Tetracarboxylic Acid Research Articles

Perylene-functionalized graphene sheets modified with chitosan for voltammetric discrimination of tryptophan enantiomers.

A composite was prepared from graphene functionalized with 3,4,9,10-perylene tetracarboxylic acid and chitosan (rGO-PTCA-chitosan) by a chemical method. It involves non-covalent functionalization of rGO with PTCA followed by amidation reaction with chitosan. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and electrochemical methods were used to characterize the composites. By combining the chiral features of chitosan and the excellent electrochemical behaviors of rGO-PTCA, a graphene-based material with enantioselectivity was constructed for electrochemical chiral recognition of tryptophan (Trp) enantiomers. A glassy carbon electrode (GCE) modified with rGO-PTCA-chitosan had a higher recognition capability for L-Trp than for D-Trp. Best operated at a working voltage near 0.78 V (vs. SCE), the enantioselectivity coefficient is 3.0. The sensor has a linear response in the 1mM to 10mM Trp concentration range and a 1.2μM detection limit (at S/N= 3) for L-Trp, and of 3.0μM to D-Trp. The sensor was successfully used to detect Trp enantiomers in real samples, and a recognition mechanism is presented. Graphical abstract Schematic presentation of a composoie prepared by graphene functionalized with 3,4,9,10-perylene tetracarboxylic acid and chitosan (rGO-PTCA-chitosan) via a chemical method. It involves non-covalent functionalization of rGO with PTCA followed by amidation reaction with chitosan and voltammetric determination of tryptophan enantiomers.

Novel aliphatic polyamide membrane with high mono-/divalent ion selectivity, excellent Ca2+, Mg2+ rejection, and improved antifouling properties

Monomer design and reconstruction is typically a preferred route to tune the inner structure and screen the performance of polyamide nanofilms for their efficiency and ease of scaling up in industrial production. Herein, two kinds of novel acyl chloride monomers, 1,2,3,4-cyclobutane tetracarboxylic acid chloride (BTC) and 1,2,4,5-cyclohexanetetracarboxylic acid chloride (HTeC), have been designed and synthesized. The BTC and HTeC monomers can rapidly react with amine molecule at interface to form an aliphatic polyamide nanofilm that is denser than that of TMC based polyamide membrane. The resulting mean effective pore size of the BTC and HTeC polyamide nanofilms is 0.184 nm and 0.197 nm, which is lower than that of the TMC nanofilm at 0.238 nm. Desalination experiments revealed that the aliphatic polyamide membrane shows more than a 98% rejection rate for CaCl2, MgCl2, and MgSO4 and a water flux of 84.4 kg m−2 h−1 MPa−1 (for 2000 ppm MgSO4). Moreover, the ion selectivity of Na+/Mg2+ and Na+/Ca2+ of the BTC membrane is as high as 126 and 31.5, respectively. These are much higher than those of the related TMC and commercial nanofiltration membranes. Fouling experiments indicate that the flux decline rate (FDR) of the aliphatic polyamide membrane is only 38%, whereas the FDR of the full-aromatic polyamide membrane is 60%. Further investigations confirmed that surface roughness is the main factor affecting the fouling behaviors of polyamide membranes. Our results demonstrate that BTC and HTeC monomers are unique potential materials in the fabrication of nanofiltration membranes used for water treatment such as water softening and ion sieving.

Two zinc coordination polymers constructed by 4′-hydroxy-[1,1′-biphenyl]-3,5-dicarboxylic acid (H2BDA) and 4-hydroxy-[1,1′-biphenyl]-3,3′,5,5′-tetracarboxylic acid (H3BTA): Synthesis, structures and luminescence identifying properties

Two new Zn centered coordination polymers (CPs), namely, [Zn(BDA)] (1) and [Zn3(BTA)2(H2O)4] (2) have been synthesized from 4′-hydroxy-[1,1′-biphenyl]-3,5-dicarboxylic acid (H2BDA) and 4-hydroxy-[1,1′-biphenyl]-3,3′,5,5′-tetracarboxylic acid (H3BTA) under solvothermal conditions. Their structures were determined by single crystal X-ray diffraction and further characterized by elemental analysis, IR, TGA and X-ray powder diffraction. CP 1 based on H2BDA is a 3D framework featuring (4,4)-connected net topology with a point symbol of {43.62.8}, while 2 with H3BTA as ligand displays a (2,3)-connected net with a point symbol of {63} and hcb topological type structure. Both CPs 1 and 2 exhibited luminescence identification properties toward nitro aromatic compounds and Fe3+ cation.

