Isophthalic Acid Research Articles

Synthesis, crystal structures, photochromism and selective luminescence sensing property of Zn/Cd-viologen coordination polymers

Three Zn/Cd-viologen coordination polymers (CPs), namely, {Zn[(bcbpy)0.5(ipa)(H2O)]·H2O}n (1), {Zn[(bcbpy)0.5(ipa)(H2O)0.5]·H2O}n (2), and {Cd[(bcbpy)(SO4)]·2H2O}n (3), have been constructed using aromatic carboxylic acid and viologen-derived ligands, where H2bcbpy·2Cl represents 1,1′-bis((4-carboxyphenyl)-4,4′-bipyridine) dichloride and H2ipa stands for isophthalic acid. All three CPs display photochromic properties, transforming from yellow to dark blue upon irradiation with a xenon lamp. Notably, the photoresponse rates vary among these CPs, with compound 1 showing the fastest photoresponse, followed closely by compounds 2 and 3. Furthermore, CPs 1, 2, and 3 display a unique sensitivity to different concentrations of Cr2O72- anion solutions. When immersed in these solutions, the compounds exhibit varying degrees of fluorescence quenching effects, allowing for the monitoring of even the lowest ion concentrations. Additionally, upon exposure to ammonia vapor, the three compounds undergo a color change from yellow to dark brown, indicating their sensitivity to ammonia vapor.

Two Mixed-Ligand Co(II) Complexes as Luminescent Materials and Loaded with Temozolomide-gel Particles in Nursing Against Glioma.

By employing a mixed-ligand strategy, we synthesized two new coordination polymers (CPs) featuring Co(II): {Co(H2L)(bib)]·2H2O}n (1) and {Co(L)(bib)2]·2H2O}n (2), where H4L represents 5-(3,5-dicarboxybenzyloxy) isophthalic acid, and bib denotes 1,4-bis(1-imidazolyl)benzene. These CPs were obtained through the reaction of H4L, a flexible carboxylic acid ligand, with Co(NO3)2·6H2O in various solvent mixtures, along with the N-donor co-ligand bib. Complexes 1 and 2 are formed through distinct coordination modes, resulting in their distinct structural features and excellent fluorescent properties. Based on ligand-centered fluorescence emission and the blue shift (CP 1) along with red shift (CP 2) characteristics, both complexes show promise for applications in fields such as blue fluorescence sensing materials and luminescent materials. After successfully synthesizing two CPs, CP 1 was chosen as the carrier for loading temozolomide (TMZ). Subsequently, leveraging the unique advantages of hydrogels, we developed a novel metal gel formulation loaded with TMZ. The inhibitory effect of this formulation on the growth of glioblastoma was evaluated. Our results demonstrate a significant suppression of glioblastoma cell proliferation by this system, providing an effective avenue for glioblastoma treatment.

Interfacial Modification of NiOx for Highly Efficient and Stable Inverted Perovskite Solar Cells

AbstractNickel oxide is one of the most promising hole‐transporting materials in inverted perovskite solar cells (PSCs) but suffers from undesired reactions with perovskite which leads to limited device performance and stability. Self‐assembled monolayers (SAMs) are demonstrated to effectively optimize the NiOx/perovskite interface, but the significance of the compactness of the SAM at the interface is less investigated. Here, a series of methoxy‐substituted triphenylamine functionalized benzothiadiazole (TBT) based SAM molecules, TBT‐BA, TBT‐FBA, and TBT‐DBA, with benzoic acid, 2‐fluorobenzoic acid and isophthalic acids as anchoring groups are used to modify NiOx. TBT‐BA with the simplest structure is demonstrated to form the densest SAM on NiOx, thus optimized NiOx/SAM/perovskite interface is achieved with enhanced charge collection and suppressed interfacial reaction and recombination. TBT‐BA can also passivate the perovskite most effectively due to the highest binding energy toward perovskite, thus the corresponding inverted PSCs show the highest PCE of 24.8% and maintain 88.7% of the initial PCE after storage at 60 °C for 2635 h in the glovebox. The work provides important insights into designing SAM molecules for modification transporting layers for efficient and stable PSCs.

