Benzene Carboxylate Research Articles

Ciprofloxacin salts of benzene mono/di-carboxylate: crystal structures and the improvement of solubility

Ciprofloxacin salts were constructed and structurally characterized through single-crystal X-ray diffractions. The cocrystallization of benzene carboxylates, including salicylate coformers, may significantly improve the solubility of ciprofloxacin.

Ag@MOF-199 metal organic framework for selective detection of nickel ions in aqueous media

Monitoring heavy metal ions (HMIs) in water is always a challenging and vital issue due to their hazardous effects on the environment and human health. Therefore, it is necessary to detect heavy metals in the water. Herein, we first-time report the use of silver nanoparticles (Ag NPs) incorporated copper benzene carboxylate (MOF-199) metal organic framework (Ag@MOF-199) for detection of heavy metal ions in water. A glassy carbon electrode-modified Ag@MOF-199 electrochemical sensor probe was fabricated and showed a selective and sensitive response towards nickel (Ni(II)) ions only by cyclic voltammetry. The Ag@MOF-199-based sensor did not offer any cyclic voltammetric sensing response towards cadmium (Cd(II)), lead (Pb(III)), chromium (Cr(III)), and ferric (Fe(III)) ions (1 μM/L) at pH values ranging from 3 to 10. The Ag@MOF-199 sensor displayed high sensitivity of 1.48 μA/nM on the exponential scale for Ni(II) ions at pH 7 and a lower detection limit of 6.06 nM/L with good reproducibility below US EPA suggested maximum contamination limit. The synthesized Ag@MOF-199 was characterized by spectroscopic (viz. UV–visible spectroscopy, Raman spectroscopy and mapping, energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy), surface area (viz. Brunauer–Emmett-Teller surface area analysis), electrochemical activity (viz. cyclic voltammetry, electrochemical impedance spectroscopy), morphological (viz. field emission scanning electron microscopy (FE-SEM)), structural (viz. X-ray diffraction (XRD)), and thermogravimetric analysis.

Bilastine Based Drugs as SARS-CoV-2 Protease Inhibitors: Molecular Docking, Dynamics, and ADMET Related Studies

Bilastine drugs, structurally piperidine-1-carboxylate and sulfonyloxyethyl carboxylate derivatives, have significantly been employed as the medication of second-generation antihistamine drugs, and are used for the treatment of allergic rhinoconjunctivities and urticarial (hives). The bilastine drugs, composed of benzene carboxylate, propanoate, carboxylate, methyl-sulfonate, propanoic acid, butanoic acid, and pentanoic acid derivatives, were investigated through computational tools against SARS-CoV-2. The COVID-19 virus consists of five proteases where the curial function is performed by main proteases (Mpro) and Spike proteases (Spro). The Mpro and Spro were selected for calculation of molecular docking by these bilastine drugs which showed higher binding energy (<-6.5 kcal/mol) for both proteases. The main carboxylic acid group in bilastine drugs is found the primary key for a high binding score to show the large binding affinity with Mpro and Spro, and is highly responsible for forming the hydrogen bond although the various hydrophobic bonds were produced as a weak interaction. For justification, the stability of molecular docked ligand-protein complexes was investigated with molecular dynamics. It showed that the root mean square deviation (RMSD) and root mean square fluctuation (RMSF) of all these drugs were below the 0.9 Å after residue interaction. Moreover, the HOMO-LUMO gap, hardness, and softness provided full details for their chemical reactivity. In this view, the pharmacokinetics and Lipinski rule were calculated, and all of these molecules had satisfied the Lipinski rule. Finally, using the admetSAR online database, absorption, distribution, metabolism, excretion, and toxicity have been calculated which indicated that these bilastine drugs are non-carcinogenic and less harmful for both aquatic and non-aquatic species. DOI: http://dx.doi.org/10.17807/orbital.v14i1.1642

Molecular structure perspective on Temperature-Sensitive properties of rhodamine aqueous solutions

As one of the most commonly used organic fluorescent dyes, recently rhodamines have been successfully employed in temperature sensing. However, few works have been reported on their temperature-sensitive properties, which inevitably limiting their further applications. In order to solve such problem, we investigated temperature-sensitive properties of rhodamine 110, 123, 19, 6G, B and 3B focusing on their fluorescence emission spectra; and analyzed them in the molecular structure perspective. It is demonstrated that the fluorescence emission intensities of all studied rhodamines decreased with higher temperature, which inevitably enhances the probability of collisions among molecules, thus definitely leads to energy loss in fluorescence emission. While these rhodamines still have various temperature sensitivities mainly due to the substitutes: the substitute on the benzene carboxylate has little effect; the amino substituents of the three-ring xanthene enhance the temperature sensitivity due to their rotation weakening the rigidity of the three-ring xanthene; and the methyl substituents on the three-ring xanthene reduce the temperature sensitivity by enhancing the rigidity and stability of the three-ring xanthene as well as hindering the rotation of ethylamino. These findings can also be extended to other organic fluorescent dyes proved by coumarins comparable to rhodamines. The results provided by this work can be useful reference and guidance to further develop organic fluorescent dyes especially for temperature sensing.

