Interpenetrated Metal Organic Framework Research Articles

Harvesting Multicolor Photoluminescence in Nonaromatic Interpenetrated Metal-Organic Framework Nanocrystals via Pressure-Modulated Carbonyls Aggregation.

Interpenetrated metal-organic frameworks (MOFs) with nonaromatic ligands provide a unique platform for adsorption, catalysis, and sensing applications. However, nonemission and the lack of optical property tailoring make it challenging to fabricate smart responsive devices with nonaromatic interpenetrated MOFs based on ligand-centered emission. In this paper, the pressure-induced aggregation effect is introduced in nonaromatic interpenetrated Zn4O(ADC)4(Et3N)6 (IRMOF-0) nanocrystals (NCs), where carbonyl groups aggregation results in O─O distances smaller than the sum of the van der Waals radii (3.04 Å), triggering the photoluminescence turn-on behavior. It is noteworthy that the IRMOF-0 NCs display an ultrabroad emission tunability of 130nm from deep blue (440nm) to yellow (570nm) upon release to ambient conditions at different pressures. The eventual retention of through-space n-π* interactions in different degrees via pressure treatment is primarily responsible for achieving a controllable multicolor emission behavior in initially nonemissive IRMOF-0 NCs. The fabricated multicolor phosphor-converted light-emitting diodes based on the pressure-treated IRMOF-0 NCs exhibit excellent thermal, chromaticity, and fatigue stability. The proposed strategy not only imparts new vitality to nonaromatic interpenetrated MOFs but also offers new perspectives for advancements in the field of multicolor displays and daylight illumination.

Reticular access to triptycene-based cationic metal–organic frameworks for protein-bound uremic toxins sorption

P-cresyl sulfate (pCS) and indoxyl sulfate (IS), a class of protein-bound uremic toxins, cannot be effectively cleared through hemodialysis treatment due to their strong binding to human serum albumin, posing a potential risk of cardiovascular disease in patients with chronic renal failure. Herein, we designed and prepared novel cationic metal–organic frameworks (MOFs), denoted as ZJU-X18, for the efficient removal of pCS and IS. A triptycene-based rigid trigonal prismatic ligand was utilized to link with Ag+ to yield a rare 4-fold interpenetrated MOF with abundant hydrophobic channels, affording high sorption capacity, excellent selectivity, and decent recyclability toward uremic toxins. Furthermore, the anion-exchange process between ZJU-X18 and uremic toxins is verified through density functional theory (DFT) calculations. This study provides a proactive example of the rational design of cationic MOFs from the perspective of reticular chemistry and demonstrates their promising application in uremia treatment.

A Highly Chemically Robust 3D Interpenetrated MOF Heterogeneous Catalyst for the Synthesis of Hantzsch 1,4-Dihydropyridines and Drug Molecules.

Metal-organic frameworks (MOFs) have attracted immense attention as efficient heterogeneous catalysts over other solid catalysts, however, their chemical environment instability often limits their catalytic potential. Herein, utilizing a flexible unexplored tetra-acid ligand and employing the mixed ligand approach, a 3D interpenetrated robust framework is strategically developed, IITKGP-51 (IITKGP stands for Indian Institute of Technology Kharagpur), which retained its crystallinity over a wide range of pH solution (4-12). Having ample open metal sites (OMSs), IITKGP-51 is explored as a heterogeneous catalyst in one-pot Hantzsch condensation reaction, with low catalyst loading for a broad range of substrates. The synthesis of drug molecules remains one of the most significant and emergent areas of organic and medicinal chemistry. Considering such practical utility, biologically important Nemadipine B and Nifedipine drug molecules (calcium channel protein inhibitor) are synthesized for the first time by using this catalyst and fully characterized via SC-XRD and other spectroscopic methods. This report inaugurates the usage of a MOF material as a catalyst for the synthesis of drug molecules.

Active Sites Decorated Nonpolar Pore-Based MOF for One-step Acquisition of C2 H4 and Recovery of C3 H6.

