Tribenzoic Acid Research Articles

An imidazole functionalized copper(II)‐organic framework for highly selective sensing of picric acid and metal ions in water

An imidazole functionalized metal–organic framework (MOF), [Cu(HL)(H2O)]·(H2O)·(DMA) (HBU‐166, H3L = 4,4′,4″‐(1H‐imidazole‐2,4,5‐triyl)tribenzoic acid, DMA = N,N‐dimethylacetamide) was synthesized and characterized by single‐crystal X‐ray diffraction. HBU‐166 was observed as a two‐dimensional MOF and showed good stability in water, an acidic solution (pH = 4), and an alkaline solution (pH = 9). HBU‐166 exhibited ligand‐based luminescence with a blue shift, which could be attributed to the coordination effect. Moreover, HBU‐166 could be applied to detect nitroaromatic compounds (NACs) and metal ions in water with preferable selectivity and sensitivity. In particular, HBU‐166 could be used as a promising luminescent sensor for picric acid (PA) with enhancement of emission intensity. The mechanism for PA detection likely involved electron transfer and weak interaction between ligand and electron‐deficient of NACs at the beginning to increase the emission intensity. Additionally, HBU‐166 exhibited excellent selectivity in the sensing of 4‐nitrophenol and Fe3+ through fluorescence quenching.

Syntheses and structures of two novel fluorescent metal-organic frameworks generated from a tridentate donor-acceptor motif ligand.

The tridentate organic ligand 4,4',4''-(4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-2,6,10-triyl)tribenzoic acid (H3L) has been synthesized (as the methanol 1.25-solvate, C48H39NO6·1.25CH3OH). As a donor-acceptor motif molecule, H3L possess strong intramolecular charge transfer (ICT) fluorescence. Through hydrogen bonds, H3L molecules construct a two-dimensional (2D) network, which pack together into three-dimensional (3D) networks with an ABC stacking pattern in the crystalline state. Based on H3L and M(NO3)2 salts (M = Cd and Zn) under solvothermal conditions, two metal-organic frameworks (MOFs), namely, catena-poly[[triaquacadmium(II)]-μ-10-(4-carboxyphenyl)-4,4'-(4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-2,6-diyl)dibenzoato], [Cd(C48H37NO6)(H2O)3]n, I, and poly[[μ3-4,4',4''-(4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-2,6,10-triyl)tribenzoato](μ3-hydroxido)zinc(II)], [Zn2(C48H36NO6)(OH)]n, II, were synthesized. Single-crystal analysis revealed that both MOFs adopt a 3D structure. In I, partly deprotonated HL2- behaves as a bidentate ligand to link a CdII ion to form a one-dimensional chain. In the solid state of I, the existence of weak interactions, such as O-H...O hydrogen bonds and π-π interactions, plays an essential role in aligning 2D nets and 3D networks with AB packing patterns for I. The deprotonated ligand L3- in II is utilized as a tridentate building block to bind ZnII ions to construct 3D networks, where unusual Zn4O14 clusters act as connection nodes. As a donor-acceptor molecule, H3L exhibits fluorescence with a photoluminescence quantum yield (PLQY) of 70% in the solid state. In comparison, the PL of both MOFs is red-shifted with even higher PLQYs of 79 and 85% for I and II, respectively.

High C2 hydrocarbons capture and selective C2/C1 separation in A Tb(III)-organic framework

By employing a tripod rigid ligand with six coordination sites, 4,4’,4”-(pyridine-2,4,6-triyl)tribenzoic acid (H6PTA), a microporous terbium(III)-organic framework, [(Me)2NH2]1.5[Tb1.5(PTA)]·9H2O (1) has been synthesized under the solvothermal condition. Structural analysis demonstrates that 1 is a 3D anionic framework based on two kinds of Tb(III) units, which presents a rare framework constructed from ternary secondary building units (SBUs) and shows a new (4,5,6)-connected topology. Gas adsorption measurements reveal that 1 exhibits the significant C2H2 and C2H4 adsorption capacity but negligible uptake of CH4, which makes 1 as a promising adsorbent for C2H2/CH4 and C2H4/CH4 separation.

