Isophtalic Acid Research Articles

Synthesis of novel coordination polymer Cd-MOF and fluorescent probe detection of Fe3+, Cr2O72−, and ceftriaxone sodium (CRO)

In this contribution, Cd-MOF (1) complex with stable fluorescence properties was constructed by using 3dpu (N, N' -bis(3-pyridyl) urea) and H2IPA (isophtalic acid) as the organic ligands and Cd(NO3)2·4H2O as the metal nodes. The structure of the complex 1 was characterized by infrared spectroscopy, single crystal X-ray diffraction, powder X-ray diffraction (XRD), thermal gravimetric analysis (TGA), ultraviolet-visible spectroscopy, SEM and ICP-MS. The Cd-MOF with Cd cluster as the node, and 3dpu and IPA2− as linkers, exhibited excellent thermal and chemical stabilities. It was extended to the three-dimensional supramolecular framework by π - π stacking interaction and hydrogen bonding interaction. Importantly, complex 1 can be used as excellent fluorescent sensors toward Fe3+, Cr2O72−, and CRO (ceftriaxone sodium) with a low limit of detection and a high quenching constant, and have good anti-interference and recyclable characteristics. In addition, complex 1 has the advantages of high sensitivity and selectivity for detecting CRO in simulated human urine.

Experimental and theoretical characterization of chelidonic acid structure

Chelidonic acid (4-oxo-4H-pyran-2,6-dicarboxylic acid) is present in plants of Papaveraceae family, especially in Chelidonium majus. Due to its anticancer, antibacterial, hepatoprotective, and antioxidant properties, it has been used in medical treatments. In this work, the X-ray structure of methanol solvate of chelidonic acid was determined. Layers of chelidonic acid are held by hydrogen bonds via COOH and C = O fragments and additionally bridged by methanol. The formed H-bond network between two acid units is different from typical –COOH dimers observed, e.g., in crystals of isophtalic acid. The molecular structure of 2,6-dimethyl-γ-pyrone (2Me4PN) and chelidonic acid, a 2,6-dicarboxylic derivate of γ-pyrone (4PN), was verified in silico using density functional theory (DFT-B3LYP) combined with large correlation-consistent basis sets. The impact of –CH3 and –COOH substituents on 4PN ring structure, dipole moments, geometric/magnetic indexes of aromaticity, and NBO charges was assessed following unconstrained geometry optimization in the gas phase, chloroform, methanol, DMSO, and water with solvent effect introduced using the polarized continuous model (PCM). H-bond network formed in chelidonic acid–methanol complex was analyzed and their interaction energy estimated. Theoretical modeling enabled prediction of accurate structural parameters, dipole moments, and geometric/magnetic indexes of aromaticity of the studied 4PN, 2Me4PN, and chelidonic acid molecules.

The synthesis and characterization of s-Triazine polymer complexes containing epoxy groups

Abstract It has been synthesized in this study that s-triazine based monomeric complexes including epoxy groups and their polymeric structures. For this reason, cyanuric chloride (I) has been used as starting material. 5-(4,6-dicholoro-2-1,3,5-triazine-2-ylamino)isophtalic acid coded as “III” has been obtained from the reaction of 5-aminoisophtalic acid II and I at −5 °C with sodium bicarbonate in aqua/acetone media. Bis(oxiran-2-ylmethyl)-5-(4,6-dichloro-1,3,5-triazine-2-ylamino)izophtalate coded as “V” was synthesized from the reaction of epichlorohydrin (IV) and III in aqua/acetone media with KOH at 2 °C. In aqua/ethanol media at 60 °C, monomeric metal complexes (VI, VII and VIII) were obtained from the reaction of V and/or Mn+2, Co+2 and Ni+2. s-Triazine based polymeric metal complexes (IX-XIV) were obtained from the reaction of the monomeric metal complexes and 3,4-dihydroxybenzaldehyde/o-phenylenediamine in 1,4-diaxane media with DIPEA at 60 °C. The structure of ligands, monomers and polymers were characterized using 1H NMR and 13C NMR, FTIR, ESI-MS, UV–vis spectrophotometers, TGA and elemental analyses. Metal contents in the prepared monomeric and polymeric complexes were determined by inductively coupled plasma atomic emission spectrophotometer (ICP-AES). Magnetic behaviors of the synthesized novel monomeric and polymeric complexes were also investigated. And, these compounds were determined to be high-spin distorted octahedral Mn(II), distorted octahedral Co(II) and distorted octahedral Ni(II).

Decolorization and biotransformation pathway of textile dye by Cylindrocephalum aurelium.

Due to environmental concern, the research to date has tended to focus on how textile dye removal can be carried out in a greener manner. Therefore, this study aims to evaluate the decolorization and biotransformation pathway of Mordant Orange-1 (MO-1) by Cylindrocephalum aurelium RY06 (C. aurelium RY06). Decolorization study was conducted in a batch experiment including the investigation of the effects of physio-chemical parameters. Enzymatic activity of C. aurelium RY06 during the decolorization was also investigated. Moreover, transformation and biodegradation of MO-1 by C. aurelium RY06 were observed using the gas chromatography-mass spectrometry. Manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase, and 2,3-dioxygenase enzymes were detected during the decolorization. In general, the present work concluded that the MO-1 was successfully degraded by C. aurelium RY06 and transformed to be maleic acid and to be isophtalic acid.

