Isostructural 3D Research Articles

Structural and synthesis study of eight isostructural coordination polymers formed by 5-sulfoisophthalic acid and lanthanide ions

This work presents the synthesis and structural characterization of eight isostructural 1D coordination polymers formed by the coordination of 5-sulfoisophthalic acid with various lanthanides ions: Ln = CeIII,PrIII,SmIII,GdIII,DyIII,HoIII,Er(III)andTm(III). The structures were synthetized via a two-step process, wherein a solution of lanthanide ions was added to a mixture of 5-sulfoisophthalic acid and 1,3-bis(4-pyridyl)propane, the latter serving as an auxiliary ligand. This method has proven to be a simpler approach compared to those described in the literature. The compounds were characterized by X-ray single crystal diffraction, FT-IR and Raman spectroscopy, and elemental analysis. Structural analysis revealed a significant correlation between atomic number of the lanthanide ion, unit cell parameters, and space group. On the other hand, the Hirshfeld surface analysis and the two-dimensional fingerprint plot revealed that the set of the intermolecular forces remains unchanged across different lanthanide ion.

Redox Synergy: Enhancing Gas Sensing Stability in 2D Conjugated Metal-Organic Frameworks via Balancing Metal Node and Ligand Reactivity.

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have emerged as promising candidates in gas sensing, owing to their tunable porous structure and conductivity. Nevertheless, the reported gas sensing mechanisms heavily relied on electron transfer between metal nodes and gas molecules. Normally, the strong interaction between the metal sites and target gas molecule would result poor recovery and thus bad recycling property. Herein, we propose a redox synergy strategy to overcome this issue by balancing the reactivity of metal sites and ligands. A 2D c-MOF, Zn3(HHTQ)2, was prepared for nitrogen dioxide (NO2) sensing, which was constructed from active ligands (hexahydroxyltricycloquinazoline, HHTQ) and inactive transition-metal ions (Zn2+). Substantial characterizations and theoretical calculations demonstrated that by utilizing only the redox interactions between ligands and NO2, not only high sensitivity and selectivity, but also excellent cycling stability in NO2 sensing could be achieved. In contrast, control experiments employing isostructural 2D c-MOFs with Cu/Ni metal nodes exhibited irreversible NO2 sensing. Our current work provides a new design strategy for gas sensing materials, emphasizing harnessing the redox activity of only ligands to enhance the stability of MOF sensing materials.

Constant potential energetics of metallic and semiconducting electrodes: A benchmark study on 2D materials.

Grand-canonical (GC) constant-potential methods within an implicit solvent environment provide a general approach to compute the potential-dependent energetics at electrified solid-liquid interfaces with first-principles density-functional theory. Here, we use a mindfully chosen set of 27 isostructural 2D metal halides MX2 to analyze the variation of this energetics when the electronic structure changes from metallic to semiconducting and insulating state. Apart from expectable changes due to the opening up of the electronic bandgap, the calculations also show an increasing sensitivity to the numerical Brillouin zone integration and electronic smearing, which imposes computational burdens in practice. We rationalize these findings within the picture of the total interfacial capacitance arising from a series connection of the electrochemical double-layer capacitance and the so-called quantum capacitance resulting from the filling of electronic states inside the electrode. For metals, the electrochemical double-layer capacitance dominates at all potentials, and the entire potential drop takes place in the electrolyte. For semiconductors, the potential drop occurs instead fully or partially inside the electrode at potentials within or just outside the bandgap. For 2D semiconductors, the increased sensitivity to numerical parameters then results from the concomitantly increased contribution of the quantum capacitance that is harder to converge. Fortunately, this understanding motivates a simple extension of the CHE + DL approximation for metals, which provides the approximate GC energetics of 2D semiconductors using only quantities that can be obtained from computationally undemanding calculations at the point of zero charge and a generic double-layer capacitance.