Herein, a 2-fold interpenetrated metal-organic framework (MOF) Zn-BPZ-TATB with accessible N/O active sites in nonpolar pore surfaces was reported for one-step C2 H4 purification from C2 H6 or C3 H6 mixtures as well as recovery of C3 H6 from C2 H6 /C3 H6 /C2 H4 mixtures. The MOF exhibits the favorable C2 H6 and C3 H6 uptakes (>100 cm3 g-1 at 298 K under 100 kPa) as well as selective adsorption of C2 H6 and C3 H6 over C2 H4 . The C3 H6 - and C2 H6 -selective feature were investigated detailedly by experimental tests as well as sorption kinetic studyies. Molecular modelling revealed the multiple interactions between C3 H6 or C2 H6 molecules and methyl groups as well as triazine rings in pores. Zn-BPZ-TATB not only can directly generate 323.4 L kg-1 and 15.4 L kg-1 of high-purity (≥99.9 %) C2 H4 from C3 H6 /C2 H4 and C2 H6 /C2 H4 mixtures, but also provide a large high-purity (≥99.5 %) C3 H6 recovery capacity of 60.1 L kg-1 from C3 H6 /C2 H4 mixtures. More importantly, the high-purity C3 H6 (≥99.5 %) and C2 H4 (≥99.9 %) with the productivities of 38.2 and 12.7 L kg-1 can be simultaneously obtained from C2 H6 /C3 H6 /C2 H4 mixtures through a single adsorption/desorption cycle.

Gigantic blue shift of two-photon–induced photoluminescence of interpenetrated metal–organic framework (MOF)

Abstract As an important means of modern science and technology, multiphoton fluorescence plays an essential role in high-resolution imaging, photochemistry, micro- and nano-processing and clinical diagnosis. Multiphoton fluorescence usually shares the same radiative channel as its intrinsic fluorescence. Under multiphoton excitation, except for red shift fluorescence caused by the reabsorption effect, gigantic blue shift of multiphoton fluorescence is rarely reported. In this work, metal–organic frameworks (MOFs) with 7-fold and 8-fold interpenetration are successfully synthesized. The synthesized 8-fold interpenetrated MOFs show unexpectedly giant blue-shifted (∼40 nm) two-photon–induced fluorescence compared with its fluorescence emission. Specific optical selection rules lead to different final transition states in one-photon absorption and two-photon absorption. The density functional theory (DFT) and time-dependent density functional theory (TDDFT) simulations show that, under two-photon excitation, electrons and holes can be more delocalized, and intermolecular interactions mainly govern the emission process of 8-fold interpenetrated MOFs. Highly excited electronic states of the interpenetrated MOFs are effectively excited and emitted under two-photon excitation, thus generating the inevitable blue-shifted two-photon–induced fluorescence emission. Our work provides a guide for exploring the excitation mechanism of fluorescent MOFs and offers an access to a tunable all-optical single-crystal device.

Hetero-interpenetrated metal-organic frameworks.

Interpenetrated metal-organic frameworks (MOFs) comprise two or more lattices that are mutually entangled. Interpenetration can be used to tune the structures and pore architectures of MOFs to influence, for example, their stability or interactions with guest molecules. The interpenetrating sublattices are typically identical, but hetero-interpenetrated MOFs, which consist of sublattices that are different from one another, have also been serendipitously produced. Here we describe a strategy for the deliberate synthesis of hetero-interpenetrated MOFs. We use the cubic α-MUF-9 framework as a host sublattice to template the growth of a second sublattice within its pores. Three different secondary sublattices are grown-two of which are not known as standalone MOFs-leading to three different hetero-interpenetrated MOFs. This strategy may serve to combine different properties into one material. We produce an asymmetric catalysis by allocating separate roles to the interpenetrating sublattices in a hetero-interpenetrated MOF: an achiral secondary amine on one sublattice provides the catalytic activity, while the chiral α-MUF-10 host imparts asymmetry to aldol and Henry reactions.

Bifunctional metal-organic frameworks as selective turn-on fluorescence sensors for tryptophan and heterogeneous catalysts for Knoevenagel condensation reaction