Synthesis, structure, fluorescence and magnetic studies of two oxygen bridged polycarboxylic acid ligands and rare earth metal ion Pr, Gd, and Er complexes

In order to further enrich the research on the synthesis of complexes with polycarboxylic acid ligands and rare earth metal ion. In this study, four rare earth complexes, namely, [Gd(cpia)]n (1), [Er(cpia)]n (2), [Pr(cpna)2·2H2O]n (3) and [Gd(Hcpna)(cpna)•3H2O]n (4) have been synthesized by solvothermal method based on 5-(2-carboxyphenoxy)isophthalic acid (H3cpia) and 5-(4-carboxyphenoxy)nicotinic acid ligand (H2cpna) with rare earth metal ions Pr3+, Gd3+ and Er3+. Single crystal X-ray diffraction analyses reveal that complexes 1, 2 and 3 are two-dimensional network structure, 4 is one-dimensional chain structures. The fluorescence test results show that the fluorescence intensity of complexes 1 and 2 were lower than that of the H3cpia ligand, the fluorescence intensity of complexes 3 and 4 were lower than that of the H2cpna ligand. Magnetic results indicate complex 1 has ferromagentic behavior and weak antiferromagentic behavior in the complexes 2, 3 and 4.

Synthesis, magnetic and fluorescence detection properties of four metal-organic frameworks based on imidazole carboxylic acid ligands

Four new metal-organic frameworks (MOFs), namely [M(HL)H2O]n (1–3) [M = Co (1), Ni (2), Cu (3)] and [Cd(HL)]n (4), were successfully structured based on imidazole carboxylic acid ligands [H3L = 5-(((1H-imidazol-2-yl)methyl)amino) isophthalic acid]. X-ray single-crystal diffraction analysis showed that MOFs 1–3 possess the same two-dimensional (2D) planar structure, while MOF 4 exhibited a three-dimensional (3D) coordination network. The magnetic test results showed that MOFs 1–3 have typically antiferromagnetic behavior. The sensing experimental showed that MOF 4 could be considered as a promising bifunctional fluorescent sensor for Cu2+ and Fe3+ ions with excellent selectivity and sensitivity, and the detection limit were 4.11 μM and 4.89 μM, with Ksv values of 1.37 × 104 M−1 and 1.24 × 104 M−1, respectively. The cycling experiment illustrated the good reusability of the material. In addition, the fluorescence quenching mechanism of MOF 4 was further explored in detail.

Evaluation of 2,5‐Furandicarboxylic Acid as Building Block for Unsaturated Polyester Resins

AbstractThis article presents partially bio‐based unsaturated polyester resins (UPR) based on 2,5‐furandicarboxylic acid (FDCA). Three different FDCA‐based resins are prepared, which are potentially suited as i) general purpose resin (composed of 1,2‐propylene glycol), ii) resin for pultrusion (composed of diethylene glycol and 1,2‐propylene glycol), and iii) resin for pipe liners (composed of neopentyl glycol and 1,2‐propylene glycol). The mechanical and thermal properties of the bio‐based UPR are systematically investigated and compared with analogous fossil‐based UPR composed of phthalic and isophthalic acid, signaling comparable or even better properties for the bio‐based resins depending on the application targeted.

Novel photoresponsive molecularly imprinted polymers based on etched silicon core with enabling enhanced selectivity and sensitivity for the detection of sulfamethazine

AbstractSulfamethymidine, a commonly employed sulfonamide, is introduced into the human body through the food chain, posing a threat to human health. Consequently, the development of a rapid and efficient detection technique is imperative. In this investigation, a photoresponsive sulfamethyridiazine‐imprinted polymer was synthesized to etch a silicon core, thereby effectively addressing the limitations encountered with conventional molecularly imprinted polymers including diminished binding capacity, restricted site accessibility and sluggish binding kinetics. The photosensitive monomer utilized in the molecularly imprinted polymers is 5[(4 (methylacryloxy) phenyl) diazene] isophthalic acid, which exhibits a stimulating reaction mechanism. The N=N bond undergoes photoisomerization, transitioning between trans and cis configurations. The adsorption experiment provides additional evidence that the hollow molecularly imprinted polymers exhibit a higher adsorption capacity, achieving a value of 0.192 mmol L−1. The experiments conducted to assess selectivity and repeatability confirm that the photoresponsive molecularly imprinted polymers exhibit a high level of selectivity and favorable repeatability. Following four cycles, the adsorption rate remains consistently at 64.3%. Additionally, the recoveries of the actual samples ranged from 95.6% to 99.7%. This finding presents a novel approach to detecting the concentration of trace pollutants in intricate substrates. © 2024 Society of Industrial Chemistry.

