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The reasonable design and preparation of cheap, Earth-abundant, efficient, and durable heterogeneous electrocatalytic materials are a probable solution to the key problems of energy shortages and e...

The separation of C2 H2 from C2 H4 is one of the most challenging tasks due to the similarity of their physical properties. In addition, green synthetic protocol and adsorbent's stability are also the major concerns during the separation. Herein, under hydrothermal green synthesis conditions, an ultrastable ultramicroporous Zn-MOF was designed and synthesized with a high yield. The pore diameter of the Zn-MOF is 3.6 A, which lies in between the diameters of C2 H2 (3.3 A) and C2 H4 (4.2 A) molecules, leading to an efficient separation of the C2 H2 /C2 H4 mixtures by the sieving effect. The practical separation performance of C2 H2 /C2 H4 was confirmed by the dynamic breakthrough experiments. Moreover, the high stability enables the adsorption capacity of the Zn-MOF to C2 H2 , which can be maintained under a wide range of pH (1-13). Molecular simulations were also performed to identify the different C2 H2 - and C2 H4 -binding sites in Zn-MOF.

A new porous metal–organic framework (MOF) {[Cd(Hbptc)]·H2O}n (Cdbptc) was assembled by Cd(II) ions and a rigid (1,1′-biphenyl)-2,4,6-tricarboxylic acid (H3bptc) ligand via a solvothermal method. C...

The two functional fluorinated ligands 2-fluoro-4-(1H-tetrazol-5-yl)benzoic acid (2-F-H2tzba) and 3-fluoro-4-(1H-tetrazol-5-yl)benzoic acid (3-F-H2tzba) were obtained by modifying 4-(1H-tetrazol-5-...

On the basis of an undeveloped asymmetrical pyridylcarboxylate ligand, 2-(2-carboxypyridin-4-yl)terephthalic acid (H3CPTA), an indium pyridylcarboxylate framework, [(Me)2NH2]1.5[In1.5(CPTA)2]·5.5NMF·6H2O (1), is synthesized under solvent thermal conditions. 1 displays a 3D anionic framework with a large void space, which contains open square channels with a cross section of 14.6 A and a pore surface decorated with carboxylic oxygen atoms. Depending on the anionic skeleton and high water stability, 1 exhibits high adsorption selectivity and capacity for cationic dyes in aqueous solution. Furthermore, the luminescence performance illustrates that 1 has selectivity and sensitivity to nitenpyram with good recyclability.

A bifunctional ligand strategy for modification of the functional pores is of great significance in the structural design of metal-organic frameworks (MOFs). Herein, a new 2-fold interpenetrated "pillared-layer" 3D Co-MOF, {[Co(HL)(4,4'-bipy)]·DMF·2H2O}n (1), was successfully synthesized by using two kinds of ligands, imidazolecarboxylic acid and pyridine. The metal-carboxylic layers are pillared by the 4,4'-bipy ligand, displaying a 3D framework with rectangular 3D channels (high BET surface of 190.9 m2 g-1 and maximum aperture of 3.9 A) that are decorated with abundant uncoordinated N and O atoms. 1 shows good water stability and thermal stability (320 °C). The proper pores and active sites endowed 1 with a selective adsorption of Congo red in aqueous solution. In addition, a high CO2 adsorption capacity and an excellent CO2 chemical conversion were observed.

Tuning the emissive color changes of lanthanide (Ln) complexes is an important and appealing project for promoting the applications of Ln-complexes. A solvothermal reaction of 4-cyano-3-methylbenzoic acid (HL) and Ln(NO3)3·6H2O affords three isostructural Ln-complexes [Eu(L)3(H2O)2]n (1-Ln) (Ln = Eu, Gd and Tb) with one-dimensional chain structures. 1-Eu and 1-Tb show bright red and green emissions with absolute quantum yields of 3.06% and 11.96%, respectively, and the energy transfer was analyzed in detail through combined calculations. Interestingly, a series of heterometallic doped 1-TbxEu1-x coordination polymers were also obtained by mixing different ratios of Eu3+ and Tb3+ ions, which possess continuous luminescent color changes from green to yellow, orange and red. In addition, 1-Eu exhibits high quenching efficiency and low detection limit (∼10-4 M) for the simultaneous sensing of MnO4-, CrO42- and Cr2O72- ions in water.