Structural Transformation Pathways of Alkaline Earth Family Coordination Polymers Containing 3,3',5,5'-Biphenyl Tetracarboxylic Acid.

The understanding of crystal stepwise transformation is very important to enclose the "black box" in the preparation of crystal materials. In this work, different structural intermediates were isolated prior to the formation of the final alkali earth coordination polymers (CPs) during the preparation of three pairs of alkali earth CPs through solvothermal method and convenient oil-bath reactions. Single crystal X-ray diffraction analysis demonstrated the structural transformation from a 0 D to 1 D inorganic connectivity for the Ca-CPs and Sr-CPs, but a 1 D to 0 D inorganic connectivity for Ba-CPs, involving the breakage/formation of chemical bonds in the reaction solutions. Further analyses indicated that these two different structural transformation pathways are determined by the deprotonation of organic acid, competitive balance between the inorganic and organic connectivity, and the twist of the linker. FT-IR spectra, thermogravimetric and luminescence behaviors agree with their structural characteristics.

Balancing Noncovalent Interactions in the Self-Assembly of Nonplanar Aromatic Carboxylic Acid MOF Linkers at the Solution/Solid Interface: HOPG vs Au(111).

This study explores directed noncovalent bonding in the self-assembly of nonplanar aromatic carboxylic acids on gold and graphite surfaces. It is the first step in developing a new design strategy to create two-dimensional surface metal-organic frameworks (SURFMOFs). The acid molecules used are tetraphenylethene-based and are typically employed in the synthesis of three-dimensional (3D) MOF crystalline solids. They include tetraphenylethene tetracarboxylic acid, tetraphenylethene bisphenyl carboxylic acid, and tetraphenylethene tetrakis-phenyl carboxylic acid. The two-dimensional structures formed from these molecules on highly ordered pyrolytic graphite (HOPG) and Au(111) are studied by scanning tunneling microscopy in a solution environment. The process of monolayer formation and final surface linker structures are found to be strongly dependent on the combination of the molecule and substrate used and are discussed in terms of intermolecular and molecule-substrate interactions, bonding geometry, and symmetry of the acid molecules. In the case of linker self-assembly on HOPG, the molecule-substrate interactions play a significant role in the resulting surface structure. When the acid molecules are adsorbed on Au(111), the intermolecular interactions tend to dominate over the weaker molecule-substrate bonding. Additionally, the interplay of π-π interactions and hydrogen bonding that directs the surface self-assembly on different supports can be modified by varying the linker concentration. This is particularly applicable for the case of the acid molecules adsorbing on the Au(111) substrate. Precise control over predesigned surface structures and orientation of the nonplanar aromatic carboxylic linkers open up an exciting prospect for manipulating the direction of SURFMOF growth in two dimensions and potentially in 3D.

Simultaneous and sensitive detection of ascorbic acid in presence of dopamine using MWCNTs-decorated cobalt (II) phthalocyanine modified GCE

The synthesis of tetra­8­[(E)­(4­methoxybenzylidene)amino] naphthalene­1­amine cobalt (II) phthalocyanine (CoTMBANAPc) from cobalt (II) tetracarboxylic acid phthalocyanine (CoTCAPc) via amide bridge has been described for the first time. These macromolecules displayed admirable solubility in aprotic organic solvents and compound has been characterized by UV–Vis, FT-IR, 1H NMR, XRD, TGA and Mass spectroscopic methods in addition to elemental analysis. The CoTMBANAPc was found to be electrochemically active and was immobilized on the GCE by decorating with MWCNT. The modified electrode was used for the simultaneous detection of two important biomolecules: Ascorbic acid (AA) and Dopamine (DA) by cyclic voltammetry, differential pulse voltammetry and amperometry methods. AA and DA exhibited two different and well-resolved cathodic peaks on the GCE/MWCNT-CoTMBANAPc electrode. The linear response was observed in the concentration range of 7.5 to 70 nM with detection limit of 6.6 μM and 0.33 nM for AA and DA, respectively on the modified electrode. The modified electrode is highly stable, sensitive and reproducible for the micromolar detection of AA and DA.