A self-penetrated three-dimensional zinc(II) coordination framework based on 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid and 1,3-bis[(imidazol-1-yl)methyl]benzene ligands: synthesis, structure and properties.

With the rapid development of metal-organic frameworks (MOFs), a variety of MOFs and their derivatives have been synthesized and reported in recent years. Commonly, multifunctional aromatic polycarboxylic acids and nitrogen-containing ligands are employed to construct MOFs with fascinating structures. 4,4',4''-(1,3,5-Triazine-2,4,6-triyl)tribenzoic acid (H3TATB) and the bidentate nitrogen-containing ligand 1,3-bis[(imidazol-1-yl)methyl]benzene (bib) were selected to prepare a novel ZnII-MOF under solvothermal conditions, namely poly[[tris{μ-1,3-bis[(imidazol-1-yl)methyl]benzene}bis[μ3-4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoato]trizinc(II)] dimethylformamide disolvate trihydrate], {[Zn3(C24H12N3O6)2(C14H14N4)3]·2C3H7NO·3H2O}n (1). The structure of 1 was characterized by single-crystal X-ray diffraction, IR spectroscopy and powder X-ray diffraction. The properties of 1 were investigated by thermogravimetric and fluorescence analysis. Single-crystal X-ray diffraction shows that 1 belongs to the monoclinic space group Pc. The asymmetric unit contains three crystallographically independent ZnII centres, two 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoate (TATB3-) anions, three complete bib ligands, one and a half free dimethylformamide molecules and three guest water molecules. Each ZnII centre is four-coordinated and displays a distorted tetrahedral coordination geometry. The ZnII centres are connected by TATB3- anions to form an angled ladder chain with large windows. Simultaneously, the bib ligands link ZnII centres to give a helical Zn-bib-Zn chain. Furthermore, adjacent ladders are bridged by Zn-bib-Zn chains to form a fascinating three-dimensional self-penetrated framework with the short Schläfli symbol 65·7·813·9·10. In addition, the luminescence properties of 1 in the solid state and the fluorescence sensing of metal ions in suspension were studied. Significantly, compound 1 shows potential application as a fluorescent sensor with sensing properties for Zr4+ and Cu2+ ions.

A terbium(III)-functionalized zinc(II)-organic framework for fluorometric determination of phosphate.

A terbium(III)-functionalized zinc(II)-organic framework (Tb-MOF-Zn) is shown to be a viable fluorescent probe for phosphate. The organic ligands 4,4',4″-[((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(oxy)]tribenzoic acid (H3L3) contains multiple carboxyl groups that canreact with zinc(II) to yield tubular MOF-Zn. The MOF-Zn was further functionalized with Tb(III) to produce a lanthanide composite of type Tb-MOF-Zn which displays strong fluorescence with excitation/emission maxima at 285/544nm. Fluorescence is quenched by phosphate because of the specific interaction with Tb(III) in Tb-MOF-Zn. The concentration of Tb-MOF-Zn, reaction time and pH value of the solution were optimized. Fluorescence drops linearly in the 0.01 to 200.0μM phosphate concentration range, and the detection limit is 4.0nM. The fluorescent probe was also used to prepare a microdot array on a glass slide for visual detection of phosphate under illumination with UV light. Graphical abstractA terbium(III) functionalized zinc(II)-organic framework was synthesized and used as fluorescent probe for determination of phosphate ions.

Covalent polybenzimidazole-based triazine frameworks: A robust carrier for non-steroidal anti-inflammatory drugs.

