A Novel Open-Framework Zinc Phosphite, Zn3(HPO3)4·Ni(en)2(H2O)2, Templated by a Transition-Metal Complex

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

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.

Amine-controlled assembly of metal-sulfite architecture from 1D chains to 3D framework

Whereas open-framework materials have been made in a variety of chemical compositions, few are known in which 3-connected SO3(2)- anions serve as basic building units. Here, we report four new metal-sulfite polymeric structures, (ZnSO3)Py (1, py = pyridine), (ZnSO3)2(2,2'-bipy)H2O (2, 2,2'-bipy = 2,2'-bipyridine), (ZnSO3)2(TMDPy) (3, TMDPy = 4,4'-trimethylenedipyridine), and (MnSO3)2en (4, en = ethylenediamine) that have been synthesized hydrothermally and structurally characterized. In these compounds, low-dimensional 1D and 2D inorganic subunits are assembled into higher 2D or 3D covalent frameworks by organic ligands. In addition to the structure-directing effect of organic ligands, the flexible coordination chemistry of Zn2+ and SO3(2)- also contributes to the observed structural diversity. In compounds 1-3, Zn2+ sites alternate with trigonal pyramidal SO3(2)- anions to form three types of [ZnSO3]n chains, whereas in compound 4, a 2D-corrugated [MnSO3]n layer is present. Compound 1 features a rail-like chain with pendant pyridine rings. The pi-pi interaction between 2,2'-bipy ligands is found between adjacent chains in compound 2, resulting in 2D sheets that are further stacked through interlayer hydrogen bonds. Compound 3 exhibits a very interesting inorganic [(ZnSO3)2]n chain constructed from two chairlike subunits, and such chains are bridged by TMDPy ligands into a 2D sheet. In compound 4, side-by-side helical chains permeate through 2D-corrugated [MnSO3]n layers, which are pillared by neutral ethylenediamine molecules into a 3D framework that can be topologically represented as a (3,6)-connected net. The results presented here illustrate the rich structural chemistry of metal-sulfites and the potential of sulfite anions as a unique structural building block for the construction of novel open-framework materials, in particular, those containing polymeric inorganic subunits that may have interesting physical properties such as low-dimensional magnetism or electronic properties.