To help address efficient separation of CH light hydrocarbons and CH/CO in the chemical industry, the self-assembly via an azolate-carboxylate ligand and Co(II) ion gave rise to a new porous MOF material, [Co(btzip)(Hbtzip)]·2DMF·2HO () (Hbtzip = 4,6-bis(triazol-1-yl)isophthalic acid). In the MOF, the pores are modified by rich uncoordinated triazolyl Lewis basic N atoms and acidic -COOH groups, which strengthen interactions with CH hydrocarbons and CO molecules, leading to high adsorption amounts for CH CH, CH, and CO and remarkable separation efficiency for CH-CH, CO-CH, and CH-CO mixtures, as confirmed by breakthrough experiments on the realistic gas mixtures. The MOF also reveals outstanding selective adsorption ability for benzene/toluene, methanol/1-propanol, methanol/2-propanol, and 2-propanol/1-propanol isomers. Molecular simulations disclose the different adsorption sites in the MOF for various adsorbates.

Herein, the synthesis of borodepsipeptides utilizing boron-containing isocyanides is described. The target compounds were synthesized via Passerini three-component reaction (P-3CR), in which H2O was utilized as the solvent. Further, unlike conventional P-3CR, where Lewis acid catalysts are often required, the reported method requires no catalyst and proceeds in room temperature. A variety of aldehydes and acids were used as the building blocks to generate the desired products.

The efficient backbone-directed self-assembly of cyclic metalla[3]catenanes by the combination of tetrachloroperylenediimide (TCPDI)-based dinuclear rhodium(III) clips and 4,4'-diazopyridine or 4,4'-dipyridylethylene ligands is realized in a single-step strategy. The topology and coordination geometry of the cyclic metalla[3]catenanes are characterized by NMR spectroscopy, ESI-TOF-MS spectrometry, UV/Vis-NIR spectroscopy, and X-ray diffraction studies. The most remarkable feature of the formed cyclic metalla[3]catenane is that it contains π-aggregates (ca. 2.6 nm) incorporating six TCPDIs. Further studies revealed that cyclic metalla[3]catenanes can be converted reversibly to their corresponding sodium adducts and precursor building blocks, respectively. This strategy opens the possibility of generating unique supramolecular structures from discrete functional π-aggregates with precise arrangements.

Utilizing 5,5′-oxidiisophthalic acid (H4odip) ligand, one 3D framework {[Ni2(odip)(H2O)4(DMF)]·DMF·2H2O}n (1) with a rare 3-nodal (3,3,4)-connected topological net based on two types of Ni12(odip)1...

The first isolable silylene-germylene complex 5 was assembled by a salt metathesis reaction between the germylene anion 3 and the N-heterocyclic chlorosilylene 4, and structurally characterized. The central structure of 5 demonstrates a remarkable gauche-bent geometry with the silylene and germylene units, which are interconnected by a Si-Ge bond with a length of 2.4498(9) A. This value is not only perceptibly longer than the distances known in doubly bonded germasilenes, and also slightly longer than those in germylsilanes. The DFT calculations on 5 confirmed a nearly nonpolar SiI -GeI single-bond nature and its bonding orbital, as well as the aromaticity of the C3 NGe-rings in 3 and 5. The latter increases the molecular stability of 3 and 5, and makes the preparation of silylene-germylene complex 5 a reality.

With the aid of a pyridyl tetracarboxylate ligand, 2,5-bis(2',5'-dicarboxylphenyl)pyridine (H4L), two indium-organic frameworks, [In2(L)(OH)2]·2DMF·2H2O (1) and [Me2NH2][In(L)]·2.5NMF·4H2O (2), with (6,8)- and (4,4)-connected nets have been constructed in different solvent systems. Both 1 and 2 exhibit high thermal and chemical stability. Gas sorption behavior of 1 and 2 for N2, C2H2, C2H4, CO2, and CH4 indicate excellent separation selectivities of C2Hx/CH4 and CO2/CH4. Furthermore, 1 possesses a high density of Bronsted sites and shows efficient catalytic conversion for CO2 cycloaddition with epoxides. Meanwhile, luminescence investigations reveal that 2 can detect nitrofurazone efficiently.

The coordination preference of different metal ions and ligands have an immense influence on the constructions of functional MOF materials. In this work, two new monometallic complexes, namely [Ag(HL)(bipy)0.5 ] (1) and {[Tb(L)1.5 (H2 O)]⋅4 H2 O}n (2) (bipy=4,4-bipyridine), have been synthesized successfully by employing a bifunctional 2-(imidazol-1-yl)terephthalic acid (H2 L) ligand. After that, two new different heterometallic-organic frameworks (HMOFs), namely {[TbAg(L)2 (H2 O)3 ]⋅H2 O}n (3) and [TbAg(L)2 (H2 O)]n (4), were obtained from complexes 1 and 2 as the precursors based on a rational stepwise construction strategy and the theory of hard and soft acids and bases (HSAB principle), respectively. The HMOFs bearing dual metallic catalytic sites (Tb and Ag) can be used as heterogeneous catalysts without losing performance for the chemical fixation of CO2 with epoxides including the sterically hindered epoxides, demonstrating some of the highest reported catalytic activity values. This work may provide a new synthetic route toward tailoring new HMOFs with excellent catalytic activity.

