We demonstrate herein a general strategy for developing acentric or chiral nonlinear optical MOFs from centrosymmetric ligands by shifting the asymmetrical roles to the metal centers through heterometalation. With 1,3,5-benzenetricarboxylic acid (H3BTC), a very common polyfunctional centric ligand, the Li+/Zn2+, Li+/Co2+, or Li+/Cd2+ heterometallic combinations successfully led to five new noncentrosymmetric metal–organic frameworks, namely, {[Zn(HBTC)(H2O)]}n (SNNU-71), {Li4[Cd2(HBTC)(BTC)2]}n (SNNU-72), {CoLi(BTC)(DMA)2}n (SNNU-73), {CdLi2(BTC)4/3(H2O)3}n (SNNU-74), and {Li2[Zn3Li5(BTC)4(MTAZ)(H2O)4]}n (MTAZ = 5-methyl tetrazole, SNNU-75). All these MOFs are acentric or chiral on the base of helical chain building blocks and four colorless members of them show remarkable and tunable SHG effects. Remarkably, more than 1000 metal-BTC frameworks are reported to date and most of them are centrosymmetric due to the C3-symmery of BTC ligands. Clearly, our heterometalation approach greatly increases the possibility for induction of spontaneous resolution, which provides a fresh opportunity for the development of noncentrosymmetric functional MOF materials.

A general preparative method for multifunctional halogeno(cyano)cuprate materials in ionic liquids is developed in this work. Under ionothermal conditions, alkylimidazolium-based ionic liquids serving as solvent, charge-compensating, and structure-directing agent, as well as reactant lead to 12 members of the novel hybrid halogeno(cyano)cuprate family with a general formula of [R1R2R3IM]b+c−a[CuaXb(CN)c] (R1R2R3IM = alkylimidazolium cations, X = halide anions). X-ray single-crystal diffractions show that diverse inorganic halogeno(cyano)cuprate components vary from discrete complexes (1 and 2), one-dimensional (1D) chains (3–7), two-dimensional (2D) layer (8), to three-dimensional (3D) open frameworks (9–12). 1 and 2 are of zero-dimensional discrete structures containing triangular [CuX3]2– anions. In complexes 3–7, pentagonal bipyramidal [Cu2X3] units are bridged by CN groups to give 1D [Cu2X3(CN)]2– inorganic chains, which are charge-balanced by the surrounded alkylimidazolium cations. 2D inorganic [Cu5ClI2(CN)4]2– layer in complex 8 is alternately packed with [VMIM]+ organic cations. In complex 9, left- and right-handed Cu–CN helical chains connect each other to give a 3D open framework, which are further entrapped by 1D zigzag Cu–CN chains and [PMIM]+ cations. Diverse unique Cu(I) atoms and cyanide or halide bridging groups in 10, 11, and 12 are extended into 3D anionic open frameworks with 1D channels, which are occupied by alkylimidazolium cations. For all hybrid halogeno(cyano)cuprate complexes, the extensively existing C–H···X or C–H···π hydrogen bonds help to stabilize the ultimate supramolecular packing structures. Notably, the distances between adjacent Cu(I) centers range from 2.420(2) to 2.989(2) Å in all polymeric frameworks, which indicate strong Cu···Cu interactions. Thanks to the cooperation of conjugate π electron cyanide systems with halide ions and/or Cu···Cu interactions, compounds 1–12 all demonstrate strong solid-state photoluminescence and semiconducting performance. Specially, hybrid halogeno(cyano)cuprates reported herein first exhibit excellent photocatalytic degradation of organic dye. To the best of our knowledge, fewer than 10 crystalline halogeno(cyano)cuprate compounds were obtained before this work, although different synthetic routes have been involved. Clearly, the discovery of this large hybrid material family under ionothermal conditions is important for the further development of novel functional halogeno(cyano) filled-shell d10 metal crystalline materials.

The mimic of classic [Co(en)3]-like (en = ethylenediamine) structure generates a 3D chiral indium-imidazoledicarboxylate framework (SNNU-50) exhibiting significant SHG effects. 1D rod building units in SNNU-50 lead to a band gap value comparable to that of In2O3. Different from the high temperature metal oxide semiconducting sensor, MOF sensor prepared by the SNNU-50 sample demonstrates remarkable selectivity and low detection limit to four butanol isomers at room temperature. Notably, SNNU-50 represents the first MOF sensor showing the ability for structural isomer identification, which may open up a new promising application for porous metal–organic frameworks.

Reported herein is the new application of ionothermal synthesis for inorganic optical materials. Under ionothermal conditions with different imidazolium ionic liquids, novel quaternary heterometallic frameworks based on [Pb4(OH)4] cubane and [CuCl4] or [CuBr4] chains and [Cu2I6] binuclear clusters have been successfully produced. Simple chlorine, bromine and iodine replacement leads to not only the space group change (tetragonal I41/acd for 1 and 2, and orthorhombic Fddd for 3) but also the topological net transformation (8,12-net for 1 and 2, and 6,6-net for 3). Notably, compounds 1, 2 and 3 all show tunable solid-state semiconducting and luminescence properties.

