A strategy based on metal–ligand directed assembly of metal–organic squares (MOSs), built-up from four-membered ring (4MR) secondary building units (SBUs), has been employed for the design and construction of isoreticular zeolite-like supramolecular assemblies (ZSAs). Four porous Co-based ZSAs having the same underlying gis topology, but differing only with respect to the capping and bridging linkers, were successfully isolated and fully characterized. In this series, each MOS in ZSA-3–ZSA-6 possess an ideal square geometry and is connected to four neighboring MOS via a total of 16 hydrogen bonds to give a 3-periodic porous network.To systematically assess the effect of the pore system (size and functionality) on the gas adsorption properties, we evaluated the MOSs for their affinity for different probe molecules such as CO2 and light hydrocarbons. ZSA-3–ZSA-6 showed high thermal stability (up to 300 °C) and was proven highly porous as evidenced by gas adsorption studies. Notably, alkyl-functionalized MOSs were found to offer potential for selective separation of CO2, C3H6, and C3H8 from CH4 and H2 containing gas stream, such as natural gas and refinery-off gases.Keywords: alkyl-functionalization; gas separation; metal−organic squares; MOFs; porous materials; zeolite-like supramolecular assemblies;

A novel proton-conducting MOF material has been synthesized by using 3,3′,4,4′-biphenyltetracarboxylic acid (H4bptc) as organic ligands, which linked to four [Zn(COO)4]2– secondary building units and K ions through four carboxyl groups, and generated a 3D framework [Zn3K2(bptc)3(DMF)2][Me2NH2]4 (JLU-Liu44). The proton-conducting properties of JLU-Liu44 were investigated by impedance spectroscopy. JLU-Liu44 exhibits low conductivity under anhydrous conditions, but the proton conductivity under humidified conditions was significantly enhanced due to the cooperation of guest [Me2NH2]+ cations, water molecules, and host carboxylates. JLU-Liu44 exhibits high proton conductivity of 8.4 × 10–3 S cm–1 at ambient temperature (27 °C) and 98% relative humidity; it is comparable to the most reported proton-conducting MOFs materials under the same condition for powdered sample. The activation energy (Ea) obtained from an Arrhenius plot was 0.25 eV, indicating that the proton conduction behaviors occur through a Grotthuss mechanism.

A Zn4O clusters based flexible doubly interpenetrated metal–organic framework [(Zn4O)2(DCPB)6DMF]·2DMF·8H2O (JLU-Liu33, H2DCPB = 1,3-di(4-carboxyphenyl)benzene, DMF = N,N-dimethylformamide) with pcu topology has been solvothermally synthesized. Because of its flexible structure, JLU-Liu33 exhibits a breathing behavior upon N2 and CO2 adsorption at low temperature, and C2H6 and C3H8 adsorption at 273 and 298 K. Furthermore, by adopting the direct synthesis method, two isomorphic compounds—JLU-Liu33L and JLU-Liu33H—have been obtained by partial substituting Zn with different amounts of Co into the JLU-Liu33 framework. The gas adsorption study of Co-doped materials reveals that the gate opening effect of JLU-Liu33 can be modulated by introducing different contents of Co2+ into Zn4O clusters. Meanwhile, with the increasing amount of Co2+, the adsorption amount and isosteric enthalpy values for CO2 have been improved. It is worth mentioning that JLU-Liu33H exhibits commendable selectivity for CO2 over CH4 which may be a good candidate for industrial gas purification and air separation applications.

A pair of homochiral porous supramolecular organic frameworks (JLU-SOF1-R and JLU-SOF1-S) has been assembled from brand-new enantiopure blocks via hydrogen bonding and π–π interactions. The frameworks not only maintain crystallinity well until 250 °C but also exhibit a steep slope N2 adsorption isotherm at 77 K with moderately high surface areas, indicating that the new materials own robust structure and permanent porosity. JLU-SOF1-R shows excellent adsorption capacity for CO2 and C2H6 at ambient conditions. Remarkably, the material takes up a significant amount of CO2, up to 213 cm3 g–1 at 195 K under 1 bar. Furthermore, JLU-SOF1-R exhibits high selectivity toward CO2 over N2 and CH4 as well as C2H6 over CH4.

By using a modulated synthetic strategy, three isostructural Zr-based metal organic frameworks [Zr6O4(OH)4(EDDC)6] (JLU-Liu34), [Zr6O4(OH)4(EDDC-NO2)6] (JLU-Liu35), and [Zr6O4(OH)4(EDDC-NH2)6] (JLU-Liu36) (H2EDDC = (E)-4,4′-(ethene-1,2-diyl)dibenzoic acid, H2EDDC-NO2 = (E)-2,2′-dinitro-4,4′-(ethene-1,2-diyl)dibenzoic acid, H2EDDC-NH2 = (E)-2,2′-diamino-4,4′-(ethene-1,2-diyl)dibenzoic acid) which possess different substituent groups have been successfully synthesized. Significantly, the framework and crystallinity of the functionalized Zr-metal–organic frameworks (Zr-MOFs) are well-retained even though the nature of the functional group is different (NO2 is electron-withdrawing, whereas NH2 is electron-releasing). All of the three analogues display 12-connected fcu topology, and the classical Zr6 clusters in the porous crystal make the whole framework approach high chemical and thermal stability. As a result of the functionalization effect, the three analogues show different sorption and separation abilities to small gases, especially for JLU-Liu34 which exhibits a significant C3H8 uptake capacity of 303 cm3 g–1 at 273 K under 1 bar. Although JLU-Liu36 shows lower Brunauer–Emmett–Teller surface area than JLU-Liu34, it possesses enhanced CO2 adsorption enthalpy and selectivity for CO2 over CH4 influenced by the additional amino groups. Ligand modification provides an efficient strategy to design and synthesize porous MOFs materials for small gases sorption and separation.

Two highly porous MOFs, [Co2(μ2-OH)(bpdc)(Htpim)2][SiF6]·3.5DMA·2.5CH3OH (JLU-Liu37, H2bpdc = biphenyl-4,4′-dicarboxylate, Htpim = 2,4,5-tri(4-pyridyl)imidazole) and [Ni2(μ2-OH)(bpdc)(Htpim)2][SiF6]·7.5DMA·6CH3OH (JLU-Liu38), have been solvothermally synthesized by using the mixed ligand strategy. Both of the compounds possess finite binuclear [M2(μ2-OH)(COO)2] (M = Co, Ni) secondary building units (SBUs) which formed with a polar functional group, μ2-OH. JLU-Liu37 and JLU-Liu38 exhibit notable adsorption capacities for CO2 and light hydrocarbons (CH4, C2H6, and C3H8). Moreover, both of the materials exhibit arrestive natural gas selective separation ability, especially for C3H8/CH4 (206 for an equimolar mixture under 1 bar and 298 K, for JLU-Liu37). Both of the MOFs may be effectively applied in the separation of industrial light hydrocarbons.

