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Showing papers on "Benzoic acid published in 2017"


Journal ArticleDOI
TL;DR: In this article, N-doped graphene samples were synthesized using dicyandiamide, melamine, and urea as the nitrogen precursors, and an excellent catalytic oxidation of p-hydroxylbenzoic acid (PHBA) was observed on the as-synthesized samples via peroxymonosulfate activation.
Abstract: N-doped graphene has been considered as a promising catalyst with surface metal-free active sites for environmental remediation. Several MIL-100 (Fe)-templated N-doped graphene samples were synthesized using dicyandiamide, melamine, and urea as the nitrogen precursors. Excellent catalytic oxidation of p-hydroxylbenzoic acid (PHBA) was observed on the as-synthesized samples via peroxymonosulfate (PMS) activation. The mechanism was investigated by both electron paramagnetic resonance (EPR, 5,5-dimethyl-1-pyrroline N-oxide and 2,2,6,6-tetramethyl-4-piperidinol as the trapping agents) and quenching tests (ethanol and sodium azide as the radical scavengers). Benzoic acid and furfuryl alcohol were also employed as probing reagents for hydroxyl/sulfate radicals and singlet oxygen, respectively. The results confirmed that singlet oxygen was generated and dominated the PHBA degradation on N-doped graphene, rather than hydroxyl/sulfate radicals. With the novel N-doped graphene, this study illustrates the formation ...

225 citations


Journal ArticleDOI
TL;DR: Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products.
Abstract: Benzoic acid is an aromatic carboxylic acid naturally present in plant and animal tissues, which can also be produced by microorganisms. Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products. As a result of their widespread occurrence, production, and uses, these compounds are largely distributed in the environment and found in water, soil, and air. Consequently, human exposure to them can be high, common, and lengthy. This review is mainly focused on the presence and use of benzoic acid in foods but it also covers the occurrence, uses, human exposure, metabolism, toxicology, analytical methods for detection, and legal limits for benzoic acid and its derivatives. Their controversial effects and potential public health concerns are discussed.

185 citations


Journal ArticleDOI
08 Mar 2017-PLOS ONE
TL;DR: The risks from benzene will be lower from e-cigarettes than from conventional cigarettes, however, ambient benzene air concentrations in the U.S. have typically been 1 μg/m3, so that benzene has been named the largest single known cancer-risk air toxic in the United States.
Abstract: Background/Objective The heating of the fluids used in electronic cigarettes (“e-cigarettes”) used to create “vaping” aerosols is capable of causing a wide range of degradation reaction products. We investigated formation of benzene (an important human carcinogen) from e-cigarette fluids containing propylene glycol (PG), glycerol (GL), benzoic acid, the flavor chemical benzaldehyde, and nicotine. Methods/Main results Three e-cigarette devices were used: the JUULTM “pod” system (provides no user accessible settings other than flavor cartridge choice), and two refill tank systems that allowed a range of user accessible power settings. Benzene in the e-cigarette aerosols was determined by gas chromatography/mass spectrometry. Benzene formation was ND (not detected) in the JUUL system. In the two tank systems benzene was found to form from propylene glycol (PG) and glycerol (GL), and from the additives benzoic acid and benzaldehyde, especially at high power settings. With 50:50 PG+GL, for tank device 1 at 6W and 13W, the formed benzene concentrations were 1.9 and 750 μg/m3. For tank device 2, at 6W and 25W, the formed concentrations were ND and 1.8 μg/m3. With benzoic acid and benzaldehyde at ~10 mg/mL, for tank device 1, values at 13W were as high as 5000 μg/m3. For tank device 2 at 25W, all values were ≤~100 μg/m3. These values may be compared with what can be expected in a conventional (tobacco) cigarette, namely 200,000 μg/m3. Thus, the risks from benzene will be lower from e-cigarettes than from conventional cigarettes. However, ambient benzene air concentrations in the U.S. have typically been 1 μg/m3, so that benzene has been named the largest single known cancer-risk air toxic in the U.S. For non-smokers, chronically repeated exposure to benzene from e-cigarettes at levels such as 100 or higher μg/m3 will not be of negligible risk.

