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The anhydrous proton conductivity of Im@IEF-11 resulting from the integration of imidazole and porous IEF-11 has been investigated, and the highest proton conductive value can reach up to 7.64 × 10−2 S cm−1. Furthermore, IEF-11 is also developed to reduce CO2 due to its reasonable structure and suitable energy band, and its CO formation rate is 31.86 μmol g−1 h−1. [ABSTRACT FROM AUTHOR]

The photocatalytic conversion of CO2 into widely adjustable syngas (CO/H2 mixture) has been considered as an extraordinarily promising but challenging strategy to realize high value-added utilization of CO2 to alleviate worldwide environmental problems and energy crisis. To achieve this goal, we report a newly designed crystalline covalent organic framework (COF-TVBT-Bpy) that embedded a series of metal active sites to efficiently convert CO2 and H2O into syngas under visible-light illumination. COF-TVBT-Bpy not only provides a coordination environment for the metal center, but also enhances electron delocalization by the extended conjugated moiety, thus facilitating electron transfer. The optimized Co@COF-TVBT-Bpy achieves the highest photocatalytic CO2-to-syngas conversion efficiency in pure CO2 (up to 2291.1 μmol g−1 h−1, CO/H2 ≈ 1 : 1). The intrinsic reason for a CO/H2 ratio of 1 : 1, electron transfer pathway, and syngas generation mechanism over Co@COF-TVBT-Bpy are explored by the combination of in situ measurements and theoretical calculations. The experimental results confirm that the ratio of CO/H2 can be widely modulated by adjusting the metal active sites and photoreaction conditions. This work proves the immense potential of utilizing COFs as platforms to anchor metal active sites for syngas formation and provides a facile method to regulate the ratio of syngas in a wide range. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) provide an ideal platform for loading various guests owing to their available space, and can be developed as a class of multifunctional materials. Herein, we cover the design and synthesis of two kinds of exchanged frameworks with multifunctional applications based on H3ImDC and In(NO3)3·2H2O through guest exchange inside the framework. The guest ammonium ion (NH4+) and [Ru(2,2′-bipyridine)3]2+ (Rubpy) are selected to exchange the dimethylammonium cation (Me2NH2+) encapsulated within In-MOF, giving birth to two kinds of new MOFs, named NH4+@In-MOF and Rubpy@In-MOF respectively. The proton conduction of NH4+@In-MOF and the CO2 photoreduction of Rubpy@In-MOF are investigated. Under different test conditions, the proton conductive behaviors of NH4+@In-MOF are evaluated and the best proton conductive value can reach up to 9.81 × 10−3 S cm−1. Compared to the original In-MOF, Rubpy@In-MOF exhibits a significantly enhanced CO2 photoreduction performance under a pure CO2 atmosphere. Furthermore, its photocatalytic activity is retained even under a 10% CO2 gas atmosphere, displaying a synergistic effect between Rubpy and In-MOF24 within Rubpy@In-MOF. [ABSTRACT FROM AUTHOR]

Two unprecedented 3D porous anionic metal–organic frameworks, [Me2NH2]2[Cd2(bpdc)3]·4dma 1and [Me2NH2]2[Cd2(NH2bdc)3]·4dma 2(dma = N,N′-dimethylacetamide, bpdc = 4,4′-biphenyldicarboxylate, NH2bdc = 2-amino-1,4-benzenedicarboxylate) have been solvothermally synthesized with a dimethylammonium cations template. Both 1and 2are constructed from low-symmetry SBUs. 1has a chiral framework with helical nanotube-like channels, and 2has a MOF-5-like motif. The fluorescence, N2adsorption and ion-exchange properties for 1have been examined. [ABSTRACT FROM AUTHOR]

Abstract: Three novel polymers, {[Cd(m-bdc)(L)]·H2O} n (1), [Co(m-bdc)(L)0.5(H2O)] n (2) and [Zn5(L)2(p-bdc)5(H2O)] n (3) based on 1,1′-bis(pyridin-3-ylmethyl)-2,2′-biimidazole (L) ligand and benzenedicarboxylate isomers, have been prepared and structurally characterized. Compound 1 exhibits a 2D architecture with (42·6)(42·67·8) topology, which is synthesized by L and 1,3-benzenedicarboxylate (m-bdc) ligands. Compound 2 is constructed from 1D chains that are linked by L ligands extending a 2D (4,4) grid. Compound 3 is a 3D framework with (43)(46·618·84) topology, which is composed of trinuclear clusters and five-coordinated metal centers joined through 1,4-benzenedicarboxylate (p-bdc) and L ligands. Moreover, the fluorescent properties of L ligand, compounds 1 and 3 are also determined. [Copyright &y& Elsevier]

Abstract: A novel three-dimensional (3D) polymer [Cd2(Hbiim)4] n (H2biim=2,2′-biimidazole) 1 was obtained through hydrothermal reaction and characterized by single crystal X-ray diffraction, and the fluorescent property was also determined. Compound 1 crystallizes in a monoclinic chiral space group P21 and contains two types of helical chains. Hbiim− partially deprotonated of H2biim exhibits two different coordination modes, which contributes greatly to the formation of the 3D chiral framework. Compound 1 exhibits blue fluorescence at 488nm in the solid-state upon excitation at 430nm. [Copyright &y& Elsevier]

Abstract: Two new lead-carboxylate complexes based on nicotinic acid N-oxide ligand, [Pb(NNO)(FA)0.5] (1) (HNNO=nicotinic acid N-oxide, FA=fumaric acid) and [Pb2(NNO)(BTC)] (2) (H3BTC=1,3,5-benzenetricarboxylic acid) were hydrothermally synthesized and characterized by the elemental analyses, IR spectra and single crystal X-ray diffraction. Significant phosphorescent properties of two compounds were observed at room temperature. [Copyright &y& Elsevier]

Abstract: A new metal–organic frameworks (MOFs), [Cd3(pmb)2(bpdc)2] 2H2O (1) (pmb=3,5-bis(4-pyridylmethylenoxyl)benzoate, bpdc=2,2′-biphenyldicarboxylate), has been synthesized by hydrothermal method and structurally characterized through IR, TG and single-crystal X-ray analysis. The infinite wave-like 1D metal–oxygen chains made by Cd3N4O12 clusters in 1 bridged by the carboxylate of bpdc ligand, construct a 2D framework in which interesting meso-helical chains are constructed by metal centers and pmb ligands. Solid state luminescent spectrum of 1 also has been investigated at room temperature. [Copyright &y& Elsevier]