•Three novel bismuth-based coordination polymers were constructed from different coordination numbers of bismuth.•Compounds 1 and 2 feature 3D frameworks constructed from 9-coordinated and 8-coordinated Bi3 +, respectively.•Compound 1 exhibits tunable luminescence by doping lanthanide ions and high detection efficiency for nitro explosives.Three novel bismuth-based coordination polymers, [(CH3)2NH2][Bi(pdc)(bdc)]·2DMF, [(CH3)2NH2][Bi(tdc)2]·1.5DMF and [Bi(bpdc)2H2O]·xGuest (compounds 1–3) (H2pdc = 3,5-pyridinedicarboxylic acid, H2bdc = 1,4-benzenedicarboxylic acid, H2tdc = 2,5-thiophenedicarboxylic acid, H2bpdc = 4,4′-biphenyldicarboxylic acid), have been successfully synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction. Compounds 1 and 2, which are constructed by 9-coordinated or 8-coordinated Bi3 +, feature three-dimensional structures with hms and dia topology, respectively. However, 5-coordinated Bi3 + based compound 3 is a two-dimensional layered structure. Compound 1 can tune emissive performance by doping different lanthanide ions Tb3 +, Eu3 + and Dy3 +. Furthermore, detection of nitro explosives is investigated. All of the compounds are characterized by elemental analysis, IR spectrum and thermogravimetric analysis.Three novel Bi-based coordination polymers (compounds 1–3) have been constructed from different coordination numbers of bismuth. Compound 1 exhibits tunable luminescence by doping lanthanide ions into the structure and high detection efficiency for nitro explosives.Download high-res image (404KB)Download full-size image

By reacting with indium nitrate and tetrakis(4-carboxyphenyl)-porphyrin (H4TCPP), a mesoporous indium–porphyrin framework, named JLU-Liu7, which features a rare (4,4)-connected frl net based on 1D inorganic indium rod SBUs, has been constructed. It exhibits high performance for gas adsorption and light hydrocarbon separation.

A novel metal–organic framework, [(CH3)2NH2]2[Cu3O(SO4)3Cu2L2(DMF)(H2O)]·9DMF (JLU-Liu39) H2L = pyridine-3,5-bis(phenyl-4-carboxylic acid), has been successfully synthesized under solvothermal conditions. Structure analysis indicates that the framework of JLU-Liu39 is constructed by ternary building units which include a rare hexa-nuclear [Cu6O2(SO4)6] cluster, a classical [Cu2(CO2)4] paddlewheel, and a 3-connected hetero-N, O donor ligand. The whole 3D framework possesses a (3,4,4)-connected fjh topology and a large window size of 25.3 Å with high solvent-accessible volume accounting for approximately 75.8% of the cell volume. On the basis of the anionic framework and large pore volume, JLU-Liu39 can efficiently adsorb cationic dyes such as MLB, MV, RhB and neutral dye NR but exclude anionic dyes such as MO and Orange II. Moreover, JLU-Liu39 also exhibits size-exclusion performance for dyes of different sizes, and the dye adsorption amounts decrease with the increase of dye size. With respect to the proportional mixture dyes with different charges for MO & MLB and Orange II & MLB, JLU-Liu39 can be able to selectively adsorb the cationic dye MLB efficiently. Based on the aforementioned considerations, JLU-Liu39 is a good anionic-skeleton MOF material for the adsorption and separation of organic dyes.

Herein, three functional isoreticular zeolite-like supramolecular assemblies (ZSAs), [Co4(NH2-ImDC)4(1,2-PDA)4]·8H2O (ZSA-7), [Co4(CH2OH-ImDC)4(1,2-PDA)4]·8H2O (ZSA-8), and [Co4(Pr-ImDC)4(1,2-PDA)4]·9H2O (ZSA-9), NH2-ImDC = 2-amino-4,5-imidazoledicarboxylic acid, CH2OH-ImDC = 2-hydroxymethyl-4,5-imidazoledicarboxylic acid, Pr-ImDC = 2-propyl-4,5-imidazoledicarboxylic acid, 1,2-PDA = 1,2-propanediamine, were hydrothermally synthesized and structurally characterized. All three compounds are isoreticular to ZSA-1, with the modification of different functional groups of –NH2, –CH2OH, and –Pr in imidazole dicarboxylate ligands. ZSA-7 and ZSA-8 display high CO2 adsorption abilities (109.8 and 114.0 cm3 g−1 at 273 K, respectively, under 1 bar) and outstanding natural gas selectivity separation, especially for CO2 over CH4 (39.8 and 35.7 for CO2/CH4 = 0.5/0.5 and 76.0 and 51.6 for CO2/CH4 = 0.05/0.95, respectively, under 1 bar at 298 K). In contrast, ZSA-9 is used for comparison to illustrate the effect of the introduction of Lewis basic sites (LBSs). Thus, all three ZSAs are promising materials for gas adsorption and purification applications.

We report a Johnson hexadecahedronal coordination cage, constructed via 10 Ni4-p-tert-butylthiacalix[4]arene (Ni4-TC4A) units as vertices and 16 5-(pyridin-4-yl)isophthalate (PIP) ligands as tiles. It features a gyroelongated square bipyramidal geometry, equivalent to two square pyramids pillared by a square antiprism, a J17 Johnson solid. Remarkably, the cage compound exhibits a much higher uptake capacity of C3H8 than CH4, representing a promising material for separation of these two gases. In contrast, Co4-TC4A units are linked by PIP ligands and rare {Co4O4Cl2} clusters, providing a one-dimensional bamboo stick-like polymer.

A novel homochiral zeolite-like metal–organic framework (ZMOF), [(Cu4I4) (dabco)2]·[Cu2(bbimb)]·3DMF (JLU-Liu23, dabco =1,4-diazabicyclo[2.2.2]-octane, H2bbimb =1,3-bis(2-benzimidazol)benzene, DMF = N,N-dimethylformamide), has been successfully constructed to host unprecedented DNA-like [Cu2(bbimb)]n polymers with double-helicity. The host–guest chirality interplay permitted the induced formation of an unusual gyroid MOF with homochirality and helical channels in the framework for the first time, JLU-Liu23. Importantly, the enantiomeric pairs (23P, 23M) can be promoted and isolated in the presence of appropriate chiral inducing agents, affording enantioselective separation of chiral molecules as well as small gas molecules.