The synthetic design of new porous open-framework materials with pre-designed pore properties for desired applications such as gas adsorption and separation remains challenging. We proposed one such class of materials, rod metal–organic frameworks (rod MOFs), which can be tuned by using rod secondary building units (rod SBUs) with different geometrical and chemical features. Our approach takes advantage of the readily accessible metal–triazolate 1-D motifs as rod SBUs to combine with dicarboxylate ligands to prepare target rod MOFs. Herein we report three such metal–triazolate–dicarboxylate frameworks (SNNU-21, -22 and -23). During the formation of these three MOFs, Cd or Zn ions are firstly connected by 1,2,4-triazole through the N1,N2,N4-mode to form 1-D metal–organic ribbon-like rod SBUs, which further joint four adjacent rod SBUs via eight BDC linkers to give 3-D microporous frameworks. However, tuned by the different NH2 groups from metal–triazolate rod SBUs, different space groups, pore sizes and shapes are observed for SNNU-21–23. All of these rod MOFs show not only remarkable CO2 uptake capacity, but also high CO2 over CH4 and C2-hydrocarbons over CH4 selectivity under ambient conditions. Specially, SNNU-23 exhibits a very high isosteric heat of adsorption (Qst) for C2H2 (62.2 kJ mol−1), which outperforms the values of all MOF materials reported to date including the famous MOF-74-Co.

•Thermal decomposition of indium-organic framework.•Ag-loaded mesoporous In2O3 materials.•Fast and high responses to HCHO.Mesoporous Ag/In2O3 composite materials with different concentrations of Ag particles have been prepared by the calcination of Ag+-entrapped indium-organic frameworks (InOFs). The structures and components of these MOF-derived Mesoporous Ag/In2O3 composite materials have been characterized thoroughly. Gas sensing measurements indicated that the incorporation of metallic Ag particles into the mesoporous structure significantly improves the gas-sensing properties of In2O3. Specially, the response of 5% Ag-loaded In2O3 sensor to 50 ppm formaldehyde is 5 times higher than that of pure In2O3 particles at 210 °C, which is among the best formaldehyde sensor materials reported to date. Also, Ag/In2O3 composite sensor exhibit short response time (~22 s) and excellent recovery. These results indicated that the InOF-derived mesoporous Ag/In2O3 materials maybe can be used to fabricate high performance formaldehyde sensors in practice.Mesoporous Ag/In2O3 materials have been produced by calcining indium-organic frameworks showing very fast and extremely high response towards HCHO.Download high-res image (230KB)Download full-size image

Different from popular mimics of bimetallic nuclear centers bridged by a hydroxide, a total coordination sphere of the active center of organophosphorus hydrolase was assembled in metal–organic frameworks by rational design and combination of ligands, which resulted in efficient destruction of nerve agent stimulants without a base as a co-catalyst.

Highly connected crystalline porous materials are rare but promising for gas adsorption and separation since varying pore shape and size as well as high framework stability may be achieved by tuning the framework connectivity. We demonstrate herein two highly connected frameworks, namely, {[Cd7(BDC)6(MTAZ)2(DMF)6]·3DMF}n (SNNU-11) and {[Cd5(BDC) (PTAZ)8(DMF)2]·4DMF}n (SNNU-12) (BDC = 1,4-benzenedicarboxylic acid, MTAZ = 5-methyl-tetrazole, and PTAZ = 5-(4-pyridyl)-tetrazole). In SNNU-11, BDC ligands link S-shaped [Cd7(MTAZ)2] motifs to form a novel 10-connected framework, which is related to but different from the reported 10-connected bct and gpu nets. Under the similar synthesis condition, the utilization of 5-(4-pyridyl)-tetrazole produced SNNU-12, which is constructed from zigzag Cd5 clusters and exhibits a 12-connected fcu net. Notably, SNNU-12 decorated with uncoordinated nitrogen sites shows not only high CO2 uptake capacity (87.9 cm3 g–1, 1 atm, and 273 K) but also high CO2 over CH4 and C2 hydrocarbons over CH4 selectivity, which is among the highest values of highly connected MOF materials (connectivity ≥10) including famous UiO-66 and rare-earth fcu-MOFs under the same temperature and pressure.

•Multi-functional tripodal rigid ligands.•The 1-2 reveal new (3,5)-net and alb-(3,6)-net topology, and containing a novel double-helical chains respectively.•Good fluorescence properties of 1-2, and antiferromagnetic magnetic for 2.Two three-dimensional coordination polymers (CPs), namely [Cd(bpydb)- (H2bpydb)]n·0.5nH2O (1), and [Cu2(bpydb)2]n (2) (2,6-di-p-carboxyphenyl-4,4’- bipyridine1 = H2bpydb), containing a novel double-helical chains, which have been solvothermal synthesized, characterized, and structure determination. CPs 1-2 reveal the new (3,5)-net and (3,6)-net alb topology, respectively. The fluorescence properties of CPs 1-2 were investigated, and magnetic susceptibility measurements indicate that compound 1 has dominating antiferromagnetic couplings between metal ions.

•Mesoporous In2O3 materials prepared by thermal decomposition of InOFs;•Tunable surface areas of porous In2O3 controlled by the calcination temperature;•Mesoporous In2O3 materials showed the highest responses to HCHO.Mesoporous In2O3 materials were synthesized by calcining indium-organic frameworks (InOFs, CPM-5 and MIL-68), which were further successfully utilized to detect toxic HCHO vapor. By taking the intrinsic structural features of two InOF precursors into account, the surface areas of produced indium oxides were well investigated via controlling the calcination temperature. The influence of surface area on the gas sensing performance was studied in detail. Porous In2O3 prepared by heat treatment at 650 °C showed the highest responses to 50 ppm HCHO (Rg/Ra = 31.8 and 38.0, respectively; Rg, resistance in gas; Ra, resistance in air) at 210 °C, which surpass the values of all the reported In2O3 materials to date under the similar conditions. The promising HCHO-sensing properties enable these InOF-templated mesoporous In2O3 materials to be competitive candidates for detecting poisonous formaldehyde in practice.Mesoporous In2O3 materials successfully produced by calcining indium-organic frameworks showing tunable porosity and high responses to HCHO, which surpass the values of all the reported In2O3 materials under the similar conditions.