150 citations


Journal ArticleDOI
TL;DR: The findings suggest that the role of temperature in the persulfate-based treatment systems is not limited only to controlling the rates of sulfate and hydroxyl radical generation, and could be important to the transformation of a number of organic contaminants.

149 citations


Journal ArticleDOI
TL;DR: The evolution of the degradation by-products of an acetaminophen (ACE) solution was monitored by HPLC-UV/MS and IC in parallel with its ecotoxicity during electro-Fenton (EF) oxidation performed on carbon felt, and a relationship was established between the degradation pathway of ACE and the global toxicity Evolution of the solution.

123 citations


Journal ArticleDOI
TL;DR: In this article, the degradation of one of the major organic pollutants, benzoic acid (BA), has been performed using persulfate activated with sulfidized Fe 0 (nFe/FeS) for the abatement of pollutants of various categories.

105 citations


Journal ArticleDOI
TL;DR: An investigation of the mechanism of benzoic acid/thiourea co-catalysis in the asymmetric Pictet-Spengler reaction is reported, andortion-interaction analyses of the transition structures for deprotonation indicate that differential π-π and C-H···π interactions within a scaffold organized by multiple hydrogen bonds dictate stereoselectivity.
Abstract: An investigation of the mechanism of benzoic acid/thiourea co-catalysis in the asymmetric Pictet–Spengler reaction is reported. Kinetic, computational, and structure–activity relationship studies provide evidence that rearomatization via deprotonation of the pentahydro-β-carbolinium ion intermediate by a chiral thiourea·carboxylate complex is both rate- and enantioselectivity-determining. The thiourea catalyst induces rate acceleration over the background reaction mediated by benzoic acid alone by stabilizing every intermediate and transition state leading up to and including the final selectivity-determining step. Distortion–interaction analyses of the transition structures for deprotonation predicted using density functional theory indicate that differential π–π and C–H···π interactions within a scaffold organized by multiple hydrogen bonds dictate stereoselectivity. The principles underlying rate acceleration and enantiocontrol described herein are expected to have general implications for the design o...

86 citations


Journal ArticleDOI
TL;DR: Electron paramagnetic resonance detected 5,5-dimethyl-2-hydroxypyrrolidine-N-oxyl (DMPO-OH), which was probably produced by the oxidation of DMPO by Cu3+ or OH formed as a product of Cu3+.

86 citations


Journal ArticleDOI
TL;DR: In this article, the effects of four pyridazine derivatives (2-(6-chloropyridazin-3-yl)-2-phenylacetonitrile (P1), 3-(6chloro-3pyridaxinyl)-1H-indole (P2), 4-(6 chloropyridine-3yl)benzoic acid (P3), and 3-( 6-chloro-, 3-pyride-inhibitor-inhibitor)-inhibite (P4) on electrochemical dissolution of mild

77 citations


Journal ArticleDOI
TL;DR: In this article, a new way of fuel desulfurization, namely selective oxidation of organic S-compounds present in fuels to water-soluble sulfur compounds followed by in situ extraction of the latter into an aqueous phase, is presented.
Abstract: Our contribution demonstrates a new way of fuel desulfurization, namely selective oxidation of organic S-compounds present in fuels to water-soluble sulfur compounds followed by in situ extraction of the latter into an aqueous phase. Different from common oxidative desulfurization (ODS) processes, we demonstrate a technique that converts sulfur compounds in fuel to a large extent to sulfate (60–70%) using oxygen as the oxidant and an aqueous H8PV5Mo7O40 (HPA-5) solution as the catalyst phase. Other water-soluble desulfurization products are sulfoacetic acid (SAA) with a share of 10–20%, 2-sulfobenzoic acid (2-SBA), and 2-(sulfooxy)benzoic acid (2-SOBA), the latter two with a share of <10%. The new desulfurization method has been optimized for removing benzothiophene from isooctane, giving the best results with a degree of desulfurization of 99% applying 120 °C, 20 bar oxygen pressure, and 1000 rpm of 6 h reaction time using a volume water/oil ration of 10/1. Furthermore, we also successfully demonstrated ...