Structural diversity and fluorescent sensing of four novel complexes based on rigid terphenyl-3,3″,5,5″-tetracarboxylic acid

Based on H4TPTC and 1,2-bimb/1,3-bimb ligands, four novel complexes, namely, {[Cu(TPTC)(1,2-bimb)2]·4.5(H2O)}n (1), [Cu(TPTC)0.5(1,3-bimb)]n (2), {[Eu2(TPTC)1.5(H2O)4]·4.5(H2O)·2(1,4–DOX)}n (3) and {[Ce(TPTC)(H2O)4]·0.5(H2O)·0.5(1,4–DOX)}n (4) have been constructed under solvothermal conditions [H4TPTC = terphenyl-3,3″,5,5″-tetracarboxylic acid, 1,3-bimb = 1,3-bis (imidazol-1-ylmethyl) benzene, 1,2-bimb = 1,2-bis (imidazol-1-ylmethyl) benzene]. Complexes 1 and 2 are 4-connected 2D networks with the topological types of sql (1) and kgm (2). Complex 3 exhibits a 4, 4, 12-connected network with the point symbol of {432.634}{44.62}{46}2. Complex 4 presents a 3D supramolecular network through hydrogen bonds. The fluorescent properties of complexes 1 and 3 showed that 1 has good fluorescence sensitivity for Cr2O72− and Fe3+ ions in aqueous solutions, and 3 can selectively detect NDVs. Furthermore, possible mechanism for luminescence quenching was also investigated.

Highly improved photoreduction of carbon dioxide to methanol using cobalt phthalocyanine grafted to graphitic carbon nitride as photocatalyst under visible light irradiation

A substantially improved methanol yield was achieved from the photoreduction of carbon dioxide under visible light by using a hybrid photocatalyst consisting of molecular cobalt phthalocyanine tetracarboxylic acid (CoPc-COOH) complex immobilized to the organic semiconductor graphitic carbon nitride (g-C3N4) and triethylamine as sacrificial electron donor. The structural and morphological features of the hybrid photocatalyst determined by various techniques like FTIR, UV–Vis, Raman, XPS, TGA, BET etc. After 24 h of light irradiation, the methanol yield by using g-C3N4/CoPc-COOH photocatalyst (50 mg) was found to be 646.5 µmol g−1cat or 12.9 mmol g−1cat with conversion rate 538.75 µmol h−1 g−1cat. However, the use of homogeneous CoPc-COOH (6.5 µmol Co, equivalent to g-C3N4/CoPc-COOH) and g-C3N4 (50 mg) provided 88.5 μmol (1770 μmol g−1cat) and 59.2 μmol (1184 μmol g−1cat) yield of methanol, respectively under identical conditions. The improved photocatalytic efficiency of the hybrid was attributed to the binding ability of CoPc-COOH to CO2 that provided the higher CO2 concentration on the support. Further, the semiconductor support provided better electron mobility and charge separation with the integrated benefit of facile recovery and recycling of the material at the end of the reduction process.

Synthesis, crystal structure and photoluminescence of a three-dimensional zinc coordination compound with NBO-type topology.

The assembly of metal-organic frameworks (MOFs) with metal ions and organic ligands is currently attracting considerable attention in crystal engineering and materials science due to their intriguing architectures and potential applications. A new three-dimensional MOF, namely poly[[diaqua(μ8-para-terphenyl-3,3',5,5'-tetracarboxylato)dizinc(II)] dimethylformamide disolvate monohydrate], {[Zn2(C22H10O8)(H2O)2]·2C3H7NO·H2O}n, was synthesized by the self-assembly of Zn(NO3)2·6H2O and para-terphenyl-3,3',5,5'-tetracarboxylic acid (H4TPTC) under solvothermal conditions. The compound was structurally characterized by FT-IR spectroscopy, elemental analysis and single-crystal X-ray diffraction analysis. Each ZnII ion is located in a square-pyramidal geometry and is coordinated by four carboxylate O atoms from four different TPTC4- ligands. Pairs of adjacent equivalent ZnII ions are bridged by four carboxylate groups, forming [Zn2(O2CR)4] (R = terphenyl) paddle-wheel units. One aqua ligand binds to each ZnII centre along the paddle-wheel axis. Each [Zn2(O2CR)4] paddle wheel is further linked to four terphenyl connectors to give a three-dimensional framework with NBO-type topology. The thermal stability and solid-state photoluminescence properties of the title compound have also been investigated.

