Porosity Properties of the Conformers of Sodalite-like Zeolitic Imidazolate Frameworks.

The conformational isomers of zeolitic imidazolate frameworks (ZIFs) can have their own unique porosity and structural stability. We report that a new sodalite-like ZIF (termed ß-ZIF-65(Zn)) is polymorphous with as the existing ZIF-65(Zn) (Zn(nIm)2, nIm = 2-nitroimidazolate) but has a different linker conformation in the six-membered rings of sodalite cages. This conformational isomerism leads to distinctive permanent porosity for each conformer, which has been verified by gas adsorption measurements. In addition, variable-temperature X-ray diffraction analyses indicate that ß-ZIF-65(Zn) is more resistant to displacive phase transitions than ZIF-65(Zn). The activated ß-ZIF-65(Zn) conformer adsorbs 2.8 times more benzene than the activated ZIF-65(Zn) at P/ P0 = 0.3 and 298 K. This work suggests that other types of ZIF conformers can be discovered.

Poly[(µ3-5-tert-butyl-benzene-1,3-di-carboxyl-ato)di-pyridine-cobalt(II)].

In the title compound, [Co(C12H12O4)(C5H5N)2] n , the Co(II) cation is coordinated by four O atoms from three 5-tert-butyl-benzene-1,3-di-carboxyl-ate anions and two N atoms from pyridine mol-ecules in a distorted octa-hedral geometry. One carboxyl-ate group of the anionic ligand chelates a Co(II) cation while another carboxyl-ate group bridges two Co(II) cations, resulting in a polymeric layer parallel to (101). Weak C-H⋯O hydrogen bonds occur between adjacent polymeric layers. In the crystal, one of pyridine mol-ecules is equally disordered over two positions.

Metal imidazolate sulphate frameworks as a variation of zeolitic imidazolate frameworks.

Sulphate ions can be incorporated into zinc imidazolate frameworks to give rise to zinc imidazolate sulphate frameworks, that is, a square-grid network, a zeolite-like GIS framework, or a porous pillar-layered structure where interlayer octahedral Zn2+ ions connect honeycomb-like layers.

Formation and Encapsulation of All-Inorganic Lead Halide Perovskites at Room Temperature in Metal-Organic Frameworks.

Improving the stability and tuning the optical properties of semiconducting perovskites are vital for their applications in advanced optoelectronic devices. We present a facile synthetic method for hybrid composites of perovskites and metal-organic frameworks (MOFs). A simple two-step solution-based method without organic surfactants was employed to make all-inorganic lead-halide perovskites (CsPbX3; X = Cl, Br, I, or mixed halide compositions) form directly in the pores of MIL-101 MOF. That is, a polar organic solution of lead halide (PbX2) was impregnated into the MOF pores to give PbX2@MIL-101, which was then subjected to a perovskite-formation reaction with cesium halide (CsX) dissolved in methanol. The compositions of the halogen anions in the perovskites can be modulated with various halide precursors, leading to CsPbX3@MIL-101 composites with X3 = Cl3, Cl2Br, Br2Cl, Br3, Br2I, I2Br, and I3 that exhibit gradual variation of band gap energies and tuned emission wavelengths from 417 to 698 nm.

Thermal decomposition pathways of nitro-functionalized metal-organic frameworks.

The decomposition behavior of high energy metal-organic frameworks (MOFs) with extensive nitration is disclosed. In contrast to the detonation behavior observed in molecular energetic compounds, deflagration transforms cubic MOFs into anisotropic carbon structures with highly dispersed metal. Both the structural metal and intimate mixing are found to be critical.

Connection of zinc paddle-wheels in a -type metal-organic framework with 2-methylimidazolate and subsequent incorporation of charged organic guests.

A microporous metal-organic framework (mIm-MOF-14) has doubly interpenetrated anionic frameworks resulting from 2-methylimidazolate linking Zn(ii) paddle-wheels of charge-neutral -type networks, and allows the inclusion of tetramethylammonium ion to exert an enhanced CO2 affinity.