72 citations


Journal ArticleDOI
Jinming Wang1, Ya Zheng1, Tianyou Peng1, Jing Zhang1, Renjie Li1 
TL;DR: An asymmetric zinc porphyrin derivative bearing one benzoic acid and three 3-pyridines as meso-position substituents (zinc-5-(4-carboxyphenyl)-10,15,20-tri(3-pridyl)porphyrin, ZnMT3PyP) was used to sensitize graphitic carbon nitride (g-C3N4) for visible-light-driven photocatalytic H2 production as mentioned in this paper.
Abstract: An asymmetric zinc porphyrin (ZnPy) derivative bearing one benzoic acid and three 3-pyridines as meso-position substituents (zinc-5-(4-carboxyphenyl)-10,15,20-tri(3-pridyl)porphyrin, ZnMT3PyP) was used to sensitize graphitic carbon nitride (g-C3N4) for visible-light-driven photocatalytic H2 production. It was found that ZnMT3PyP exhibits more excellent photosensitization and stability on g-C3N4 than its counterpart bearing one benzoic acid and three phenyls (zinc-5-(4-carboxyphenyl)-10,15,20-triphenylporphrin, ZnMTPP) under visible light (λ > 420 nm) irradiation even though they have very similar physicochemical properties such as optical absorption capacities and energy band structures. Especially, ZnMT3PyP-Pt/g-C3N4 gives an apparent quantum yield (AQY) up to 25.1% at λ = 420 nm light illumination, greater than that (11.6%) of ZnMTPP-Pt/g-C3N4. The differences in photosensitization and stability between ZnMT3PyP and ZnMTPP are mainly due to the substitution of 3-pyridine for the phenyls in ZnMTPP, which...

Journal ArticleDOI
TL;DR: Estrogenicity assays showed that methyl paraben was more estrogenic than EP; however, parabens are slightly estrogenic compared to 17β-estradiol, and liquid chromatography-time of flight mass spectrometry revealed the formation of methylParaben, 4-hydroxybenzoic acid, benzoic Acid and phenol as primary transformation by-products.

Journal ArticleDOI
TL;DR: In situ DRIFTS were conducted to identify adsorbed ozone and/or adorbed oxygen species on CaO, ZnO, γ-Al2O3, CuO and α-Fe 2O3 surfaces at room temperature.

Journal ArticleDOI
TL;DR: In this paper, a segmented flow, microwave-assisted reactor was used where rapid nucleation in the microwave zone was separated from growth processes in an oil bath, which can result in the formation of polydisperse products through agglomeration that reduces the available surface area.
Abstract: In this study, microwaves and chemical modulators were used in combination to improve the uniformity of synthesized MOF-74(Ni) materials. A segmented flow, microwave-assisted reactor was used where rapid nucleation in the microwave zone was separated from growth processes in an oil bath. High temperatures in the microwave zone induce fast nucleation, which can result in the formation of polydisperse products through agglomeration that reduces the available surface area. Benzoic acid was used as a chemical modulator where higher benzoic acid to Ni2+ concentration ratios resulted in a substantial increase in apparent reaction activation energies for short reaction times (∼1 s). Optimization of the synthetic process resulted in MOF-74(Ni) particles with high crystallinity, high surface area, and narrow particle size distributions. These synthesized MOF-74(Ni) particles were used to prepare metal–organic framework-Nafion matrix based membranes to investigate the removal of metal ions from aqueous solutions wi...