Metal-organic frameworks (MOFs) with zeolitic structure process fantastic structural metrics and display excellent applications in many aspects; however, they are difficult to assemble. Herein, on the basis of a tetrahedral Zn

Novel main-chain liquid crystalline Diels-Alder dynamic networks (LCDANs) were prepared that exhibit unprecedented ease for actuator programming and reprocessing compared to existing liquid crystalline network (LCN) systems. Following cooling from 125 °C, LCDANs are deformed with aligned mesogens self-locked at room temperature by slowly formed Diels-Alder (DA) bonds, which allows for the formation of solid 3D actuators capable of reversible shape change, and strip walker and wheel-capable light-driven locomotion upon either thermally or optically induced order-disorder phase transition. Any actuator can readily be erased at 125 °C and reprogrammed into a new one under ambient conditions. Moreover, LCDANs can be processed directly from melt (for example, fiber drawing) and from solution (for example, casting tubular actuators), which cannot be achieved with LCNs using exchangeable covalent bonds. The combined attributes of LCDANs offer significant progress toward developing easily programmable/processable LCN actuators.

Based on the mixed carboxylate ligands synthesis strategy, an indium-organic framework, (Me2NH2)1.5[In1.5(FBDC)(BDC)]·2.5NMF·CH3CN (1) has been constructed by using the mixed (2,5-di(2',5'-dicarboxylphenyl)-difluorobenzene (H4FBDC) and terephthalic acid (H2BDC). Compound 1 contains a 3D intersecting pore system which surface is modified by F atoms, and it has excellent stability in pH = 2-12 aqueous solutions. The activated 1 shows high separation for C2H2/CO2 and C2H2/CH4. Moreover, 1 not only has strong luminescence but also has the high selectivity and sensibility of fluorescence detection to nitrofurazone (NZF) in antibiotic sensing experiments, which can be used as a luminescence sensor for NZF detection.

Three new pairs of 2-fold interpenetrated and self-entangled three-dimensional isostructural porous metal-organic frameworks (MOFs), [Zn(L1)(x)0.5]·0.5H2O (x = bipy for 1, bpa for 2, and bpe for 3) and [Zn(L2)(x)0.5]·0.5H2O (x = bipy for 4, bpa for 5, and bpe for 6) [bipy = 4,4'-bipyridine, bpa = 1,2-bis(4-pyridyl)ethylene, and bpe = 1,2-bis(4-pyridyl)ethylene], have been created and fine-tuned via similar skeleton ligands 2-(imidazol-1-yl)terephthalic acid (H2L1) and 2-(1H-1,2,4-triazol-1-yl)terephthalic acid (H2L2) and N-auxiliary coligands with different linking groups. Interestingly, the porosities of the MOFs can be effectively increased via the insertion of -CH2CH2- or -CH═CH- spacers into the N-auxiliary bipy ligand. As a result, complexes 5 and 6 displayed highly enhanced CO2 uptake capacities. Furthermore, complex 5 also had a higher C2/C1 selectivity as well as great CO2 cycloaddition efficiency.

Palladium-catalyzed alkene-directed cross-coupling of aryl iodide with another aryl halide through C-H arylation opens a unique avenue for unsymmetrical biaryl-derived molecules. However, homo-coupling of aryl iodides often erodes the overall synthetic efficiency. Reported herein is a highly chemoselective Pd0 -catalyzed alkyne-directed cross-coupling of aryl iodides with bromophenols, which was subsequently followed by phenol dearomatization to furnish a very attractive [2+2+1] spiroannulation. Notably, possible homo-coupling of aryl iodides was not observed at all. Mechanistic studies indicated that a five-membered aryl/vinyl palladacycle most likely accounts for promoting the key step of biaryl cross-coupling.

Three new isostructural 3D lanthanide metal-organic frameworks (Ln-MOFs), {H[LnL(H2 O)]⋅2 H2 O}n (1-Ln) (Ln=Eu3+ , Gd3+ and Tb3+ ), based on infinite lanthanide-carboxylate chains were constructed by employing an ether-separated 5,5'-oxydiisophthalic acid (H4 L) ligand under solvothermal reaction. 1-Eu and 1-Tb exhibit strong red and green emission, respectively, through the antenna effect, as demonstrated through a combination of calculation and experimental results. Moreover, a series of dichromatic doped 1-Eux Tby MOFs were fabricated by introducing different concentrations of Eu3+ and Tb3+ ions, and they display an unusual variation of luminescent colors from green, yellow, orange to red. 1-Eu with channels decorated by ether O atoms and the open metal sites displays good performance for CO2 capture and conversion between CO2 and epoxides into cyclic carbonates.

