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Two new lead(II) borate-sulfate mixed-anion compounds, namely, Pb 4 (BO 3 ) 2 (SO 4 ) and Pb 2 [(BO 2 )(OH)](SO 4 ), have been prepared by using high-temperature melt method or hydrothermal reaction. These compounds exhibit two different types of 3D structures composed of the same anionic units of BO 3 triangles and SO 4 tetrahedra which are interconnected by lead(II) cations. In Pb 4 (BO 3 ) 2 (SO 4 ), the lead(II) ions are bridged by borate anions into 3D [Pb 4 (BO 3 ) 2 ] 2+ architectures with 1D tunnels of 8-member rings along the a -axis, which are filled by the sulfate anions. In Pb 2 [(BO 2 )(OH)](SO 4 ), the lead(II) ions are interconnected by borate and sulfate anions into 2D Pb-B-O and Pb-S-O layers parallel to the ab plane, respectively, and these layers are further condensed into the 3D lead(II) borate-sulfate framework. TGA and DSC studies indicate that Pb 4 (BO 3 ) 2 (SO 4 ) is congruently melting with a melting point of 689 °C whereas Pb 2 [(BO 2 )(OH)](SO 4 ) decomposes at approximately 335 °C. UV/Vis/NIR optical diffuse reflectance spectrum measurements reveal the optical band gaps of 4.03 and 4.08 eV for Pb 4 (BO 3 ) 2 (SO 4 ) and Pb 2 [(BO 2 )(OH)](SO 4 ), respectively. Furthermore, the electronic structures of Pb 4 (BO 3 ) 2 (SO 4 ) have also been calculated. [ABSTRACT FROM AUTHOR]

To systematically investigate the influence of the flexible or rigid auxiliary ligands on the structures and properties of transition metal compounds, we synthesized four new d 10 coordination polymers (CPs) from 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (4-Hpzpt) and flexible/rigid dicarboxylate ligands, [Cd(4-pzpt) 2 ] n ( 1 ), [Cd 3 (4-pzpt) 2 (suc) 2 ] n ( 2 ), [Cd 2 (4-Hpzpt)(nbc) 2 (H 2 O)] n ( 3 ) and {[Cd 2 (4-pzpt) 2 (tfbdc)(H 2 O) 4 ]·H 2 O} n ( 4 ) (H 2 suc=1,2-ethanedicarboxylic acid, H 2 nbc=hthalene-1,4-dicarboxylic acid, H 2 tfbdc =2,3,5,6-tetrafluoroterephthalic acid). Single crystal X-ray analysis indicates that compound 1 shows a 4 4 - sql layer, which is extended to a 3D network via nonclassical C–H … N hydrogen bonds. Compound 2 possesses a 6-connected pcu -4 12 0.6 3 net composed of trinuclear Cd II -clusters. Compound 3 represents a rare 3D (3,4,4,5)-connected topology with a Schläfli symbol of (4·6·7)(4·5 3 ·7 2 )(5 3 ·6·7·9)(4 2 ·5 5 ·6·7 2 ). Compound 4 exhibits a 2D+2D→2D parallel interpenetrated 6 3 - hcb network. The adjacent 2D networks are interdigitated with each other to form the resulting 3D supramolecular architecture through classical O–H … N and O–H … O hydrogen bonds. Structural diversities indicate that the nature of flexible/rigid-dicarboxlates plays crucial roles in modulating structures of these compounds. Moreover, the luminescent properties of them have been briefly investigated. [ABSTRACT FROM AUTHOR]