•Ionothermal synthesis of crystalline inorganic materials•Unprecedented quaternary Ag–I–Pb–OH heterometallic framework•[Pb4(OH)4] cubane and [Ag2I6] dimeric building blocks•Remarkable luminescence and tuneable semiconducting propertiesWe reported herein an unprecedented quaternary heterometallic framework, namely, [AgPb2I3(OH)2] (1), which was successfully produced under ionothermal condition. In the title compound, [Pb4(OH)4] cubane and [Ag2I6] building blocks are jointed together to give a (6,6)-connected pcu topology. Compound 1 shows not only remarkable luminescent emissions, but also semiconducting properties tuned by the corresponding metal halide components.A novel quaternary heterometallic framework based on [Pb4(OH)4] cubane and [Ag2I6] building blocks was successfully produced under ionothermal conditions, which shows tuneable semiconducting and luminescent properties.

Reported herein is a novel porous metal–organic framework (MOF) exhibiting unique nanoscale cages derived from the 3-fold self-interpenetration of chiral eta networks based on trifurcate {Zn2(CO2)3} building blocks and 1,3,5-tris(4-carboxyphenyl)benzene ligands. The attractive self-interpenetrated structural features contribute to the highest CO2 uptake capacity and CO2 binding ability among the interpenetrated MOFs.

•Pillar-layered 3D Zn–triazolate–carboxylate frameworks•Diverse 3,4-connected topologies tuned by the bend angles of pillars•High thermal stability and blue photoluminescenceIn the utilization of three ditopic ligands with different bend angles as pillars, we reported herein three pillar-layered Zn–triazolate–carboxylate frameworks, namely, [Zn2(ATRZ)2(BDC)]n (1), [Zn2(ATRZ)2(TPDC)]n·2nDMF (2) and [Zn2(ATRZ)2(ADDC)]n (3) (ATRZ = 3-amino-1,2,4-triazole, H2BDC = 1,4-benzenedicarboxylic acid, H2TPDC = 2,5-thiophenedicarboxylic acid, and H2ADDC = 1,3-adamantanedicarboxylic acid). Single crystal structural analyses demonstrate that different geometries of ditopic carboxylate pillars not only result in Zn–ATRZ layers adopting various corrugated configurations, but also give rise to 3,4-connected self-interpenetrated net of 1 and non-interpenetrated nets of 2 and 3. All these compounds exhibit high thermal stability and blue photoluminescence.Reported herein three 3D pillar-layered MOFs designed by appropriate selection of well-known Zn–triazolate motifs as 2D layers, and ditopic aromatic carboxylate ligands as pillars.

•Zn-1,2,4-triazolate-dicarboxylates MOFs•Porous pillar-layered framework•Remarkable H2 and CO2 gas adsorption performance•tuneable CO2/CH4 selectivityTake advantage of the readily accessible layered Zn-1,2,4-triazolate motif and two isometric dicarboxylate ligands with different functional groups (trans,trans-1,3-butadiene-1,4-dicarboxylic acid, TTBDC and 2,5-dihydroxyterephthalic acid, DOBDC), we report herein two porous Zn-triazolate-dicarboxylate pillar-layered MOFs. Flexible TTBDC led to the formation of MOF 1 crystallizing in Pna21 space group, but rigid DOBDC produced MOF 2 in P4/ncc space group. Both pillar-layered MOFs show not only remarkable H2 and CO2 uptake capacity, but also high CO2 over CH4 selectivity.Two microporous Zn-triazolate-dicarboxylate pillar-layered MOFs decorated with different functional groups exhibit not only remarkable H2 and CO2 uptake performance but also high CO2/CH4 selectivity.

Nine members of the novel Ln–pyridine-3,5-dicarboxylate coordination polymer family, namely, [Ln(PDC)(GA)]n (Ln = Gd (1), Tb (2), Dy (3), Er (4)), [Ln(PDC)(OAc)(H2O)]n·nH2O (Ln = Sm (5), Eu (6), Gd (7)), [Gd(PDC)(OAc)(H2O)2]n·nH2O (8), and [Tb(PDC)1.5(H2O)]n (9) (PDC = pyridine-3,5-dicarboxylate, GA = glycolate, OAc = acetate), have been successfully obtained by carefully regulating the ancillary ligand or reaction temperatures. Complexes 1–4 are isomorphous two-dimensional networks generated by Ln–glycolate chains and bridging PDC ligands. When the HOAc was utilized instead of glycolic acid, isomorphic three-dimensional compounds 5–7 were isolated. The Ln3+ atoms are first bridged by acetate anions to give dinuclear clusters, which are extended by nearby six PDC ligands forming a 3D (3,6)-connected flu-topological framework. Notably, the increase of reaction temperature from 160 to 180 °C during the synthesis of compound 7 led to compound 8, the other 3D (3,6)-connected structure on the base of dinuclear subunits with rtl topology. Furthermore, the absence of HOAc introduced the formation of compound 9, in which each binuclear cluster links adjacent eight PDC anions to give a 3D (3,8)-connected tfz-d topological structure. The elemental analyses, XRPD, FT-IR, and TGA were also investigated to characterize compounds 1–9. Furthermore, solid-state photoluminescence measurements show that these Ln–pyridine-3,5-dicarboxylate coordination polymers produce strong emissions at room temperature.

Two supramolecular isomeric anionic porous coordination frameworks synthesised using ion liquids contain similar linear trinuclear zinc motifs but exhibit quite different (4,7)- and (4,6)-connected topologies. Isomer 1 can degrade methylene blue (MB) effectively under UV-light-irradiation, but isomer 2 showed remarkable visible-light-driven degradation of diverse organic dyes.