Covalent triazine-based polymers (CTPs) are a new class of porous materials that can be used for the intercalation of therapeutic agents. The main purposes of designing new drug carriers include protecting them from degradation, enhancing their poor aqueous solubility, and investigating their controlled release properties. In this context, a novel polybenzimidazole-based CTP (BZ-CTP) was prepared by a solvothermal reaction between 4,4',4″-((1,3,5-triazine-2,4,6-triyl) tris(azanediyl)) tribenzoic acid (TCA) and 3,3'-diaminobenzidine. Piroxicam (PRX) and mefenamic acid (MFA) were loaded thoroughly into the CTP by using ultrasonication to form MFA-loaded CTP (MFA@BZ-CTP) and PRX-loaded CTP (PRX@BZ-CTP) with drug loading efficiencies of 49% and 53%, respectively. We attribute the increased loading efficiencies to the formation of π-π stacking forces between the aromatic rings present in the CTP structure and drugs. The in vitro release experiments were assessed in simulated physiological conditions using the dialysis method. Moreover, the release mechanisms were evaluated by Korsmeyer-Peppas kinetic studies and the obtained results showed excellent sustained releases of 81% after 96h and 87% after 24h for the PRX@BZ-CTP and MFA@BZ-CTP hybrids, respectively.

Self-Assembly and Antitumor Activity of a Polyoxovanadate-Based Coordination Nanocage.

A new supramolecular nanocage, VMOP-31, based on polyoxovanadate as the molecular building block, has been designed and synthesized under solvothermal conditions. The structure of VMOP-31 was determined by single-crystal and powder X-ray diffraction, FTIR spectroscopy, UV/Vis spectrophotometry, and thermogravimetric analysis. The nanocage exhibits octahedral geometry and is constructed of six {V5 O9 Cl(COO)4 } at the vertices and eight TATB (H3 TATB=4,4',4''-(s-triazine-2,4,6-triyl)tribenzoic acid) ligands on the faces. Impressively, VMOP-31 exhibited high efficiency in the inhibition of cell growth of solid tumors, such as human liver cancer cells SMMC-7721, and superior results in the treatment of liver tumors in mice compared with classic cisplatin. Detailed studies revealed that the potential mechanism of cell death induced by VMOP-31 involves cell cycle arrests, DNA damage, and subsequent apoptosis. Moreover, VMOP-31 exhibited negligible side effects in the mice compared with cisplatin. To the best of our knowledge, VMOP-31 is the first supramolecular nanocage applied to hepatic tumors both in vitro and in vivo.

RETRACTED ARTICLE: Synthesis, Crystal Structures of Two Novel Metal Coordination Polymers and Study of Their Inhibition of Human Hemangioma Cells

In this work, two new InIII-based coordination polymers {(H2NMe2)3[In(TATAB)2](H2O)6}n (1, H3TATAB = 4,4′,4″-s-triazine-1,3,5-triyl-tri-p-aminobenzoic acid) and {(Me2NH2)2[In2(TTA)2(FA)2] (DMF)3}n (2, H3TTA = 4,4′,4″-{[(2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene)]tris(oxy)}tribenzoic acid, HFA = 2-fluorobenzoic acid, DMF = N,N-dimethylformamide) are successfully prepared under solvothermal conditions and structurally characterized by the single crystal X-ray study (SCXRD) and the powder X-ray analysis (PXRD). In addition, the in vitro anticancer activity of compounds 1 and 2 on three human hemangioma cells (HMEC-1, EAhy926 and SV40) is further investigated.

Lanthanide (III) Metal‐Organic Frameworks: Syntheses, Structures and Supercapacitor Application

AbstractThree new lanthanide‐MOFs, [(TATMB)2Ce2⋅3DMSO‐H2O]⋅7H2O (MOF−Ce), [(TATMB)2Pr2⋅4DMSO]⋅7H2O⋅DMF (MOF−Pr) and [(TATMB)2Nd2⋅3DMSO⋅H2O]⋅6H2O (MOF−Nd) were synthesized by the reaction of hydrated lanthanide salts and 3,3′,3′′‐((1,3,5‐triazine‐2,4,6‐triyl)tris(azanediyl))tribenzoic acid (H3TATMB) under solvothermal reaction condition. All MOFs were characterized by standard instrumentation techniques, for example, FT‐IR spectroscopy, elemental analysis, etc. The solid‐state structures were determined by single‐crystal X‐ray diffraction analyses. It revealed that all MOFs formed two‐dimensional frameworks by the coordination assisted pathway of ligand molecules and lanthanide(III) ions. All MOFs were investigated as supercapacitor electrode material by using the conventional three‐electrode method by using TEABF4 in acetonitrile as electrolyte. It was observed that MOF−Ce exhibited a maximum specific capacitance of 572 Fg−1 at a current density of 1 A g−1 among all three MOFs. The specific capacitance retention of the material was found to be 81% after successful completion of 5000 charging‐discharging cycles. To the best of our knowledge, the specific capacitance of MOF−Ce is highest reported for lanthanide MOFs without any redox‐active additive until now. Moreover, for the first time, MOF−Ce has been used to fabricate a device, which exhibited significant responses for various LED lights and showed a maximum specific capacitance of 88 Fg−1 at a current density of 2 A g−1.