Bio-based, closed-loop chemical recyclable aromatic polyamide from 2,5-furandicarboxylic acid: Synthesis, high performances, and degradation mechanism

The resource and environmental challenges posed by the extensive use and disposal of plastics have increased the urgency of research into plastic recycling and the hunt for bio-based alternative feedstocks. As one of the five general engineering polymers, polyamide has not yet been systematically explored in terms of its recycling performance or mechanism, especially aromatic polyamides. In addition, research on novel structured bio-based aromatic polyamides has not received sufficient attention due to the harsh polymerization conditions. In this work, bio-based fully aromatic polyamides based on 2,5-furandicarboxylic acid (FDCA) was successfully synthesized through the acyl chloride method, exhibiting thermal, mechanical, and barrier properties comparable to or superior to those of fossil derived isophthalic acid based polyamides. Moreover, both synthesized polyamides could be hydrolyzed in alkaline environments through the cleavage of amide bonds, as demonstrated by molecular dynamics simulations. The presence of furan rings lowered the energy barrier of hydrolysis as compared to benzene rings. Furthermore, a simple and efficient acidification followed by filtration approach with high recovery yields was developed to recover initial monomers from degradation solutions, thus achieving closed-loop chemical recovery of two polyamides. This work will further expand the application of bio-based feedstock, FDCA, and open new avenues for polyamide recycling research.

Enhancing the efficient degradation of BPS using the BPNS-CdS composite catalyst under visible light

Black phosphorus nanosheets (BPNS), a novel two-dimensional nanomaterial, find extensive applications in the field of photocatalysis. With the prohibition of bisphenol A (BPA), the utilization of bisphenol S (BPS), which is more resistant to degradation than BPA, has been steadily increasing. In this study, few-layer BPNS was prepared using an improved liquid-phase exfoliation method, showcasing its commendable specific surface area and notable adsorption capacity. Subsequently, a new type of nanocomposite material, BPNS-Cadmium sulfide (CdS), was hydrothermal synthesized involving BPNS and CdS. We conducted comparative assessments of BPNS, CdS, and their composite materials to identify the most efficient catalysts. Ultimately, we found that the composite material BPNS-CdS exhibited the highest capability for degrading BPS in an alkaline environment, achieving an impressive degradation rate of 86.9%. Notably, the degradation rate remained higher in an acidic environment compared to a neutral one. Through Electron Spin Resoance (ESR) experiments, it is revealed that BPNS-CdS, when exposed to visible light, generates •O2−, •OH, and h+ as confirmed. Additionally, we tested and validated the carrier separation and migration abilities of BPNS-CdS while also calculating the band gap for each material. Building upon these results, a possible photocatalysis mechanism experiment was proposed. Finally, the degradation products were analyzed using High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) and put forth a plausible pathway for the BPS degradation, and it was found that 4-Phenolsulfonic acid, Ethyl protocatechuate and Isophthalic acid are the main intermediates of BPS. This study contributes to a deeper understanding of the synergy between non-metallic catalysts like BPNS and metal catalysts like CdS. It also offers new insights into the degradation mechanisms and pathways for BPS.

Two novel multifunctional chromic compounds: Synthesis, photochromism, ammonia sensing, and anion sensing

Two new Zn (II)-viologen chromic compounds, named {[(4-BCBPY)0.5(HIPA)]·H2O}n (1) and {[Zn3(IPA)4(4-BCBPY)]·2H2O}n (2) (4-BCBPY2+ = 1,1′-bis(4-cyanobenzyl)-4,4′-bipyridinium dication, H2IPA = isophthalic acid) have been synthesized through varying reaction conditions. Structural analysis reveals that compound 1 possesses a supramolecular compound, while compound 2 exhibits a metal-organic framework (MOF) structure built from trinuclear metal building units. Under the irradiation of a 300 W Xe lamp, compound 1 undergoes a color change from orange to brown, while compound 2 transitions from yellow to green. The introduction of metal ions in compound 2 enhances its light response rate compared to compound 1. Additionally, compound 2 displays a visible color change in the presence of ammonia, whereas compound 1 does not exhibit this capability. Meanwhile, the stable product 2P of 2 was obtained through irradiation, and the structural differences between 2 and 2P were analyzed. Furthermore, the study of time-dependent density functional theory (TDDFT) provides theoretical support for understanding the properties of 1 and 2. Both compounds exhibit intriguing photomodulated luminescence properties and demonstrate remarkable sensing abilities toward Cr2O72−. Notably, the introduction of metal ions was found to modulate the photochromic behavior as well as the ammonia/anion sensing properties of these compounds.

