Different Phenomena in Magnetic/Electrical Properties of Co(II) and Ni(II) Isomorphous MOFs

Abstract

Two unprecedented and stable metal–organic frameworks, {[Co 2 (H 2 O) 2 (L)(OH)]·2.5H 2 O·0.5DMF} n ( 1 ) and {[Ni 2 (H 2 O) 2 (L)(OH)]·1.75H 2 O} n ( 2 ), have been synthesized (H 3 L = 5-(5-carboxy-pyridin-3-yloxy)-isophthalic acid, DMF = N , N -dimethylformamide). Structural analysis shows that 1 and 2 are heteronuclear isomorphous, possessing a three-dimensional (3D) (4,8)-connected flu/fluorite topological framework formed through the interconnection of tetranuclear butterfly {M 4 (COO) 6 (OH) 2 } clusters and the ligands. Although the frameworks of these two compounds are similar, their magnetic properties are different. Compound 1 exhibits an antiferromagnetic interaction in the high-temperature region, while 2 shows a weak ferromagnetic interaction in the whole-temperature region. Furthermore, considering the presence of hydroxyl groups and water molecules in the frameworks, we tested their proton conductivity. The efficient proton transfer pathway in the framework endowed 1 and 2 with excellent proton conductivities of 9.07 × 10 –5 and 1.29 × 10 –4 S·cm –1 at 363 K and 98% relative humidity (RH), respectively.

R-Substituent-Induced Structural Diversity and Single-Crystal to Single-Crystal Transformation of Coordination Polymers: Synthesis, Luminescence, and Magnetic Behaviors

“…49 In 6, the carboxylate groups of n-BuO-ip ligands adopting chelated bidentate and monodentate bridge modes link the adjacent Zn II centers to yield a 1D [Zn(n-BuO-ip)] n linear chain along the a-axis (Figure 4b). Each μ 2 -bridging 3-bpdb ligand connects the adjacent [Zn(n-BuO-ip)] n linear chains leading to a 2D 4 4 -sql network via the ab plane (Figure 4c). Within each layer, the rhomboid windows have dimensions of 10.16 × 12.52 Å with angles of 117.31°and 62.69°(defined by Zn•••Zn distances and Zn•••Zn•••Zn angles).…”

“…Coordination polymers (CPs) have recently attracted enormous attention not only because of their structural and topologically diversity but also for their important properties and broad application prospects, such as sensing, magnetism, proton conduction, gas adsorption, and catalysis, and so on. During CPs’ evolution, researchers have made great progress in controlling and tuning of the network topology; nevertheless, prediction of the structural network is largely considered to be serendipitous. , This may be attributed to, except for the proper choice of metals and linkers in CPs synthesis, some weak factors, such as the ratio of metal to ligand, reaction time, pH values; more often than not, the substituent groups of carboxylate ligands also have a great and delicate influence on the structures of the resulting CPs.…”

“…Coordination polymers (CPs) have recently attracted enormous attention not only because of their structural and topologically diversity but also for their important properties and broad application prospects, 1 such as sensing, 2 magnetism, 3 proton conduction, 4 gas adsorption, 5 and catalysis, 6 and so on. During CPs' evolution, researchers have made great progress in controlling and tuning of the network topology; nevertheless, prediction of the structural network is largely considered to be serendipitous.…”

A mixed strategy to fabricate two bifunctional ligand-based Ag-complexes with high proton conductivity

“…Over the past few decades, proton-conducting materials have attracted significant attention owing to their applications in fuel cells, 1,2 electrochemical sensors, 3,4 and as electrochromic materials. 5,6 Promising proton exchange materials have to meet the following requirements: (1) high proton conductivity, (2) good chemical properties under harsher conditions (high temperature and high humidity) and thermal stability, (3) low production cost, and (4) easy mass production.…”

Multiple Strategies to Fabricate a Highly Stable 2D CuIICuI–Organic Framework with High Proton Conductivity

“…Over the past decades, proton conduction materials have attracted significant interest due to their applications in fuel cells, , electrochemical sensors, , electrochromics, , and so on . Nafion is the first and currently the most widely used proton conduction material .…”