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Metal-organic frameworks (MOFs) are a class of nanoporous materials. The development of efficient and environmentally friendly methods for activating MOFs is of great significance for its industrial application. In this work, nanoscale magnetic core-shell Cu-BTC@Fe 3 O 4 was prepared through a secondary growth strategy. The effects of different activation solvents (dichloromethane and ethanol, respectively) and temperatures on the surface area, pore structures and the adsorption of xylene isomers on Cu-BTC@Fe 3 O 4 were investigated. Ethanol as an activation solvent could more easily displace the precursors remaining in the channels of Cu-BTC@Fe 3 O 4 than dichloromethane, while the temperature change has no significant influence on the pore structure. The adsorption separation of xylene isomers on Cu-BTC@Fe 3 O 4 composite materials was studied using the batch vapor-phase adsorption, and liquid-phase breakthrough experiments. The activated Cu-BTC@Fe 3 O 4 (CH 2 Cl 2 -200 ​°C ​− ​C 2 H 5 OH) material has the highest adsorption capacity of 210.26 ​mg ​g−1 for p -xylene (p X). Cu-BTC@Fe 3 O 4 (C 2 H 5 OH) and Cu-BTC@Fe 3 O 4 materials have excellent adsorption capacity for m -xylene (m X), with the values of 200.19 ​mg ​g−1 and 219.63 ​mg ​g−1, respectively, which is about 4 times higher than that of Cu-BTC@Fe 3 O 4 (CH 2 Cl 2). The adsorption capacity sequence of xylene on Cu-BTC@Fe 3 O 4 (C 2 H 5 OH) and Cu-BTC@Fe 3 O 4 materials is m -xylene (m X) ​> ​ p -xylene (p X) ​> ​ o -xylene (o X), and that of other materials is p X ​> ​ m X ​> ​ o X. Nanoscale magnetic core-shell Cu-BTC@Fe 3 O 4 was prepared through a secondary growth strategy towards the adsorption separation of xylene isomers. [Display omitted] • Nanoscale magnetic core-shell Cu-BTC@Fe 3 O 4 was prepared through a secondary growth strategy. • The effects of different activation solvents and temperatures on the xylene isomers adsorption of Cu-BTC@Fe 3 O 4 were studied. • Using ethanol as an activation solvent could more easily displace the precursors remaining in the channels of Cu-BTC@Fe 3 O 4. [ABSTRACT FROM AUTHOR]

Two isomorphic metal-organic frameworks, [Co 2 (4-Ptz) 2 (BDC)(DMA)] n ( 1 ) and [Co 2 (4-Ptz) 2 (2-NH 2 -BDC)(DMA)] n ( 2 ) (4-Ptz=5-(4-Pyridyl)tetrazole, H 2 BDC=Terephthalic Acid, 2-NH 2 -H 2 BDC=2-Aminoterephthalic Acid, DMA=N,N-dimethylacetamide), have been successfully constructed through solvothermal reactions. Crystallographic data analysis reveals a binuclear Co(II) cluster-based structure for 1 and 2 , which were constructed by bridging two neighboring Co(II) ions with teterazole rings of 4-Ptz ligand together with one DMA oxygen atom. Simplifying Co 2 cluster as a 6-connecting node, complexes 1 and 2 reveal bcu-6 net. The CO 2 adsorption isotherms measurement at 273 K manifests higher adsorption quantities for 2 (33.8 cm 3 /g) than 1 (26.2 cm 3 /g), which was attributed to the introduction of NH 2 -group in 2 . [ABSTRACT FROM AUTHOR]

In the current research, the moisture-resistant of Mg-MOF-74 was successfully improved by coating with two-dimensional (2-D) hexagonal boron nitride (h -BN) during the facile hydrothermal synthesis process. Both TEM and SEM results revealed that 2-D h -BN is coated on Mg-MOF-74's surface. The crystal structure, morphology, surface area, thermal stability and CH 4 uptake capacity of Mg-MOF-74 were not drastically influenced by coating with h -BN as examined by XRD, FTIR, SEM, and TEM. Further, the coated Mg-MOF-74 demonstrated better stability than uncoated Mg-MOF-74, when being exposed to high humidity, in terms of surface area and CH 4 uptake capacity. It was observed that the coated Mg-MOF-74 with 1 ​wt % h -BN has reached to 1959 ​m2 ​g−1 surface area and CH 4 uptake capacity of 43 ​cm3 ​g−1 after exposure to high humidity for a duration of 1 month. Thus, this research work has opened a new window towards the improvement of the water stability of Mg-MOF-74. [Display omitted] • The water resistance capacity of Mg-MOF-74 could be improved by coating with two dimensional materials h -BN. • Application of h -BN as coating material of Mg-MOF-74. • h -BN coated Mg-MOF-74 provide high surface area and enhanced CH 4 uptake capacity. • The sample Mg-MOF-74@1 wt.% h -BN exhibited the highest water stability. [ABSTRACT FROM AUTHOR]