A doubly interpenetrated metal–organic framework (MOF) [Zn4(L)3O]·8DMF·H2O (1, DMF = N,N-dimethylformamide) including the [Zn4O] clusters was first synthesized by employing a rigid 2,6-bis(4′-carbo...

Metallosupramolecular poly-NHC-metal assemblies were prepared from trigonal hexakis (H6 -1 a(PF6 )6 and H6 -1 b(PF6 )6 ) or nonakis (H9 -3(BF4 )9 ) imidazolium salts and Ag2 O. Complexes [Ag6 (1 a)2 ](PF6 )6 and [Ag6 (1 b)2 ](PF6 )6 are built from six Ag+ ions sandwiched between two trigonal hexacarbene ligands with an inner and an outer NHC donor in each of the three ligand arms. The metal atoms are arranged in two triangles. The hexakis-NHC ligands bear cinnamic ester groups at the outlying NHC donors, used in postsynthetic [2+2] cycloaddition reactions linking two hexakis-NHC ligands by three cyclobutane units to give complexes [Ag6 (2 a)](PF6 )6 and [Ag6 (2 b)](PF6 )6 bearing a dodecacarbene ligand. From the related nonakisimidazolium salt H9 -3(BF4 )9 , complex [Ag9 (4)](BF4 )9 bearing an octadecacarbene ligand was obtained. Removal of the template metals yielded very large, stable, polyimidazolium cations with 12 or 18 internal imidazolium groups.

By using a new 4,6-bis(imidazol-1-yl) isophthalic acid ligand (H2 bimip) with imidazolyl and carboxyl bifunctional groups, three new MOFs, [Co(bimip)(H2 O)0.5 ]⋅0.5 H2 O (1), [Zn(bimip)] (2), and [Mn(bimip)(H2 O)2 ]⋅H2 O (3), have been solvothermally synthesized in different solvent systems. H2 bimip displays three different coordinated modes through the imidazolyl and carboxyl groups, and different cis-cis and trans-cis configurations, which result in distinct 3D topological frameworks: a (4,8)-connected scu net for 1; a twofold interpenetrated (4,4)-connected pts net for 2; and a four-connected sra net for 3. Compounds 1 and 3 show antiferromagnetic properties, and 2 emits strong solid-state blue luminescence. Compound 1 shows good chemical stability in acidic and basic environments and in boiling water. Additionally, the polar channels in 1, which are decorated by uncoordinated carboxylate O atoms and imidazolyl fragments, allow it to adsorb CO2 molecules selectively over CH4 , and the CO2 binding sites in the framework were distinguished by molecular simulations.

To construct desired metal–organic framework (MOF) sensors, the predesigned functionalized ligands 2,5-bis(2′,5′-dicarboxylphenyl)pyridine (L-N) and 2,5-bis(2′,5′-dicarboxylphenyl)difluorobenzene (...

Metal sulfides with excellent redox reversibility and high capacity are very promising electrode materials for sodium-ion batteries. However, their practical application is still hindered by the poor rate capability and limited cycle life. Herein, a template-based strategy is developed to synthesize nitrogen-doped carbon-coated Cu9 S5 bullet-like hollow particles starting from bullet-like ZnO particles. With the structural and compositional advantages, these unique nitrogen-doped carbon-coated Cu9 S5 bullet-like hollow particles manifest excellent sodium storage properties with superior rate capability and ultra-stable cycling performance.

The ability to optically reconfigure an existing actuator of a liquid crystal polymer network (LCN) so that it can display a new actuation behavior or function is highly desired in developing materials for soft robotics applications. Demonstrated here is a powerful approach relying on selective polymer chain decrosslinking in a LCN actuator with uniaxial LC alignment. Using an anthracene-containing LCN, spatially controlled optical decrosslinking can be realized through photocleavage of anthracene dimers under 254 nm UV light, which alters the distribution of actuation (crosslinked) and non-actuation (decrosslinked) domains and thus determines the actuation behavior upon order-disorder phase transitions. Based on this mechanism, a single actuator having a flat shape can be reconfigured in an on-demand manner to exhibit reversible shape transformation such as self-folding into origami three-dimensional structures. Moreover, using a dye-doped LCN actuator, a light-fueled microwalker can be optically reconfigured to adopt different locomotion behaviors, changing from moving in the laser scanning direction to moving in the opposite direction.

An interpenetrated indium pyridylcarboxylate framework, [NH2(CH3)2][In(L)2]·2.5DMF·5H2O (1), has been synthesized by employing a pyridylcarboxylate ligand, 4-(3-carboxylphenyl)picolinic acid (H2L), and an In3+ ion, with both chemical stability and framework flexibility. The desolvated 1 exhibits an uncommon breathing sorption behavior and shows highly selective adsorption for C2H2, C2H4, and CO2 over CH4. Furthermore, 1 shows rapid and higher adsorption efficiency for methylene blue and neutral red in aqueous solution.