Journal ArticleDOI
TL;DR: In this article, a new Schiff base ligand (HL) with the IUPAC name 2-(((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)imino)(phenyl)methyl)benzoic acid.
Abstract: The condensation of o-benzoyl benzoic acid and 4-aminoantipyrine resulted in the formation of novel Schiff base ligand (HL) with the IUPAC name 2-(((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)imino)(phenyl)methyl)benzoic acid. The synthesized Schiff base ligand and its complexes with M(II)/(III) transition elements (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)) were characterized by elemental, magnetic susceptibility, molar conductivity, spectroscopic (1H NMR, mass, UV–visible, FTIR, ESR), thermal and X-ray powder diffraction. The data showed that the complexes had composition of the MHL type. The diffused reflectance spectra, magnetic susceptibility and ESR spectral data of the complexes confirm an octahedral geometry around metal ions. The thermal analysis data revealed the decomposition of the complexes in three to five successive decomposition steps within the temperature range of 30–1000°C, and the activation thermodynamic parameters were reported. The molecular structures of the Schiff base ligand and its Mn(II) and Zn(II) metal complexes are optimized theoretically, and the quantum chemical parameters are calculated. In order to predict the binding between o-benzoyl benzoic acid, 4-aminoantipyrine and HL ligand with the Escherichia coli bacterial RNA (4p20) receptor, molecular docking was carried out. The in vitro antimicrobial screening of the newly synthesized compounds was tested against different bacterial and fungal organisms. The results showed that the metal complexes have biologically activity more than the new Schiff base ligand against the tested organisms. The Schiff base ligand and its complexes were also screened for their anticancer activity against breast cancer cell line (MCF7). The Mn(II), Cr(III) and Cd(II) complexes were found to have low IC50 values which support the possibility of using them as cytotoxic agents and hence might become good anticancer agent in clinical trials.

Journal ArticleDOI
TL;DR: It was concluded that benzyl alcohol, benzoic acid and its salts, and benzyl benzoate are safe in the present practices of use and concentration described in this safety assessment.
Abstract: Benzyl alcohol, benzoic acid and its salts, and benzyl benzoate function mostly as fragrance ingredients/preservatives in cosmetic products. The Cosmetic Ingredient Review Expert Panel previously established concentration limits for benzyl alcohol, benzoic acid, and sodium benzoate in cosmetics and determined that the available data were insufficient to support the safety of these ingredients during inhalation exposure. After reviewing newly available data, it was concluded that benzyl alcohol, benzoic acid and its salts, and benzyl benzoate are safe in the present practices of use and concentration described in this safety assessment.

Journal ArticleDOI
TL;DR: In this article, a kinetic model for the oxidation of benzyl alcohol over Au-Pd is proposed, which has been found satisfactory after a model discrimination procedure was applied to a number of simplified candidate models developed from microkinetic studies.

Journal ArticleDOI
13 Mar 2017-Langmuir
TL;DR: Relationships between the ligand chemical structure and surface binding on magnetic IONPs for a series of related benzoic acid and catechol derivatives are determined to help guide future ligand-design and lig and-exchange strategies toward realizing truly custom-built IonPs.
Abstract: The excellent performance of functionalized iron oxide nanoparticles (IONPs) in nanomaterial and biomedical applications often relies on achieving the attachment of ligands to the iron oxide surface both in sufficient number and with proper orientation. Toward this end, we determine relationships between the ligand chemical structure and surface binding on magnetic IONPs for a series of related benzoic acid and catechol derivatives. Ligand exchange was used to introduce the model ligands, and the resultant nanoparticles were characterized using Fourier transform infrared–attenuated internal reflectance spectroscopy, transmission electron microscopy, and nanoparticle solubility behavior. An in-depth analysis of ligand electronic effects and reaction conditions reveals that the nature of ligand binding does not solely depend on the presence of functional groups known to bind to IONPs. The structure of the resultant ligand–surface complex was primarily influenced by the relative positioning of hydroxyl and c...