Two new isomorphous polyhedron-based MOFs (JLU-Liu20 and JLU-Liu21), with dual functionalities of OMSs and LBSs, have been synthesized by using the SBB strategy. By judiciously avoiding the DABCO axial ligand, JLU-Liu21 possesses more OMSs than JLU-Liu20, and exhibits a significant enhancement of CO2 uptake capacity 210 versus 162 cm3 g−1 for JLU-Liu20 at 273 K under 1 bar.

Bacillus subtilis lipase (BSL2) has been successfully immobilized into a Cu-BTC based hierarchically porous metal–organic framework material for the first time. The Cu-BTC hierarchically porous MOF material with large mesopore apertures is prepared conveniently by using a template-free strategy under mild conditions. The immobilized BSL2 presents high enzymatic activity and perfect reusability during the esterification reaction. After 10 cycles, the immobilized BSL2 still exhibits 90.7% of its initial enzymatic activity and 99.6% of its initial conversion.

Four metal–organic frameworks (MOFs) based on indium and a tetracarboxylate ligand have been synthesized through regulation of the reaction solvent conditions. The resultant compounds exhibited not only rich structural topologies (pts, soc, and unique topologies) but also interesting charge reversal framework features. By regulating the solvent, different building units (indium monomer, trimer) have been generated in situ, and they are connected with the ligand to form ionic frameworks 1–4, respectively. Among the synthesized four ionic frameworks, compounds 3 and 4 maintained keep their crystallinity upon heating temperature up to 300 °C and full removal of solvent guest molecules. Particularly, they also exhibit the charge reversal framework features (3 adopts an overall cationic framework, whereas 4 has an anionic framework). Both compounds 3 and 4 exhibit a notable significant uptake capacity for CO2 and H2; besides that, compounds 3 and 4 also offer excellent selective adsorption of CO2 over N2 and CH4.

Tunable Cu-BTC mesoporous metal–organic frameworks (mesoMOFs) are prepared conveniently through a template-free strategy under solvothermal conditions. Nanosized microporous Cu-BTC particles pack to form mesopores with sizes that can be controlled (26–72 nm) by simply varying the synthesis temperature. This template-free and controllable strategy can be applied using other organic solvents to obtain mesoMOF materials that possess similar tunable mesopores. Furthermore, the as-synthesized hierarchically porous MOFs materials are demonstrated as the electrocatalysts for oxygen reduction reaction under mild conditions.

Two fof-type porous metal–organic frameworks (MOFs), [Cu2(bdfdpa)(H2O)2]·8DMF·2H2O (JLU-Liu29) and [Cu2(btadpa)(H2O)2]·7DMF·8H2O (JLU-Liu30) (H4bdfdpa = 5,5′-(benzo[1,2-b:4,5-b′]difuran-2,6-diyl)diisophthalic acid and H4btadpa = 5,5′-(benzo[c][1,2,5]thiadiazole-4,7-diylbis(ethyne-2,1-diyl))diisophthalic acid), have been successfully synthesized by using different expanded tetracarboxylate ligands. Both of them exhibit good permanent porosity and high surface areas of 2205 and 1791 m2 g–1, respectively. Due to open metal sites, different functional groups, and suitable pore spaces, the two porous MOFs exhibit high adsorption performance for small molecule gases (CO2, CH4, C2H6, and C3H8) and removal of refractory organosulfur compounds.

Two porous MOFs, [NO3][In3OL3]·4DMF·3H2O (JLU-Liu18) and [CdL]·0.5DMF (JLU-Liu19), H2L = pyridine-3,5-bis(phenyl-4-carboxylic acid), have been solvothermally synthesized and structurally characterized. Both of the two compounds possess a saturated coordination metal centre without open metal sites (OMSs) leading to remarkable thermal and water vapour stability. JLU-Liu18 displays a rare occurrence of 9-connected, trinuclear [In3O(CO2)6N3] secondary building units (SBUs) in a porous crystal, with high adsorption for small gases, especially CO2 (129 and 400 cm3 g−1 at 273 and 195 K, respectively, under 1 bar). It also performs with commendable selectivity for O2 over N2, and CO2, C2H6, C3H8 over CH4. JLU-Liu19 possesses outstanding performance for sieving small gases owing to its ultramicropores of 3.5 Å. Both of the two MOFs are promising materials for gas adsorption and purification.

By using the supermolecular building block (SBB) strategy, a polyhedron-based metal–organic framework (PMOF), which features three types of cages with multiple sizes and shapes, has been synthesized. It exhibits high performance for CO2 capture (170 cm3 g−1 at 273 K under 1 bar) and selectivity of CO2/CH4 (9.4) and C3H8/CH4 (271.5).

Three metal–organic frameworks, [Mn(bpydc)]·DMA (JLU-Liu11), [Co(bpydc)DMSO]·(DMSO)(H2O) (JLU-Liu12) and [Co(bpydc)H2O]·H2O (JLU-Liu13), were solvothermally synthesized by reacting a T-shaped linker, 2,2′-bipyridyl-5,5′-dicarboxylic acid (H2bpydc) ligand with transition metals. These compounds exhibit three different types of structures. In JLU-Liu11, two oxygen atoms and two nitrogen atoms of the H2bpydc ligand coordinate to five manganese centers to form an ant net, and JLU-Liu11 displays two types of helical chains with opposite helical directions, which are composed of vertex-sharing 4-rings propagating along the [100] direction. In JLU-Liu12, H2bpydc ligands coordinate to cobalt centers to form a new (3,3)-connected net with two different tiles (6·124) and (62·126). In JLU-Liu13, H2bpydc ligands coordinate to cobalt centers to form a two-dimensional layer which then interacts with terminal water molecules via hydrogen bonds to construct a three-dimensional supramolecular structure, JLU-Liu13 shows exceptional stability in water. Additionally, the magnetic properties of all the compounds were studied.

A novel three-dimensional metal–organic framework, [Cu2I2]0.5[Cu2(CO2)4(C10H7N2)4]0.5·2DMF (JLU-Liu14), has been synthesized under solvothermal conditions, which is constructed by ternary secondary building units (SBUs): classical Cu2(CO2)4 paddle-wheel unit, Cu2I2 dimer unit, and organic SBU. In JLU-Liu14, the pyrimidine groups of 4-PmBC (4-(pyrimidin-5-yl) benzoic acid) ligands coordinated to copper paddle-wheel and Cu2I2 dimer units to form a zigzag chain, and the zigzag chains then connected together by 4-PmBC ligands to generate a three-dimensional framework with (3,4,6)-connected topology. There are two types of channels along the c axis with the dimensions of 14 × 14 Å and 5 × 5 Å, respectively, in which the big hexagonal channel is surrounded by six small trigonal channels. In addition, JLU-Liu14 displays the interesting ability of the uptake and release of iodine.