Owing to the rapid increase of Hg(II) ions in water resources, the design and development of new adsorbents for Hg(II) removal are becoming a significant challenge in environmental protection. Herein, a thiol-functionalized metal-organic framework (SH-MiL-68(In)) was successfully prepared through a post-synthesis modification procedure, and the framework intactness and porosity were well maintained after this process. SH-MiL-68(In) exhibited selective adsorption performance for Hg(II) ions in water. Meanwhile, SH-MiL-68(In) also shows a high adsorption capacity (450 mg g-1), large adsorption rate (rate constant k2 = 1.25 g mg-1 min-1), and good recycling of adsorption capacity toward Hg(II) ions. The excellent adsorption performance resulted from the strong binding interactions between -SH soft basic groups and Hg(II) soft acidic ions.

A novel palladium-catalyzed [4+1] spiroannulation was developed by using a C(sp3 )-H activation/naphthol dearomatization approach. This bimolecular domino reaction of two aryl halides was realized through a sequence of cyclometallation-facilitated C(sp3 )-H activation, biaryl cross-coupling, and naphthol dearomatization, thus rendering the rapid assembly of a new class of spirocyclic molecules in good yields with broad functional-group tolerance. Preliminary mechanistic studies indicate that C-H cleavage is likely involved in the rate-determining step, and a five-membered palladacycle was identified as the key intermediate for the intermolecular coupling.

To better understand the factors determining the multi-step relaxation processes in polynuclear lanthanide single molecule magnets (SMMs), two Dy(iii)4 SMMs showing two-step relaxation processes were elaborately designed and investigated for their structure-dependent magnetic properties. Through targetedly fine-tuning the auxiliary ligand (from the anion of 1-phenylbutane-1,3-dione to 2-acetylcyclopentanone) on specific Dy(iii) sites while retaining the same type of coordination atoms, one of the two relaxation processes shifted to higher temperature with an increase of energy barrier, which permits the unambiguous assignment of the relaxation processes to specific metal sites. Therefore, the present {Dy4} systems provide a good example to probe the factors determining the relaxation dynamics, and point to a simple way to optimize the magnetic performance of polynuclear dysprosium SMMs.

A facile template-engaged strategy is developed to synthesize hollow NiFe mixed metal oxyphosphide spheres using different Fe ions (Fe2+ and Fe3+) as modulators. Benefiting from the optimized compositional and structural features, the as-obtained hollow spheres show excellent performance for the oxygen evolution reaction.

Five new 3D MOFs: {[Zn3(HL)2H2O]·4H2O}n (1), {[Ba2L5H2O]·2H2O}n (2), {[Ba4(L)2·5H2O]·2H2O}n (3), {[Cd3(HL)2·Cl2·2H2O]·2H2O}n (4) and {[Cu2(L)2·2H2O]·4H2O}n (5), were constructed based on 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid. Structural analysis shows that 1–5 have 3D frameworks, among which 1(Zn) exhibits high luminescence sensing for Fe3+ ions, excellent framework stability and reusability. The sensing mechanism of 1(Zn) is briefly discussed. In addition, 5(Cu) displays antiferromagnetic exchange phenomena.

A new three-dimensional (3D) porous Mn(II)-based metal–organic framework [Mn4(L)2(H2O)4]n·4DMF·H2O (1) has been synthesized using Mn(II) and the rigid 2,6-di(2′,5′-dicarboxylphenyl)pyridine (H4L) ligand under solvothermal conditions. Structural analysis revealed that MOF 1 is an open framework with exposed active nitrogen atoms and rectangular-shaped channels along the b axis (with effective aperture sizes of 11.3 × 8.8 A2 and 10.7 × 8.7 A2). Gas sorption behaviors showed that MOF 1 has a relatively high capacity and selectivity for CO2 over CH4. Thus, the CO2 cycloadditions were studied using different epoxides, displaying the high efficiency of the catalyst. It was also found that MOF 1 shows rapid adsorption for the organic dyes. Therefore, MOF 1 should be explored as a multifunctional porous material for gas separation, catalysis and dye adsorption.