Two new doubly interpenetrated metal-organic frameworks (MOFs) with formulas [{Zn(L1)(5-nipa)}·DMA]α (1a) and [{Cd(L2)(5-nipa)(H2O)}]α (1b) have been discussed herein, where [L1 = N,N'-(oxybis(4,1-phenylene))diisonicotinamide; L2 = N,N'-(methylenebis(4,1-phenylene)) diisonicotinamide; 5-H2nipa = 5-nitroisophthalic acid; DMA = dimethylacetamide]. A single crystal X-ray analysis reveals that 1a exhibits a 2D-interpenetrated interwoven sheet and finally adapts a 3D framework structure with the help of π···π stacking interactions. Similarly, 1b displays a two-fold interpenetrated 2D sheet-like architecture and is finally adjusted to a 3D structure. Both 1a and 1b feature channels with a cross-section of 25.06 × 25.06 Å2 and 24.01 × 24.01 Å2, respectively, running along the b-axis. Topological analysis of 1a and 1b by ToposPro suggests a (4)-connected uninodal sql topology with point symbol {44.62}. Further, 1a and 1b were exploited as molecular sensors for several amino acids exposing different shapes and sizes and exhibiting selective turn-on fluorescence sensing towards biologically important D/L-tryptophan with the notable limit of detection values of 0.084/0.110 μM and 0.143/0.141 μM, respectively, in aqueous medium. In addition, 1a and 1b were also exploited as heterogeneous catalysts towards several assorted aldehydes having different electronic environments, including sterically demanding aldehydes, under mild reaction conditions and obtained up to 97% of the respective Knoevenagel condensation product. Importantly, sterically hindered aldehydes also worked well with the MOF catalysts 1a and 1b, but showed comparatively low conversion. It is important to mention that in both cases, these MOF materials are recyclable for up to five consecutive runs without displaying any substantial loss in their sensing or catalytic activities. Moreover, the present investigation cultivates a new vision to design novel luminescent MOFs that can be used as multifunctional materials for the turn-on sensing of small organic molecules as well as instigated as heterogeneous catalysts in diverse organic transformation reactions.

A separation MOF with O/N active sites in nonpolar pore for One-step C2H4 purification from C2H6 or C3H6 mixtures

Here, a 2-fold interpenetrated metal–organic framework (MOF) was synthesized by imidazole derivative and carboxyl co-ligands, which features nonpolar pore environment with accessible N/O sorption sites, resulting in the suitable pore sizes (8.78 Å × 11.45 Å) to optimally interact with C2H6 and C3H6 compared to C2H4. The C3H6- and C2H6-selective phenomena were rigorously studied by combining pure-component sorption isotherms, ideal adsorbed solution theory (IAST) calculations, molecular simulations and breakthrough curves. The MOF exhibits high C3H6 uptake (53.6 cm3 g−1 at 10 kPa and 298 K) and benchmark C3H6/C2H4 selectivity (17.1), surpassing all of the reported porous materials for C3H6/C2H4 separation. Molecular simulations revealed both nonpolar pore environment and accessible O/N sites synergistically “match” better with C3H6 and C2H6 to provide stronger multiple interactions than C2H4. Experimental breakthrough curves and transient breakthrough simulations revealed that the MOF not only can realize one-step C2H4 purification (purity ≥ 99.9%) from various ratios of C2H6/C2H4 and C3H6/C2H4 mixtures with great recyclability, but also greatly increase the purity of C3H6 (such as from 28.5% to 87.7% for 2/5 C3H6/C2H4 mixture).

Mixed-Component Metal–Organic Framework for Boosting Synergistic Photoactivation of C(sp3)–H and Oxygen

Synergistic catalysis is an efficient and powerful strategy for simultaneously activating reactants by multiple active sites to promote the efficiency of difficult and challenging catalytic reactions. Meanwhile, enzymes with multi-active-site synergistic catalytic properties possessing high efficiency and high selectivity have become the goal pursued in the field of catalytic chemistry in recent years. Metal-organic frameworks (MOFs), as an effective heterogeneous catalytic platform, that can integrate multiple active sites for synergistic catalysis like enzymatic systems have recently attracted interest. Herein, we report a doubly interpenetrated metal-organic framework with dual active sites, MnIII-porphyrin sites to directly activate molecular oxygen and fluoren-9-one sites to produce a hydrogen atom transfer (HAT) agent by the proton-coupled electron transfer (PCET) process to simultaneously activate inert C(sp3)-H bonds for efficient inert C(sp3)-H bond oxidation under mild conditions. The bifunctional mixed-component MOF structure forced the two catalytic sites closer together to a more suitable distance, exhibiting high photocatalytic activity for inert C(sp3)-H bond oxidation with almost unique selectivity under mild conditions. The density functional theory (DFT) calculation of free energy during the whole catalytic process demonstrated that it is likely that the synergistic catalytic process occurred in the interframework to accelerate the catalytic reaction. The assembling mixed-component MOF for synergistic catalysis would be a prospective approach for the inert C(sp3)-H photoactivation and functionalization.