Polyfunctional Application on Modified Cotton Fabric

A simple and facile method for fabricating the cotton fabric with flame retardancy is adopted in the present work. This study deals with crosslinking of cotton fabric using different polycarboxylic acids such as citric acid and 1,2,3,4-butane tetracarboxylic acid and using different catalysts such as sodium hypophosphite and sodium propionate through conventional pad-dry-cure method for flame-retardant application. The results exhibited moderate waterproofing durability and flame retardancy of the cotton fabric after treatment, offering a good opportunity to accelerate the large-scale production textile materials for new industrial applications.

A Homochiral Coordination Polymer Based on Copper(II), S-Malic Acid, and Biphenyl-3,3′,5,5′-Tetracarboxilic Acid

The [Cu8(S-mal)4(bptc)(H2O)12] · 0.5H4bptc · 7.5H2O coordination polymer is obtained by heating the copper(II) nitrate, S-malic acid (H3mal), and biphenyl-3,3′,5,5′-tetracarboxylic (H4bptc) acid solution in the water-N,N-diethylformamide mixture. The crystal structure is determined from XRD data. The compound has a three-dimensional homochiral framework with channels filled by crystallization molecules of tetracarboxylic acid and water. The composition and structure of the coordination polymer obtained are confirmed by X-ray powder diffraction, IR spectroscopy, thermogravimetric analysis, and elemental analysis.

Coordination Nanosheets of Phthalocyanine as Multifunctional Platform for Imaging-Guided Synergistic Therapy of Cancer.

"All-in-one" nanodrugs integrating various functionalities into one nanosystem are highly desired for cancer treatment. Coordination nanosheets as one type of two dimensional (2D) nanomaterials offer great opportunities, but there is lack of enough candidates. Here, a new kind of coordination nanosheets based on phthalocyanine are constructed. Manganese phthalocyanine (MnPc) tetracarboxylic acid is employed as photoactive ligand to form MnPc nanosheets; meanwhile, hyaluronic acid (HA) is coated on their surface. The obtained MnPc@HA nanosheets exhibit superior near-infrared (NIR) photothermal effect with photothermal conversion efficiency of 72.3%, much higher than those of the previously reported photothermal agents. Due to their 2D nanostructures, MnPc@HA nanosheets possess superhigh drug-loading capacity for chemotherapy drug curcumin. With HA as a targeting group, the nanosheets selectively accumulated in CD44 overexpressed tumors, followed by drug release under the control of NIR light. Moreover, MnPc@HA nanosheets with intrinsic paramagnetism can serve as T1 contrast agent for magnetic resonance imaging. The synergistic effect of phototherapy and chemotherapy endows curcumin-loaded MnPc@HA nanosheets with superior tumor-eradicating efficacy. Besides, MnPc@HA nanosheets are biocompatible and safe for biomedical applications. This work provides novel insight for developing new multifunctional platforms based on 2D coordination nanosheets to synergistically combat cancer.

Synthesis, structure and selective luminescence sensing for iron(III) ions of a three-dimensional zinc(II) (4,6)-connected coordination network.

Coordination polymers constructed from conjugated organic ligands and metal ions with a d10 electronic configuration exhibit intriguing properties for chemical sensing and photochemistry. A ZnII-based coordination polymer, namely poly[aqua(μ6-biphenyl-3,3',5,5'-tetracarboxylato)(μ2-4,4'-bipyridine)dizinc(II)], [Zn2(C16H6O8)(C10H8N2)(H2O)2]n or [Zn2(m,m-bpta)(4,4'-bipy)(H2O)2]n, was synthesized from a mixture of biphenyl-3,3',5,5'-tetracarboxylic acid [H4(m,m-bpta)], 4,4'-bipyridine (4,4'-bipy) and Zn(NO3)2·6H2O under solvothermal conditions. The title complex has been structurally characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis, and features a μ6-coordination mode. The ZnII ions adopt square-pyramidal geometries and are bridged by two syn-syn carboxylate groups to form [Zn2(COO)2] secondary buildding units (SBUs). The SBUs are crosslinked by (m,m-bpta)4- ligands to produce a two-dimensional grid-like layer that exhibits a stair-like structure along the a axis. Adjacent layers are linked by 4,4'-bipy ligands to form a three-dimensional network with a {44.610.8}{44.62} topology. In the solid state, the complex displays a strong photoluminescence and an excellent solvent stability. In addition, the luminescence sensing results indicate a highly selective and sensitive sensing for Fe3+ ions.