A metal organic cage with semi-rigid ligand for heterogeneous alcoholysis of epoxides

A metal organic cage, [Cu6(L)4(DMF)2(H2O)4](1,4-Dioxane)2(DMF)10(H2O)4 (H3L = 4,4′,4″-(benzene-1,3,5-triyltris(oxy))tribenzoic acid) (FJU-18), has been constructed by six Cu2(CO2)4 paddle-wheel building units and eight semi-rigid L. The porous FJU-18 containing large cage of 1.6 nm shows high catalytic activity for the ring opening of styrene oxide in methanol at 65 °C under nitrogen atmosphere.

A series of three isostructural 1D lanthanide coordination network based on 4,4′,4″-((benzene-1,3,5-triyltris(methylene))tris(oxy))tribenzoate ligand: Synthesis, crystal structure and photophysical properties

Three 1D-coordination networks namely {[Ln(L)(DMF)(H2O)]·DMF}n. represented as EuL, GdL and TbL were obtained using the synthetized 4,4′,4″-((benzene-1,3,5-triyltris(methylene))tris(oxy))tribenzoic acid (H3L) as a ligand and lanthanide nitrate salts (Ln(NO3)3) (Ln = EuIII, GdIII or TbIII). The reactions were carried out under solvothermal conditions using a mixture of DMF and H2O. Single crystal X-ray analyses revealed that all three compounds are isostructural crystalizing in the triclinic space group P1-. They show an interesting binodal connected one-dimensional structure, with a static crystal disorder due to the different spatial orientations of DMF molecules. The triplet state energy of the H3L ligand obtained from {[Gd(L)(DMF)(H2O)]·DMF}n lies energetically above the main emitting states of both EuIII and TbIII. The photophysical properties were investigated in terms of excitation, emission spectra and emission lifetime at three different temperatures. EuL and TbL exhibit characteristic emission bands of the EuIII and TbIII with emission lifetimes of 0.51 ms and 0.90 ms, respectively. The emission lifetime values of EuL and TbL remain practically constant in the temperature range from 77 to 300 K. Furthermore, it is mentioned a possible effect of a crystal disorder on the luminescence profile of EuIII in EuL.

Metal-Organic Gel-Derived Multimetal Oxides as Effective Electrocatalysts for the Oxygen Evolution Reaction.

Exploring efficient and durable catalysts derived from earth-abundant and cost-effective materials is a highly desirable route to overcome the sluggish anodic oxygen evolution reaction (OER). A series of multinary metal-organic gels (MOGs) with various and alterable metal element compositions are prepared by straightforward mixing of metal ions with ligand 4,4',4''-[(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)]tribenzoic acid (H3 TATAB) in solution at room temperature. Spinel-type metal oxides with excellent electrocatalytic OER performance were then obtained through calcination of the as-synthesized MOGs. In electrochemical testing, the trimetallic oxide CoFeNi-O-1 (derived from the MOG with a Co/Fe/Ni molar ratio of 5:1:4) exhibits remarkable catalytic activity with a low overpotential of 244 mV at a current density of 10 mA cm-2 and a small Tafel slope of 55.4 mV dec-1 in alkaline electrolyte, outperforming most recently reported electrocatalysts. This work not only provides a promising OER catalyst and enriches the application of MOGs in the catalytic field, but also offers a facile new route to acquiring multicomponent metal oxides with high electrocatalytic activity.