Mechanistic investigation of benzene esterification by K2CO3/TiO2: the catalytic role of the multifunctional interface.

Potassium carbonate dispersed over a defective TiO2 support (K2CO3/TiO2) is an efficient catalyst for benzene esterification with CO2 and CH3OH. Density functional theory calculations reveal that this unique catalytic reactivity originates from the cooperation of the Ti3+/K+ surface sites. The K2CO3 promotor steers the stabilization of surface intermediates thus preventing catalyst deactivation.

Theoretical research on the direct carboxylation of benzene with CO2 catalyzed by different carbene‐CuOH compounds

AbstractThe direct carboxylation between the benzene C–H and CO2 is a long‐standing challenge in catalysis. Based on the known experimental process for the direct carboxylation of fluorobenzene, herein, a theoretical design of efficient carbene‐copper catalysts for the direct carboxylation of benzene was reported. It was found that the reaction included two steps: C–H bond breaking and CO2 insertion into Cu‐phenyl. C–H breaking is the rate‐determining step. To find out a more effective catalyst, totally, 16 carbene‐copper compounds with different electronic and steric structures were investigated. The energy barriers for the C–H bond breaking range from 104.2 to 153.7 kJ/mol. Two effective methods are proposed for improving the catalytic reactivity: reducing the electronically active substituent on carbene and introducing interaction to stabilize the transition state (TS). Based on these findings, adopting a well‐known (amino)(silyl)carbene modified by a –NH2 group gives the most effective catalyst for the direct carboxylation of benzene. Using –NH2 group can introduce two strong interactions (OOH···HNH2 and NNH2···Cu) during the formation of TS, which can greatly stabilize the structure of TS and dramatically reduce the energy barrier. The catalytic reactivity of the most effective carbene‐copper catalyst is comparable with the noble metal‐based ruthenium pincer carboxylate complexes.

Syntheses, Structures, and Catalytic Properties of Three Copper(II) Coordination Polymers Based on 2,3,5,6‐Tetrafluoro‐1,4‐bis(triazole‐ylmethyl)benzene and Benzene Carboxylate Ligands

Three new mixed‐ligand coordination polymers of CuII, namely, [Cu(Fbtx)(L1)(H2O)]n (1), [Cu(Fbtx)0.5(HL2)(H2O)2]n (2), and {[Cu(Fbtx)1.5(HL3)(H2O)]·H2O}n (3) [Fbtx = 2,3,5,6‐tetrafluoro‐1,4‐bis(1,2,4‐triazole‐1‐ylmethyl)benenze, H2L1 = terephthalic acid, H3L2 = trimesic acid, NaH2L3 = 5‐sulfoisophthalic acid monosodium salt], were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectra, and single‐crystal and powder X‐ray diffraction techniques. All the complexes have a two‐dimensional (2D) coordination layer structure. Of these, 1 displays a planar 44‐sql structure whereas both 2 and 3 are highly undulated 63‐hcb nets. Moreover, their thermal stability and catalytic behaviors in the aerobic oxidation of 4‐methoxybenzyl alcohol were also investigated as well. The results indicate that the benzene dicarboxylate ligands have an effective influence on the structures and catalytic properties of the resulting coordination polymers.

New macrocyclic Cu(II) complex with bridge terephthalate: Synthesis, spectral properties, in vitro cytotoxic and antimicrobial activity. Comparison with related complexes