Crystal structures, Hirshfeld surface analysis, thermogravimetric, and spectroscopic properties of three Zn(Ⅱ) complexes bridged by 4,4′-bipy with organic sulfonate anions as counterions

Three Zn(Ⅱ) sulfonate compounds: {[Zn3(Ac)4(4,4′-bipy)4]·2(3-pySO3)·H2O}n (1), {[Zn(4,4′-bipy)(H2O)4]·2(Me-phSO3)}n (2), and {[Zn(4,4′-bipy)(H2O)4]·2(NH2-phSO3)}n (3), were synthesized through solvent diffusion method at room temperature (3-pySO3H = Pyridine-3-Sulfonic acid; Me-phSO3H = P-Toluene Sulfonic acid; NH2-phSO3H = Sulfanilic acid). Single-crystal X-ray diffractions reveal that the crystal structure of compound 1 contains a 2D cationic layer with pseudo-square grid motifs formed by trinuclear Zn(II) units which connected by 4,4′-bipy ligands. Water molecule forms hydrogen bonds with free 3-PySO3− anions which are located in the voids of the cationic grids. Compounds 2 and 3 show isostructural 1D [Zn(4,4′-bipy)(H2O)4]2+ chains with sulfonate anions connected to the chain via hydrogen bonding. The weak interactions in the structures of the three compounds have been assessed using Hirshfeld surface analyses and 2D fingerprint plots. The Hirshfeld surface shows that the most important contributions for the crystal packing are from H···H and H··O/O··H interactions, which indicate dominant van der Waals interactions. In addition, the compounds were investigated by powder X-ray diffraction (PXRD), elemental analyses, UV–vis, FT-IR, solid-state fluorescence spectroscopy, and thermal analyses (TG-DSC).

Fine-tuning the pore environment of ultramicroporous three-dimensional covalent organic frameworks for efficient one-step ethylene purification

The construction of functional three-dimensional covalent organic frameworks (3D COFs) for gas separation, specifically for the efficient removal of ethane (C2H6) from ethylene (C2H4), is significant but challenging due to their similar physicochemical properties. In this study, we demonstrate fine-tuning the pore environment of ultramicroporous 3D COFs to achieve efficient one-step C2H4 purification. By choosing our previously reported 3D-TPB-COF-H as a reference material, we rationally design and synthesize an isostructural 3D COF (3D-TPP-COF) containing pyridine units. Impressively, compared with 3D-TPB-COF-H, 3D-TPP-COF exhibits both high C2H6 adsorption capacity (110.4 cm3 g−1 at 293 K and 1 bar) and good C2H6/C2H4 selectivity (1.8), due to the formation of additional C-H···N interactions between pyridine groups and C2H6. To our knowledge, this performance surpasses all other reported COFs and is even comparable to some benchmark porous materials. In addition, dynamic breakthrough experiments reveal that 3D-TPP-COF can be used as a robust absorbent to produce high-purity C2H4 directly from a C2H6/C2H4 mixture. This study provides important guidance for the rational design of 3D COFs for efficient gas separation.

Tuning the CO2 selective adsorption performance in MOFs by incorporating functional groups on the isophthalate skeleton

By introducing functional groups into the isophthalate ligand to decorate the pore of the MOFs, gas adsorption and separation performance can be tunable. In this paper, two isostructural 2D Co-MOFs, [Co(5-MIA)(bpy)]·H2O (1) and [Co(5-EIA)(bpy)]·H2O (2) (5-H2MIA = 5-methoxyl-isophthalic acid; 5-H2EIA = 5-ethyoxyl-isophthalic acid; bpy = 4,4′-bipyridine), with different functionalized pore surfaces and channel sizes were designed and constructed. The structures and performance of the two Co-MOFs were analyzed by SCXRD, PXRD, IR, TGA, and gas sorption (CO2, C2H2, CH4, CO, and N2). Attributed to the methoxyl of isophthalate skeleton, 1a (activated 1) shows enhanced CO2 uptake over other gases. In spite of decreased pore sizes (3.49 Å) compared with 2a (4.38 Å), the CO2 uptake of 1a (43.41 cm3 g−1) is larger than that of 2a (22.39 cm3 g−1) at 298 K and 100 kPa. Compound 1 incorporates methoxyl groups into the narrow channel, and exhibits the cooperative effect of CO2-preferential due to adsorbent-adsorbate coactions and size sieving. GCMC simulation has been used to explore the adsorption coactions of CO2 and 1, and the results confirmed that the methoxyl groups in the channel are the main binding sites of CO2. At ambient temperature and 100 kPa, the IAST selectivities of CO2/C2H2 (1:1), CO2/CH4 (1:1), C2H2/CH4 (1:1), CO2/CO (1:2) and CO2/N2 (15:85) on 1a were 2.6, 39.3, 13.3, 282 and 1433, respectively. The easy activation and regeneration, excellent thermal and humidity stability, and good reusability, make 1a hopeful adsorbent for adsorption and separation of CO2.

