Three Keggin POMs-based coordination polymers constructed by linear N-heterocyclic ligand for proton conduction, photocatalytic activity and magnetic property

Construction of Four γ-Octamolybdate-Based Coordination Polymers Using Linear Nitrogen Heterocyclic Ligands for Proton Conduction

“…Nitrogen heterocyclic ligands have attracted many researchers′ attention because they not only possess definite active sites, rich coordination patterns, and strong coordination capabilities, but also make for the formation of hydrogen bonds and π···π stacking interactions. − Up to now, it has been discovered that imidazole, triazole, pyridine ligands, and their derivatives have been widely utilized in the synthesis of POM-based compounds, such as the linear and V-type ligands, among others. − Compared with V-type ligands, linear ligands exhibit more defined coordination patterns, facilitating the intentional design and construction of desired compounds. Our group has conducted several studies using linear nitrogen heterocyclic ligands and synthesized some compounds, underscoring that linear organic ligands are an excellent choice. , …”

“…Our group has conducted several studies using linear nitrogen heterocyclic ligands and synthesized some compounds, underscoring that linear organic ligands are an excellent choice. 40,41 In this work, we utilized the linear organic ligand 1-(4H-1,2,4triazole-4-yl)-4-(imidazole-1-yl) benzene (tib), which simultaneously possesses imidazole and triazole rings at both ends of a benzene ring, and the existence of multiple coordination sites on this ligand is conducive to the formation of diverse coordination modes. Additionally, the uncoordinated nitrogen atoms are easily protonated and can form hydrogen bonds with water molecules or oxygen atoms in POMs, which is beneficial for proton conduction.…”

High H2O-Assisted Proton Conduction in One Highly Stable Sr(II)-Organic Framework Constructed by Tetrazole-Based Imidazole Dicarboxylic Acid

“…For instance, carboxylic acid groups carried by organic ligands, can not only coordinate with metal ions to constitute a stable MOF framework but can also act as proton sources and carriers, as well as participate in the construction of H-bonds within the framework to provide proton transport pathways [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Moreover, it has also been discovered that the electron absorption induction of N -heterocyclic groups such as imidazole and triazole increases the acidity of the carboxyl group, thereby improving the structural stability of MOFs, resulting in high water resistance and chemical inertia, laying the groundwork for future practical applications [ 18 , 30 , 31 , 32 , 33 ]. For example, in 2012, the Banerjee group used In(III) and Cd(II) metal salt to react with 5-triazoline phenylic acid (5-TIA) to generate two proton-conducting MOFs, In-5TIA and Cd-5TIA [ 34 ].…”

Two New Compounds Based on Bi-Capped Keggin Polyoxoanions and Cu-Bpy Cations Contain Both CuII and CuI Complexes: Synthesis, Characterization and Properties

“…As one of the fundamental polyanions, the Keggin POMs anions have gained much attention, and a variety of structures composed of “substituted Keggin polyanions” [ 36 , 37 , 38 , 39 , 40 , 41 ], “capped Keggin polyanions” [ 42 , 43 , 44 , 45 ] and “substituted and capped Keggin polyanions” [ 46 , 47 , 48 , 49 , 50 , 51 , 52 ] have been reported, in which Keggin-type POMs anions are also regarded as the most desirable building blocks for the construction of inorganic–organic hybrid materials attributed to its intrinsic nonlinear optics, thermal stability, diverse electrons, redox properties, and so on [ 53 , 54 , 55 , 56 ]. Up to now, a new advancement has produced plenty of fascinating structures and better-performing hybrid materials passing through the intelligent selection between capped Keggin-type POMs and TMCs, and more researchers are devoted to the study of POM-TMC materials.…”