POMs-based coordination polymers are promising materials for their potential application in the fields of proton conduction, catalysis and magnetism. Three new coordination polymers namely, {[Co 2 (bib) 3 (H 2 O) 2 (H 4 W 12 O 40)]·7H 2 O} n (1), {[Zn 3 (bib) 8 (H 3 ZnW 12 O 40) 2 ]·12H 2 O} n (2) and {[Ag 5 (bib) 5 (H 3 W 12 O 40)]·5H 2 O} n (3) were synthesized under hydrothermal conditions based on linear nitrogen heterocyclic ligand 1,4-bis(1-imidazolyl)benzene (bib). In compound 1 , CoII ions are linked with [H 4 W 12 O 40 ]4– anions to form a planar network and can be simplified as kgd topology, which are further linked with bib ligands to form a 3D framework. Zn2 ions of compound 2 alternately connect with bib ligands and [H 3 ZnW 12 O 40 ]3– anions to form 1D chain structure, while Zn1 ion forms isolated unit with three bib ligands and one [H 3 ZnW 12 O 40 ]3– anion, and a 3D framework is finally constructed through π ... π stacking interactions. In compound 3 , the 3D structure is constructed from a number of 1D chains formed by AgI ions and bib ligands in different directions through π ... π stacking interaction and Ag⋯O weak connection. The proton conductivity of 1 – 3 are 2.03 ​× ​10−5, 1.04 ​× ​10−6 and 1.87 ​× ​10−4 ​S ​cm−1 at 98% RH and 358 ​K, respectively. In addition, compounds 1 – 3 exhibit photocatalytic degradation capacity towards RhB and compound 1 displays antiferromagnetic behavior. Three Keggin POM-based coordination polymers have been prepared under hydrothermal condition and characterized by single-crystal X-ray diffraction, IR, XRD and TGA. The highest proton conductivity of 3 is up to 1.87 ​× ​10−4 ​S ​cm−1 at 358 ​K and 98% RH. [Display omitted] • Three Keggin POM-based coordination polymers have been prepared under hydrothermal condition. • Their structures were characterized by single-crystal X-ray diffraction, IR, XRD and TGA. • The highest proton conductivity of 3 is up to 1.87 ​× ​10−4 ​S ​cm−1 at 358 ​K and relative humidity of 98% RH. [ABSTRACT FROM AUTHOR]

Under solvothermal conditions, the reactions of Co II /Zn II ions with bent ligand 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (4-Hpzpt) afford two compounds {[M(4-pzpt) 2 ] guest} n (guest=H 2 O, M=Co II ( 1 ), Zn II ( 2 )). Both compounds are the thermally and hydrolytically robust 4-connected 3D NbO framework, which formed by double helical chains to give rise to 1D hollow nanochannel with uncoordinated nitrogens completely exposed on the pore surface. Compound 1 exhibits improved N 2 , CO 2 and H 2 uptake capacities, while compound 2 displays the strong luminescent emission with obvious red shift. [ABSTRACT FROM AUTHOR]

A novel multifunctional coordination polymer {[Zn(HCOO) (bcbpy)Cl]·H 2 O} n (1) with multiple colour-changing has been synthesized from Zn(NO 3) 2 ·6H 2 O, and viologen ligand 1,1′-bis-((3-carboxylatobenzyl)-4,4′-bipyridinium) dichloride (H 2 bcbpy·2Cl). In coordination polymer (CP) 1 , bcbpy ligands bridge Zn2+ cations to form a 1D wave-like chain. CP 1 exhibited photochromic properties under xenon lamp and blue light irradiation while obtaining a structurally stable light product 1T. CP 1 thermochromic properties can also be observed during heating. 1 showed photo-controlled fluorescence properties during color rendering and decolorization, and its properties were studied. Interestingly, CP 1 can be deposited in filter paper by coating it with a solution of H 2 O. The filter paper can be used as a printing medium without ink. [Display omitted] • CP 1 was synthesized using viologen ligand 1,1′-bis-((3-carboxylatobenzyl)-4,4′-bipyridinium) dichloride (H 2 bcbpy·2Cl). • CP 1 exhibited photochromic properties under xenon lamp and blue light irradiation. • CP 1 obtaining a structurally stable light product 1T after irradiation. • CP 1 can be used as a good ink-free printing medium. [ABSTRACT FROM AUTHOR]

Abstract: Two new coordination polymers, [Ag(tza)]∞ (1) (Htza=tetrazole-1-acetic acid) and [Cu(tza)2]∞ (2) have been prepared at room temperature and characterized by X-ray crystallography, IR, UV–vis, fluorescence spectra and magnetism analysis. Compound 1 exhibits extended helical chains through bridging ligand tza. The Ag ctions between the adjacent chains form a 3-D framework featuring the extended tza-connected Ag chains that obviously affect the photoluminescent property. Compound 2 features undulated layered structure with hourglass-shaped [Cu4(tza)4] as subunits with the weak ferromagnetic interactions between Cu(II) ions, which are further stabilized by inter-lamellar Ch name="rad" /> n bonds in the resulting 3-D supramolecular framework. [Copyright &y& Elsevier]