Tuning of Second-Harmonic Generation in Zn-Based Metal–Organic Frameworks by Controlling the Structural Interpenetrations: A First-Principles Investigation

To explain the huge difference in the second harmonic generation (SHG) response of two novel interpenetrated metal–organic frameworks (MOFs) that consist of Zn2+ ions coordinated to the trans-2-(4-pyridyl)-4-vinylbenzoate (pvb) ligand, eightfold interpenetrated Zn(pvb)2 (M1) and sevenfold interpenetrated [Zn(pvb)2]·DMF (M2), first-principles calculations were performed to study the geometries, band structures, and various linear and second-order nonlinear optical properties of M1 and M2 and two other hypothetical Zn-MOFs. Our results indicate that the structural transformation from M2 to M1 by the loss of the DMF guest is energetically favorable, and the M1 compound with the most tightly packed structure has the largest dielectric constant. For MOFs with the same order of interpenetration, the presence of the DMF guest has a small effect on the optical anisotropy of the system. Due to the different coordination environments of two kinds of Zn atoms, eightfold interpenetrated M1 shows more significant optical anisotropy than M2, and correspondingly, the range of phase matchability of M1 (>863 nm) is wider than that of M2 (>1126 nm). This means that at an experimental wavelength of 950 nm, M1 has a favorable phase-matching feature and displays strong SHG response, while the phase-mismatched behavior of M2 with sevenfold interpenetration leads to a weak SHG signal. Therefore, the difference in the interpenetrated structure induced by the guest DMF solvent is the main reason for the giant deviation in SHG intensity between M1 and M2 compounds. The present work provides new insights into how the phase-matching ability can be tuned by switching of the degree of interpenetration to enhance SHG response of MOFs.

Dimensional expansion of 1D zigzag chains to a 2D two-fold interpenetrated metal–organic framework for adsorption of lanthanide cations and white light emission

A novel layered MOF with a 2D two-fold interpenetrated structure was rationally fabricatedviaa dimension expansion strategy and was utilized as the host matrix to encapsulate lanthanide hydrates for white-light emission.

An ethynyl-modified interpenetrated metal-organic framework for highly efficient selective gas adsorption.

An ethynyl-modified interpenetrated MOF material with lvt topology, [Cu2(BTEB)(NMF)2]·NMF·8H2O (compound 1, H4BTEB = 4,4',4'',4'''-(benzene-1,2,4,5-tetrayltetrakis(ethyne-2,1-diyl))tetrabenzoic acid, NMF = N-Methylformamide), was successfully synthesized by using an alkynyl-functionalized H4BTEB organic ligand under solvothermal conditions. Structural analysis shows that compound 1, consisting of a tetradentate carboxylic acid ligand and classical [Cu2(CO2)4] paddle-wheel structure building units, has a rare 4-connected lvt topology with dual interpenetrating structure, which can improve the framework stability, as well as the gas adsorption capacity and selectivity due to the restricted pore channel. According to the study of gas adsorption performance, compound 1 with a larger surface area, boasts a superior adsorption capacity for small gas molecules. Also, ideal adsorption solution theory (IAST) computational simulation shows that compound 1 has good gas adsorption selectivity for C3H8/CH4, indicating its potential application in gas separation.

Tailor-Made Multiple Interpenetrated Metal-Organic Framework for Selective Detection and Adsorption of ReO4.

Rationally designed new materials for the selective detection and adsorption of 99Tc, a problematic element in nuclear waste, are important and challenging in environmental monitoring. Here, we utilize an interpenetration approach to develop a cationic fluorescent metal-organic framework (NCU-2), which was constructed by a flexible tridentate nitrogen-containing ligand and Ag+ metal ions. The NCU-2 is a scarce case of 14-fold interpenetrated with excellent chemical stability even under 0.5 M HNO3, which is helpful for the detection and removal of ReO4-/TcO4- from nuclear waste. Excitingly, the fluorescence signal of NCU-2 was obviously quenched in the presence of ReO4- (a nonradioactive surrogate of TcO4-) due to the robust interaction between ReO4- and the host for the formation of a non-fluorescent complex. Furthermore, the NCU-2 exhibits a high selectivity sensing of ReO4- in the presence of excess competitive ions. The superior response of NCU-2 toward ReO4- is ascribed to the high-fold structure and the luxuriant unsaturated Ag metal sites on the wall of 1D pore channels, which can enhance the framework positive charge and accelerate the transport of guest molecules to strengthen the interaction between them. Notably, NCU-2 successfully quantified trace levels of ReO4- in simulated Hanford waste with a broad linear range (0.2-200 μM) and a low detection limit of 66.7 nM. Moreover, NCU-2 also shows a high adsorption capacity to ReO4- (541 mg/g) and rapid sorption kinetics, making it extremely attractive for waste monitoring and emergency remediation.