Construction of Naphthalenediimide Lanthanide(III)‐MOFs and Composites Incorporated Electron‐Rich Pyrene Derivative as Multifunctional Fluorescence Sensing for Nitro Aromatic Compounds and Aldehydes

Comprehensive SummaryThe development of host‐guest MOF luminescent composites has attracted considerable attention. However, it is still a challenge to reasonably design large scale conjugated polycarboxylic acids metal‐organic framework (MOF) and modulate donor‐acceptor interaction. Herein, a series of isostructural 3D porous lanthanide MOF [Ln2(BINDI)0.5(NO3)(DMA)(H2O)]∙DMA∙2.5H2O (Ln = La (1), Ce (2), Pr (3) and Nd (4); H4BINDI (N,N’‐bis(5‐isophthalic acid)‐1,4,5,8‐naphthalenediimide) were synthesized. Considering the electron‐deficient performances of Ln‐BINDI MOFs, D‐A type composites Ln‐MOFs (1—4@H4TBAPy) were prepared via the incorporation of electron‐rich H4TBAPy (1,3,6,8‐tetrakis(p‐benzoic acid) pyrene), which more improved the luminescence performance of complexes 1—4 and can be used as fluorescence sensors for the detection of nitro compounds and aldehydes. High sensitivity of 1@H4TBAPy towards pNBA, pNA PNP, DNP, and TNP could be achieved through hydrogen bond interactions between MOF and analytes, as well as the π‐π interaction between H4TBAPy and the naphthalene ring of BINDI, thus the fluorescence quenching efficiency of 1@H4TBAPy was better than that of the complex 1. In addition, it is found that 1@H4TBAPy has high selectivity and sensitivity to aromatic aldehyde SA, 5‐Mesal and HMBA. Such strategy to enhance the emission of NDI based Ln‐BINDI MOFs, will open up an avenue to obtain more fluorescent MOFs for sensing.

Structure, fluorescence and energy transfer of 2D multinuclear-LnIII-incorporated organic–inorganic hybrid arsenotungstates

A family of isostructural 2D multinuclear LnIII-incorporated organic–inorganic hybrid arsenotungstates were fleetly synthesized, denoted as K4[{Ln(H2O)7}2 {As4W44O143(OH)8(H2O)6(DL-ala)2}{Ln2(H2O)4(DL-ala)}2]‧54H2O (Ln=Sm (1), Eu (2), Gd (3)), containing a centrosymmetric polyanion [{As4W44O143(OH)8(H2O)6(DL-ala)2}{Ln2(H2O)4(DL-ala)}2]8–. The polyanion is constituted of two {As2W19O62(OH)2(H2O)3}6– building blocks encapsulating a deca-nuclear Ln-W heterometallic cluster [W6O21(OH)4(DL-ala)2{Ln2(H2O)4(DL-ala)}2]6–. Obtained compounds were characterized by means of elemental chemical analysis, thermogravimetric, single crystal X-ray and powder diffraction and FT-IR studies. The optical band-gaps of 1 and 2 are 3.05 eV and 3.09 eV, respectively, according to the UV–Vis diffuse reflectance. In addition, 1 and 2 demonstrate the solid-state fluorescence performance (1: orange, 2: red), of which the POMs chromophore can be considered as an antenna ligand to improve luminescence efficiency of LnIII centers via energy migration.

