Bimetallic Cage-Based Metal-Organic Frameworks for Electrochemical Hydrogen Evolution Reaction with Enhanced Activity.

A cage-based metal-organic framework (Ni-NKU-101) with biphenyl-3,3',5,5'-tetracarboxylic acid was synthesized via solvothermal method. Ni-NKU-101 contains two types of cages based on trinuclear and octa-nuclear nickel-clusters that are connected with each other by the 4-connected ligands, to form a 3D framework with a new topology. A mixed-metal strategy was used to synthesize isostructural bimetallic MOFs of Mx Ni1-x -NKU-101 (M=Mn, Co, Cu, Zn). The electrocatalytic studies showed that the hydrogen evolution reaction (HER) activity of Cux Ni1-x -NKU-101 is much higher than that of other Mx Ni1-x -NKU-101 catalysts in acidic aqueous solution, owing to the synergistic effect of the bimetallic centers. The optimized Cu0.19 Ni0.81 -NKU-101 has an overpotential of 324 mV at 10 mA cm-2 and a Tafel slope of 131 mV dec-1 . The mechanism of HER activity over these bimetallic MOF-based electrocatalysts are discussed in detail.

Synthesis of novel boron chelate complexes and proposed mechanism of new rearrangement.

We synthesized novel boron chelate complexes by the reaction of pyrazoline derivatives and boron trifluoride diethyl etherate followed by a new rearrangement. The structures of the compounds were characterized by IR, NMR and HRMS, especially, a typical compound 3c was confirmed by X-ray single crystal analysis. We proposed a mechanism of the rearrangement. Moreover, the absorption and fluorescence spectroscopy of these compounds were measured.