Three new metal–organic frameworks (MOFs) based on hetero-O, N donor ligands, (Cu4I4)[Cu2(PDC)2DMF2]2·2DMF·H2O (JLU-Liu15), (Cu4I4)[Cu3(CPNA)3(Dabco)0.5DMF3]·4DMF·4H2O (JLU-Liu16), and (Cu4I4)[Cu3(CPNA)3(H2O)0.5DMF3]·4DMF·4H2O (JLU-Liu17), (H2PDC = pyridine-3,5-dicarboxylic acid, H2CPNA = 5-(4′-carboxylphenyl) nicotinic acid, Dabco = 1,4-diazabicyclo[2.2.2]octane), have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction analyses. JLU-Liu15 features a (3,4,4)-c sqc5588 net, whereas JLU-Liu16 and JLU-Liu17 are isostructural and possess a new (3,4,4)-c topology. All of these compounds are composed of the binodal inorganic Cu2(CO2)4 paddlewheel and Cu4I4 cluster secondary building units (SBUs). It is worthy to note that the linkage between two nearby Cu4I4 clusters in JLU-Liu16 is μ2-Dabco, which changed to a μ2-water molecule in JLU-Liu17. Furthermore, JLU-Liu15 exhibits high CO2 adsorption behaviors as well as I2 uptake and release features.

Two unique entangled Cd(II) coordination polymers, {[Cd2(m-pdoa)2(dpa)3(H2O)]}n (1) and {[Cd(m-pdoa)(bpp) (H2O)]·2H2O}n (2) (m-H2pdoa = 1,3-phenylenedioxy diacetic acid, dpa = 4,4′-dipyridylamine; bpp = 1,3-di(4-pyridyl)propane), have been modulated using flexible/semi-rigid mixed aromatic carboxylate and pyridine derivative ligands and characterized using elemental analysis, infrared spectra (IR), powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1 shows the first topological motifs of mutual-embedded bilayers originating from two reverse 2D 44-sql layers with 1D single side arms in an alternating fashion, and thus affording a 3D polythreaded structure featuring poly-pseudo-rotaxane that exhibits a new 3D (3,3,3,3,3,5,5,5)-connected self-penetrated H-bonding net. Whereas 2 displays rare 2D → 2D homochiral interpenetrated layers propagating from 44-sql chiral layers. Additionally, thermal stabilities and luminescent properties for 1 and 2 were also discussed.

A novel three-dimensional metal–organic framework (MOF), [H3O][Cd3Cl(PZC)3(H2O)3] (1), has been synthesized based on a trinuclear Cd(II) cluster and H2PZC ligand (H2PZC = 1H-pyrazole-4-carboxylic acid). Compound 1 crystallizes in a trigonal crystal system with the space group R3m. Trinuclear Cd(II)-clusters as secondary building units (SBU) are further connected by the H2PZC ligand to form a two-fold interpenetrated 3D framework. Compound 1 exhibits excellent water-stability and good luminescence properties for various organic solvents and different metal ions. The systematic investigation for luminescence indicates that compound 1 possesses unique performance for the detection of acetone, Fe2+ and Na+ based on a fluorescence quenching and enhancing mechanism, thus it can be regarded as a potential luminescence probe for the detection of acetone, Fe2+ and Na+.

A luminescent metal–organic framework, [Cd2(TBA)2(bipy)(DMA)2] (1), has been synthesized under solvothermal conditions by employing mixed ligands of 4-(1H-tetrazol-5-yl)-benzoic acid (H2TBA) and 4,4′-bipyridine (bipy). Structure analysis shows that compound 1 is a three-dimensional network with a new (3,4,4)-connected topology. Compound 1 possesses the advantages of good water stability and exceptional thermal stability; it can retain framework crystallinity when it was suspended in water vapor for 10 hours or heated in air at 320 °C. Interestingly, when compound 1 detected different volatile organic solvent molecules, the variation of luminescence intensity depends on the various organic solvents and acetone shows the best quenching behavior. The results indicate that compound 1 may be considered as a potential luminescent probe for the detection of acetone.

Two novel MMOFs, JLU-Liu5 and JLU-Liu6, are based on ternary building units and exhibit high adsorption selectivity for CO2, C2H6 and C3H8 over CH4, which is attributed to steric effects and host–guest interactions. These MMOFs are promising materials for gas adsorption and natural gas purification.

[Co3(bpydc)2(HCOO)2H2O]·2DMF (JLU-Liu3) and [Zn3(bpydc)2(HCOO)2]·H2O·DMF (JLU-Liu4), two kinds of chiral flexible metal–organic frameworks, have been synthesized using 2,2′-bipyridyl-5,5′-dicarboxylate ligand (H2bpydc) and trinuclear clusters. The two materials reveal ant topology and exhibit uncommon stepwise N2 and CO2 adsorption behaviors with large hysteresis loops. The three-dimensional frameworks of JLU-Liu3 and JLU-Liu4 undergo structural transformation upon the removal of the guest molecules in the pores, which is indicated by the shift of powder X-ray diffraction peaks and the alteration of the peak intensity. These two flexible metal organic frameworks can be switched between the unique “closed” and “opened” forms via the removal of guest molecules. Moreover, after activation, both samples show high selective CO2 uptake over N2 and CH4.

The reaction of 5,5′-(1,2-ethynediyl)bis(1,3-benzenedicarboxylic acid) (H4EBDC) and dinuclear lanthanide building blocks generates five new three-dimensional lanthanide metal–organic frameworks (Ln-MOFs) with different topologies under mild conditions. Isomorphic compounds |C2H7N|[Ln2(EBDC)(NO3)2(C3H7NO)4] [Ln = Eu (1), Tb (2), or Er (3)] crystallize in monoclinic symmetry space group C2/c and adopt PtS topology. Under modified conditions, new phases |(NO3)0.5(H3O)0.5|[Yb2(EBDC)(NO3)2(C3H7NO)4] (space group C2/c, compound 4) and |(H3O)2(C3H7NO)2.5|[Eu2(EBDC)2(C3H7NO)(H2O)] (space group P21/c, compound 5) are obtained. In 4, both of the inorganic and organic building blocks can be simplified into a four-coordinate node, forming an Lvt topological network. For compound 5, the dinuclear Ln unit works as an 8-connected node and the organic ligand serves as a 4-connected node; these two kinds of nodes connect and then present an unprecedented (4,8)-connected topology. The aforementioned Ln-MOFs are all characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analysis, and their luminescent properties have been studied, showing emission characteristic of inorganic species at room temperature.