The reactions of an unexploited N,N'-5-carboxyl-1,3-phenylenebis(ethyl oxamate) (HEt2 L) ligand with different Mn2+ and Cd2+ salts under solvothermal conditions afforded four three-dimensional (3D) coordination polymers (CPs): [Mn1.5 L(H2 O)2 ]⋅H2 O (1) [Mn2 L(C2 O4 )0.5 (NMP)(H2 O)] ⋅ NMP (2), [Cd1.5 L(H2 O)2.5 ] ⋅ H2 O (3) and [Cd2 L(C2 O4 )0.5 (H2 O)3 ] ⋅ H2 O (4) (NMP=N-methyl pyrrolidone). L, generated by the in-situ hydrolysis of HEt2 L, displays four kinds of coordinating modes through oxamate and carboxylate groups as well as different syn-syn and syn-trans configurations. The resulting novel (3,4,5)-, (3,4,6)-, (4,5)- and (4,4,4,5)-connected topologies for 1-4 were formed. Among them, 1 has interesting 1D metal-oxamate zigzag chains, 2 contains 1D channels with a free void of 52.5 %, 3 consists of an unprecedented Cd-oxamate layer, 4 has a novel Cd-oxamate-oxalate chain. The antiferromagnetic interactions of 1 and 2 were observed, meanwhile 3 and 4 exhibit solid-state luminescence with the maximum emission bands at 483 and 479 nm, respectively, under an excitation of 332 nm.

The five new Ni(II) coordination polymers (CPs) {[Ni(bitp)(bpe)0.5(H2O)2]·0.5bpe}n (1), {[Ni(bitp)(bpa)0.5(H2O)2]·0.5bpa}n (2), {[Ni(bitp)(4,4′-bpy)0.5(H2O)]·H2O}n (3), {[Ni1.5(bitp)(Hbitp)(2,2′-bp...

By employing a pyridyl-decorated dicarboxylic acid ligand, 3-(2′,5′-dicarboxylphenyl)pyridine acid (H2dcpy), a three-dimensional In3+-based metal–organic framework, H3O[In3(dcpy)4(OH)2]·3DMF·4H2O (1), with a good chemical stability toward acid and base has been synthesized. The compound 1 shows an uncommon (3,8)-connected tfz-d; UO3 topological net based on linear In3(COO)4(OH)2 clusters and also contains one-dimensional open channels. Particularly, 1 contains two types of dcpy2– linkers, in which the pyridyl group in one participates in coordination with the In3+ ion, whereas that in the other is uncoordinated but hangs in the inner sides of the channels as functionalized sites. Gas adsorption experiments demonstrate that 1 is able to selectively adsorb C2H2, C2H4, and CO2 over CH4. Simultaneously, 1 shows a highly selective and sensitive fluorescence detection toward Fe3+ ion in water with good recyclability.

The incorporation of functional groups into the cavity of discrete supramolecular coordination cages (SCCs) will bring unique functions and applications. Here, three dicarboxylate ligands (H2 L1Cl, H2 L2Cl and H2 L3Cl) containing N-heterocyclic carbene (NHC) precursors as linkers were introduced to construct SCCs by combining with two C3 -symmertic (CpZr)3 (μ3 -O)(μ2 -OH)3 clusters as three-connect vertices, resulted in a series of rugby-like V2 E3 (V=vertex, E=edge) type homoleptic cages (SCC-1, SCC-2 and SCC-3). However, V4 E6 -type tetrahedral cages (SCC-4 and SCC-5), incorporating six Au-NHC moieties, were obtained when the corresponding NHC-gold(I) functionalized ligands (H2 L1Au , H2 L2Au ) were applied. For the first time, we present a trackable CpZr-involved cage to cage conversion to generate a heteroleptic V2 E3 cage (SCC-6) from two homoleptic cages (SCC-2 and SCC-5) with different geometries of V2 E3 and V4 E6 . The heteroleptic assembly SCC-6 can also be formed upon a subcomponent displacement strategy. The structural transformation and reassembly processes were detected and monitored by 1 H NMR spectroscopy and electrospray-ionization mass spectrometry. The formation of heteroleptic assembly was further supported by single crystal X-ray diffraction analysis. Moreover, homoleptic cage SCC-2 possesses a trigonal bipyramidal cationic cavity allowing the encapsulation of a series of sulfonate anionic guests.

To develop efficient adsorbent materials for storage and separation of C2 H2 , an unprecedented supercage MOF, [Me2 NH2 ]⋅[Zn3 (ALP)(TDC)2.5 ]⋅3.5DMF⋅2 H2 O (1) was constructed through medicinal molecule allopurinol (ALP) and S-containing 2,5-thiophenedicarboxylic acid (H2 TDC). 1 contains a novel linear trinuclear cluster that is composed by ALP and carboxylates and forms a final uncommon 5-connected yfy topological framework. The framework possesses three types of interlinked cages decorated by rich functional sites, and reveals not only high adsorption capacity for C2 H2 but also excellent selective separation for C2 H2 /CO2 and C2 H2 /CH4 at 298 K. Dynamic breakthrough experiments on C2 H2 /CO2 (1:1) mixture and C2 H2 /CH4 (1:1) mixture also demonstrated the potential of the material to separate C2 H2 from CO2 or CH4 mixtures. Molecular simulations were also studied to identify the different CO2 - and C2 H2 - binding sites in 1, such as carboxylate groups, S atoms and carbonyl groups.