A novel 3D Zn (II)-based coordination polymer, [ZnL(H 2 O) 2 (complex 1) (H 2 L ​= ​2,5-di(1H-1,2,4-triazol-1-yl)terephthalic) with some active uncoordinated carboxylic groups, exhibiting excellent luminescence and good stability in water, harsh acidic and basic conditions (pH ​= ​2-12). 1 can act as a promising dual functional sensor for detecting and recognizing NFs (nitrofurazone, NZF; nitrofurantoin, NFT) and Fe3+ ions through fluorescence quenching with highly selectivity and sensitivity in aqueous phase. Besides, the probable mechanisms of the quenching effects are attributed to a competitive absorption mechanism between 1 and analytes. The present work contributes to the development of coordination polymers research, specifically in the application as biological and environmental fluorescent sensor. A water-stable luminescent Zn (II)-based coordination polymer was successfully synthesized by hydrothermal method and acts as a promising dual functional sensor for detecting and recognizing NZF, NFT and Fe3+ ion through fluorescence quenching with highly selectivity and sensitivity in aqueous phase. Image 1 • A luminescent Zn-CP was solvothermally synthesized. • The Zn-CP exhibits good stability in water, harsh acidic and basic conditions. • The Zn-CP exhibits high selectivity for NZF, NFT and Fe3+ ion in aqueous solution. • The mechanism of sensing properties was discussed in details. [ABSTRACT FROM AUTHOR]

It still remains a tremendous challenge in exploring high efficient electrocatalysts for hydrogen evolution reaction (HER). Herein, reaction of Co2+ ions and 3-(pyrid-4′-yl)-5 -(4″- carbonylphenyl) -1,2,4-triazolyl (H 2 Pycz) in a mixed solvent system has obtained a new 3D metal organic framework (MOF) formulated as Co 2 (Hpycz) 4 ·H 2 O (1). Compound 1 shows a 3D 8-fold interpenetrating 66- dia topological network with antiferromagnetic interactions between the Co(II) ions. The obtained Co-MOF exhibits a good HER performance: it displays a low onset potential of 101 mV, a small Tafel slope of 121 mV dec−1, exchange current density of 1.62 × 10−4 A cm−2 and long term stability of at least 72 h. This work may enrich the new candidates of MOFs materials for HER application. Herein, reaction of Co2+ ions and 3-(pyrid-4′-yl)-5-(4″-carbonylphenyl)-1,2,4-triazolyl (H 2 Pycz) in a mixed solvent system has obtained a new 3D metal organic framework (MOF) formulated as Co 2 (Hpycz) 4 ·H 2 O (1). Compound 1 shows a 3D 8-fold interpenetrating 66- dia topological network with antiferromagnetic interactions between the Co(II) ions. The obtained Co-MOF exhibits a good HER performance: it displays a low onset potential of 101 mV, a small Tafel slope of 121 mV dec−1, exchange current density of 1.62 × 10−4 A cm−2 and long term stability of at least 72 h. Image 1 [ABSTRACT FROM AUTHOR]

The small-size and efficient charge separation of MOFs catalysts are essential for improving photocatalytic performance. In this work, a series of small-size NH 2 -UiO-66 nanoparticle-modified Mo 2 C photocatalysts were successfully prepared by hydrothermal synthesis with in situ growing NH 2 -UiO-66 on the surface of Mo 2 C. The addition of Mo 2 C can not only obtain small-size NH 2 -UiO-66 nanoparticles, but also significantly increase the separation efficiency of photo-generated carriers and prolongs the carrier lifetime, thereby promoting the photoreduction of CO 2 in water vapor with excellent stability. The resulting 11-Mo 2 C/NH 2 -UiO-66 (11-MCNU) exhibits excellent catalytic activity for CO 2 reduction to CO product at room temperature and atmospheric pressure. The yield of CO can reach 11 μmol g−1 in the absence of organic solvents, sacrifice agents and photosensitizers, which is much higher than that of the isolated NH 2 -UiO-66 and Mo 2 C. [Display omitted] • A series of small-size NH 2 -UiO-66 nanoparticle-modified Mo 2 C photocatalysts were successfully prepared by hydrothermal synthesis. • The resulting 11-Mo 2 C/NH 2 -UiO-66 (11-MCNU) exhibits excellent catalytic activity for CO 2 reduction to CO. • The yield of CO can reach 11 μ mol g−1 in the absence of organic solvents, sacrifice agents and photosensitizers. [ABSTRACT FROM AUTHOR]