New cationic mixed-ligand tetranuclear complex [Cu4(tpht) (tpmc)2](ClO4)6·5H2O (tpmc = N,N′,N″,N‴-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane, H2tpht = terephthalic acid (benzene-1,4-dicarboxylic acid)) was prepared and characterized by elemental analysis (C, H, N, Cu), UV/Vis, IR, EPR (X-band) spectra, conductivity, cyclic voltammetry and magnetic measurements (SQUID). Five coordinated geometry for new Cu(II) complex is proposed. The central metal ion is coordinated with two pyridyl and two cyclam nitrogens and bridged with N(CH2)3N fragments of the cyclam ring and OCO− of the terephthalate anion. Copper (II) ions are coordinated out of cyclam rings and one OCO− group from tpht bridges two Cu(II) inside tpmc unit and two Cu2tpmc units are bridged by dicarboxylate tpht dianion engaging all four oxygen atoms. Weak ferromagnetic interaction between copper (II) ions in new tetranuclear complex is observed, Weiss constant θ = 0.21 K and C = 0.398 cm3Kmol−1.The new complex, related Cu(II) complexes with bridged benzene carboxylate, [Cu2(C6H5COO)tpmc](ClO4)3·CH3OH, [Cu2(Hpht)tpmc](ClO4)3·3H2O (H2pht = phthalic acid), [Cu4(ipht) (tpmc)2](ClO4)6·NaClO4·2CH3CN (H2ipht = isophthalic acid), solvents, starting salts and ligands were in vitro evaluated for antiproliferative and antibacterial activity. Antiproliferative evaluation was carried out using tumour cell lines: HeLa (human adenocarcinoma) and K562 (chronic myelogenous leukaemia). Among all tested compounds, the ipht complex revealed the highest antiproliferative activity. According to antibacterial screening results, most active compound was the benzoate complex against Micrococcus lysodeikticus.

Inhibition of benzene, toluene, phenol and benzoate in single and combination on Anammox activity: implication to the denitrification-Anammox synergy.

A previous study demonstrated that denitrification synergized with Anammox could accelerate the anaerobic degradation of benzene. The inhibitory effects of benzene, toluene, phenol and benzoate in single and combination on Anammox activity were investigated by short-term batch tests. The results indicated that the inhibition of single compounds on Anammox could be well fitted with the extended non-competitive and Luong inhibition kinetic models. The inhibitions of the individual compound were in order as follows: benzene > toluene > phenol > benzoate. The joint inhibitions of bi-component mixtures of benzene with toluene, benzene with phenol and benzene with benzoate on Anammox activity were additive; the joint inhibition of a tri-component mixture (benzene, toluene and phenol) was partly additive; and the joint inhibition of a multicomponent mixture (benzene, toluene, phenol and benzoate) was synergistic. The effect of benzoate on the denitrification-Anammox synergy for benzene degradation was evaluated using a long-term test. Although the average rate of benzene degradation decreased by 13% with the addition of 10mgL-1 benzoate, the average rate of NO3- and NH4+ increased by approximately 1- and 0.56-fold, respectively, suggesting that benzoate favors the stability of the denitrification-Anammox synergy. The carboxylation of benzene would be a more favorable pathway for the anaerobic degradation of benzene under denitrification synergized with Anammox.

CeO2@C derived from benzene carboxylate bridged metal–organic frameworks: ligand induced morphology evolution and influence on the electrochemical properties as a lithium-ion battery anode

Spherically shaped MOF-derived CeO2@C shows a superior performance as a lithium-ion battery anode with high specific capacity, rate performance and cycling stability.

Syntheses and Crystal Structures of Three Cu(II) Coordination Polymers Based on 1,3,5-Tris(imidazol-1-yl)benzene and Benzene Carboxylate Ligands

Three coordination polymers, namely, Cu(HL1)(timb) (1), Cu3(L2)3(timb)2(H2O)2 ·2H2O·4CH3CN (2) and Cu(L3)0.5(timb)·H2O (3) (timb = 1,3,5-tris(imidazol-1-yl)benzene, H3L1 = 1,2,4-benzenetricarboxylic acid, H3L2 = 1,3,5-benzenetricarboxylic acid and H4L3 = 1,2,4,5-benzenetetracarboxylic acid), have been synthesized and characterized by elemental analyses, infrared spectra (IR), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. Single crystal structure analysis shows that complex 1 possesses a three-dimensional (3D) twofold interpenetrating architecture with a very rare (3,5)-connected (3·72)(32·75·83) topology. Complex 2 features an interesting 3D (3,4)-connected framework with an unprecedented (4·82)4(42·82·102)2(84·122) topology, whereas complex 3 exhibits a novel 3D (3,4,5)-connected framework with an unusual (4·63·86)2(42·84)(63)2 topology. The results reveal that the carboxylic building blocks play a significant role in promoting the diversity of the observed structural motifs. In addition, their thermal stabilities have also been investigated. Three Cu(II) complexes with unique topology have been constructed by three different benzene carboxylates and the timb ligand. The results reveal that the carboxylic building blocks play a significant role in promoting the diversity of the observed structural motifs.