Twelve novel three-dimensional (3D) lanthanide metal–organic frameworks with formula {[LnK(C4N2O4S)2(H2O)2](H2O)0.5} (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8)), {[Ln2K2(C4N2O4S)2(C4O4H2)2(H2O)4](H2O)} (Ln = La (9), Ce (10)), and {[Ln2(C4N2O4S)3(H2O)](H2O)} (Ln = La (11), Ce (12)), are solvothermally synthesized by reacting the 1,2,5-thiadiazole-3,4-dicarboxylate (H2tdc) ligand with the corresponding lanthanide nitrate. These compounds exhibit three different types of structures which changed from nonporous to open-framework MOFs by adjusting the reaction conditions. Compounds 1–8 (type I) with a moc topology are constructed of 1D zigzag chains and pillared water molecules. Fumaric acid (Fac) as the coligand is introduced in the reaction to replace the pillared water and link similar zigzag chains to assemble compounds 9 and 10 (type II) with a dia topology. Compounds 11 and 12 (type III) with the chiral space group exhibit 1D right/left helical chains along the b axis, and the helical chains alternatively link together to form 3D frameworks with a new (3,4,5)-connected topology. The luminescence study shows that compounds 5, 6, 8 display intense orange, red and green luminescence and exhibit typical Sm3+, Eu3+ and Tb3+ ion emission, respectively. Furthermore, compounds 1, 7, 9 and 11 also exhibit intense green and blue luminescence arising from the H2tdc ligand.

[In(bpydc)(NO3)(DMA)0.5]·(DMA)(H2O)4.5 (JLU-Liu8), [In(bpydc)(HCOO)H2O]·(DMF)2(H2O)3 (JLU-Liu9) and [In(bpydc)Cl]·(DMF)2(H2O)3 (JLU-Liu10), three novel 3D monoatomic indium–organic frameworks, have been synthesized from the 2,2′-bipyridine-5,5′-dicarboxylic acid (H2bpydc) ligand under solvothermal conditions. These three compounds are constructed from the same ligand, but templated using three different anions (NO3−, HCOO− and Cl−), and they exhibit three different 4-connected ung, crb and cbo network topologies. JLU-Liu8 exhibits two types of single-helical chains with opposite helical directions (left-handed and right-handed), all of the left-handed and right-handed helical chains alternate together. In the structure of JLU-Liu9, there are two types of metal–ligand channels: the smaller square channels with dimensions 3.45 Å × 4.03 Å and the bigger square channels with dimensions of 11.5 Å × 11.5 Å. JLU-Liu10 displays an interesting feature of double-helical chains: both helical chains are interconnected with each other by sharing indium ions which entangle one spiral shaft. Furthermore, the role of anions in assisting the formation of distinct structures has been discussed. These three compounds display strong luminescence in the solid state at room temperature.

A porous sodalite-type metal–organic framework based on tetrazolcarboxylate ligands and [Cu4Cl]7+ squares was successfully synthesized, which exhibited permanent porosity and high adsorption abilities of H2, CO2 and organic chemical pollutants.

By using 4-(pyrimidin-5-yl) benzoic acid (4-PmBC) as a ligand, a porous metal–organic framework based on unique octa-nuclear copper clusters was constructed, which exhibited highly selective CO2 uptake over N2 and CH4.

Six novel coordination polymers based on a multifunctional ligand, 5,5′-(1,2-ethynyl)bis-1,3-benzenedicarboxylic (H4EBDC), namely, |(C3H7NO)2(H2O)7(C2H5OH)3|[Zn2(C18H6O8)(C10H8N2)2] (1), |(C3H7NO)3(H2O)30(CH3CN)2|[Zn6(C18H6O8)3(C6H12N2O2)2] (2), |(C3H7NO)2(H2O)2(H3O)2|[Cd3(C18H6O8)2] (3), |(C3H7NO)|[Mn(C18H8O8)(C3H7NO)2] (4), |(C3H7NO)2(H2O)(C2H7N)3|[Mn6(C18H7O8)4(H2O)8] (5), and [Mn2(C18H6O8)(C3H7NO)2] (6), have been constructed under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction. In these compounds, the ligand, H4EBDC, exhibits different coordination modes and conformations, constructing various architectures by bridging a variety of metal ions or polynuclear clusters. Compound 1 forms a three-dimensional (3D) FSC network constructed from two-dimensional (2D) layer motifs joined by EBDC4– and 4,4′-bipyridine bridges. Compound 2 possesses an NbO topology by linking Zn2(CO2)4 units with the ligand, coordinated amine molecules fill the pores, while compound 3 exhibits a 3D FLU network with Cd2+ as the cation and features an infinite framework built from tricadmium clusters. Compound 4 is based on PtS net, constructed of 4-connected rectangular H4EBDC units with tetrahedral monometallic Mn(CO2)4 nodes. Compound 5 is composed of 2D layers with (3,6)-connected KGD topology, and compound 6 consists of a 3D PtS-X network, built by bridging a metal chain with the ligand. The structures of these compounds have been discussed together with their corresponding properties, such as gas storage, separation, and magnetic properties.

Four three-dimensional (3D) Cd-based metal–organic frameworks (MOFs), [Cd(pyip)(dmf)] (1), [Cd(pyip)(doa)] (2), [Cd(pyip)(pz)] (3) and [Cd(pyip)(bipy)(H2O)0.5] (4) (dmf = N,N′-dimethylformamide, doa = 1,4-dioxane, pz = pyrazine, bipy = 4,4′-bipyridine) have been rationally designed and systematically synthesized by using 5-(pyridine-4-yl)isophthalic acid (H2pyip) and Cd(NO3)2·4H2O under solvothermal conditions. Compound 1 possesses a mineral-like 3,6-connected rtl network, and compounds 2–4 exhibit a 3,5-connected interpenetrating hms network constructed with 2-fold layers and bridging coligands pillars (doa, pz, and bipy), respectively. In compounds 2–4, doa, pz, and bipy act as pillars to extend the distance between the two layers from 7.34 to 11.36 Å, and the different conformations and lengths of the coligands have influenced the angles between the bridging ligands and the layers. Additionally, the four compounds exhibit strong luminescent emissions in the solid state at room temperature, and the latter three compounds exhibit robust architectures as evidenced by their permanent porosity and high thermal stability.

