Mixed Ligand Strategy To Construct Cluster-based Metal-Organic Frameworks

Over the past ten years,a large number of metal-organic framework?MOF?materials were synthesized and widely used so that they gradually came into view.MOFs are inorganic-organic hybrid materials formed by metal ions or metal clusters as inorganic building units and organic ligands connected through coordination bonds.Relative to single metal ions,metal clusters have many advantages such as more coordination numbers and more rich coordination modes.At the same time,the choice of ligand greatly influences the type of the framework.In this work,metal clusters are used as inorganic building units and mixed ligands are used as organic parts.The cluster-based MOFs materials are synthesized in situ,and their energy storage and adsorption separation fields are studied.Designing a strategy of choosing{Zn₄PMo₁₂O₄₀}units as the POM node,Hbzt ligands regulating the angle and H₂bdc as the secondary bridging ligand,we successfully synthesized the first ZPOMOF,NENU-601.Through characterization analysis,NENU-601 showed its superior thermal and chemical stability.Based on strong electronic transmission capabilities and stability,we utilized NENU-601 as anode material for LIBs directly.Under a current density of 100 mA g^-1,NENU-601delivered reversible capacity of 780 mAh g^-1,indicating it is an excellent material for LIBs with high and stable performance.?TBA?_5/2[PMo₈^?Mo₄^?O₃₇?OH?₃Zn₄?bzt?_3/2?bdc?_1/2]·3/2H₂O?NENU-601?Hbzt=1,2,3-Benzotrialole,H₂bdc=1,4-dicarboxybenzene acidTBA⁺=tetrabutylammonium ionUsing Co?NO₃?₂ and tridentate ligand?4,4',4''-Tricarboxytriphenylamine?in the mixed solvent of dimethyl sulfoxide and isopropanol,we successfully obtained a two-dimensional planar structure based on{Co₃}cluster-based MOF material,NENU-602.Then we introduced the linear ligand 4,4'-Bipyridine to in-situ synthesize three-dimensional structure MOF material,NENU-603.Seen along the b-axis,NENU-603has a 1.0 nm diameter channel.Due to the large porosity and high specific surface area,we conducted NENU-603 nitrogen,carbon dioxide and methane gas adsorption tests.The result shows that NENU-603 exhibits selective adsorption of carbon dioxide gas under the same conditions.[Co₃?TCA?₂?DMSO?₂?iPrOH?₂]?NENU-602?TCA=4,4',4''-Tricarboxytriphenylamine,DMSO=Dimethyl sulfoxide,iPrOH=isopropanol[Co₃?TCA?₂?bpy?]?NENU-603?TCA=4,4',4''-Tricarboxytriphenylamine,bpy=4,4'-Bipyridine...