The functional design of efficient and stable proton exchange membrane materials is an important research direction in the field of proton exchange membrane fuel cells (PEMFCs). In this work, ammonia molecules were successfully encapsulated into the one-dimensional pores of MOF-74(Co) through fumigation with ammonia vapor. Alternating current (AC) impedance tests showed that the proton conductivity of NH 3 modified NH 3 @ MOF-74(Co) reaches an impressive value of 6.8 × 10−3 S/cm, being 10000 times that of the pristine MOF-74(Co) at 98% relative humidity (RH) and 50 °C. Various and abundant hydrogen bonds can improve the proton conduction of NH 3 modified compound. This strategy provides an efficient and convenient way to construct high proton conducting porous MOFs materials by attaching NH 3 molecules. [Display omitted] • Ammonia molecules were successfully encapsulated into the pores of MOF-74(Co) through fumigation with ammonia vapor. • The proton conductivity of NH 3 @ MOF-74(Co) reaches the maximum value of 6.8 × 10−3 S/cm, which is 10000 times that of the pristine MOF-74(Co) at same conditions. • This strategy provides an efficient and convenient way to construct high proton conducting porous MOFs materials. [ABSTRACT FROM AUTHOR]

Herein, the postsynthetic ligand exchange process was adopted to construct a series of 1,4-naphthalenedicarboxylic acid (H 2 NDC) and 6-sulfonate-1,4-naphthalenedicarboxylic acid (H 3 SNDC) based Zr(IV)-MOFs (Zr-(NDC) x (SNDC) 1-x). This strategy anchored functional sulfonic acid groups in the pore of the MOFs. Among them, Zr-(NDC) 0.3 (SNDC) 0.7 exhibited outstanding proton conductivity of 3.18 ✕ 10−4 S cm−1 at 90 °C and 98% relative humidity (RH), which was approximately three orders of magnitude greater than that of pristine Zr-NDC. This work demonstrated a facile in situ ligand exchange approach for constructing functional group modified MOFs with high proton conductivity. [Display omitted] • A series of 1,4-naphthalenedicarboxylic acid (H 2 NDC) and 6-sulfonate-1,4-naphthalenedicarboxylic acid (H 3 SNDC) based Zr(IV)-MOFs were synthesized. • The functional sulfonic acid groups were anchored in the pore of the MOFs by ligand exchange approach. • Zr-(NDC) 0.3 (SNDC) 0.7 demonstrated remarkable proton conductivity of 3.18 × 10−4 S cm−1 at 90 °C and 98% relative humidity (RH). [ABSTRACT FROM AUTHOR]

Four Zn(II) coordination polymers (CPs), [Zn(4-pzpt) 2 (H 2 O)] n ( 1 ), {[Zn(4-pzpt) 2 ]·CH 3 OH} n ( 2 ), [Zn 2 (4-pzpt) 2 (suc)(H 2 O)] n ( 3 ) and [Zn 2 (4-pzpt) 2 (ndc)] n ( 4 ) were obtained from 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (4-Hpzpt), 1,4-Naphthalenedicarboxylic acid (H 2 ndc) and succinic acid (H 2 suc) ligands. Structural analysis reveals that 1 represents a five coordinated 0D structure. 2 possess a network featuring 2D 4 4 grid-like layers structure. 3 displays a network featuring 2D (6 3 )- hcb layered structure. 4 shows a rare 3D (4,4)-connected topology with a Schläfli symbol of (4.6 4. 7) 2 (6 4. 7 2 ). Complexes 1 and 2 can mutual conversion between different solvent ratios. Luminescence properties reveal that 1 and 2 exhibit excellent selectivity for Hg 2+ and Cr 2 O 7 2- ions in aqueous solution, in which suggests that 1 and 2 is a promising multifunctional sensing materials. The possible sensing mechanism is also discussed. [ABSTRACT FROM AUTHOR]

Construction of heterojunction-based photocatalyst is a fascinating approach to improve the conversion efficiency of CO 2 photoreduction. Herein, we report a series of low-cost heterojunction catalysts (x% MSNM) assembled by 1T MoS 2 nanosheets and NH 2 -MIL-68 for photocatalytic CO 2 reduction conjugated with H 2 O oxidation under visible-light irradiation. Notably, 8% MSNM exhibits enhanced photocatalytic activity for the photoreduction of CO 2 to CH 4 in the absence of organic solvent, sacrificial agent and photosensitizer. The evolution rate of CH 4 can reach to 12.56 ​μmol ​g−1, higher than that of isolated MoS 2 and NH 2 -MIL-68. Systematic investigations demonstrate that the 1T MoS 2 fragments are uniformly dispersed on the NH 2 -MIL-68 surface during the assembly and crystallization process of NH 2 -MIL-68. Under light conditions, the NH 2 -MIL-68 crystals serve as light collectors to absorb visible light and generate electron-hole pairs, and the photo-excited electrons rapidly transferred to the surface of 1T MoS 2 , prolonging the lifetime of the photo-induced excitons. This work provides a new direction for the rational design of composite catalysts in artificial photosynthesis. [Display omitted] • The heterojunction-based 1T MoS 2 @NH 2 -MIL-68 (x% MSNM) photocatalysts have been prepared. • Notably, 8% MSNM exhibits enhanced photocatalytic CO 2 reduction activity. • The evolution rate of CH 4 can reach to 12.56 ​μmol ​g−1, higher than that of isolated MoS 2 and/or NH 2 -MIL-68. [ABSTRACT FROM AUTHOR]