Route to Renewable PET: Reaction Pathways and Energetics of Diels–Alder and Dehydrative Aromatization Reactions Between Ethylene and Biomass-Derived Furans Catalyzed by Lewis Acid Molecular Sieves

Silica molecular sieves that have the zeolite beta topology and contain framework Lewis acid centers (e.g., Zr-β, Sn-β) are useful catalysts in the Diels–Alder and dehydrative aromatization reactions between ethylene and various renewable furans for the production of biobased terephthalic acid precursors. Here, the main side products in the synthesis of methyl 4-(methoxymethyl)benzene carboxylate that are obtained by reacting ethylene with methyl 5-(methoxymethyl)-furan-2-carboxylate are identified, and an overall reaction pathway is proposed. Madon–Boudart experiments using Zr-β samples of varying Si/Zr ratios clearly indicate that there are no transport limitations to the rate of reaction for the synthesis of p-xylene from 2,5-dimethylfuran and ethylene and strongly suggest no mass transport limitations in the synthesis of methyl p-toluate from methyl 5-methyl-2-furoate and ethylene. Measured apparent activation energies for these reaction-limited systems are small (<10.5 kcal/mol), suggesting that appa...

(Invited) Thin Film Thermoelectric Metal-Organic Framework with High Seebeck Coefficient and Low Thermal Conductivity

Metal-organic frameworks (MOFs) are extended, crystalline compounds consisting of metal ions interconnected by organic ligands such as benzene carboxylates, forming a crystalline, nanoporous structure. The low atomic density and long, bridge-like bonding characteristic implies that MOFs should exhibit low thermal conductivity, which is an attractive feature for thermoelectric energy conversion. However, most MOFs are electrical insulators due to the non-conjugated character of the organic ligands and poor overlap between their pi orbitals and the valence orbitals of the metal ions. Recently, we discovered that infiltrating the pores of the copper-containing MOF Cu3(BTC)2 with redox-active guest molecules TCNQ (7,7,8,8-tetracyanoquinododimethane) increases the electrical conductivity of thin film devices by as much as seven orders of magnitude [1]. Density functional theory indicates that electrical conductivity results from a donor-bridge-acceptor geometry, in which TCNQ binds to two Cu(II) dimer units within the MOF pore. In this paper we report the first thermoelectric properties characterization of a MOF thin film which yield a positive Seebeck coefficient of ~400 uV/K, in qualitative agreement with DFT calculations which also indicate that holes should be the dominant charge carriers in TCNQ@Cu3(BTC)2. Finally, we present results of molecular dynamics simulations which indicate that the phonon thermal conductivity of Cu3(BTC)2 MOF is indeed low, thus further suggesting that conducting MOFs are promising materials for thermoelectric energy conversion [2]. [1] A. A. Talin, A. Centrone, M. E. Foster, V. Stavila, P. Haney, R. A. Kinney, V. Szalai, F. El Gabaly, H. P. Yoon, F. Léonard, M. D. Allendorf, Science 343, 66 (2014) [2] K. J. Erickson , F. Léonard , V. Stavila , M. E. Foster, C. D. Spataru , R. E. Jones , B. M. Foley, P. E. Hopkins, M. D. Allendorf, and A. A. Talin, Adv. Mater. DOI: 10.1002/adma.201501078 (2015).

Crystal structure of ethyl (E)-4-(4-chlorophen-yl)-4-meth-oxy-2-oxobut-3-enoate.

In the title compound, C13H13ClO4, the dihedral angle between the chloro­benezene ring and the least-squares plane through the 4-meth­oxy-2-oxobut-3-enoate ethyl ester residue (r.m.s. deviation = 0.0975 Å) is 54.10 (5)°. In the crystal, mol­ecules are connected by meth­oxy–ketone and benzene–carboxyl­ate carbonyl C—H⋯O inter­actions, generating a supra­molecular layer in the ac plane.

A New 3D Supramolecular Structure of Zn(II) Coordination Polymer Constructed by 1,4-bis(1-imidazol-yl) -2,5- Dimethyl Benzene and Semirigid Carboxylate Ligand

A new coordination polymer, [Zn(oba)(bib)0.5(H2O)]n (1), has been constructed from 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene (bib) with the asymmetric semirigid dicarboxylate ligand [2-(3-carboxyphenoxy)benzoic acid]. The complex 1 shows 2D layer structure. Via intermolecular bonding interactions, the 3D supramolecular structure is constructed with five-connected topological nets. Furthermore, the luminescent property of 1 is investigated.