Construction of Anderson−type polyoxometalate−based complexes involving in situ ligand transformation with capacitive and electrochemical sensing performances

For developing polyoxometalate−based hybrids as potential energy storage and electrochemical materials, 3, 5−di(1H−imidazol−1−yl)benzonitrile (DICN) and 5−(1H−imidazol−1−yl)isophthalonitrile (IMIPN) as precursors were employed, and three Anderson−type polyoxometalate−based complexes, [{Cu3(H2O)8(HDIBA)2}{TeMo6O24}]·6H2O (1), [{Cu4(H2O)10(HIMIPA)2}{TeMo6O24}]·2H2O (2) and Ni(H2O)6[{Ni2(H2O)4(H2IMIPA)2}{TeMo6O24}]·4H2O (3), were prepared under hydrothermal condition. The initial DICN and IMIPN were transformed in situ into 3,5−di(1H−imidazol−1−yl)benzoic acid (HDIBA) and 5−(1H−imidazol−1−yl)isophthalic acid (H2IMIPA). In 1, the polyoxometalate−based inorganic chains containing single−bridged copper linkages were extended by the imidazole groups of HDIBA ligand, but the chains in 2 and 3 embodied the double−bridged copper and nickel linkages, further linked by the imidazole and carboxyl groups from HIMIPA ligand. Complexes 1−3 demonstrated outstanding capacitive performances (i.e., specific capacitances of 944 F·g–1 for 1, 1548.6 F·g–1 for 2 and 718.6 F·g–1 for 3 at 1 A·g–1), as well as electrochemical sensing activities for bromate. The results provided a feasible way for the design and synthesis of Anderson−type POM−based complexes used as high−performing electrode materials in energy store and sensor−related applications.

Retraction Note to: Synthesis, Crystal Structure, and Anticancer Activity of a In(III) Coordination Polymer Based on a Flexible 5-(4-Carboxybenzyl)Isophthalic Acid Ligand

Retraction Note to: Synthesis, Crystal Structure, and Anticancer Activity of a In(III) Coordination Polymer Based on a Flexible 5-(4-Carboxybenzyl)Isophthalic Acid Ligand

Synthesis and structure of a manganese(II) coordination polymer assembled with 5-(tert-butyl)isophthalic acid and 1,3-dimethyl-2-imidazolidinone

Abstract A manganese(II) coordination polymer [Mn(tbip)(DMI)] n (1), (tbipH2 = 5-(tert-butyl)isophthalic acid, DMI = 1,3-dimethyl-2-imidazolidinone), has been synthesized under “urea-thermal conditions” (i.e. in an excess of urea). Its structure has been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectra. Complex 1 crystallizes in the monoclinic space group P21/c with Z = 4. In 1, the [tbip]2− ligand bridges the Mn(II) cations to form infinite chains, and the neighbouring chains are connected through [tbip]2− ligands into layers.

A bifunctional Zn(II) coordination polymer for fluorescence recognition towards hazardous matters and its high adsorption removal of dye pollutant

In this work, a novel Zn(II) coordination polymer (denoted as Zn-CP) was constructed by the mixed ligands of 6-(3′,4′-Dicarboxy phenoxy)isophthalic acid (H4L) and 4,4′-bis(imidazolyl)biphenyl (bib) under solvothermal method. And based on the Zn-CP, the surfactant agent sodium dodecyl sulfate (SDS) was further introduced into the structure, thus obtaining the Zn-CP(S) which possessed the same phase but a smaller size compared with the Zn-CP. Interestingly, the Zn-CP(S) presented a significantly ameliorated fluorescent intensity, about 4.36 times higher than that of the Zn-CP prepared in the absence of SDS. Taking advantage of the improved fluorescence trait of the Zn-CP(S), a fluorescence recognition towards hazardous matters was further carried out. The results showed that Zn-CP(S) could simultaneously recognized for Hg2+, Cr2O72− and a broad range of hazard nitroaromatic explosives with the satisfactory limits of detection (LODs). In addition, Zn-CP could also be used as a recyclable adsorbent to remove methyl orange (MO) in aqueous medium. The maximum equilibrium adsorption capacity of Zn-CP for MO was 61.01 mg/g, and the adsorption mechanism could be attributed to the weak inter-molecular interaction involved π-π stacking and hydrogen bonding between Zn-CP and the MO molecule. Therefore, the bifunctional material has potential application prospects in fluorescence recognition and adsorption.