A new family of lanthanide-based coordination polymers with azoxybenzene-3,3′,5,5′-tetracarboxylic acid as ligand

Reactions by solvothermal methods of lanthanide nitrates and azoxybenzene-3,3′,5,5′-tetracarboxylic acid (H4aobtc) lead to a family of isostructural lanthanide-based coordination polymers with general chemical formula [Ln(Haobtc)(H2O)2·2H2O]∞ with Ln = Nd − Er plus Y. The crystal structure has been solved on the basis of the Y3+-derivative. It crystallizes in the triclinic system, space group P-1 (n°2) with the following cell parameters: a = 6.6890(18)Å, b = 10.052(3)Å, c = 13.879(4)Å,α = 75.756(9)°, β = 77.551(9)°, γ = 83.964(9)° and Z = 2. The crystal structure is two-dimensional (2D). Thermal properties and luminescent properties of the Nd3+-containing compound have been studied.

Cellulose Nanocrystals (CNCs) Induced Crystallization of Polyvinyl Alcohol (PVA) Super Performing Nanocomposite Films.

This study is aimed to explore the properties of cellulose nanocrystals (CNC)/polyvinyl alcohol (PVA) composite films with and without 1,2,3,4-butane tetracarboxylic acid (BTCA), a nontoxic crosslinker. CNC and CNC-PVA nanocomposite films are prepared using solution-casting technique. Differential scanning calorimetry (DSC) analyses show that crosslinking increased the glass transition temperature but reduced the melting temperature and crystallinity. Furthermore, high CNC concentrations in the PVA matrix interfere with PVA crystallinity, whereas in specific ratio between CNC and PVA, two different crystalline structures are observed within the PVA matrix. Film surfaces and fracture topographies characterized using scanning electron microscope indicate that at certain CNC-PVA ratios, micron-sized needle-like crystals have formed. These crystalline structures correlate with the remarkable improvement in mechanical properties of the CNC-PVA nanocomposite films, that is, enhanced tensile strain and toughness to 570% and 202MJm-3 , respectively, as compared to pristine PVA. BTCA enhances the tensile strain, ultimate tensile stress, toughness, and modulus of CNC films compared to pristine CNC films. Water absorption of crosslinked CNC and CNC-PVA nanocomposite films is significantly reduced, while film transparency is significantly improved as a function of PVA and crosslinker content. The presented results indicate that CNC-PVA nanocomposite films may find applications in packaging, and though materials applications.

A Novel Zinc Luminescent Coordination Polymer Based on a Tetracarboxylate Acid Ligand for the Detection of Nitrobenzene

AbstractA novel 1D Zinc compound, formulated as [Zn(H2L2−)(H2O)]n (1) (H4L = 3‐(3′,5′‐dicarboxyphenyl)pyridine‐2,6‐dicarboxylic acid), is synthesized by a rigid organic multi‐carboxylic acid ligand under hydrothermal conditions. Compound 1 crystallizes in the orthorhombic P212121 space group and exhibits a 1D fishbone‐like chain, exhibiting strong blue fluorescence emission at room temperature upon excitation. Fluorescence titration shows that the emission intensity of the compound 1 varied upon contacting with different solvents or analytes, exhibiting selective emission quenching responses towards nitrobenzene (NB) which suggests that compound 1 is a promising luminescent sensor material for nitrobenzene.

Enhanced Stain Removal and Comfort Control Achieved by Cross-Linking Light and Thermo Dual-Responsive Copolymer onto Cotton Fabrics.

