 O) 2 |[Ge 7 O 14 F 3 ],14 FJ‐1,15 SUT‐1, SUT‐2,16 and JU‐63 (also known as CJ63) 17…”