Solubility measurement, molecular simulations, Hansen solubility parameter and thermodynamic properties of isophthalic acid in binary solvents at 283.15–323.15 K

The solubility of isophthalic acid (IPA) in four different binary solvent systems (water + methanol, water + ethanol, water + 1-propanol, and water + isopropanol) was measured by the gravimetric method at atmospheric pressure from 283.15 K to 323.15 K. Under certain solvent compositions, the solubility of IPA increased with increasing temperature. The trend of solubility under isothermal conditions setting differs as the mole fraction of organic solvent increases. The solubility of IPA in water + methanol and water + ethanol systems increased with the mole fraction of methanol or ethanol. In the system of water + 1-propanol and water + isopropanol, as the mole fraction of organic solvent increased, the solubility of IPA increased firstly and then decreased gradually. The Hansen solubility parameters of IPA and selected solvents were analyzed, the analysis showed that the miscibility of IPA with the selected solvent was the result of many factors. Molecular electrostatic potential surface (MEPS) and Hirshfeld surface (HS) analysis were used to investigate the intermolecular interactions. The solubility data were correlated using the Apelblat equation, van't Hoff equation, λh equation, and Jouyban–Acree model. Besides, the vant Hoff equation was employed to analyze the apparent thermodynamic properties of dissolving process including the Gibbs energy, enthalpy and entropy. All positive values indicated that the dissolving process of IPA was non-spontaneous, endothermic, and entropy-driven.

Finely Tuning Metal Ion Valences of [Fe3-xMx(μ3-OH)(Carboxyl)6(pyridyl)2] Cluster-Based ant-MOFs for Highly Improved CO2 Capture Performances.

Solvothermal reactions of different trinuclear precursors and 5-(pyridin-4-yl)isophthalic acid (H2L) successfully led to four anionic ant topological MOFs as Fe3-xMx(μ3-OH)(CH3COO)2(L)2·(DMA+)·DMF [M = Mn(II), Fe(II), Co(II), x = 0, 1, 2 and 3], namely, NJTU-Bai79 [NJTU-Bai = Nanjing Tech University Bai's group, Mn3(μ3-OH)], NJTU-Bai80 [Fe2Mn(μ3-OH)], NJTU-Bai81 [Fe3(μ3-OH)], and NJTU-Bai82 [Fe2Co(μ3-OH)], which possess the narrow pores (2.5-6.0 Å). NJTU-Bai80-82 is able to be tuned to the neutral derivatives [NJTU-Bai80-82(-ox), ox = oxidized] with M2+ ions oxidized to M3+ ones in the air and the OH- ions coordinated on M3+ ions. Very interestingly, selective CO2/N2 adsorptions of NJTU-Bai80-82(-ox) are significantly enhanced with the CO2 adsorption uptakes more than about 6 times that of NJTU-Bai79. GCMC simulations further revealed that neutral NJTU-Bai80-82(-ox) supplies more open frameworks around the -CH3 groups at separate spaces to the CO2 gas molecules with relatively more pores available to them after the removal of counterions. For the first time, finely tuning metal ion valences of metal clusters of ionic MOFs and making them from electrostatic to neutral were adopted for greatly improving their CO2 capture properties, and it would provide another promising strategy for the exploration of high-performance CO2 capture materials.

Solar-Driven Ammonia Production through Engineering of the Electronic Structure of a Zr-Based MOF.

As a hydrogen carrier and a vital component in fertilizer production, ammonia (NH3) is set to play a crucial role in the planet's future. While its industrial production feeds half of the global population, it uses fossil fuels and emits greenhouse gases. To tackle this issue, photocatalytic nitrogen fixation using visible light is emerging as an effective alternative method. This strategy avoids carbon dioxide (CO2) emissions and harnesses the largest share of sunlight. In this work, we successfully incorporated a 5-nitro isophthalic acid linker into MOF-808 to introduce structural defects and open metal sites. This has allowed modulation of the electronic structure of the MOF and effectively reduced the band gap energy from 3.8 to 2.6 eV. Combination with g-C3N4 enhanced further NH3 production, as these two materials possess similar band gap energies, and g-C3N4 has shown excellent performance for this reaction. The nitro groups serve as acceptors, and their integration into the MOF structure allowed effective interaction with the free electron pairs on N-(C)3 in the g-C3N4 network nodes. Based on DFT calculations, it was concluded that the adsorption of N2 molecules on open metal sites caused a decrease in their triple bond energy. The modified MOF-808 showed superior performance compared with the other MOFs studied in terms of N2 photoreduction under visible light. This design concept offers valuable information about how to engineer band gap energy in MOF structures and their combination with appropriate semiconductors for solar-powered photocatalytic reactions, such as N2 or CO2 photoreduction.

