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Developing a new type of proton conductive material is key to improve the energy conversion performance of proton exchange membrane fuel cell (PEMFC). In recent years, metal organic framework (MOF) matrix conductive materials have become one of the research hotspots in the field of MOF. However, the grain boundaries in MOF particles and MOF@polymer composite films make it difficult to form long‐range ordered proton transport channels. Reducing crystallinity and changing the internal structural properties of MOF matrix may effectively improve its proton conductivity. In this study, some synthesis strategies were used to induce the crystallinity of MOF matrix to improve the proton conductivity, and low‐crystallinity MOG materials were obtained. In all, eight materials were prepared. The morphology characterization and proton conductivity of MOF and MOG materials were studied to explore the influence of different crystallinities and internal structures on proton conductivity. The results explicitly indicated that for the hydrophilic materials, the proton conductivity of MOG‐MOF‐808, MOG‐UiO‐66, MOG‐HKUST‐1 was significantly improved, compared with the corresponding MOFs at 75% RH. Among them, MOG‐MOF‐808 and MOG‐UiO‐66 show strong water stability and thermal stability, ensuring that it can be applied in special and complex environments. For the hydrophobic ZIF‐8 and MOG‐ZIF‐8, both their proton conductivities are low due to the material characteristics and network structures, while the proton conductivity of MOG‐ZIF‐8 is also higher than that of ZIF‐8 at 303 K. The results show that the abundant low‐crystallinity network structure in MOG materials played a very important role in improving the proton conductivity of the hydrophilic materials. Highlights: MOG materials have higher proton conductivity than MOFs at 75% RH. At 303 K, the conductivity of MOG‐MOF‐808 (1.35×10−2 S·cm−1) increased 196% relative to MOF‐808, and MOG‐UiO‐66 (3.89×10−3 S·cm−1) is about 73 times that of UiO‐66.The three‐dimensional MOG structure has a coherent three‐dimensional hydrogen bonding network, which can provide long‐range ordered proton transfer channels and enhance proton transfer efficiency.Improving proton conductivity of MOF materials by reducing crystallinity provided a new idea for the design and adjustment of proton conductivity of MOF materials. [ABSTRACT FROM AUTHOR]

The chemistry of transition‐metal complexes with unusually high coordination numbers has been of interest because of their application in catalytic and biological systems. Deprotonation of the ionogenic tetradentate ligand 6,6′‐bis(1H‐tetrazol‐5‐yl)‐2,2′‐bipyridine [H2bipy(ttr)2] in the presence of iron(III) and tetra‐n‐butylammonium bromide, [n‐Bu4N]Br, in solution resulted in the synthesis of a rare octacoordinated anionic mononuclear complex, tetra‐n‐butylammonium bis[6,6′‐bis(tetrazol‐1‐id‐5‐yl)‐2,2′‐bipyridine]iron(III) methanol hemisolvate dihydrate, (C16H36N)[Fe(C12H6N10)2]·0.5CH3OH·2H2O or [n‐Bu4N][Fe{bipy(ttr)2}2]·0.5CH3OH·2H2O (1), which has been structurally characterized by elemental analysis, powder X‐ray diffraction (PXRD) and single‐crystal X‐ray diffraction. In 1, the coordination sphere of the iron(III) ion is a distorted bis‐disphenoid dodecahedron, in which the eight coordination positions are occupied by eight N atoms from two independent tetradentate [bipy(ttr)2]2− anionic ligands, therefore forming the anionic [Fe{bipy(ttr)2}2]− unit, with the negative charge balanced by a free [n‐Bu4N]+ cation. An investigation of the magnetic properties of 1 revealed a gradual incomplete spin‐crossover behaviour below 150 K. [ABSTRACT FROM AUTHOR]