PH-dependent fluorescence sensing activities of two water-stable 2-D zinc(II) compounds

Two 2-D Zn(II) compounds, namely, [Zn(HL1)(bpy)]n (1) and {[Zn(HL2)(bpe)]·0.5bpe}n (2) (H3L1=5-(2′-carboxyl phenoxy)isophtalic acid, H3L2=1,3-bis(2-carboxylphenoxy)benzoic acid, bpy=4,4′-bipyridine, bpe=4,4′-vinylenedipyridine), have been solvothermally synthesized from two flexible phenolic carboxylic acid ligands. Both compounds exhibit 2-D layered structures with 4-conneted 44 and 3- connected 63 topology, respectively. PXRD indicated that these compounds were stable in the basic conditions with pH range of 7–11 and their fluorescence intensities are strongly correlated with the pH value. The protonated carboxylic groups may have influences on the resulting fluorescence intensities. The possible proton transfer mechanism was discussed for such pH sensors in details through FTIR and ICP measurements. In addition, the analytical efficiency and accuracy in practical applications of these sensors were performed on the real lake water.

Electrochemical immunosensor based on an azo compound for thyroid-stimulating hormone detection

An electrochemical immunosensor based on the electroactive azo compound (E)-5-[(4-dodecyloxyphenyl)diazenyl]isophtalic acid was developed for thyroid-stimulating hormone (TSH) detection. This organic molecule was employed as a multifunctional platform actuating simultaneously as redox probe and active site for covalent immobilization of the monoclonal anti-TSH antibody (ab-TSH) via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) chemistry by means of the carboxylic groups present in the azo compound. The functioning principle of the immunosensor is the decrease in electrochemical response arising from the azo compound film deposited on the surface of a glassy carbon electrode (GCE) due to the presence of TSH antigen, which interacts specifically with ab-TSH antibodies immobilized on the electrode surface. The signal inhibition is proportional to the amount of antigens present in the analyzed sample. The electrochemical performance was studied by cyclic and square-wave voltammetry and electrochemical impedance spectroscopy. The immunosensor surface was characterized by electron microscopy. Under optimal conditions, a linear range of 0.2 to 20.0μIUmL−1 with a calculated detection limit of 0.04μIUmL−1 was achieved. The evaluation of some potential interfering compounds (glucose, ascorbic acid, uric acid and creatine) resulted in a low degree of interference (<10%) and the immunosensor presented a good inter-assay precision (<5%). The proposed immunosensor was successfully applied for TSH determination in simulated blood serum showing good accuracy and sensitivity.

Isophtalic acid terminated graphene oxide modified glassy carbon nanosensor electrode: Cd2+ and Bi3+ analysis in tap water and milk samples

ABSTRACTIn this study, graphene oxide was derivative with 5-aminoisophtalic acid by amidization reaction. The nanomaterial in suspension was denoted as graphene oxide-isophtalic acid. The graphene oxide-isophtalic acid suspension was covered on the glassy carbon electrode surface under the infrared lamb. The graphene oxide was characterized with transmission electron microscopy and x-ray diffraction. Surface characterization of the glassy carbon/graphene oxide-isophtalic acid was performed with x-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The ultrasensitive nanoplatform for the simultaneous electrochemical square-wave anodic stripping voltammetry assay of Bi3+ and Cd2+ in aqueous solution has been developed on the glassy carbon/graphene oxide-isophtalic acid. The linearity range of Bi3+ and Cd2+ were 1.0×10−8 – 1.0×10−12 M (S/N = 3). The responses of species were practically unaltered with the increase of various species concentration. The detection limits of Cd2+ and Bi3+ were determined as 8.1×10−13 M and 1.06×10−13 M, respectively. The electrode performance was checked with tap water and commercially milk samples.

Heterogeneous catalitic activity of Novel Indium MOFs

Generally, group IIIA metal-based polycarboxylates are less studied, compared with those of transition or rare earth metals. However, In-MOFs have received recently much attention due to their interesting network topologies, which are mainly owing to the variety of coordination modes (6, 7 or 8) in indium MOFs with O- and N-donor ligands. [1]. Some of In-MOFs exhibit an exceptional gas absorption, fluorescent, ion-exchange properties, and can be used as heterogeneous Lewis acid catalysts in various organic transformations. The high relevance of Indium materials in catalytic studies for important organic reactions led to development of indium MOFs. [2-3] Here we report the solvothermal synthesis, structural characterization, topological analysis and catalytic studies of six new indium-based MOFs using 5-(4-carboxy-2-nitrophenoxy)isophtalic acid (H3popha) together with N-donor ancillary ligands (Figure 1). The three indium compounds showing 3D networks are the following: [In8(OH)6(popha)6(H2O)4]·xH2O (1), [In2(popha)2(4,4-bipy)2] (2) and [In3(OH)3(popha)2(4,4'-bipy)2]·xH2O (3). Meanwhile, compounds with a 2D network have a composition [In(popha)(1,10-phen)]·xH2O (4), [In(popha)(1,10-phen)]·xH2O (5) and [In(popha)(2,2'-bipy)]·xH2O (6). The catalytic study performed using indium compounds 1-6 as catalysts in a Lewis acidity promoted organic reaction, allows for establishing a connection between the corresponding MOF network dimensionality and its catalytic behavior.