We report the preparation of multivalent amide-sialoside-decorated human serum albumin (HSA) and bovine serum albumin (BSA) as mimics of natural mucin and bioshields against influenza virus infection. Free sialic acid with an amine on C-2 was covalently attached to the protein scaffolds using di-(N-succinimidyl) adipate. Dynamic light scattering (DLS) showed that the synthetic neomucins were able to act as bioshields and aggregate the influenza virion particles. The dissociation constants (KD) of the interactions between the prepared glycoconjugates and three different viral strains were measured by isothermal titration calorimetry (ITC) indicating the multivalent presentation of sialyl ligands on the HSA and BSA backbones can dramatically enhance the adsorbent capability compared to the corresponding monomeric sialoside. Hemagglutinin inhibition (HAI) and neuraminidase inhibition (NAI) assays showed that the glycoconjugates acted as moderate HA and NA inhibitors, thus impeding viral infection. Moreover, the different binding affinities of the glycoproteins to HA and NA proteins from different influenza viruses demonstrated the importance of HA/NA balance in viral replication and evolution. These findings provide a foundation for the development of antiviral drugs and viral adsorbent materials based on mimicking the structure of mucin.

We describe the preparation of thiosialoside-modified poly (methyl vinyl ether-alt-maleic anhydride) as second-generation polymeric conjugates for the inhibition of influenza virus infection. These synthetic glycopolymers show significantly enhanced neuraminidase inhibitory and antiviral activity in enzyme and cellular levels, respectively. The polyvalent thiosialosides also exhibit comparable inhibitory activity to the first-line anti-influenza drugs Zanamivir® and Oseltamivir® against the PR8 influenza virus strain in virus growth inhibition assays, which may be attributed to multivalent binding to neuraminidase on the virion particles, leading to the virion aggregation and further inhibiting the attaching/fusion and releasing steps in the influenza virus life-cycle. These findings suggest that attaching monomeric sialoside with neuraminidase inhibitory activity to a polymeric scaffold will synergistically disturb both the early and late stages of influenza virus infection, and provides a basis for the development of efficacious anti-viral agents against both wild-type and drug-resistant mutant strains.

Polyimidazolium-based cages are considered promising materials based on their fascinating properties and potential applications. These three-dimensional functional structures are highly desirable for the recognition of particular guest molecules, however, their synthesis remains challenging. In this work, we have designed and synthesizes a pure [n]-imidazolium (n=16) cage, the hexadecakisimidazolium salt H16 -2(PF6 )16 , from tetragonal octakisimidazolium salt H8 -1(PF6 )8 . The synthetic method involves formation of metal-carbene templates, a quadruple photochemical [2+2] cycloaddition reaction and subsequent removal of metal ions. Specifically, the synthesized cage, featuring sixteen imidazolium moieties, demonstrated high efficiency for the selective fluorescent recognition of 8-hydroxy-1,3,6-pyrene trisulfonate (HPTS). The present work not only further develops the metal-carbene template strategy by exploiting a new type of polyimidazolium cage, but also provides encouraging prospects for the design of versatile imidazolium-based functional acceptors.

Recent materials research based on fluorescent nanocelluloses (NCs) used in the field of sensing and bioimaging is reviewed. Many designed morphologies have been reported, such as nanoparticles, fibers, nanopapers, hydrogels and aerogels, that have been produced by physical or chemical methods. In the field of sensing and bioimaging, these studies have involved, but not been limited to, special optical properties including fluorescence, long-lived luminescence, polarized light, and/or aggregation-induced emission. The fluorescence sensing platforms can be categorized according to stimuli such as pH and temperature, as well as the presence of toxic compounds, and anions and metal cations. In addition, NCs exhibit unique low toxicity, good biocompatibility, biodegradability and cell membrane penetration, and can be modified into fluorescent nanoprobes for in vivo imaging and tracing. As an excellent platform for fluorescent sensing and bioimaging, NCs are bound to be increasingly studied and widely applied in the field of production and life sciences.

Utilizing the oxygen-bridged 5,5′-oxidiisophthalic acid (H4L) linker, one Co(II)-based 3D porous MOF {[Co5(L)2(OH)2(OH2)2(H2O)4]·2DMF·H2O}n (1) with pentanuclear [Co5(μ3-OH)2(μ2-OH2)2]8+ cluster was prepared. The glassy carbon electrode was modified by 1, and the obtained electrode revealed electrocatalytic performance for glucose oxidation. The porous MOF matrix is beneficial for dispersing Ag nanoparticles evenly in the interior cages or channels, so Ag@1 composite composed of both Ag nanoparticles and MOF was further prepared through deposition-reduction method to enhance electrocatalytic activity. The result demonstrates that the glucose oxidation by Ag@1 was greatly increased with low detection limit (1.32 μM) and good selectivity and sensitivity (0.135 μA μM–1), which promote the application of MOF-template porous composites as advanced electrochemical sensor materials. Furthermore, 1 shows an interesting magnetic spin-glass slow dynamics for the existing of peculiar pentanuclear Co(II) clusters.