Chiral Motifs in Highly Interpenetrated Metal-Organic Frameworks Formed from Achiral Tetrahedral Ligands.

Formation of highly interpenetrated frameworks is demonstrated. An interesting observation is the presence of very large adamantane-shaped cages in a single network, making these crystals new entries in the collection of diamondoid-type metal-organic frameworks (MOFs). The frameworks were constructed by assembling tetrahedral pyridine ligands and copper dichloride. Currently, the networks' degree of interpenetration is among the highest reported and increases when the size of the ligand is increased. Highly interpenetrated frameworks typically have low surface contact areas. In contrast, in our systems, the voids take up to 63 % of the unit cell volume. The MOFs have chiral features but are formed from achiral components. The chirality is manifested by the coordination chemistry around the metal center, the structure of the helicoidal channels, and the motifs of the individual networks. Channels of both handednesses are present within the unit cells. This phenomenon shapes the walls of the channels, which are composed of 10, 16, or 32 chains correlated with the degree of interpenetration 10-, 16-, and 32-fold, respectively. By changing the distance between the center of the ligand and the coordination moieties, we succeeded in tuning the diameter of the channels. Relatively large channels were formed, having diameters up to 31.0 Å×14.8 Å.

Modulated self-assembly of an interpenetrated MIL-53 Sc metal–organic framework with excellent volumetric H2 storage and working capacity

To achieve optimal performance in gas storage and delivery applications, metal–organic frameworks (MOFs) must combine high gravimetric and volumetric capacities. One potential route to balancing high pore volume with suitable crystal density is interpenetration, where identical nets sit within the void space of one another. Herein, we report an interpenetrated MIL-53 topology MOF, named GUF-1, where one-dimensional Sc(μ2-OH) chains are connected by 4,4′-(ethyne-1,2-diyl)dibenzoate linkers into a material that is an unusual example of an interpenetrated MOF with a rod-like secondary building unit. A combination of modulated self-assembly and grand canonical Monte Carlo simulations are used to optimise the porosity of GUF-1; H2 adsorption isotherms reveal a moderately high Qst for H2 of 7.6 kJ/mol and a working capacity of 41 g/L in a temperature–pressure swing system, which is comparable to benchmark MOFs. These results show that interpenetration is a potentially viable route to high-performance gas storage materials comprised of relatively simple building blocks.

Designing of three mixed ligand MOFs in searching of length induced flexibility in ligand for the creation of interpenetration

Interpenetrated metal organic frameworks (IMOFs) have occupied a top priority of interest in the last few decades due to their unexpected better potential applications in the various growing field. Interpenetrated framework is generally formed by coordination of metals with rigid ligands but flexible ligand shows more interesting results in some cases. It is well established that the length of used ligands, irrespective of flexibility and rigidity plays a vital role in making of these type of structures. In searching of IMOFs, we have synthesized three MOFs, {Cd(bix)0.5(adp)0.5(H2O)}n (1), {[Cd(bix)(2,2ꞌ–dmglu)].(H2O)}n (2) and {Cd(bpmp)(2,2ꞌ–dmglu)(H2O)].(H2O)}n (3) by using two different N,N-donor linkers bix {bix = 1,4-bis(imidazol-1-ylmethyl)- benzene}, bpmp { bpmp = 1,​4-​bis(4-​pyridinylmethyl)​piperazine} and two different substituted dicarboxylate adp {adp = adipate}, 2,2ꞌ–dmglu {2,2ꞌ–dmglu = 2,2ꞌ–dimethylglutarate}. Among the three complexes, three fold interpenetrated framework has been shown by complex 3 where long length more flexible N,N-donor ligand, bpmp { bpmp = 1,​4-​bis(4-​pyridinylmethyl)​piperazine}has been used. Gas sorption studies (H2, N2, and CO2) are performed with the three synthesized MOFs which substantially correlate with their framework. In case of complex 3, better hydrogen adsorption occurs compared to the other two complexes due to the greater lengths of NN donor connectivity and flexibility of bpmp ligand while all the three complexes show similar carbon dioxide and nitrogen adsorption.