Smart Stimulation Response of a Pyrene-Based Lanthanide(III) MOF: Fluorescence Enhancement to HX (F and Cl) or R-COOH and Artificial Applicable Film on HCl Vapor Sensing.

Toxic acids produced by industries are major hazards to the environment and human health, and luminescent pyrene-based crystalline metal-organic frameworks (MOFs) demonstrate promising performance in the detection of toxic acids. Herein, two novel isostructural 3D porous lanthanide MOFs, H3O·[Ln3(TBAPy)2(μ2-H2O)2(OH)2]·2DMA·2Diox·6.5H2O (Ln = Pr (1) and Ce (2); H4TBAPy (1,3,6,8-tetrakis(p-benzoic acid)pyrene); and DMA: N,N-dimethylacetamide) were synthesized, which showed alb topology. Based on the protonation and hydrogen bond mechanism, complex 1 could be used as a fluorescence recognition sensor for HX (X = F, Cl, Br, and I) acid solutions with different luminescence behaviors. It is worth noting that complex 1 exhibited high sensitivity in the fluorescence enhancement sensing of hydrofluoric acid, oxalic acid, and trichloroacetic acid. In particular, complex 1 had a low limit of detection (LOD) for OA (0.1 μM) and was applied to real monitoring of orange fruit samples. In addition, the PVA@1 film could selectively, sensitively, and quantitatively respond to hydrochloric acid (HCl) vapor through fluorescent quenching; due to its protonation and adsorption capacity, the LOD was 0.18 ppm. Therefore, the portable optical device, the PVA@1 film, can detect HCl gas in trace amounts, achieving the ultimate goal of real-time and rapid detection, which has potential application value for industrial production safety.

Highly Luminescent Lanthanide Metal‐Organic Frameworks with Tunable Color for Nanomolar Detection of Iron(III), Ofloxacin and Gossypol and Anti‐counterfeiting Applications

AbstractSolvothermal reaction of 5,5′‐(pyridine‐2,6‐diylbis(oxy))diisophthalic acid (H4L) with europium(III) or terbium(III) nitrates in acetonitrile‐water (1 : 1) at 120 °C gave rise to isostructural 2D coordination polymers, [Ln(HL)(H2O)3]∞ (NIIC‐1‐Eu and NIIC‐1‐Tb), the layers of which are composed by eight‐coordinated lanthanide(III) ions interconnected by triply deprotonated ligands HL3−. The layers are packed in the crystal without any specific intermolecular interactions between them, allowing the facile preparation of stable water suspensions, in which NIIC‐1‐Tb exhibited top‐performing sensing properties through luminescence quenching effect with exceptionally low detection limits towards Fe3+ (LOD 8.62 nM), ofloxacin (OFX) antibiotic (LOD 3.91 nM) and cotton phytotoxicant gossypol (LOD 2.27 nM). In addition to low detection limit and high selectivity, NIIC‐1‐Tb features fast sensing response (within 60–90 seconds), making it superior to other MOF‐based sensors for metal cations and organic toxicants. The photoluminescence quantum yield of NIIC‐1‐Tb was 93 %, one of the highest among lanthanide MOFs. Mixed‐metal coordination polymers NIIC‐1‐EuxTb1−x demonstrated efficient photoluminescence, the color of which could be modulated by the excitation wavelength and time delay for emission monitoring (within 1 millisecond). Furthermore, an original 2D QR‐coding scheme was designed for anti‐counterfeiting labeling of goods based on unique and tunable emission spectra of NIIC‐1‐Ln coordination polymers.

Highly Luminescent Lanthanide Metal-Organic Frameworks with Tunable Color for Nanomolar Detection of Iron(III), Ofloxacin and Gossypol and Anti-counterfeiting Applications.