Enhanced capabilities of stain removal and comfort control are simultaneously achieved by the light and thermo dual-responsive copolymer poly(triethylene glycol methyl ether methacrylate- co-ethylene glycol methacrylate- co-acrylamide azobenzene) (P(MEO3MA- co-EGMA- co-AAAB)) cross-linked on cotton fabrics. P(MEO3MA- co-EGMA- co-AAAB) is synthesized by sequential atom transfer radical polymerization with a molar ratio of 8 (MEO3MA):1 (EGMA):1 (AAAB). The MEO3MA units induce a thermoresponsive behavior to the copolymer. The hydrophilicity of the copolymer films can be further improved by the light-induced trans- cis isomerization of the AAAB units with UV radiation. The copolymer is facilely immobilized onto cotton fabrics with 1,2,3,4-butane tetracarboxylic acid as cross-linker. Due to the immobilization of P(MEO3MA- co-EGMA- co-AAAB), the hydrophilicity of the fabric surface is increased under UV radiation. Therefore, by simply installing a UV light source in the washing machine, better capability of stain removal is realized for the cross-linked cotton fabrics. It can prominently reduce the consumption of energy, water, and surfactants in laundry. In addition, the trans-AAAB units of the copolymer cause the cross-linked P(MEO3MA- co-EGMA- co-AAAB) layer to be more hydrophobic under ambient conditions. Hence, the copolymer can more easily collapse and form a porous structure on the fabrics. Thus, the air permeability of cotton fabrics cross-linked with P(MEO3MA- co-EGMA- co-AAAB) is enhanced by 13% at human body temperature as compared to P(MEO3MA- co-EGMA), giving improved comfort control during daily wear.

A New Biscarbazole-Based Metal-Organic Framework for Efficient Host-Guest Energy Transfer.

A new metal-organic framework (MOF), [Zn6 L4 (Me2 NH2 + )4 ⋅3 H2 O] (1) was constructed based on [9, 9'-biscarbazole]-3, 3', 6, 6'-tetracarboxylic acid (H4 L) and Zn2+ ions. The porous framework and intense blue fluorescence of the MOF based on the biscarbazole moiety of the ligand could facilitate efficient host to guest energy transfer, which makes it an ideal platform for the tuning of luminescence.

Complex Monolayer Growth Dynamics of a Highly Symmetric Molecule: NTCDA on Ag(111)

The growth dynamics of the highly symmetric planar organic molecule NTCDA (1,4,5,6-naphthalene tetracarboxylic acid dianhydride) on Ag(111) is rather complex, already in the monolayer regime. This dynamics was investigated in situ with high lateral resolution using the aberration-corrected spectro-microscope SMART. Although the molecular structure of NTCDA is very similar to that of the slightly larger molecule PTCDA, the growth behavior of these two molecules is very different. Several differences of the static geometric, electronic, and vibrational structure have been described previously by several authors, but some dynamic properties hardly accessible by other techniques could be observed in the present real time experiments using the SMART. For instance, it is found by direct observation that after decoration of steps and step bunches and depending on substrate temperature and surface morphology, a two-dimensional lattice gas of diffusing NTCDA molecules is formed. This increases in density upon continuous deposition of molecules before islands nucleate which subsequently grow in size while the density of the lattice gas first remains constant and then is reduced. Furthermore, in a certain temperature and coverage range some macroscopic islands (of micrometer size) abruptly change their shape and position on the time scale of few seconds. These “jumping 2-dim droplets” are observable for adsorption as well as for desorption. Moreover, previously observed 2-dimensional phase transitions can now be followed in real time, yielding further insight into an interesting but complex adsorption system.

Гомохиральный координационный полимер на основе меди(II), S-яблочной и бифенил-3,3',5,5'-тетракарбоновой кислот

Нагреванием раствора нитрата меди(II), S-яблочной (H3mal) и бифенил-3,3',5,5'-тетра­карбоновой (H4bptc) кислот в смеси вода—N,N-диэтилформамид получен координационный полимер [Cu8(S-mal)4(bptc)(H2O)12]·0.5H4bptc⋅7.5H2O. Кристаллическая структура установлена методом РСА. Соединение обладает трехмерным гомохиральным каркасом, имеющим каналы, заполненные кристаллизационными молекулами тетракарбоновой кислоты и воды. Состав и строение полученного координационного полимера подтверждены данными рентгеновской дифракции на порошках, ИК спектроскопии, термогравиметрического и элементного анализа.