•Rare sulfonate and imidazole co-ligand system•Unique 3D interpenetrated framework triggered by ligand configuration•Good degradation efficiency of organic dye under visible light irradiationThe combination of 1,4-bis(imidazol-1-ylmethyl)benzene (BIYB) and anthraquinone-2,7-disulfonic acid (H2AQDA) ligands leads to a copper coordination polymer, namely, {[Cu(BIYB)2(AQDA)]·H2O}n (1). The cis-BIYB ligands link one unique Cu(II) atoms to give 1D double chains, but trans-BIYB connects the other Cu(II) centers to generate 2D (4,4)-layers. Each H2AQDA ligand acts as a μ2-bridging linking the double chains and (4,4)-layers to generate the 3D framework of 1. Cu(1) and Cu(2) can be viewed as 6- and 4-connected nodes, which lead to a (4,6)-connected self-penetrated network. Notably, complex 1 represents the rare example of coordination polymer-based visible-light-driven photocatalyst, and shows good degradation efficiency of organic dye.A unique 3D interpenetrated Cu coordination polymer framework triggered by the cis- and trans-configurations of organic ligand exhibits remarkable visible-light-driven photocatalytic activity.

Seven novel d10-metal–imidazole-4,5-dicarboxylate compounds namely [Zn(H2EIMDC)2(H2O)2]·2.25H2O (1), [Ag2(HPIMDC)(HPIM)2] (2), [Zn(HPIMDC)(H2O)]n (3), {[Cd(H2PIMDC)2]}n (4), {(H3O)[Cd(MIMDC)]}n (5), {(H3O)[Cd(EIMDC)]}n (6) and {(H3O)[Cd2(PIMDC)(HPIMDC)]}n (7), (H3MIMDC = 2-methyl-1H-imidazole-4,5-dicarboxylic acid, H3EIMDC = 2-ethyl-1H-imidazole-4,5-dicarboxylic acid, and H3PIMDC = 2-propyl-1H-imidazole-4,5-dicarboxylic acid, HPIM = 2-propyl-1H-imidazole), have been synthesized by careful control of the synthetic conditions such as the solvent, pH value and the metal-to-ligand molar ratios. X-ray single-crystal structural analyses reveal that the change of alkyl groups on the 2-position of the ligand leads to the diversity of their structures, which range from discrete compounds (1 and 2), one-dimensional chain (3), two-dimensional layer (4) to three-dimensional frameworks (5, 6 and 7). Specially, under the same reaction conditions, the extending of the 2-position alkyl substitutents gradually reduces the symmetry of the ultimate 3D frameworks, which vary from tetragonal I4/mmm (5), tetragonal P42/nmc (6) to orthorhombic Pbam (7) space groups. Alkyl-substituted imidazole-4,5-dicarboxylate ligands exhibit either singly, doubly, or triply deprotonated fashion, and coordinate to Zn(II), Cd(II) or Ag(I) ions in terminal μ2-, μ3- or μ4-modes. Compounds 1–7 have also been characterized by means of elemental analyses, X-ray powder diffractions, FT-IR, TGA and gas-adsorption. Furthermore, solid-state photoluminescence measurements show that all these d10-metal compounds produce strong blue emissions at room temperature.

•Novel cuprous bromide skeletons introduced by alkali metal cations•Organic–inorganic hybrid solids based on Cu(I) bromides and 1,6-Bi(benzotriazole)hexane•Blue photoluminescence attributed to intraligand π–π* transition.The addition of alkali metal bromide effectively controlled the assembly processes of flexible 1,6-Bi(benzotriazole)hexane (BBTH) ligand and CuBr under solvothermal conditions, and led to four different crystalline solids, namely, {K[Cu6Br7](BBTH)}n (1), {[CuBr]4(BBTH)}n (2), {[CuBr]2(BBTH)}n (3), and Cs3Cu2Br5 (4). The cuprous bromide inorganic skeletons vary from [Cu4Br4] double chain (in 2), [Cu6Br7] zigzag ribbon (in 1), [Cu2Br2] single helix (in 3) to binuclear [Cu2Br5] cluster (in 4) with the alkali metal cations changing from Na+, K+, Rb+ to Cs+. Cisoid-BBTH ligands in 1 and 2 link adjacent inorganic chains to form 2D organic–inorganic hybrid layers, but transoid-BBTH in 3 connects cuprous bromide chain to give a 3D rod-packing framework.Alkali metal bromide effectively modulated the assembly of flexible 1,6-Bi(benzotriazole)hexane (BBTH) ligand and CuBr under solvothermal conditions.

•Combination of 1,2,4-triazolate derivative and cyanide anion as the co-ligands•Unique hybrid Cu(I)–CN-1,2,4-triazolate open-framework•(4,6)-Connected fsc topology with 2-fold interpenetration•Strong fluorescence emissions at room temperatureSelf-assembly of CuCN, K3Fe(CN)6 and 3,5-bis(4-pyridyl)-1,2,4-triazole (BPy-4Trz) ligand under hydrothermal conditions generated a novel hybrid crystalline compound, namely, {Cu2(BPy-4Trz)(CN)}n (1). Two kinds of binuclear motifs, [Cu2(Trz)2] and [Cu2CN], link each other through the 4-pyridyl and cyanide groups to give a three-dimensional (4,6)-connected open-framework of 1 with 2-fold interpenetrated fsc topology. The green fluorescence emissions are observed in the solid state at room temperature.Hydrothermal synthesis and photoluminescence of a unique Cu(I)–CN-1,2,4-triazolate open-framework with 2-fold interpenetrated (4, 6)-connected fsc topology.