Solvothermal reaction of 5,5'-(pyridine-2,6-diylbis(oxy))diisophthalic acid (H4 L) with europium(III) or terbium(III) nitrates in acetonitrile-water (1 : 1) at 120 °C gave rise to isostructural 2D coordination polymers, [Ln(HL)(H2 O)3 ]∞ (NIIC-1-Eu and NIIC-1-Tb), the layers of which are composed by eight-coordinated lanthanide(III) ions interconnected by triply deprotonated ligands HL3- . The layers are packed in the crystal without any specific intermolecular interactions between them, allowing the facile preparation of stable water suspensions, in which NIIC-1-Tb exhibited top-performing sensing properties through luminescence quenching effect with exceptionally low detection limits towards Fe3+ (LOD 8.62 nM), ofloxacin (OFX) antibiotic (LOD 3.91 nM) and cotton phytotoxicant gossypol (LOD 2.27 nM). In addition to low detection limit and high selectivity, NIIC-1-Tb features fast sensing response (within 60-90 seconds), making it superior to other MOF-based sensors for metal cations and organic toxicants. The photoluminescence quantum yield of NIIC-1-Tb was 93 %, one of the highest among lanthanide MOFs. Mixed-metal coordination polymers NIIC-1-Eux Tb1-x demonstrated efficient photoluminescence, the color of which could be modulated by the excitation wavelength and time delay for emission monitoring (within 1 millisecond). Furthermore, an original 2D QR-coding scheme was designed for anti-counterfeiting labeling of goods based on unique and tunable emission spectra of NIIC-1-Ln coordination polymers.

Facile prepared 2D Ni-based metal-organic framework nanosheets for boosting one-pot catalytic synthesis of cyclic carbonates

Two isostructural Ni-based MOF 2D nanosheets (NiBDC NS and NiBDC-NH2 NS) were facilely constructed by reflux method, which exhibited excellent activity for one-pot epoxidation-CO2 cycloaddition catalysis. Combining our activity evaluations, detailed kinetics and molecular simulation results, we revealed that the amino groups of these materials played a positive role in CO2 cycloaddition step but a negative role in epoxidation step. By using NiBDC NS, the conversion and yield of the targeted products under mild condition (80 °C, 1 bar and 12 h) could achieve 95% and 87%, respectively. The calculated Thiele modulus and effectiveness factor indicated that NiBDC NS exhibited a higher catalyst utilization degree with negligible diffusion constraint. We further confirmed the stability of these catalysts by repeatedly running the catalysis six times without observing significant loss of activity. Finally, the reaction mechanism was proposed by combining the results from experiment and simulations.

Differential supercapacitor and Schottky diode behaviours in two new isostructural coordination polymers based on redox active metal ions

Two isostructural 2D coordination polymers utilizing redox-active metal ions, Fe(ii) and Mn(ii), were synthesized. The Mn-based compound showed higher capacitance values and ten times higher conductivity compared to the Fe-based compound.

Two isostructural Ln-MOFs containing triazole groups as luminescent probes for efficient sensing of NACs and Fe3+

Two new isostructural 3D lanthanide metal–organic frameworks (Ln-MOFs), [Ln2(L)3(H2O)2]·2H2O·2DMF (1-Ln, Ln = Eu3+ and Tb3+, H2L = 5-triazole isophthalic acid) with uncoordinated triazole groups decorating the channels were successfully synthesized via solvothermal reaction. The uncoordinated triazole groups act as reserved host–guest binding sites to adjust the luminescence intensity of the Ln3+ ion. Luminescence studies reveal that 1-Eu and 1-Tb as fluorescent probes both exhibit high sensitivities and excellent selectivities towards nitroaromatics (NACs) and Fe3+ in DMF system by luminescence quenching process. The quenching mechanisms were investigated through PXRD, DFT theory calculation, XPS, UV–vis and discussed in details.