Fluorescent MOF and Its Gel Composite for the Fluorescence Recovery "Turn-On" Detection of Al3+ Ions and "Turn-Off" Detection of Oxo-Anions.

The exploration of smart sensors is of great significance for the selectivity, sensitivity, and ability to show the low detection limit for the target analyte. Here, we have used the linker H2L (5-((anthracen-9-ylmethyl)amino)isophthalic acid) for the construction of {[Cd(L)(DMF)(H2O)2]·H2O}n (1) which is in order with the chromophore anthracene moiety and the free -NH functionality as a guest interaction site. This framework showed the luminescence recovery "turn-on" detection of the Al3+ ion in an aqueous solution. An exhaustive mechanism study disclosed that the Lewis acid-base-type interaction between the Al3+ ion and the -NH functionality of the linker in the framework revealed that the absorbance caused an enhancement for the "turn-on" sensing event. Besides the "turn-on" sensing event, the "turn-off" sensing phenomenon of 1 is also noticed when it detects the hazardous oxo-anions (MnO4- and CrO42-) with limit of detection values of 17.08 and 19.91 ppb, respectively. The detection of these diverse analytes are very fast (10 s) and they can also be recognized through a colorimetric response. The sensing mechanisms for these analytes are established by photoinduced electron transfer, Forster resonance energy transfer, and inert filter effect along with theoretical investigation. Furthermore, to show the sensing application of 1 in a versatile podium, a MOF gel composite, 1@AA (AA = Agar-Agar), was developed from 1 with AA. Interestingly, 1@AA showed the colorimetric detection of these analytes under UV light. Therefore, sensor 1 behaves as a smart sensory material for the recognition of the above analytes through a simultaneous "turn-on" and "turn-off" effect.

Co(II) Metal-Organic Complex: Fluorescence Performances and Loaded With Drug Vitamin B2 Hydrogels Against Recurrent Oral Ulcers.

A new coordination polymer (CP) based on Co(II), namely, {[Co3(L)2(4,4'-bipy)(DMA)2]·H2O}n(1) has been synthesized after reacting Co(NO3)2·6H2O with H3L ligand in the existence of N-donor ligand 4,4'-bipyridine (4,4'-bipy), via utilizing a flexible tricarboxylic acid ligand 5-((formic acid-3-sulfur)methyl)isophthalic acid (H3L) with -S-CH2- joint. Additionally, the excellent blue fluorescence properties of CP 1 were confirmed through fluorescence spectroscopy compared to the original ligand. Using natural polysaccharide hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) as raw materials, HA/CMCS hydrogel was prepared by chemical synthesis method. Taking vitamin B2 as the drug model, we designed and synthesized gels loaded with vitamin B2 metal framework and evaluated their efficacy in the treatment of recurrent oral ulcer.

Two Zn(II)/Cd(II) coordination polymers based on 5-(3,5-dicarboxybenzyloxy)isophthalic acid for selective detection 4-nitrophenol and fluazinam in aqueous medium

Two new Zn(II)/Cd(II) coordination polymers, namely, {[Zn2(L)(CAS)]·H2O}n (1) and {[Cd2(L)(CAS)]·DMF·H2O}n (2) [H4L = 5-(3,5-dicarboxybenzyloxy)isophthalic acid, CAS = 1,2,4,5-tetra(4-pyridyl)benzene] were synthesized by solvothermal method and characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis and powder X-ray diffraction. In complex 1, CAS and Zn(II) are interconnected to form a 2D diamond structure. The 2D layers are interlinked by L4− ligands to generate a 3D network structure. The L4− ligands, CAS and Cd(II) in complex 2 are cross-linked to form a 2D planar structure. The 3D structure is formed by coordination bonds between the two layers. Complexes 1 and 2 could detect p-nitrophenol (4-NP) by fluorescence quenching, and the detection limits were 0.344 and 0.554 μM, respectively. Complex 1 can also be used for sensitive and selective detection of fluazinam (FLU) by fluorescence quenching with the detection limit of 0.185 μM. Additionally, the fluorescence quenching mechanism was also investigated. These new Zn(II)/Cd(II) coordination polymers could be used as dual-functional sensors on NACs and pesticides.