Interpenetrated metal-organic frameworks with enhanced photoluminescence for selective recognition of m-xylene from xylene isomers.

Two novel luminescent metal-organic frameworks (MOFs), [Zn3(TCA)2(BPB)2]n (DZU-101, where H3TCA = 4,4',4''-tricarboxyltriphenylamine and BPB = 1,4-bis(pyrid-4-yl)benzene) and [Zn3(TCA)2(BPB)DMA]n (DZU-102), based on the same ligands and metal ions were synthesized by regulating the amount of water in the solvothermal reaction system. Structural analyses show that the two MOFs have pillar-layered frameworks with Zn3 clusters connected by the TCA3- and BPB ligands. Interestingly, DZU-102 possessed a two-fold interpenetrated framework distinct from the individual network of DZU-101. As a result, DZU-102 showed a visual fluorescence color change from chartreuse to azure in m-xylene, while the fluorescence color was turquoise in p-/o-xylene with no change. Furthermore, compared with p/o-xylene, the fluorescence emission peak of DZU-102 in m-xylene suspension produced an obvious blue shift. Moreover, selective fluorescence sensing experiments were also carried out, which demonstrated that the degree of peak shift was related to the concentration of m-xylene, indicating the potential application of DZU-102 in fluorescence sensing of m-xylene from xylene isomers and further revealed the application of structural interpenetration for luminescence tuning of MOFs.

Three-fold interpenetrated metal–organic framework as a multifunctional fluorescent probe for detecting 2,4,6-trinitrophenol, levofloxacin, and l-cystine

A robust Zn(ii) MOF with good chemical and thermal stability, was prepared as an effective fluorescent probe for 2,4,6-trinitrophenol (TNP), levofloxacin (LVX) and l-cystine (l-Cys) with recyclability.

Impact of the Structural Modification of Diamondoid Cd(II) MOFs on the Nonlinear Optical Properties.

A change in the degree of interpenetration (DOI) in metal-organic frameworks (MOFs) prompted by heat, pressure, or exchange of solvents is a fascinating phenomenon that can potentially impact the functional properties of MOFs. Structural transformation involving two noncentrosymmetric MOFs with different DOIs provides a rare opportunity to manipulate their optical properties. Herein, we report an unusual single-crystal-to-single-crystal (SCSC) transformation of a noncentrosymmetric 7-fold interpenetrated diamondoid (dia) Cd(II) MOF into another noncentrosymmetric but 8-fold interpenetrated dia MOF upon the removal of guest solvents. A hydrogen-bond network formed between the lattice solvents and linker trans-2-(4-pyridyl)-4-vinylbenzoate (pvb) in a 7-fold interpenetrated noncentrosymmetric MOF results in a significant increase in the two-photon absorption cross-section (11 times) as compared to that in the desolvated 8-fold interpenetrated MOF. Also, an increase in the DOI in the noncentrosymmetric crystals strengthened the π···π interaction between the individual diamondoid networks and enhanced the second-order nonlinear optical (NLO) coefficient (deff) by 4.5 times. These results provide a way to manipulate the optical properties of MOFs using a combined strategy of the formation of hydrogen bonds and interpenetration for access to tunable single-crystal NLO devices in an SCSC manner. By changing the experimental conditions, another dia Cd(II) MOF with 4-fold interpenetration can be isolated. In this centrosymmetric MOF, the olefin groups in the backbone of the ligand (pvb) undergo a [2 + 2] cycloaddition reaction quantitatively under UV light but in a non-SCSC fashion.

A Two-Fold Interpenetrated Dual-Emitting Luminescent Metal-Organic Framework as a Ratiometric Sensor for Chromium(III).

A novel two-fold interpenetrated metal-organic framework, namely Co-EDDA, was synthesized by hydrothermal reaction of 5,5'-[ethane-1,2-diylbis(oxy)]diisophthalic acid (H4EDDA), Co(NO3)2·6H2O, and 1,4-di(1H-imidazol-1-yl)benzene in water in an alkaline environment and structurally characterized. Co-EDDA could display clear dual-emission signals at 350 and 430 nm, representing the charge transfer emission between metal ions and the ligand and the ligand-based emission, respectively, which represents the ratiometric luminescence response to chromium(III) with high selectivity and sensitivity (limit of detection of 0.54 μM). Comprehensive studies indicate that the detection can be attributed to the interaction between the Cr3+ ions and the O atoms on the ether bond in Co-EDDA.