Reaction of Tb 3+ ions with p -terphenyl-3,3″,5,5″-tetracarboxylic acid (H 4 ptptc) in a mixed solvent system has afforded a new metal-organic framework formulated as [Tb 2 (ptptc) 1.5 (H 2 O) 2 ] n ( 1 ). Compound 1 displays a 3D (5,6,8)-connected framework with fascinating one-dimensional triangle open channels. The luminescence explorations demonstrated that 1 exhibits highly selective and sensitive response to Fe 3+ in DMF solution and biological system through luminescence quenching effects. In addition, 1 also shows high detection for the Cr 2 O 7 2- , making it a promising dual functional materials for detecting Fe 3+ cation and Cr 2 O 7 2- anion with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

Two new Co(II) coordination polymers(CPs), namely [Co 2 (bpe) 2 (Hbppc)] n ( 1 ) and [Co 3 (μ 3 -OH)(bppc)(bpm)(H 2 O)]·3H 2 O ( 2 ) (H 5 bppc=biphenyl-2,4,6,3′,5′-pentacarboxylic acid, bpe=1,2-bis(4-pyridyl)ethene, bpm=bis(4-pyridyl)amine), have been obtained and characterized by elemental analysis, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectra and thermogravimetric analysis (TGA). 1 shows a binodal (4,6)-connected fsc net with a (4 4 ·6 10 ·8)(4 4 ·6 2 ) topology, while 2 shows a binodal (5,7)-connected 3D network based on trinuclear [Co 3 (μ 3 -OH)] 5+ units with unusual (3.4 6 .5 2 .6)(3 2 .4 6 .5 7 .6 5 .7) topology. Variable-temperature magnetic susceptibility measurements reveals that complex 1 shows ferromagnetic interactions between the adjacent Co(II) ions, whereas 2 is a antiferromagnetic system. [ABSTRACT FROM AUTHOR]

For the first time, sodium caprylate has been investigated to direct the crystal growth of 3D Ag-MOF, [Ag 2 (ddcba)(4,4′-bipy) 2 ] ( 1 ), constructing from 3,5-(di(2′,5′-dicarboxylphenyl)benozoic acid and 4,4′-bipy. The single crystal diffraction analyses shows that complex 1 possess 3D neutral framework with a three-connected ThSi 2 (10 3 -b) topology. Compound 1 exhibits predominant catalytic activity towards the degradation of o- Nitrophenol (ONP), m- Nitrophenol (MNP) and p- Nitrophenol (PNP) in aqueous solution. The kinetics of such catalytic degradation reactions was also studied. [ABSTRACT FROM AUTHOR]

Three new coordination polymers, namely, {[Ni(H 2 L)(bix)(H 2 O) 2 ]·2h 2 O} n (1), {[Ni(HL)(Hdpa)(H 2 O) 2 ]·H 2 O} n (2), {[Ni(L) 0.5 (bpp)(H 2 O)]·H 2 O} n (3) (H 4 L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H 4 L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6 6 -dia- type framework with H 4 L ligand adopts a μ 2 -bridging mode with two symmetry-related carboxylate groups in μ 1 - η 1 : η 0 monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, in which the H 4 L ligand adopts a μ 2 -bridging mode with two carboxylate groups in μ 1 - η 1 : η 1 and μ 1 - η 1 : η 0 monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H 4 L ligand displays a μ 4 -bridging coordination mode. The H 4 L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1 – 3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. [ABSTRACT FROM AUTHOR]

