Catalytically active metal organic framework based on a porphyrin modified by electron-withdrawing groups

<p>One metal-free porphyrin, modified by electron-withdrawing groups, was synthesized by introduction of two peripheral pyridyl substituents and two metal coordination polymers, {[Zn(C₄₂H₁₆F₁₀N₆)]·2C₂H₇ N}_n (<b>1</b>) and {[Co(C₄₂H₁₆F₁₀N₆)]·C₂H₇ N}_n (<b>2</b>), were synthesized solvothermally. In <b>1</b>, each porphyrin connected four other porphyrin molecules to construct a 2-D network through coordination bonds. Similarly, in <b>2</b> every Co(II) porphyrin coordinated with four adjacent molecules to form a 2-D framework. Thermogravimetric analyses indicate that both <b>1</b> and <b>2</b> show high-thermal stabilities. The fluorescence data of <b>1</b> and <b>2</b> show that <b>1</b> may be a candidate for potential inorganic–organic photoactive materials. Catalytic oxidation results show that <b>2</b> displays high activity with the only product acetophenone quantitatively in 81.4%, and after six cycles, the catalytic activity slightly decreases. These features of <b>2</b>, including the exceptional stability, and high catalytic activity, make it outstanding among MOFs reported in the literature.</p

Nanorod In₂O₃@C Modified Separator with Improved Adsorption and Catalytic Conversion of Soluble Polysulfides for High-Performance Lithium–Sulfur Batteries

The shuttle effect of soluble lithium polysulfides (LiPSs) poses a crucial challenge for commercializing lithium–sulfur batteries. The functionalization of the separator is an effective strategy for enhancing the cell lifespan through the capture and reuse of LiPSs. Herein, a novel In2O3 nanorod with an ultrathin carbon layer (In2O3@C) was coated on a polypropylene separator. The results demonstrate the adsorption and catalysis of In2O3 on polysulfides, effectively inhibiting the shuttle effect and improving the redox kinetics of LiPSs. Besides, the ultrathin carbon layer increases the reaction sites and accelerates the electrochemical reaction rate. The cell with the In2O3@C interlayer displays excellent reversibility and stability with a 0.029% capacity decay each cycle in 2000 cycles at 2C. In addition, the In2O3@C interlayer significantly improves the cell performance under high current (888.2 mA h g–1 at 2C and room temperature) and low temperature (1007.8 mA h g–1 at 0.1C and −20 °C) conditions

Self-Assembly and External Modulation of a Flexible Porphyrin Derivative on Highly Oriented Pyrolytic Graphite

With the aid of scanning tunneling microscopy, we have examined the two-dimensional hydrogen-bonded networks of carboxyl-functionalized porphyrin derivative H₂TCPp molecules at the heptanoic acid/HOPG interface. Moreover, we have successfully modulated the self-assembly structure of H₂TCPp by introducing 1,2-di­(4-pyridyl)­ethylene molecules into the assembled system. By performing density functional theory calculations, we also revealed the formation mechanisms of the different assemblies and the modulation process. Comparing the self-assembly structures at the liquid/solid interface with those in bulk crystals, we have obtained deep insight into the differences in H₂TCPp assemblies between 2D and 3D networks. Furthermore, this research is expected to deepen our understanding of on-surface phenomena and to provide a feasible process toward 2D assembly regulation