Highlights•Antifungal agent letrozole as organic ligands.•Solvent-introduced different copper(II)–letrozolate compounds.•Supramolecular frameworks generated by complex hydrogen bonds and π⋯π interactions.•Blue emissions ascribed to the intraligand and/or ligand to metal charge transfer.A well-known antifungal agent letrozole was selected in this work to react with CuCl2·2H2O under solvothermal conditions. Two novel supramolecular coordination compounds, namely, [Cu(LTZ)3Cl2] (1) and [Cu(LTZ)4Cl2]·H2O (2) (LTZ = letrozole = 1-[bis(4-cyano-phenyl)methyl]-1,2,4-triazole), have been successfully obtained by changing the solvent. The utilization of ethanol/water solvent led to the formation of 1, which crystallizes in the monoclinic system, space group P2(1)/c. When the methanol/water solvent was used instead under the similar conditions, we got compound 2, space group C2/c. The Cu(II) center is a five-coordinated [CuN3Cl2] square pyramidal geometry in 1, but six-coordinated [CuN4Cl2] octahedral environment in 2, which maybe mainly introduced by the solvent molecule. These two large mononuclear compounds both are packed into complex three-dimensional supramolecular frameworks via the hydrogen bonds and interesting π⋯π interactions. The photoluminescence measurements show that two compounds both show strong blue emissions ascribed to the intraligand and/or ligand to metal charge transfer.Graphical abstractTwo supramolecular coordination compounds with well-known antifungal agent letrozole as ligand have been successfully synthesized and show strong blue emissions ascribed to the intraligand and/or ligand to metal charge transfer.

A 3D metal–organic framework, namely, {[EMIM][In3(μ3-OH)2(1,2,4,5-BTC)2∙2H2O]}n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), was synthesized by using 1-ethyl-3- methylimidazolium bromide ([EMIM]Br) ionic liquid as solvent. The 7-coordinated pentagonal bipyramidal In(1) and octahedral In(2) atoms are connected by the μ3-OH groups to form an infinite [In3(μ3-OH)2]n inorganic chain along the a-axis, which are further extended by 1,2,4,5-BTC ligands to generate the 3D anionic microporous framework of 1. The [EMIM]+ cations occupy the 1D channels acting as template and charge-balancing species. Compound 1 shows strong blue luminescence and remarkable photocatalytic degradation of methylthionine chloride.An anionic porous indium MOF constrcuted from [In3(μ3-OH)2]n inorganic chains exhibiting blue luminescence and remarkable photocatalytic activity.Highlights► Ionothermal synthesis ► Anionic In-MOFs based on [In3(μ3-OH)2]n inorganic chain ► Rod-packing topological net ► Blue photoluminescence and remarkable photocatalytic activity

The hydrothermal reaction of CuCN, K3Fe(CN)6 and 5-(4-pyridine)tetrazole generated a novel three-dimensional organic–inorganic hybrid framework, namely, {Cu3(5PyTAZ)(CN)2}n (1) (5PyTAZ = 5-(4-pyridine)tetrazole). X-ray single-crystal diffraction shows that two independent Cu(I) centers are four-coordinate tetrahedral and three-coordinate trigonal geometries, which are connected by μ3-CN groups to form a 1D [Cu3(CN)2]n inorganic ribbon along the c-axis direction. Each 5PyTAZ ligand links four adjacent inorganic ribbons via its five N-atoms to generate a complex 3D hybrid structure. If the 1D copper(I) cyanide ribbon was regarded as rod-shape building block, 1 exhibits a simple rod-packing topological framework. Furthermore, 1 is characterized by X-ray powder diffraction, elemental analysis, FT-IR, Raman spectra and TG/DTA. Notably, solid-state luminescence measurements indicate that 1 is a potential photoluminescence material.

In this work, it was found that some monosaccharides normally used to stabilize enzymes at high temperatures, however, actually caused a deactivation of chloroperoxidase (CPO). The red native CPO was converted to a stable pale species that lost enzymatic activity. This deactivation was irreversible and was sensitive to temperature. It was different from the general peroxide-mediated deactivation of CPO.Data from measurement of chlorination activity as well as UV–vis, fluorescent, and CD spectral analysis indicated that monosaccharide-induced deactivation can be attributed to precipitation of protein in the presence of monosaccharide and the interaction of the aldehyde group of sugar with amino groups, especially the terminal amino group, on proteins to form Schiff bases which then rearrange to the stable amino ketone.It is further noted that the deactivation efficiency depends on the stereostructure of monosaccharides. d-Glucose was the most efficient inactivating agents due to its aptitude for both of the interactions mentioned in the above paragraphs. The deactivation was specific to aldose. No deprivation of the heme iron was involved in this deactivation.Graphical abstractHighlights► Monosaccharides could cause a suicide inactivation of chloroperoxidase (CPO). ► The sixth axial ligand position of heme iron was occupied by monosaccharides. ► Absorption of Soret band decreased due to occurrence of precipitation of protein. ► Fluorescent and CD spectral analysis indicated a minor uncoiling of α-helix occurred. ► The stereostructure of monosaccharide is related with this enzymatic inactivation.

Imidazolium-based ionic liquids are firstly utilized as the solvent, structure-directing agent, charge compensating agent, as well as reaction sources to give two novel crystalline 3D open-framework halogeno(cyano)cuprates showing strong luminescence.