Proton exchange membrane (PEM) is one of the core materials which were widely used in the field of fuel cells (FCs). In recent years, the metal organic frameworks (MOFs) and polymer composite membranes as tunable proton-conducting materials have showed great potential in this field. Herein, a Cu(II)-based metal organic framework (Cu-MOF) with acid/base stability was introduced into poly(vinylpyrrolidone)/poly(vinylidene fluoride) (PVP/PVDF, PP) to fabricate hybrid membranes(Cu-MOF@PP-X, where X is the % Cu-MOF content). The effects of Cu-MOF loading amounts on the conductive behavior of Cu-MOF@PP-X composites have been documented. It is worth noting that Cu-MOF@PP-50 exhibited the proton conductivity up to 4.36 ​× ​10−4 ​S ​cm−1 at 353 ​K and 98% relative humidity (RH). In addition, the value of proton conduction is about two orders of magnitude higher than that of the parent Cu-MOF (1.91 ​× ​10−6 ​S ​cm−1). This work contributes to driving further advances of MOF/polymer composites in proton-conducting apparatus. [Display omitted] • A Cu-MOF with acid/base stability was introduced into polymers (PVP/PVDF, PP) to fabricate hybrid membranes. • The effects of Cu-MOF loading amounts on the conductive behavior of Cu-MOF@PP-X composites have been documented. • Cu-MOF@PP-50 exhibited a super protonic conductivity up to 4.36 ​× ​10−4 ​S ​cm−1 at 353 ​K and 98% relative humidity (RH). • The value of proton conduction of Cu-MOF@PP-50 is about two orders of magnitude higher than that of the parent Cu-MOF. [ABSTRACT FROM AUTHOR]

Two new interpenetrating Cu II /Ni II coordination polymers, based on a unsymmetrical bifunctional N/O-tectonic 3-(pyrid-4′-yl)-5-(4″-carbonylphenyl)-1,2,4-triazolyl (H 2 pycz), {[Cu-(Hpycz) 2 ]·2H 2 O} n ( 1 ) and {[Ni(Hpycz) 2 ]·H 2 O} n ( 2 ), have been solvothermally synthesized and structure characterization. Single crystal X-ray analysis indicates that compound 1 shows 2-fold parallel interpenetrated 4 4 - sql layers with the same handedness. The overall structure of 1 is achiral—in each layer of doubly interpenetrating nets, the two individual nets have the opposite handedness to the corresponding nets in the adjoining layers—while 2 features a rare 8-fold interpenetrating 6 6 - dia network that belongs to class IIIa interpenetration. In addition, compounds 1 and 2 both show similar paramagnetic characteristic properties. [ABSTRACT FROM AUTHOR]

A new 3D anionic metal-organic framework material, namely, [Me 2 NH 2 ] 2 [Cd 3 (L)]·2H 2 O (1 , H 4 L ​= ​2,5′-di(3′,5′-dicarboxylphenyl)pyridine) has been synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction, PXRD, thermogravimetric analysis and proton conduction investigation. In 1 , the adjacent Cd(II) ions are joined to form a trinuclear [Cd 3 (COO) 8 ] secondary building unit (SBU) by eight bridging carboxylate groups of L4− ligands. The trinuclear [Cd 3 (COO) 8 ] SBUs are connected by L4− ligands into a 3D (4,8)-connected framework with 1D channels. Most interestingly, due to the guest [Me 2 NH 2 ]+ cations, water molecules and carboxylates sites are lined the pore channels, 1 possesses a remarkable proton conductivity of 1.12 ​× ​10−1 ​S ​cm−1 ​at 60 ​°C and 98% RH, which is comparable to commercially available Nafion. The mechanism of proton conduction was also well discussed. A new 3D anionic metal-organic framework material, namely, [Me 2 NH 2 ] 2 [Cd 3 (L)]·2H 2 O (1 , H 4 L ​= ​2,5′-di(3′,5′-dicarboxylphenyl)pyridine) has been synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction, PXRD, thermogravimetric analysis and proton conduction investigation. Compound 1 exhibits a (4,8)-connected 3D network based on trinuclear [Cd 3 (COO) 8 ] cluster units with excellent water stability. It's worth noting that the value of proton conductivity of 1 reaches 1.12 ​× ​10−1 ​S ​cm−1 ​at 60 ​°C and 98% RH which is comparable to most of the dramatic proton conducting MOFs materials. The activation energy (E a) of 1 is 0.376 ​eV estimated by Arrhenius equation. [Display omitted] • A trinuclear Cd-based 3D (4,8)-connected anionic metal-organic framework were synthesized. • The [Me 2 NH 2 ]+ ​cations, H 2 O and host carboxylates could construct continuous proton-conducting pathways. • The MOF exhibited a remarkable proton conductivity of 1.12×10-1 ​S cm-1 ​at 60°C and 98% RH. [ABSTRACT FROM AUTHOR]