Carboxylation of aromatic compounds in a supercritical carbon dioxide medium

The reaction of direct carboxylation of benzene and its derivatives PhX (X = Me, Br, Ph, OPh, OMe), as well as mesitylene, durene, and ferrocene, in a supercritical CO2 medium in the presence of various Lewis acids (AlCl3, FeCl3, ZrCl4, and ZnCl2) is studied. It is shown that, in all cases, secondary reactions proceed faster than the primary reaction of carboxylic acid formation. For the thoroughly studied AlCl3-CO2toluene system, optimal conditions of the formation of n-toluic acid are determined. For the AlCl3-CO2-benzene system, as an example, quantum-chemical calculations of the characteristics of the allowed pathways of the carboxylation reaction are performed.

Spectroscopic properties of lanthanoid benzene carboxylates in the solid state: Part 3. N-heteroaromatic benzoates and 2-furanates

Europium and terbium complexes incorporating picolinate, nicotinate, isonicotinate and 2-furanates complexes were synthesised from aqueous solutions. The compositions and structures were determined using infrared spectroscopy, microanalysis, EDTA titrations and X-ray powder diffraction. Furthermore, the optoelectronic solid state properties were determined using reflectance, excitation, emission and phosphorescence spectroscopy. The data was used to quantitatively compare the light output of the luminescent complexes to other carboxylate complexes thus gain further insight into the relation between the electronic structure of the ligand and the luminescence properties. Thus absorption, excitation efficiencies, quantitative emission integrals and triplet energies were determined. The relative intensities as well as the splitting patterns of the 5D0→7FJ transitions in the europium emission spectra are also discussed and found to be in good agreement with structural features.

Thermal behaviors and grafting process of LDH/benzene derivative hybrid systems

Thermal behaviors of four hybrid layered double hydroxide (LDH) phases have been studied by thermogravimetric analyses coupled with mass spectroscopy, temperature dependence of X-ray powder diffraction measurements, and temperature dependence of infrared spectroscopy measurements. Inorganic zinc–aluminium LDH main layers (with a Zn2+/Al3+ cationic ratio of 2) inserted the following four organic anions: benzene carboxylate, 4-hydroxy-benzene carboxylate, benzene sulfonate and 4-hydroxy-benzene sulfonate. The four LDH hybrids have been synthesized by the coprecipitation method. The as-prepared samples have been characterized and their compositions were determined. Thermal evolution of the crystalline phases during the dehydration (occurring before 200°C) and the dehydroxylation (occurring between 200 and 300°C) gave evidence for organic anion grafting onto the inorganic main layer. The thermal stability of the LDH hybrid system depends on the nature of the intercalated aromatic anion. The thermal grafting process can be monitored, as well as its thermal reversibility, by choosing the functionalizations of the benzenic anion and the temperature of the applied heat treatment.

Anion-induced assembly of 2-D Cd(II) complexes with (42·6)(42·63·8) topology based on ferrocenyl dicarboxylate and tripodal ligands

Self-assembly of a flexible tripodal ligand, 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene (ttmb) and organometallic carboxylate 1,1'-bis(3-carboxy-1-oxopropyl)-ferrocene (H2bfcs) with Cd(Ac)2 · 2H2O or CdCl2 · 2.5H2O yi elds two 2-D binodal (3,4)-connected complexes {[Cd2(bfcs)(Hbfcs)2(ttmb)2] · 10H2O} n (1) and [CdCl(Hbfcs)(ttmb)] n (2), exhibiting the same topological type (42 · 6)(42 · 63 · 8). Both exhibit a layer structure, which is generated through 1-D undulated ladders connected by organometallic carboxylate, bfcs2− (in 1), or Cl− (in 2). Differential pulse voltammetry experiments indicate that half-wave potentials are slightly higher than that of H2bfcs. Both complexes exhibit similar weak fluorescent emissions at room temperature.

Spectroscopic properties of lanthanoid benzene carboxylates in the solid state: Part 2. Polar substituted benzoates

Europium and terbium complexes of ortho, meta and para substituted benzoate ligands including nitrobenzoate (NBA), aminobenzoate (ABA), hydroxybenzoate (OHBA) and methoxybenzoate (MeOBA) have been synthesised by metathesis reactions, carried out in aqueous media. The complexes were characterised by elemental, compositional and structural investigations, including microanalysis, EDTA titrations, differential thermal analysis, infra red spectroscopy, X-ray powder diffraction and single crystal structural analyses. Besides this, strong emphasis was on the determination of the optoelectronic properties of the compounds in the solid state. In this regard, reflectance, excitation and emission spectra were recorded. From these, the emission and excitation efficiencies were determined. The relative intensities as well as the splitting patterns of the 5D 0 → 7F J transitions in the europium emission spectra are discussed.