A novel 3D indium metal–organic framework, namely, {[EMIM]2[InK(1,2,4,5-BTC)1.5(H2O)2]}n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), has been synthesized under ionothermal conditions by using the ionic liquid 1-ethyl-3-methylimidazolium bromide ([EMIM]Br) as solvent. Two In and two K atoms were linked by two μ3-H2O to give a [In2K2(μ3-H2O)2] tetranuclear cluster, which are connected by 1,2,4,5-BTC ligands to form the 3D anionic framework of compound 1. Furthermore, the [EMIM]+ cations acting as extra framework charge-balancing species occupy the channels of the 3D anionic framework. Notably, compound 1 shows strong blue luminescence and remarkable photocatalytic degradation of methylthionine chloride.Ionothermal synthesis of a novel 3D indium MOFs based on tetranuclear clusters showing strong blue luminescence and remarkable photocatalytic degradation of methylthionine chloride.Highlights► Ionothermal synthesis of novel In-MOFs. ► 3D framework based on tetranuclear [In2K2(μ3-H2O)2] clusters. ► Strong blue photoluminescence attributed to the intra-ligand emission. ► Remarkable photocatalytic degradation of the methylthionine chloride.

A novel 3D (4,6)-connected topological architecture, obtained under ionothermal conditions by using 1-ethyl-3-methyl imidazolium bromide ([EMI]Br) as solvent and structure-directing agent, presents a non-centrosymmetric polar packing arrangement showing an interesting ferroelectric property.

The first ionothermal case of the heterometallic iodoplumbate, [CuPb2I2Br(OH)2] (1), was prepared using 1-ethyl-3-methyl imidazolium bromide as a solvent. It exhibits an unprecedented (4,12)-connected topology with [Pb4(OH)4] cubane as the joint points of the helices.

A novel 3D microporous metal–organic framework based on tetrahedral Zn4 clusters has been synthesized and characterized, which presents an unprecedented (3,6)-connected (4·62)3(43·66·86) topology, and the capability of selective adsorption of CO2.

Seven organic-inorganic hybrid solids, namely, [(CdI2)2(L1)2] (1), [(CdBr2)3(L1)2]n (2), [(CdCl2)5(L1)2]n (3), [(CdI2)(L2)]n (4), [(CdBr2)(L3)]n (5), [(CdBr2)2(L4)2]n (6), and [(CdI2)4(L4)4]n (7), have been obtained via the self-assembly of CdX2 (X = Cl, Br or I) with the four structurally related flexible organic ligands 1,2-bis(benzotriazole)ethane (L1), 1,3-bis(benzotriazole)propane (L2), 1,4-bis(benzotriazole)butane (L3) and 1,6-bis(benzotriazole)hexane (L4) under solvothermal conditions. Compound 1 presents a binuclear structure with a [Cd2N12C4] 18-membered cycle. In 2, the L1 ligands locate alternately on the two sides of the 1-D inorganic chain formed by papilionaceous [Cd2Br2] subunits. The 1-D hexagonal [CdCl2]n grid inorganic chains in 3 are generated by vertex-loss cubane-like [Cd3Cl4] motifs through sharing faces, which are further connected by L1 ligands to give a 2-D hybrid layer. For compound 4, the L2 ligands and 4-connected Cd centres link each other to give a 1-D single chain. In 5 and 6, [Cd2Br4] units are connected by L3 and L4 to generate a 2-D (4, 4) net and 1-D double chain structure, respectively. Four independent [CdI2] centres and four L4 ligands in 7 generate an extraordinarily large [Cd4N24C24] 52-membered cycle. The varying structures of 1–7 indicate that the spacer length of the bis(benzotriazole)alkane ligands and counter-anions play an essential role in the formation of the framework of the Cd(II) hybrid materials. Strong π–π stacking interactions between the benzotriazole ligands pack these low-dimensional hybrid chains or layers into high-dimensional supramolecular frameworks. The UV-vis diffuse reflectance spectra and solid state luminescence measurements show that compounds 1–7 are potential semiconductor and photoluminescence materials.

The unusual 10-connected self-penetrating metal–organic framework based on sixteen-nuclear hybrid cadmium clusters has been constructed using 1,2,4-triazole, SCN− and F− as coligands, which represents the highest-connected uninodal network topology presently known for self-penetrating systems.

Self-assembly of CdCl2 and 1,2,4-triazole under hydrothermal condition yields a novel three-dimensional coordination polymer, namely {[Cd8Cl4(Trz)12(H2O)]·2H2O}n (1) (Trz = 1,2,4-triazole). Single-crystal X-ray diffraction reveals that four of the five independent Cd centers are linked by two μ2-Cl and two μ3-Cl atoms to form novel heptanuclear [Cd7Cl4] clusters, which are connected by the bridging water molecules to generate an unprecedented 1D castellated inorganic chain. Furthermore, the fifth unique Cd center and the castellated Cd–Cl–O chain are joint to each other via six different μ3-Trz ligands to give a 3D organic–inorganic hybrid framework of 1.A novel 3D hybrid coordination polymer was obtained via the self-assembly of CdCl2 and 1,2,4-triazole under hydrothermal condition, which is constructed from unprecedented 1D castellated Cd–Cl–O inorganic chains and μ3-triazole ligands.Highlights► 1D castellated inorganic chain based on heptanuclear [Cd7Cl4] clusters. ► 3D organic–inorganic hybrid framework with rod-packing topology. ► Strong blue photoluminescence attributed to LMCT.