Two novel anionic indium phosphites, formulated as [H3O][In(HPO3)2] (1) and [C4H12N2][In2(HPO3)3(C2O4)] (2), were prepared under hydrothermal conditions by using piperazine (PIP) as a structure-directing agent (SDA). Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 crystallize in the hexagonal space group P63mc (No. 186) and orthorhombic space group Cmcm (No. 63), respectively. Compound 1, constructed from InO6 octahedra and HPO3 pseudo-pyramids, exhibits a rare (3,6)-connected layer structure with kgd (Kagome dual) topology. Compound 2, on the other hand, features a 3D phosphite-oxalate hybrid structure with intersecting 8- and 12-MRs channels. From a topological perspective 2 can be regarded as a (3, 5)-connected binodal net with the Schläfli symbol (42.6)(42.65.83).Graphical Abstracthighlights► Two novel indium phosphite and indium phosphite-oxalate hybrid compounds are synthesized. ► (3, 6)-connected layer structure with kgd topology. ► (3,5)-connected binodal net with the Schläfli symbol (42.6)(42.65.83).

Three novel isostructural lanthanide organic frameworks, |(H2O)(H3O)|[Ln(HPyImDC)(OX)0.5Cl] (Ln = Pr (1), Nd (2), and Sm (3), H3PyImDC = 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid, H2OX = oxalic acid) have been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis, IR spectra, and thermogravimetric analysis. The results of crystal structural analysis indicate that three compounds are isomorphous 3D frameworks, which are constructed by lanthanide polyhedral {LnNClO6}, 4-connected HPyImDC2– ligand and bridging OX2– ligand. The HPyImDC2– ligand offering its four oxygen atoms and one nitrogen atom of the pyridyl group, and the OX2– ligand offering all its four oxygen atoms coordinate with the lanthanide ions, which is a key essential for constructing the 3D frameworks. Topological analysis reveals that the 3D framework can be simplified into a 5-connected network with the lanthanide ion as a unique node, possessing the rare sqp topology. Meanwhile, the luminescent properties of three compounds in the solid state at room temperature are also investigated.

Two novel metal–organic frameworks (MOFs) |(H3O)1.5(H2O)3|[Cd2K0.5(C4N3O4)2(H2O)] (1) and |(H3O)(H2O)|[Cu4(C4N3O4)3(H2O)3] (2) were solvothermally synthesized using 1,2,3-triazole-4,5-dicarboxylic acid (H3tzdc), which exhibited novel and diverse coordination modes. In compound 1, the ligand, which shows three novel types of coordination modes, is coordinated to cadmium atoms to generate a tetranuclear cluster that leads to a 5-connected bnn network with two distinct channels along the [001] and [010] directions. In compound 2, the ligand, which serves as a T-shaped linker, is coordinated to copper atoms to form a unique metalloporphyrin-like plane, resulting in a pto network without interpenetration. Gas adsorption was investigated for compound 1. In addition, a diverse blue luminescence response toward different guest molecules by compound 1 has been observed.

Solvothermal reaction of Ln(NO3)3·6H2O (M = Eu, Tb) with a rigid tetracarboxylate organic ligand, 5,5′-(1,2-ethynediyl)bis(1,3-benzenedicarboxylic acid) (H4EBDC), affords two novel isostructural lanthanide-based metal–organic frameworks (MOFs): [Ln(HEBDC)(DMA)(H2O)2] (Ln = Eu (1) and Tb (2), DMA = N,N′-dimethylacetamide). X-ray single-crystal structural analyses reveal that both compounds crystallize in the triclinic space group P-1. The crystal structures constructed from HEBDC3 − ligand and the binuclear Ln2 building unit. Each of the noncentrosymmetric Ln atoms is bridged through carboxyl groups to generate binuclear Ln building unit, then the binuclear building units are linked together by the organic ligands to give rise to a binodal (3,6)-connected network with a rare kgd topology. The layers further extend into 3D supramolecular frameworks via aromatic π–π stacking interactions. The compounds discussed herein exhibit strong fluorescence in the visible region at room temperature and promising luminescent properties.Two novel lanthanide MOFs [Ln(HEBDC)(DMA)(H2O)2] (Ln = Eu (1) and Tb (2)), featuring unusual binodal (3, 6)-connected kgd topology, have been synthesized. Compounds 1 and 2 exhibit strong fluorescence in the visible region at room temperature.Highlights► Two novel lanthanide MOFs based on rigid tetracarboxylate ligand have been synthesized. ► (3, 6)-connected network with kgd topology. ► The compounds exhibit luminescence emission.

A cadmium compound [Cd(C10H5N3O4)(H2O)2] 1, based on 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H3PyImDC) has been solvothermally synthesized and characterized. Single-crystal structural analysis reveals that the compound crystallizes in the orthorhombic system, Pna21 space group with a = 6.8293(14) Å, b = 12.331(3) Å, c = 13.732(3) Å, V = 1156.3(4) Å3 and R1 = 0.0257. In compound 1, two nitrogen and two oxygen atoms of the H3PyImDC ligand coordinate to two Cd2+ ions to form a straight chain which then pack with each other via strong π–π and hydrogen-bondings interactions to construct a three-dimensional (3D) supermolecular structure. Further characterization of compound 1 was performed by X-ray powder diffraction (XRD), thermal gravimetric analyses (TG), infrared (IR) spectra, inductively coupled plasma (ICP) and elemental analyses. The fluorescent property was also evaluated.A supermolecular structure based on 2-(pyridine-3-yl)-4,5-imidazoledicarboxylic acid, with high hydrothermal stability and strong florescent emissions for its strong π–π and hydrogen-bondings interactions, has been synthesized and characterized.

We report the synthesis, structure, and characterization of two novel porous zeolite-like supramolecular assemblies, ZSA-1 and ZSA-2, having zeolite gis and rho topologies, respectively. The two compounds were assembled from functional metal−organic squares (MOSs) via directional hydrogen-bonding interactions and exhibited permanent microporosity and thermal stability up to 300 °C.

Three novel metal−organic frameworks (MOFs), |(C3H7NO)2(H2O)|[Zn3(C10H5N3O4)3(C3H7NO)2] (1), |(H2O)5(H3O)(NO3)|[Nd2(C10H5N3O4)3(H2O)4] (2), and |(H2O)2|[Nd3(C10H5N3O4)3(C10H4N3O4)] (3), based on the T-shaped tripodal ligands 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid and 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H3PyImDC), have been constructed under solvo-/hydrothermal conditions. The diverse coordination modes of H3PyImDC ligands have afforded the assembly of three novel compounds. In compound 1, two oxygen atoms and three nitrogen atoms of the H3PyImDC ligand, a T-shaped linker, coordinate to two zinc centers to form a novel bbm net with two distinct channels along the [100] and [001] directions. In compound 2, H3PyImDC ligands coordinate to neodymium centers to form a ladder-like chain which then interacts with a water molecules chain via hydrogen-bondings to construct a 3D supermolecular structure. In compound 3, H3PyImDC ligands, a T-shaped linker, coordinate to neodymium centers to form a (3,6)-connected net with an ant topology. In compounds 1−3, the two H3PyImDC ligands exhibit different coordination modes with zinc and neodymium centers, which afforded the expected structural diversity. Additionally, all three compounds exhibit strong fluorescence emissions in the solid state at room temperature.

