A Three-Dimensional Copper Coordination Polymer Constructed by 3-Methyl-1H-pyrazole-4-carboxylic Acid with Higher Capacitance for Supercapacitors

Abstract

A three-dimensional (3D) copper-based coordination polymer, ([Cu(H 2 mpca)-(tfbdc)], Cu-CP; H 2 mpca = 3-methyl-1H-pyrazole-4-carboxylic acid; H 2 tfbdc = 2,3,5,6tetrafluoroterephthalic acid), has been synthesized and characterized by IR spectroscopy, thermogravimetric analysis, elemental analysis, and single-crystal X-ray diffraction. In Cu-CP, each Cu(II) ion is located in a triangular bipyramid geometry, and these Cu(II) ions are linked by tfbdc 2− ligands to produce a 3D network. Variable-temperature magnetic susceptibility data display that weak antiferromagnetic interactions between the adjacent Cu (II) ions exist in Cu-CP. Cu-CP was evaluated as an electrode material for supercapacitors. It displayed a higher specific capacitance of 735 F g −1 in 1 M KOH solution at a current density of 1 A g −1 and remained at 375 F g −1 after 1500 cycles at 2 A g −1 .

Annular Tautomerism of 3(5)-Disubstituted-1H-pyrazoles with Ester and Amide Groups

“…Pyrazole is a five-membered aromatic heterocycle with two adjacent nitrogen atoms, classified as azole. Pyrazole derivatives have broad application, from engineering and polymers [1,2,3,4,5,6,7,8], to biological activity [9]; thus, new synthetic strategies are constantly developed [10,11,12,13,14,15,16,17]. Among them, there are 1 H -pyrazoles with substituents at positions 3 and 5, which reveal interesting applications [18,19,20,21,22,23,24,25], and some of them are depicted in Figure 1.…”

Supercapacitor electrodes based on metal‐organic compounds from the first transition metal series

“…So far, reported copper‐organic compounds and their composites with SC properties can be divided into copper carboxylate MOFs ( 140 ‐ 157 ), copper polyoxometalate organic frameworks (Cu‐POMOFs, 158 ‐ 176 ), copper polyamine or polyphenol MOFs ( 177 ‐ 183 ), copper porphyrin compounds ( 184 ‐ 188 ), etc. Copper can exhibit electrochemical activity through the redox reaction between Cu(0), Cu(I), and Cu(II), and its organic compounds have been widely studied in SCs 73,77,78,80,116,159‐183 . Relevant conversion process can be expressed by the following equations 164,167,174 : …”

“…Among copper polycarboxylate MOFs ( 140 ‐ 157 ), HUST‐1 (also known as MOF‐199, 140 ‐ 153 ) with H 3 BTC ligand showed interesting behavior in the electrochemically based SCs due to its large surface area and high pore volume 73,159‐168,184 . Srimuk and coworkers firstly studied the HUST‐1 as the active material for SC electrodes 159 .…”

Four new Zn(ii) and Cd(ii) coordination polymers using two amide-like aromatic multi-carboxylate ligands: synthesis, structures and lithium–selenium batteries application

“…Over past decades, coordination polymers (CPs), as crystalline functional materials with intriguing network structures by selfassembly of metal ions/clusters and organic ligands, [1][2][3][4][5] have rapidly progressed due to their versatile utility in potential applications, such as proton conductors, 6 heterogeneous catalysts, 7 magnetism, 8 gas storage and separation, 9 luminescence sensors, 10 and supercapacitors. 11 However, their crystallization is a complicated process and is dependent on many experimental factors, including the nature of the organic linkers, the coordination preferences of the metal ions, the ratios of the raw materials, the temperature and solvents, as well as the possible inclusion of guest components within the coordination lattice. 12,13 Among these factors, selection of the right ligands with a certain functionality and exibility could be the most rational way to obtain predictable frameworks and properties.…”