By heating imidazolium bromide-based ionic liquids with Pb(NO3)2 under ionothermal conditions, we have successfully generated three imidazolium bromoplumbates, namely, [(PMI)PbBr3]n (1), [(AMI)PbBr3]n (2) and [(HMI)PbBr3]n (3) (PMI = 1-propyl-3-methylimidazolium, AMI = 1-allyl-3-methylimidazolium, HMI = 1-hexyl-3-methylimidazolium). Compounds 1–3 are isomorphic and exhibit unusual supramolecular organization wherein dialkylimidazolium cations arrange themselves in a cylindrical fashion giving rise to channel structures, which are further occupied by the 1D zigzag [PbBr3]n inorganic chains. The UV–vis diffuse reflectance spectra and luminescence measurements indicate that all compounds are potential semiconductor and photoluminescence materials.Three imidazolium bromoplumbate organic–inorganic hybrid solids were obtained under ionothermal conditions and exhibit unusual supramolecular organization wherein dialkylimidazolium cations arrange themselves in a cylindrical fashion giving rise to channel structures, which are further occupied by the 1D zigzag [PbBr3]n inorganic chains.Research Highlights► Dialkyl-imidazolium bromide-based ionic liquids are utilized as solvent. ► Crystal structures for three imidazolium bromoplumbate hybrid solids. ► Strong blue photoluminescence generated from the zigzag [PbBr3]n chain. ► Three compounds are potential semiconductor materials.

Using 1,2,4-triazole and adipic acid as coligands, a novel three-dimensional metal–organic framework, namely {[Cd4Cl(trz)5(adi)]·H2O}n (1) (trz = 1,2,4-triazole, adi = adipic acid) was hydrothermally synthesized and characterized. The crystal structure reveals that three independent Cd(II) centers are linked via one μ3-Cl and two μ3-COO− groups to form a unique [Cd4Cl(CO2)2] tetranuclear cluster, which acts as a 10-connected node joining adjacent four tetranuclear subunits and six 3-connected trz nodes to give a novel (3,10)-connected topological net with the Schläfli symbol (43)(41862562).A novel 3D metal–organic framework, namely {[Cd4Cl(trz)5(adi)]·H2O}n (1) (trz = 1,2,4-triazole, adi = adipic acid) was prepared under hydrothermal condition and characterized by X-ray single-crystal diffraction, elemental analysis, X-ray powder diffraction (XRPD), FT-IR, Raman spectrum, TG/DTA and photoluminescence measurements.

The self-assembly of CuCN and 1H-TAZ ligand under hydrothermal conditions generated a novel three-dimensional hybrid supramolecular framework, namely, [Cu6(TAZ)4(CN)2]n (1) (TAZ = tetrazole). Single-crystal X-ray diffraction show that [Cu2(TAZ)2] binuclear subunits are linked by μ2- and μ3-CN groups to give a 2D double-wave-shaped network, which possesses 1D channels with four open-windows. The 2D bilayers interpenetrated each other to form the 3D supramolecular framework of 1.A novel 3D organic–inorganic hybrid supramolecular solid constructed from interpenetrating (3,4,5)-connected 2D porous nets, namely, [Cu6(TAZ)4(CN)2]n (1) (TAZ = tetrazole) was successfully synthesized under hydrothermal conditions and characterized by X-ray single-crystal diffraction, elemental analysis, FT-IR, Raman spectrum, DT/TGA and solid state photoluminescence measurements.

The solvothermal reaction of the flexible ligand 1,2-bis(benzotriazole)ethane (bbta) with CuI produced a novel two-dimensional organic-inorganic hybrid solid, namely, [(Cu6I4)2(bbta)2(bta)4]n (bta = benzotriazole) (1). Novel 1D inorganic chains [Cu6I4]n2n- constructing from unprecedented flower-basket-shaped [Cu4II4] clusters are observed, which are further linked by the bbta and bta ligands using rare μ3-bidging mode to generate the 2D organic–inorganic hybrid structure of 1.A novel 2D organic–inorganic hybrid solid [(Cu6I4)2(bbta)2(bta)4]n (1) (bta = benzotriazole, bbta = 1,2-bis(benzotriazole)ethane) constructed from unprecedented flower-basket-shaped [Cu4II4] clusters was prepared under solvothermal condition and characterized.

A novel metal–organic coordination polymer, namely, {[K2(H2O)6][Cd3(1,2,4,5-BTC)2]}n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), was synthesized in an ionothermal reaction by using an ionic liquid 1-ethyl-3-methylimidazolium bromide ([EMIM]Br) as solvent. Complex 1 features a novel 3-D (4, 8)-connected porous anionic architecture constructed by linking trinuclear Cd subunits with 1,2,4,5-BTC4− ligands, which are further filled with 1-D [K2(H2O)6] cationic chains.A novel metal–organic coordination polymer, namely, {[K2(H2O)6][Cd3(1,2,4,5-BTC)2]}n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), was synthesized in an ionothermal reaction by using an ionic liquid 1-ethyl-3-methylimidazolium bromide ([EMIM]Br) as solvent.

•Novel Zn-tetracarboxylate-formate microporous pillar layered open-framework.•New 4,4,4-connected topology and rod-packing net.•Solvent-dependent photoluminescent intensity.•Selective and reversible response for chloroform.A new 3D metal-organic framework, namely, {Zn4(H2BPTC)2(HCOO)4}n (SNNU-1, H4BPTC=biphenyl-3,3',5,5'-tetracarboxylic acid, SNNU=Shaanxi Normal University) has been solvothermal synthesized. Four independent tetrahedral Zn atoms are connected by organic ligands to form a 2D Zn-H2BPTC layer, which is further bridged by in-situ generated HCOO- to give the 3D pillar-layered framework of SNNU-1. Unique Zn and H2BPTC all act as 4-connected nodes leading to a new 4,4,4-connected topological net with point symbol of {4·5·62·82}{4·52·62·8}{52·63·7}. Notably, intense blue emission band is observed for SNNU-1, which exhibits solvent-dependent effect. Compared to other common organic solvents, chloroform can specially improve the photoluminescent intensity of SNNU-1. Further repeated response and release experiments clearly showed that SNNU-1 can act as luminescent sensor for selective and reversible detection of chloroform.Zn2+ ions are bridged by aromatic tetracarboxylate ligands and inorganic formate anions to give a microporous pillar layered open-framework, which exhibits not only strong photoluminescence but also selective and reversible luminescent sensing for chloroform.