The assembly of Cu(CH3COO)2·H2O and pyridine-4,5-imidazoledicarboxylic acid (H3PyImDC) under solvothermal conditions in the presence of different organic templates yielded two three-dimensional chiral frameworks, |(C3H10N2)(C3H7NO)0.5(H2O)2|[CuIIC10H5O4N3] (1) and |(C4H9NO)0.5(H2O)8|[CuII2CuI(C10H5O4N3)2(C10H6O4N3)] (2). Both of the compounds crystallized in the cubic, P4332 space group and possessed open helical channels in the frameworks. To the best of our knowledge, compounds 1 and 2 present the first synthesized MOFs with a bmn and lcy-a net. Further characterization of the two compounds has been performed, including X-ray powder diffraction, inductively coupled plasma analysis, CHN, IR spectra, fluorescence spectra, X-ray photoelectron spectroscopy spectrum and thermogravimetric-differential thermal analysis.

A new tetracarboxylate ligand with two alkyne functionalities has been synthesized and used to form a three-dimensional (3D) metal−organic framework {[Cu2(BDDC)(H2O)2]·DMF·3H2O}n (H4BDDC = 5,5′-(buta-diyne-1,4-diyl) diisophthalic acid) (DMF = N,N′-dimethylformamide). The single-crystal structure analysis reveals the topology is based on the NbO net, constructed by 4-connected rectangular ligands and 4-connected square Cu2(CO2)4 secondary building units (SBUs). The compound has permanent porosity with a large Langmuir surface area of 3111 m2/g, and shows excess and total H2 uptake as high as 3.98 and 4.60 wt %, respectively, at 77 K and 17 bar.

Reactions of nitrilotris(methylenephosphonic acid), [N(CH2PO3H2)3] (NTP) with cadmium acetates under different hydrothermal conditions result in two novel 3D cadmium organotriphosphonates complexes: Na|Cd2[N(CH2PO3H)(CH2PO3)2(H2O)] (1) and Na2|Cd5[N(CH2PO3)3]2(H2O)2| (2). Single-crystal X-ray diffraction analysis reveals that complex 1 crystallizes in monoclinic P21/c (No. 14), with a = 11.9730(3) Å, b = 10.5928(3) Å, c = 9.4435(2) Å, β = 97.881(2)°, V = 1186.38(5) Å3, and Z = 4. Complex 2 is monoclinic C2/c (No. 15) having unit cell parameters a = 25.377(5) Å, b = 10.543(2) Å, c = 9.7160(19) Å, β = 107.22(3)°, V = 2482.9(9) Å3, and Z = 4. The structures of complexes 1 and 2 both feature 3D coordination networks built from cadmium octahedral linked together by bridging phosphonate groups from NTP, sodium cations are deposited in the free volume of the structures. Hydrogen bonds are existed in structures. Notably, SBU-1 (Cd2(NTP)) and SBU-2 (Cd3(NTP)), formed by deprotonated NTP chelating with cadmium atoms, are present in the structure of complexes 1 and 2, respectively. The effect of the extent of deprotonation of phosphonic acids on the type of complex formed is discussed. Further characterizations of the two complexes have been performed, including X-ray powder diffraction, ICP, CHN, IR and TG–DTA analyses.

A novel anionic three-dimensional indium phosphite-oxalate hybrid material, formulated as |C6H14N2|[In2(HPO3)3(C2O4)] (1) was prepared under hydrothermal conditions by using 1,4-diazabicyclo[2.2.2]octane (dabco) as a structure directing agent (SDA). Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the orthorhombic system space group Pna21 (No. 33) having unit cell parameters a = 12.4143(13) Å, b = 7.7166(8) Å, c = 18.327(2) Å, V = 1755.6(3) Å3, and Z = 4 with R1 = 0.0282, wR2 = 0.0632. The novel 3D open framework is constructed from InO6 octahedra, HPO3 pseudo-tetrahedra and C2O4 units. The assembly of these building units generates intersecting 8- and 12-membered ring (MR) channels along two different directions. To the best of our knowledge, it is the first reported indium phosphite-oxalate hybrid material. Further characterization of compound 1 was performed using X-ray powder diffraction (XRD), infrared (IR) spectra, thermal gravimetric analyses (TGA), inductively coupled plasma (ICP) and elemental analyses.A novel three-dimensional indium phosphite-oxalate hybrid material with intersecting 8-MRs and 12-MRs channels has been prepared under hydrothermal conditions by using 1,4-diazabicyclo[2.2.2]octane (dabco) as structure direct agents.

Two novel three-dimensional vanadium phosphites |(C10H10N2)| V2IVO2(HPO3)2(H2PO3)21 and |(C4H16N3)| V2IVVIIIO2F2(HPO3)42 have been synthesized hydrothermally in the presence of structure-directing agents. Single-crystal structural analysis reveals that compound 1 has a three-dimensional open-framework with two different types of intersecting channels (monoclinic, P21/n, a = 6.3541(14) Å, b = 10.460(2) Å, c = 14.769(3) Å, β = 90.412(5)o, V = 981.6(4) Å3, Z = 2 with R1 = 0.0523), while compound 2 (orthorhombic, Pbca, a = 13.612(3) Å, b = 9.5753(19) Å, c = 14.022(3) Å, V = 1827.6(6) Å3, Z = 4 with R1 = 0.0441) presents a three-dimensional open-framework that consists of a novel {V3O14F2} trimer with mixed valence V2IVVIII linked by two bridging F atoms. In addition, it is worth noting that the organic templates play important roles in the formation of both novel structures. Further characterization of the two compounds has been performed, including X-ray powder diffraction, ICP, CHN, IR and TG–DTA analyses.

A new three-dimensional (3D) zincophosphite |Co(en)3| [Zn4(HPO3)5(H2PO3)] (1) has been solvothermally synthesized by using a racemic mixture of a chiral cobaltammine complex Co(en)3Cl3 as the structure-directing agent. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the monoclinic space group P21/c (no. 14) with a=18.6180 (4) Å, b=8.7601(18) Å, c=17.4840(4) Å, β=93.42(3)°, V=2846.4(10) Å3, Z=4 with R1=0.0530. Its structure is built up from strict alternation of ZnO4 tetrahedra and HPO3 pseudo-tetrahedra, giving rise to a 3D inorganic framework with 4-, 6-, 8-, 10- and 12 MRs, and the metal complex molecules, both the Δ and Λ enantiomers, sit in 10-MRs channels. In addition, it is worth noting that left- and right-handed helical chains exist in the framework, which is induced by chiral metal complex Co(en)3Cl3 template molecules. Further characterization of compound 1 has been performed, including X-ray powder diffraction, ICP, CHN, IR and TG analyses.A new three-dimensional zincophosphite containing left-handed and right-handed helical chains has been solvothermally synthesized using Co(en)3Cl3 as the structure-directing agent.