Synthesis, crystal structures of two novel metal coordination polymers and study of their inhibition of human hemangioma cells

In this work, two new InIII-based coordination polymers {(H2NMe2)3[In(TATAB)2](H2O)6}n (1, H3TATAB = 4,4',4''s-triazine-1,3,5-triyl-tri-p-aminobenzoic acid) and {(Me2NH2)2·[In2(TTA)2(FA)2](DMF)3}n (2, H3TTA = 4,4',4''-{[(2,4,6-trimethylbenzene-1,3,5-triyl)tris-(methylene)]tris(oxy)}tribenzoic acid, HFA = 2-fluorobenzoic acid, DMF = N,N-dimethyl­formamide) are successfully prepared under solvothermal conditions and structurally characterized by single crystal X-ray study (SCXRD) and powder X-ray analysis (PXRD). In addition, the in vitro anticancer activity of compounds 1 and 2 on three human hemangioma cells (HMEC-1, EAhy926 and SV40) is further investigated.

Unique T-Shaped Ligand as a New Platform for Metal–Organic Frameworks

The utilization of a rationally designed T-shaped ligand 4,4′,4′′-(1H-benzo[d]imidazole-2,4,7-triyl)tribenzoic acid (H3BTBA) as the platform for constructing metal–organic frameworks (MOFs) with structure diversity was achieved. Five new MOFs, [Zn4O(BTBA)2] (BUT-34), [Fe2CoO(BTBA)2(H2O)3] (BUT-35), [Cu9(BTBA)4(H2O)(DMA)] (BUT-36), [Eu2(HBTBA)2(OH)2(H2O)6] (BUT-37), and [In(BTBA)(DMF)] (BUT-38) (BUT = Beijing University of Technology), have been solvothermally synthesized and structurally characterized. Combining with several popularly used metal-cluster secondary building units, the five MOFs show novel structural features. BUT-34 with typical tetranuclear Zn4O clusters shows three-dimensional (3D) networks with a new (3,6)-connected topology. BUT-35 exhibits a (3,6)-connected flu-3 network with trinuclear [Fe2Co(μ3-O)] clusters. BUT-36 represents a mixed Cu(II)/Cu(I) based 3D framework, in which the T-shaped ligand adopts different coordination modes. However, BUT-37 and -38 consist of binuclear Eu2 padd...

Two near white light emitting Pb(II) or Cd(II) complexes

Tripodal ligand triCB-NTB (4,4′,4″-(2,2′,2″-nitrilotris(methylene)tris(1H-benzo[d]imidazole -2,1-diyl)tris(methylene))tribenzoic acid) was applied to assemble Pb(II) or Cd(II) coordination complexes, resulting in single-component near white light emission.

Postsynthetic Metalation Metal-Organic Framework as a Fluorescent Probe for the Ultrasensitive and Reversible Detection of PO43- Ions.

The self-assembly of a zinc salt with the novel ligand 4,4',4″-[(1,3,5-triazine-2,4,6-triyl)tris(sulfanediyl)]tribenzoic acid generated 3D microporous metal-organic frameworks (MOFs), namely, {[Zn4(L3-)2(O2-)(H2O)2]·4EtOH} n. The frameworks with multiple Lewis basic sites exhibit easily sensitized properties. After encapsulation of the Tb3+ cation in this Zn-MOF, the as-obtained fluorescent-functionalized Tb@Zn-MOFs not only maintain distinguished chemical stabilities but also exhibit strong characteristic emissions of trivalent terbium ions. Interestingly, Tb@Zn-MOF has been chosen to be a potential highly selective and sensitive luminescent platform for the reversible detection of PO43- ions in aqueous and living cell buffer solutions with a fast response time of 10 s and a low detection limit (0.1 ppm). Strikingly, this work presents the first example of a fluorescent sensor that can quantitate PO43- in simulated biological fluids and monitor these ions in the water system in a wide range of concentrations from 10-6 to 10-3 M.