Multistimuli-responsive pyrene-based lanthanide (III)-MOF construction and applied as dual-function fluorescent chemosensors for trace water and vitamins molecules

Three novel isostructural 3D porous metal–organic frameworks (3D MOFs) Ln-TBAPy (Ln = Sm (1), La (2), and Nd (3); H4TBAPy = 1,3,6,8-tetrakis (p-benzoic acid)pyrene) were synthesized, encompassing a π-conjugated organic ligand with a pyrene functionality. In particular, the crystal structure of [Sm3 (TBAPy)2 ((μ2-H2O)2(OH)2]∙(guests) (complex 1) was determined by X-ray single-crystal diffraction and displayed excellent performance in luminescent, which featured the alb topology and remarkable multiple pores dimensions. The complex 1 was utilized to determine the pH-dependent and temperature-dependent fluorescence under multistimuli responses, which exhibits its unusual photophysical characteristics and outstanding stability under special conditions. Markedly, the complex 1 probe achieves ultra-sensitive turn-on detection of trace water in organic solvent dioxane, exhibiting an ultra-low detection limit of 0.005% (v/v). In addition, we have explored that it has excellent fluorescence detection selective effect on various biological small molecule vitamins. On the one hand, the complex 1 can sense Vit-B6 with unique fluorescent switch ‘turn-on-off’ behavior, based on the changing concentration of Vit-B6 in MOF channel and hydrogen bond between host–guest interaction. On the other hand, complex 1 has high sensitivity to the quenching of Vit-B9 and Vit-K3, with the LOD as low as 0.32 μM, and 3.94 μM, respectively. Our synthesis strategy of Ln-TBAPy MOF materials will play simultaneously multiple roles and open up an effective avenue to dual-function fluorescence sensor of water and biological small molecule vitamins.

Efficient Room‐Temperature Phosphorescence of 1D Organic–Inorganic Hybrid Metal Halides

Room‐temperature phosphorescence (RTP) has attracted considerable attention due to its potential applications in light‐emitting, bioimaging, and chemical sensing devices, but it is full of challenges to achieve new molecular systems for efficient RTP. Herein, three imidazole derivatives involving triplet excitons as organic cations are employed to synthesize three isostructural 1D lead halides with distinct emission characteristics, in which (2‐MBI)PbBr3 and (2‐PI)PbBr3 show the blue and broadband white fluorescence, respectively, while (5‐MBI)PbBr3 (5‐MBI = 5‐methylbenzimidazole) exhibits efficient green RTP peaking at 520 nm under UV excitation. The underlying photophysical regulatory mechanism is unveiled that extra‐molecular “heavy atomic effects” and the spin–orbit coupling from [PbBr3−]∞ units enhance the intersystem crossing and Dexter‐type electron transfer of excitons from inorganic units to triplet states (Tn) in 5‐MBI cations. An information encryption pattern is also realized by combining the different photoluminescence of these 1D organic and inorganic hybrid lead halides. This study suggests a feasible strategy to modulate the photoluminescence to achieve efficient RTP in low‐dimensional hybrid metal halides.

Comparative Effect of Amino Functionality on the Performance of Isostructural Mixed‐Ligand MOFs towards Multifunctional Catalytic Application

AbstractTwo isostructural MOFs {[Cd(BDC)(L)] ⋅ CH3OH}n (1) and {[Cd(NH2‐BDC)(L)] ⋅ CH3OH}n (1‐NH2) involving Cd metal center and different dicarboxylate ligands (1,4‐benzenedicarboxylate (BDC) in 1 and 2‐amino‐1,4‐benzenedicarboxylate (NH2‐BDC) in 1‐NH2) and a common amide functionalized N‐donor ligand ((E)‐N′‐(pyridin‐3‐ylmethylene)nicotinohydrazide (L)) has been synthesized in bulk by diverse routes with phase‐purity. The MOFs were characterized by spectroscopic methods such as FT‐IR, elemental, TGA analysis, PXRD, and SXRD analysis. Amide functionality of L in 1 and both amide/‐NH2 functional groups attached to the ligands in 1‐NH2 of the interpenetrated isostructural 3D framework has been found to be catalytically active basic site towards multiple organic transformations. Both 1 and 1‐NH2 showed good catalytic activity towards both CO2‐epoxide cycloaddition and Biginelli reaction. A comparative study of the catalytic activity of 1 and 1‐NH2 for cycloaddition and Biginelli reaction revealed that the amine‐functionalized framework 1‐NH2 showed better catalytic performance than 1 due to the existence of additional amino site. Presence of accessible functionally decorated Lewis basic ‐NH2 and amide sites on BDC and N‐donor ligands of 1‐NH2 synergistically activate the substrate making this framework interesting and efficient heterogeneous base catalyst. Excellent product yield under moderate conditions with reusability is the highlight in both catalytic reactions.