A series of two‐dimensional (2D) coordination polymers (CPs), namely poly[[bis(μ‐acetato)diaqua(μ6‐biphenyl‐3,3′,5,5′‐tetracarboxylato)bis(N,N‐dimethylacetamide)digadolinium(III)] N,N‐dimethylacetamide monosolvate], {[Gd2(C16H6O8)(C2H3O2)2(C4H9NO)2(H2O)2]·C4H9NO}n (CP1), poly[[bis(μ‐acetato)diaqua(μ6‐biphenyl‐3,3′,5,5′‐tetracarboxylato)bis(N,N‐dimethylacetamide)didysprosium(III)] N,N‐dimethylacetamide monosolvate], {[Dy2(C16H6O8)(C2H3O2)2(C4H9NO)2(H2O)2]·C4H9NO}n (CP2), poly[bis(μ‐acetato)diaqua(μ6‐biphenyl‐3,3′,5,5′‐tetracarboxylato)bis(N,N‐dimethylacetamide)dineodymium(III)], [Nd2(C16H6O8)(C2H3O2)2(C4H9NO)2(H2O)2]n (CP3), poly[bis(μ‐acetato)diaqua(μ6‐biphenyl‐3,3′,5,5′‐tetracarboxylato)bis(N,N‐dimethylacetamide)disamarium(III)], [Sm2(C16H6O8)(C2H3O2)2(C4H9NO)2(H2O)2]n (CP4), has been synthesized from rigid biphenyl‐3,3′,5,5′‐tetracarboxylic acid under solvothermal conditions. Their structures have been determined by single‐crystal X‐ray diffraction analyses, elemental analyses, IR spectra, powder X‐ray diffraction and thermogravimetric analyses, and CP1–CP4 crystallize in the monoclinic space group P21/n. CP1–CP4 are isomorphous and feature similar 2D double layers, which are further extended via interlayer hydrogen‐bonding interactions into a three‐dimensional (3D) supramolecular structure. Hydrogen‐bonding interactions between N,N‐dimethylacetamide molecules and carboxylate O atoms strengthen the packing of the layers. The organic ligands interconnect with metal ions to generate 2D layered structures with a (4,4)‐connected net having {44.62} topology. CP1 has been investigated for its magnetic properties and magnetic susceptibility measurements were carried out in the range 2.0–300 K. The results of the magnetic measurements show weak antiferromagnetic coupling between the GdIII ions in CP1. Moreover, the strong luminescence of CP2 and CP4 can be selectively quenched by the Fe3+ ion and toxic solvents (e.g. acetone). A series of two‐dimensional (2D) coordination polymers has been synthesized from rigid biphenyl‐3,3′,5,5′‐tetracarboxylic acid under solvothermal conditions. The four compounds are isomorphous and feature similar 2D double layers, which are further extended via interlayer hydrogen‐bonding interactions into three‐dimensional supramolecular structures. [ABSTRACT FROM AUTHOR]

Two new two‐dimensional lanthanide coordination polymers, namely poly[[tetra‐μ2‐acetato‐tetraaquabis(μ4‐biphenyl‐3,3′,5,5′‐tetracarboxylato)tetrakis(dimethylacetamide)tetraterbium(III)] pentahydrate], {[Tb4(C16H6O8)2(C2H3O2)4(C4H9NO)4(H2O)4]·5H2O}n, (1), and poly[[tetra‐μ2‐acetato‐tetraaquabis(μ5‐biphenyl‐3,3′,5,5′‐tetracarboxylato)tetrakis(dimethylacetamide)tetraeuropium(III)] tetrahydrate], {[Eu4(C16H6O8)2(C2H3O2)4(C4H9NO)4(H2O)4]·4H2O}n, (2), have been synthesized from biphenyl‐3,3′,5,5′‐tetracarboxylic acid (H4bpt) and Ln(NO3)3·6H2O (Ln = Tb and Eu) under solvothermal conditions. Single‐crystal X‐ray structure analysis shows that the two compounds are isostructural and crystallize in the monoclinic P21/n space group. The crystal structures are constructed from bpt4− ligands (as linkers) and {Ln2(μ2‐CH3COO)2} building units (as nodes), which topological analysis shows to be a (4,6)‐connected network with sql topology. Compounds (1) and (2) have been characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction (PXRD), thermogravimetric analysis (TGA) and fluorescence analysis in the solid state. In addition, a magnetic investigation shows the presence of antiferromagnetic interactions in compound (1). [ABSTRACT FROM AUTHOR]

Two enantiomorphic MgII/carboxylate coordination polymers [Mg(bpda)(H2O)4] n ( 1M and 1P) have been obtained by spontaneous resolution from achiral precursors, 2,2′-bipyridyl-3,3′-dicarboxylic acid (H2bpda) and Mg(NO3)2 ·6H2O, upon crystallization without any chiral auxiliary. X-ray structural analysis shows that chiral transmission from molecular axially chiral conformations to crystal chirality is established through concerted coordination and H-bonding interactions. In addition, the CD data, and the thermal and photoluminescence properties in the solid state have also been discussed. [ABSTRACT FROM AUTHOR]