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A novel metal–organic framework, ZJU-196, with extraordinary acid–base resistant stability has been successfully synthesized, exhibiting highly efficient separation of acetylene from C2H2/CO2 mixtures under ambient conditions. [ABSTRACT FROM AUTHOR]

By using different N-donor organic species as additional auxiliary ligands with structure-directing roles, four three-dimensional (3D) calcium-based coordination complexes, [Ca(dbt)(H2O)]n1, [Ca(H-dbt)2(5,5′-dmbpy)2]n2, (4,4′-bpy)0.5[Ca(dbt)(H2O)2]n3, and (H2-dib)[Ca3(dbt)4(H2O)4·2H2O]n4 (H2-dbt = 2,5-dibromoterephthalic acid, 2,2′-bpy = 2,2′-bipyridine, 5,5′-dmbpy = 5,5′-dimethyl-2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine, dib = 1,4-di(1H-imidazol-1-yl)benzene), have been successfully synthesized under similar solvothermal conditions and structurally characterized. The organic amine molecules play different roles in the formation of four different metal–organic skeletons with diverse structural topologies, in which complexes 1–3 are neutral, and 4 comprises a negatively charged framework with diprotonated dib as the counterion. Complex 1 features a 3D (6,6)-connected framework structure composed of edge-sharing 1D Ca–O–Ca inorganic chains and dbt ligands. The 2,2′-bpy molecule plays an important role in the synthesis of 1 as the structure-directing agent (SDA). Complex 2 shows a 3D 2-fold interpenetrated diamondoid framework (dia, 66) formed by single metal nodes via linear H-dbt anions and bidentate chelating 5,5′-dmbpy ligands, while complex 3 exhibits a 3D noninterpenetrated pcu network with {412·63} topology constructed from binuclear [Ca2(CO2)4] secondary building units and two types of dbt ligands, in which 4,4′-bpy molecules are ordered within the 3D neutral calcium-based framework as template and space filling agents. Complex 4 is a unique (4,4,4,4,5)-connected 5-nodal topology net, in which the diprotonated dib molecules provide space filling to balance the negatively charged framework. In addition, the thermal stability and the fluorescence properties of complexes 1–4 have been investigated. [ABSTRACT FROM AUTHOR]

In this study, a highly efficient photocatalyst, NH 2 -MIL-125(Ti)/g-C 3 N 4 /NiPd (NH 2 -MIL-125(Ti)/CN/NiPd), was successfully synthesized for photocatalytic water reduction to produce H 2 . Under visible-light irradiation, the prepared NH 2 -MIL-125(Ti)/CN/NiPd composite clearly showed enhanced photocatalytic performance for H 2 evolution compared to NH 2 -MIL-125(Ti), NH 2 -MIL-125(Ti)/CN, and NH 2 -MIL-125(Ti)/NiPd. The as-synthesized NH 2 -MIL-125(Ti)/0.75CN/Ni 15.8 Pd 2.1 photocatalyst exhibited a high H 2 production rate of 8.7 mmol g −1 h −1 , 322 and 1.3 times higher than those of NH 2 -MIL-125(Ti)/0.75CN and NH 2 -MIL-125(Ti)/Ni 15.8 Pd 4.1 , respectively. The enhanced photocatalytic performance can be attributed to the intimate interfacial contact between NH 2 -MIL-125(Ti) and CN, accelerating the charge transfer, as well as loaded NiPd nanoparticles, increasing the light-absorbing capacity and accelerating the charge transfer of NH 2 -MIL-125(Ti)/CN. This work demonstrates that the addition of appropriate co-catalysts onto MOF/CN hybrid with intimate contact interface provides a new approach to design highly efficient and solar-energy-harvesting photocatalysts. [ABSTRACT FROM AUTHOR]