In this work, we demonstrate the design and fabrication of a series of cylinder-like, hexazido-terminated MI-CNHC (M = Ag, Au) complexes. Moreover, we present for the first time a process-tracing and aggregation-induced emission (AIE) study of a covalent postassembly modification (PAM) process of the AuI-CNHC cylinders, highlighting the excellent versatility and complexity of functionalised poly-NHC compounds as a new type of molecular platform for novel applications.

A series of isomorphic lanthanide metal-organic frameworks (Ln-MOFs), {[Ln(L)(H2O)2]·5H2O}n (1-Ln, where Ln = Eu, Tb, Gd, and EuxTb1-x), have been synthesized by a rigid 1,3-bis(3,5-dicarboxyphenyl)imidazolium chloride (H4L+Cl-) ligand and Ln3+ ions via a solvothermal method. Single-crystal X-ray diffraction indicated that 1-Ln exhibited similar three-dimensional porous frameworks with one-dimensional channels decorated by the uncoordinated carboxylate oxygen atoms. The luminescent sensing studies indicated that 1-Eu is an outstanding reusable luminescent probe suitable for the simultaneous detection of Cr2O72-, CrO42-, and MnO4- ions in an aqueous solution. Remarkably, the different proportions of Eu3+ and Tb3+ can be combined into the same Ln-MOF to yield a new series of differently doped 1-EuxTb1-x MOFs. At the same excitation wavelength, they generated dual-emission peaks of Eu3+ and Tb3+ to show a gradual change in luminous color between yellow-green, yellow, orange, orange-red, and red. On the basis of the excellent optical properties of 1-Ln complexes, they can be employed as promising luminescent probe and multicolor tunable photoluminescence materials.

Using a triazole carboxylic ligand (H2L = 4-(1H-1,2,4-triazol-1-yl) isophthalic acid), four water-stable lanthanide metal–organic frameworks (Ln(III)-MOFs) (1-Ln, Ln(III) = Tb, Eu, Dy, and Sm), [Ln...

By systematic change of the solvothermal synthesis, three new coordination polymers, [Cd(L)∙(H2O)]∙2H2O (1), [Cd(L)∙(H2O)]∙H2O (2), and [Cd(L)] (3), have been synthesized based on a tritopic ligand 4-(pyridin-3-yl)isophthalic acid (H2L). Compounds 1 and 2 show very similar two-dimensional (2D) bilayers further linked by interlayer hydrogen bonds into three-dimensional (3D) supramolecular structures, while 3 displays a 3D structure constructed form one-dimensional (1D) Cd-carboxyl chains. Notably, 1 and 2 have a pair of unusual isomers with the opposite orientation of coordinated H2O on the metal centers, leading to different hydrogen bonding interactions. Thermal stabilities and solid-state photoluminescences for 1–3 were also investigated.

An achiral 2,2′-bipyridyl-3,3′-dicarboxylate (H2LN) can be oxidized to a C2 axially chiral N-oxide analogy (R,S)-2,2′-bipyridyl-3,3′-dicarboxylate-1,1′-dioxide ((R,S)-H2LNO), converting normal bipyridyl-N to a charge-separated N-oxide group. The achiral H2LN connects the Ag(I) ions into a 4-connected mesomeric 3D network [Ag4(LN)2·(H2O)]·3H2O (1). However, as expected, with the introduction of N-oxide groups, {Ag4[(R,S)-LNO]2·2(H2O)}·H2O (2) and {Ag2[(R,S)-LNO]}·H2O (3) contain right- and left-handedness homochiral layers. Such opposite handedness layers are linked together to give a racemic compound in 2 but meso double-layers in 3. Notably, both ligands in 1–3 support argentophilic interactions. Moreover, a luminescent comparison of 1–3, pyridyl-N, and its functional N-oxide ligands is also investigated in detail.

A new digermylene has been synthesized through the reaction of a six-membered cyclic radical germylene precursor with a mixture of CoBr2 and a seven-membered N-heterocyclic carbene. The density functional theory simulation on the geometry of the digermylene agrees well with the experimental X-ray diffraction result. The digermylene possesses the shortest GeI–GeI bond [2.4853(6) A] compared to the known singly bonded analogues, which can be attributed to σ → π* conjugation. In addition, it is revealed that a stable dative bond cannot form for the reductive radical germylene with the oxidative metal centers.