Syntheses, Structures And Properties Of Several Novel Coordination Polymers Based On Semi-rigid Molecular

in recent decades, The rational design and assembly of the metal-organicframeworks(MOFs) has been flourishing and received remarkable attention of scholarsnot only due to MOFs can show various properties by adjusting their structuralcharacteristics through carefully selecting metal ions or metal clusters andmulti-functional linkers, then for synthesis of intriguing frameworks but also because oftheir interesting properties and potential applications, They are a new class ofcompounds between inorganic and material chemistry,such as in hydrogen storage, fuelcell, Li-ion battery, supercapacitor, solar cell, and so on.In the paper, we have adopted two ligands:1,4-bis(3-pyridylaminomethyl)benzene(L) and4-(5-(Pyridin-4-yl)-4H-1,2,4-triazol-3-yl)benzoate (HL), five metal(II)complexes have been synthesized by adopting hydrothermal(solvothermal)methods,The crystal structures and properties of these complexes have also beeninvestigated.Based on L (1,4-bis(3-pyridylaminomethyl)benzene) ligand, two MOFs formulatedas Co(L)0.5(adip)(H2adip=adipic acid)(1) and Co2(L)2(5-bdc)2(H2O)2·H2O (2)(5-H2bdc=5-nitroisophthalic acid)(2) were synthesized and structurally characterizedby single-crystal X-ray diffractions. Complex1features a uninodal4-connectednon-interpenetrated sql/Shubnikov tetragonal plane net with {44.62} topology. Incomplex2, two L link two Co(II) centers into a quadrangular cage and different cagesare further connected by two strands of5-bdc2-into1D chain. The two complexes bothexhibit electrocatalytic activities toward generating O2from water with loweredoverpotentials and enhanced currents, and they show different UV-vis absorptionspectra and thermal stabilities.Using a semi-rigid ligand,4-(5-(pyridin-4-yl)-4H-1,2,4-triazol-3-yl) benzoic acid(HL), three metal(II) organic frameworks (MOFs) formulated as M2L4·3H2O [M=Co(1),Cu (2), and Zn (3)] were synthesized and characterized by single-crystal X-raydiffraction. The three MOFs are isostructural except for different unsaturatedcoordinated metal(II) ions in the structures, and they display a uninodaltwo-dimensional layer with44-sql topology. Among the three complexes, the Co and Cucomplexes can act as electrocatalysts for water splitting, and the Co complex showsbetter electrocatalytic activity. The present work shows that the species of metal(II) ions plays an important role in the electrocatalytic activity for water splitting. The threecomplexes show different thermal stabilities, UV vis absorption characteristics, andphotoluminescence properties...