Biotransformation of cyclohexene catalyzed by chloroperoxidase (CPO) from Caldariomyces fumago was employed to prepare value-added oxygenated derivative: trans-1,2-cyclohexanediol (CHD) using H2O2 as oxidants. The conversion of substrate was enhanced to 89.2% in the presence of small quantities of quaternary ammonium salts (QAS) compared to that of only 48.1% in aqueous phosphate buffer after 150 min. The enhancement was dependent on the concentration and alkyl group length of QAS. QAS were found playing multiple functions in reaction media: phase transfer catalysis and tuning the composition of product. UV–vis, fluorescence and circular dichroism (CD) spectral assay were employed to investigate the effect of QAS on micro-environment around active center and structure of protein. The strengthening of α-helix structure of CPO and more exposure heme for easily access of substrate was found responsible for the improvement of catalytic performance of CPO. Moreover, the determined kinetic parameters indicated the affinity and selectivity of CPO to substrate was improved according to the observation of a decrease of Michaelis constant Km while an increase of the second order rate constants kcat/Km.The strategy reported in this work is environment-friendly, straightforward and applicable to large scale preparation.Graphical abstractDownload high-res image (192KB)Download full-size imageHighlights► Cyclohexene was turned to value-added derivative by CPO-catalyzed biotransformation. ► Small quantity of introduced quaternary ammonium salts played multiple functions. ► The strategy is environment-friendly, straightforward and applicable to large scale.

This work focused on a systematic investigation of the influences of the spacer length of the flexible α,ω-bis(benzotriazole)alkane ligands and counteranions on the overall molecular architectures of hybrid structures that include Cu(I). Using the self-assembly of CuX (X = Cl, Br, I, or CN) with the five structurally related flexible organic ligands (L1−L5) under hydro(solvo)thermal conditions, we have synthesized and characterized 10 structurally unique materials of the Cu(I)/X/α,ω-bis(benzotriazole)alkane organic−inorganic hybrid family, {[CuCl]2(L1)}n (1), {[CuBr](L2)}n (2), {[CuCl]2(L3)}n (3), {[CuI]2(L4)}n (4), {[CuBr]2(L4)}n (5), {[CuBr]3(L5)}n (6), {[CuCN]2(L1)}n (7), {[CuCl]4(L2)}n (8), {[CuBr]4(L2)}n (9), and {[CuCl]2(L4)}n (10), by means of elemental analyses, X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and photoluminescence measurements. Single-crystal X-ray analyses showed that the inorganic subunits in these compounds were {Cu2X2} binuclear clusters (1 and 2), {Cu4X4} cubane clusters (4, 5, and 10), {CuX}n single chains (3 and 7), a {Cu3X3}n ladderlike chain (6), and unprecedented {Cu8X8}n ribbons (8 and 9). The increasing dimensionality from 1-D (1−4) to 2-D (5 and 6) to 3-D (7−10) indicates that the spacer length and isomerism of the bis(benzotriazole)alkane ligands play an essential role in the formation of the framework of the Cu(I) hybrid materials. The influence of counteranions and π−π stacking interactions on the formation and dimensionality of these hybrid coordination polymers has also been explored. In addition, all the complexes exhibit high thermal stability and strong fluorescence properties in the solid state at ambient temperature.

The synthetic design of new porous open-framework materials with pre-designed pore properties for desired applications such as gas adsorption and separation remains challenging. We proposed one such class of materials, rod metal–organic frameworks (rod MOFs), which can be tuned by using rod secondary building units (rod SBUs) with different geometrical and chemical features. Our approach takes advantage of the readily accessible metal–triazolate 1-D motifs as rod SBUs to combine with dicarboxylate ligands to prepare target rod MOFs. Herein we report three such metal–triazolate–dicarboxylate frameworks (SNNU-21, -22 and -23). During the formation of these three MOFs, Cd or Zn ions are firstly connected by 1,2,4-triazole through the N1,N2,N4-mode to form 1-D metal–organic ribbon-like rod SBUs, which further joint four adjacent rod SBUs via eight BDC linkers to give 3-D microporous frameworks. However, tuned by the different NH2 groups from metal–triazolate rod SBUs, different space groups, pore sizes and shapes are observed for SNNU-21–23. All of these rod MOFs show not only remarkable CO2 uptake capacity, but also high CO2 over CH4 and C2-hydrocarbons over CH4 selectivity under ambient conditions. Specially, SNNU-23 exhibits a very high isosteric heat of adsorption (Qst) for C2H2 (62.2 kJ mol−1), which outperforms the values of all MOF materials reported to date including the famous MOF-74-Co.

Reported herein is the new application of ionothermal synthesis for inorganic optical materials. Under ionothermal conditions with different imidazolium ionic liquids, novel quaternary heterometallic frameworks based on [Pb4(OH)4] cubane and [CuCl4] or [CuBr4] chains and [Cu2I6] binuclear clusters have been successfully produced. Simple chlorine, bromine and iodine replacement leads to not only the space group change (tetragonal I41/acd for 1 and 2, and orthorhombic Fddd for 3) but also the topological net transformation (8,12-net for 1 and 2, and 6,6-net for 3). Notably, compounds 1, 2 and 3 all show tunable solid-state semiconducting and luminescence properties.

A novel 3D (4,6)-connected topological architecture, obtained under ionothermal conditions by using 1-ethyl-3-methyl imidazolium bromide ([EMI]Br) as solvent and structure-directing agent, presents a non-centrosymmetric polar packing arrangement showing an interesting ferroelectric property.