Two novel metal coordination polymers: anticancer activity against human osteogenic sarcoma cells

In this study, two new heterometal-organic frameworks, {(H2NMe2)2[In2Na(TATAB)3(H2O)6]}n (1, H3TATAB = 4,4′,4′′-s-triazine-1,3,5-triyl-tri-p-aminobenzoic acid acid) and {(Me2NH2)2[In2(TTA)2(DFA)2](DMF)3}n (2, H3TTA = 4,4′,4″-{[(2,4,6-trimethylbenzene-1,3,5-triyl)tris- (methylene)]tris(oxy)}tribenzoic acid, HDFA = 2,3-difluorobenzoic acid), have been successfully prepared under solvothermal conditions and structurally characterized by single crystal X-ray study. In addition, in vitro anticancer activity of compounds 1 and 2 on three human osteogenic sarcoma cells (Saos-2, MG63 and 143B) was further determined.

A porous Zn-based metal-organic framework with an expanded tricarboxylic acid ligand for effective CO2 capture and CO2/CH4 separation

A trigonal nanosized carboxylate ligand, 4, 4′,4″-(triazine-2,4,6-triyl-tris(benzene-4,1-diyl))tribenzoic acid (H3TAPB), has been applied in the construction of a highly porous metal−organic framework (MOF). A solvothermal reaction of H3TAPB and a zinc salt in a mixed solvent of DEF/dioxane/H2O produces the targeted porous MOF [Zn3(TAPB)2(H2O)2](DEF)4(H2O)3 (1, DEF = N,N-Diethylformamide). This MOF contains a linear Zn3 secondary building unit with two terminal water molecules occupied the axis positions, which is connected by the TAPB3− ligands to afford a 3-fold interpenetrated framework with a large calculated void volume (69.7%). The activated MOF shows exceptional porosities and high CO2 uptake capacities as well as good sorption selectivity of CO2/CH4 around room temperature.

Zr(IV)-Based Metal-Organic Framework with T-Shaped Ligand: Unique Structure, High Stability, Selective Detection, and Rapid Adsorption of Cr2O72- in Water.

Dichromate is known for severe health impairments to organisms. New and valid strategies have been developed to rapidly detect and efficiently remove this pollutant. Constructing stable luminescent metal-organic frameworks (MOFs) for dichromate recognition and removal from aqueous solution could provide a feasible resolution to this problem. Herein, a new luminescent Zr(IV)-MOF, Zr6O4(OH)7(H2O)3(BTBA)3 (BUT-39, BUT = Beijing University of Technology) was constructed through the reaction of a newly designed functionalized T-shaped ligand 4,4',4″-(1 H-benzo[ d]imidazole-2,4,7-triyl)tribenzoic acid (H3BTBA) with zirconium salt. BUT-39 has a unique porous framework structure, in which Zr6 cluster acts as a rare low-symmetric 9-connected node and BTBA3- as a T-shaped 3-connected linker. As far as we know, this represents the first case of a (3,9)-connected Zr(IV)-MOF. BUT-39 could retain its framework integrity in boiling water, 2 M HCl aqueous solution, and pH 12 NaOH aqueous solution. Due to its good water stability and strong fluorescent emission, BUT-39 is then employed in fluorescence sensing for various ions in aqueous solution and shows good performance toward Cr2O72- selectively, at a low concentration and a short response time (<1 min). Simultaneously, it also exhibits excellent capacity to rapidly capture Cr2O72- (within 1 min) with a high uptake up to 1 mmol g-1. Taking advantage of its excellent stability, sensitive and selective sensing, as well as rapid and high adsorption, BUT-39 is expected to be useful in Cr2O72- detection in and removal from water.

Two new metal coordination polymers: anticancer activity in endometrial carcinoma

Two new coordination polymers with the formulas of [La(BTB)(H2O)](H2O) (1) and [Sr4(OH)5(H2O)5(TATB)2]·(H2NMe2)3(H2O)3 (2) have been synthesized using two similar tritopic carboxylate ligand 1,3,5-benzenetribenzoic acid (H3BTB) and 4,4′,4′′-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid (H3TATB) as the organic linkers. The structures of the two complexes have been fully determined by the single crystal X-ray diffraction and their compositions have been studied by the elemental analysis. In addition, the in vitro proliferation inhibitory activities of complexes 1 and 2 against three human endometrial carcinoma cells (ISK, HEC-1A and KLE) were then evaluated via the MTT assay.