Structurally dynamic crystalline 1D coordination polymers enabled via the Weak-Link Approach

Supramolecular chemistry has the potential to be used to impart dynamic molecular elements into coordination polymers so that sophisticated, multifunctional materials can be prepared. Indeed, the Weak-Link Approach (WLA) to supramolecular chemistry is a coordination chemistry-based platform that can be used for the design of stimuli-responsive and switchable nanoscale architectures. Herein, we use the WLA to design and synthesize crystalline, WLA-based 1D coordination polymers. Specifically, the reaction of a closed, pyridine-functionalized WLA monomer complex with Cu(BF4)2·6H2O in acetonitrile or N,N-dimethylformamide yields three isostructural 1D zig-zag chains. One of the polymers was studied via single-crystal X-ray diffraction (SCXRD), nuclear magnetic resonance (NMR) spectroscopy, and mass spectroscopy (MS), and its response to a chemical effector (halide ion, Cl−) was investigated. Importantly, our investigation of one of the model chains displays the characteristic structural switchability of the WLA complex from which it is comprised. Upon exposure to Cl− anions, it disassembles into its molecular components, including the fully-opened congener of the initial WLA complex. Thus, one can control crystalline chain assembly via the structural state of the WLA monomer complex. Taken together, this work has demonstrated the construction of the first series of crystalline WLA-based extended solids and represents a promising method for the construction of allosteric, stimuli-responsive coordination polymers, including potentially higher-ordered structures like metal organic frameworks.

Synthesis, structure and magnetic properties of two isostructural Co/Mn (II) metal organic frameworks

Two 3D isostructural Co/Mn (II) metal organic frameworks (MOFs), namely, {[Co(BIPA-TC4-)0.5(bpbp)]·2MeCN}n (1) and {[Mn(BIPA-TC4-)0.5(bpbp)]}n (2). (H4BIPA-TC = 5,5′-(1,3,6,8-tetraoxybenzo [3], [8] phenanthroline 2–7-substituent)bis-1,3-benzoic acid and bpbp = 4,4′-bis(Pyrid-4-yl)biphenyl) have been solvothermally constructed based on H4BIPA-TC ligand and cobalt or manganese salts. And two Co/Mn (II) MOFs were further characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis and powder X-ray diffraction experiments. The structure analysis showed 1 and 2 are isostructural 3D networks with a Schläfli symbol of {44.610.8} {44.62}. Moreover, magnetic properties of 1 and 2 were also investigated.

Mixed‐Ligand Metal‐Organic Frameworks: Synthesis and Characterization of New MOFs Containing Pyridine‐2,6‐dimethanolate and Benzene‐1,4‐dicarboxylate Ligands

AbstractThe development of synthetic approaches towards new mixed‐ligand metal organic frameworks (MOFs) has been attracting considerable attention recently as they display fascinating properties due to the synergistic effect between the different ligands. Herein, the initial combination of pyridine‐2,6‐dimethanol (H2pdm) with benzene‐1,4‐dicarboxylic acid (H2bdc) has provided access to three new mixed‐ligand MOFs, [M3(bdc)2(Hpdm)2]n (MII=ZnII, 1; MnII, 2) and [Mn3(bdc)3(H2pdm)2]n (3). 1–3 are the first MOFs containing H2pdm in its neutral or anionic form. 1 and 2 are isostructural 2D MOFs with a square lattice (sql) framework topology, while 3 is a 3D MOF possessing a primitive cubic (pcu) topology. Dc magnetic susceptibility measurements for 3 demonstrate antiferromagnetic interactions between the MnII ions which is a combination of intra‐ and intertrimer exchange pathways.