A novel metal–organic framework, [(CH3)2NH2]2[Cu3O(SO4)3Cu2L2(DMF)(H2O)]·9DMF (JLU-Liu39) H2L = pyridine-3,5-bis(phenyl-4-carboxylic acid), has been successfully synthesized under solvothermal conditions. Structure analysis indicates that the framework of JLU-Liu39 is constructed by ternary building units which include a rare hexa-nuclear [Cu6O2(SO4)6] cluster, a classical [Cu2(CO2)4] paddlewheel, and a 3-connected hetero-N, O donor ligand. The whole 3D framework possesses a (3,4,4)-connected fjh topology and a large window size of 25.3 Å with high solvent-accessible volume accounting for approximately 75.8% of the cell volume. On the basis of the anionic framework and large pore volume, JLU-Liu39 can efficiently adsorb cationic dyes such as MLB, MV, RhB and neutral dye NR but exclude anionic dyes such as MO and Orange II. Moreover, JLU-Liu39 also exhibits size-exclusion performance for dyes of different sizes, and the dye adsorption amounts decrease with the increase of dye size. With respect to the proportional mixture dyes with different charges for MO & MLB and Orange II & MLB, JLU-Liu39 can be able to selectively adsorb the cationic dye MLB efficiently. Based on the aforementioned considerations, JLU-Liu39 is a good anionic-skeleton MOF material for the adsorption and separation of organic dyes.

By reacting with indium nitrate and tetrakis(4-carboxyphenyl)-porphyrin (H4TCPP), a mesoporous indium–porphyrin framework, named JLU-Liu7, which features a rare (4,4)-connected frl net based on 1D inorganic indium rod SBUs, has been constructed. It exhibits high performance for gas adsorption and light hydrocarbon separation.

Uniform multi-shelled SnO2 hollow microspheres were synthesized through a sequential hard template method, and their electrochemical properties were investigated for their use as anodes for lithium-ion batteries. The multi-shelled SnO2 hollow electrode materials not only maintain a hierarchical structure during lithium ion insertion/extraction processes, but also improve the capacity of lithium-ion batteries.

With the help of the multiple secondary building unit (SBU) strategy, two novel heterovalent Cu–MOFs, [(Cu4I4)Cu4L4(DABCO)2]·16DMF (JLU-Liu31) and [(Cu4I4)Cu3L3(DABCO)(DMF)2]·18DMF (JLU-Liu32) [H2L = pyridine-3,5-bis(phenyl-4-carboxylic acid), DABCO = 1,4-diazabicyclo[2.2.2]-octane], have been successfully solvothermally synthesized and structurally characterized. Both of the two compounds feature multiple SBUs and exhibit novel topologies. JLU-Liu31 possesses the largest sustainable pore volume among the MOFs based on Cu4I4 clusters. Moreover, the adsorption behaviours of the desolvated JLU-Liu31 material for some small gases (H2, O2, CO2, CH4, C2H6 and C3H8) have been analysed in low pressure regions; meanwhile, it exhibits commendable selectivity for O2 over N2, and C3H8 over CH4. The remarkable results illustrate that JLU-Liu31 is a good candidate for application in the separation of light hydrocarbons. Additionally, JLU-Liu32 exhibits impressive performance for I2 sorption and release in solvents.

Two new isomorphous polyhedron-based MOFs (JLU-Liu20 and JLU-Liu21), with dual functionalities of OMSs and LBSs, have been synthesized by using the SBB strategy. By judiciously avoiding the DABCO axial ligand, JLU-Liu21 possesses more OMSs than JLU-Liu20, and exhibits a significant enhancement of CO2 uptake capacity 210 versus 162 cm3 g−1 for JLU-Liu20 at 273 K under 1 bar.

By using the supermolecular building block (SBB) strategy, a polyhedron-based metal–organic framework (PMOF), which features three types of cages with multiple sizes and shapes, has been synthesized. It exhibits high performance for CO2 capture (170 cm3 g−1 at 273 K under 1 bar) and selectivity of CO2/CH4 (9.4) and C3H8/CH4 (271.5).

By using 4-(pyrimidin-5-yl) benzoic acid (4-PmBC) as a ligand, a porous metal–organic framework based on unique octa-nuclear copper clusters was constructed, which exhibited highly selective CO2 uptake over N2 and CH4.

Two novel MMOFs, JLU-Liu5 and JLU-Liu6, are based on ternary building units and exhibit high adsorption selectivity for CO2, C2H6 and C3H8 over CH4, which is attributed to steric effects and host–guest interactions. These MMOFs are promising materials for gas adsorption and natural gas purification.

Two porous MOFs, [NO3][In3OL3]·4DMF·3H2O (JLU-Liu18) and [CdL]·0.5DMF (JLU-Liu19), H2L = pyridine-3,5-bis(phenyl-4-carboxylic acid), have been solvothermally synthesized and structurally characterized. Both of the two compounds possess a saturated coordination metal centre without open metal sites (OMSs) leading to remarkable thermal and water vapour stability. JLU-Liu18 displays a rare occurrence of 9-connected, trinuclear [In3O(CO2)6N3] secondary building units (SBUs) in a porous crystal, with high adsorption for small gases, especially CO2 (129 and 400 cm3 g−1 at 273 and 195 K, respectively, under 1 bar). It also performs with commendable selectivity for O2 over N2, and CO2, C2H6, C3H8 over CH4. JLU-Liu19 possesses outstanding performance for sieving small gases owing to its ultramicropores of 3.5 Å. Both of the two MOFs are promising materials for gas adsorption and purification.

A porous sodalite-type metal–organic framework based on tetrazolcarboxylate ligands and [Cu4Cl]7+ squares was successfully synthesized, which exhibited permanent porosity and high adsorption abilities of H2, CO2 and organic chemical pollutants.

Bacillus subtilis lipase (BSL2) has been successfully immobilized into a Cu-BTC based hierarchically porous metal–organic framework material for the first time. The Cu-BTC hierarchically porous MOF material with large mesopore apertures is prepared conveniently by using a template-free strategy under mild conditions. The immobilized BSL2 presents high enzymatic activity and perfect reusability during the esterification reaction. After 10 cycles, the immobilized BSL2 still exhibits 90.7% of its initial enzymatic activity and 99.6% of its initial conversion.