Preparation of amine derivatives of persubstitued isophtalic acid arylamides and products of their chloroacetylation

Preparation of amine derivatives of persubstitued isophtalic acid arylamides and products of their chloroacetylation

Phosphoric acid doped polybenzimidazole membrane for high temperature PEM fuel cell

AbstractIn the present study, phosphoric acid doped polybenzimidazole (PBI) membranes with potential applications in high temperature PEM fuel cells were investigated. PBI was synthesized by polycondensation of 3,3′‐diaminobenzidine and isophtalic acid in polyphosphoric acid. The formation of PBI was validated by H1‐NMR and elemental analysis. PBI membranes were prepared by solution casting method and immersed in phosphoric acid in order to provide ionic conductivity. The phosphoric acid doped membranes were used to prepare membrane electrode assemblies (MEA) for PEMFC operation. Gas diffusion layer (GDL) spraying method was used to prepare the electrodes. In order to determine optimum electrode structure, the effect of electrode preparation technique on fuel cell performances was studied. Two methods were applied in which the binder differs in the catalyst ink. In the first method, 5 wt % PBI solution was used as the binder. In the second method, polyvinylidene fluoride (PVDF) was used in addition to PBI as the binder in the catalyst ink. The MEA were tested in a single cell operating at 100°C without need for humidification of reactant gases. The observed maximum power output was increased considerably from 0.015 to 0.072 W/cm2 at 150°C when the binder of the catalyst was changed from PBI to PBI and PVDF mixture (PVDF : PBI = 3 : 1). A single cell was operated up to 160°C and the power outputs of 0.032 and 0.063 W/cm2 were obtained at operating temperatures of 125 and 160°C, respectively. The PVDF : PBI ratio was 1 : 3 in the catalyst ink at both temperatures. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Preparation and Characterisation of Pd Nanoclusters in Hyperbranched Aramid Templates to be used in Homogeneous Catalysis

AbstractIn the present paper the potential use of hyperbranched (HB) aramids as metallic solution stabilisers and carriers for homogeneous catalysis is outlined. Aramids, synthesised either from A2 + B3 reagents [namely, p‐phenylenediamine (PPD) and trimesic acid (TMA)] or from an AB2 monomer [i.e., 5‐(4‐aminobenzamido)isophtalic acid, named ABZAIA], have been used to stabilise palladium nanoclusters dispersed in two solvent media, namely N,N′‐dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). The influence of the nature of the polymeric support as well as of the solvent medium on both cluster dimensions and stability of the solutions has been investigated. Indeed, the interactions between the polymeric support and the metallic precursor (PdCl2), as revealed by 1H NMR spectroscopy, involve only the amino groups of the HB aramids. Metal nanocluster dimensions and stability are strongly dependent on the polymer used as a stabilizer. Transmission electron microscopy (TEM) analysis has shown that the presence of HB polymer in the solution reduces cluster dimensions and allows the obtaining of stable systems. The low concentration of NH2 end groups in the poly(AB2) system leads to the formation of Pd particles of rather low dimensions with a high tendency to aggregate. All prepared solutions are stable under inert atmosphere for at least a month, with an improved stabilisation when using the poly(A2 + B3) system for more than five months.A TEM micrograph of poly(ABZAIA)/Pd from a DMSO solution.magnified imageA TEM micrograph of poly(ABZAIA)/Pd from a DMSO solution.

Small Angle Light Scattering Studies on Bisphenol Series Thermotropic Liquid Crystalline Wholly Aromatic Polymers

The average domain sizes in sheared nematic mesophases for aromatic copolyesters based on terephtalic acid, isophtalic acid, p-hydroxybenzoic acid and one of the following bisphenols: 4,4'-dihydroxydiphenyl methane, bisphenol A or 4,4'-dihydroxydiphenyl sulfone. A consistent result was obtained between the steric effect of the bridge groups in the bisphenols and the domain sizes

A neutron scattering investigation of the transesterification of a main-chain aromatic polyester

The kinetics of transesterification of the liquid crystal copolyester based on isophtalic acid, 4-hydroxybenzoic acid and hydroquinone were studied. From the temperature dependence of the rate constant, an activation energy of ca. 157 kJ/mol was evaluated, which is essentially identical to that obtained for poly(ethylene terephtalate).

Melting and recrystallization during mesophase transitions of a thermotropic liquid crystalline polymer

The mesophase transitions in the polymer prepared by copolycondensation of Bisphenol E diacetate, isophtalic acid and 2,6-naphtalenedicarboxylic acid were studied. It is observed that the premelting transition in this polymer is a melting-recrystallization process.