In this work two new coordination polymers (CPs) with formulas [Zn 2 (Cl)(BTC)(bmb) 2 ] (1) and [Cd 2 (H 2 O) 2 (BTC) 2 ·H 2 bmb·6H 2 O] (2) (bmb=1,4-bis(2-methylimidazol-1-yl)butane and H 3 BTC ​= ​1,3,5-benzenetricarboxylic acid), have been prepared and characterized by various spectroscopic data. The single crystal X-ray data suggests that 1 comprises a 2D layered network and 2 has a 3D porous framework with pcu -type topology. The photocatalytic properties revealed that 2 could successfully degrade organic dyes such as Rhodamine B (Rh B), methylene orange (MO), and methylene blue (MB). Further, the trapping experiment established the active species in the photodegradation process. [Display omitted] • Two new MOFs were synthesized using mixed strategy. • The two MOFs were modulated by synthesized temperature. • Photocatalytic capability was demonstrated for the MOFs. • The photodegradation process was estimated by trapping experiment. [ABSTRACT FROM AUTHOR]

Abstract: A series of lanthanide-organic complexes based on polyoxometalates (POMs) [Ln2(DNBA)4(DMF)8][W6O19] (Ln=La(1), Ce(2), Sm(3), Eu(4), Gd(5); DNBA=3,5-dinitrobenzoate; DMF=N,N-dimethylformamide) has been synthesized. These complexes consist of [W6O19]2− and dimeric [Ln2(DNBA)4(DMF)8]2+ cations. The luminescence properties of 4 are measured in solid state and different solutions, respectively. Notably, the emission intensity increases gradually with the increase of solvent permittivity, and this solvent effect can be directly observed by electrospray mass spectrometry (ESI-MS). The analyses of ESI-MS show that the eight coordinated solvent DMF units of dimeric cation are active. They can move away from dimeric cations and exchange with solvent molecules. Although the POM anions escape from 3D supramolecular network, the dimeric state structure of [Ln2(DNBA)4]2+ remains unchanged in solution. The conservation of red luminescence is attributed to the maintenance of the aggregated state structures of dimeric cations. [Copyright &y& Elsevier]

Abstract: The functionalization of porous metal–organic frameworks (Cu3(BTC)2) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N2 and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols (C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius–Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs. [Copyright &y& Elsevier]

Abstract: Reactions of different metal salts with 3-pyridin-4-yl-benzoic acid (3,4-Hpybz) under ambient condition afford a series of 3-D metal-organic frameworks with two new types of (3,6)-connected net topologies. In the isomorphic complexes [M 2(μ-H2O)(3,4-pybz)4] n (M II=MnII for 1, ZnII for 2, or CdII for 3), the octahedral metal nodes are extended by the 3-connected pybz tectons to constitute 3-D arrays with the Schläfli symbol of (3.4.5)(32.44.55.62.72), whereas [Pb(3,4-pybz)2] n (4) shows a completely different 3-D (42.6)2(44.62.89) framework, which represents a subnet of the (4,8)-connected fluorite lattice. [Copyright &y& Elsevier]

Three layered compounds CsLiCoS 2 , CsAgCoS 2 and CsLiFeS 2 have been synthesized by conventional solid-state reaction method. All of three compounds exhibit semiconducting behavior in electrical transport with small thermal activation energy gap. The crystal structure of CsLiCoS 2 is isostructural to ThCr 2 Si 2 -type CsCo 2 S 2 with random mixture of Li+ and Co2+. The latter two compounds exhibit √2 ​× ​√2 ​× ​1 superstructure of ThCr 2 Si 2 -type because the monovalent Ag+/Li+ and divalent Co2+/Fe2+ independently occupy inequivalent sites in [AMS 2 ]- layer. Through comprehensive investigation of the crystallographic lattice in CsAMS 2 , a phase boundary between disorder and ordered phases may be identified, which highlights the importance of the atomic size and lattice mismatch in determining the crystal structure. Image 1 • Three layered sulfides CsAMS 2 (A ​= ​Li, Ag; M ​= ​Co, Fe) are synthesized by solid state reaction method. • Introducing monovalent Li+/Ag+ could significantly change the structure and property of Co-based sulfides. • A phase boundary between random and ordered occupation in the [AMS 2 ]- layers is determined by the atomic size difference. [ABSTRACT FROM AUTHOR]