Journal ArticleDOI
TL;DR: In this paper, the 1D copper(II) coordination polymers were synthesized and tested as homogeneous catalysts for cyanosilylation of a variety of aldehydes to the corresponding cyanohydrin trimethylsilyl ethers.

Journal ArticleDOI
TL;DR: It was found that ionic liquid 1-octyl-3-methylimidazolium acetate as a solvent could promote the aerobic oxidation of lignin model compound 2-phenoxyacetophenone and the yields of phenol and benzoic acid from 1 could be as high as 96% and 86%, respectively.

Journal ArticleDOI
TL;DR: An iron-based photochemical process able to act via reductive and oxidative stages by tuning experimental conditions has been explored in this paper, where zero-valent iron (ZVI), added as steel wool, was used to reduce those pollutants reluctant to oxidative processes.

Journal ArticleDOI
TL;DR: A rhodium-catalyzed regioselective addition of sulfonyl hydrazides to allenes is reported, with Rh(i)/DPEphos/benzoic acid as the catalyst system, and branched allylic sulfones can be obtained, in good to excellent yields and regiOSElectivities.

Journal ArticleDOI
TL;DR: In this paper, the effect of monocarboxylic acids on synthesizing NH2-MIL-125 is systematically studied for the first time in this work, and the fantastic results are discussed in detail.
Abstract: The effect of monocarboxylic acids on synthesizing NH2-MIL-125 is systematically studied for the first time in this work, and the fantastic results are discussed in detail. We found that a small molecular acid (acetic acid, thioglycolic acid) mostly affects the morphology changes of NH2-MIL-125, while the pseudolinker acid (p-toluylic acid, benzoic acid) has a significantly impact on the crystal size on account of the nucleation and the crystal growth rates. Ar sorption measurement and transmission electron microscopy characterization show that samples synthesized with pseudolinker acid as additives have a hierarchical structure owing to the internal defects or caves formed in the crystal. These samples also show an excellent performance for the removal of organic pollutants by the combined effects of adsorption and photodegradation.

Journal ArticleDOI
TL;DR: The coordination chemistry of a series of Cu(ii) complexes of various aminoalcohol and benzoate ligands was explored and a correlation exists between the Cu-O-Cu angle and magnetic coupling in di- and trinuclear Cu(II) complexes.
Abstract: Herein, the coordination chemistry of a series of Cu(II) complexes of various aminoalcohol and benzoate ligands was explored. The pH-dependent reactions of copper(II) salts with propanolamine (Hpa), N-methyl diethanolamine (H2mdea), triethanolamine (H3tea), and nbutyl-diethanolamine (H2budea) were carried out in the presence of various benzoates (benzoic acid, 2-hydroxy benzoic acid, 4-hydroxy benzoic acid, 3-methoxy benzoic acid, and 4-methoxy benzoic acid). The resulting complexes [Cu2(pa)2(benzoate)2] (1), [Cu2(pa)2(3-methoxybenzoate)2] (2), [Cu2(pa)2(4-methoxybenzoate)2] (3), [Cu2(H2tea)2(benzoate)2]·2H2O (4), [Cu2(H2tea)2(2-hydroxybenzoate)2]·2H2O (5), [Cu2(H3tea)2(4-hydroxybenzoate)2][Cu(Htea)2]·2H2O (6), [Cu(H2mdea)2][benzoate]2 (7), [Cu(H2mdea)2][4-methoxybenzoate]2 (8), [Cu(H2bdea)2][2-hydroxybenzoate]2 (9), [Cu2(benzoate)4(benzoic acid)2] (10), [Cu2(4-methoxybenzoate)4(CH3CN)2]·4CH3CN (11) and [Cu3(H2tea)2(benzoate)2(NO3)2] (12) were formed as mono-, di- or trinuclear entities depending upon the pH conditions of the reaction. The complexes were characterized employing spectral, magnetic, single-crystal X-ray and DFT/TDDFT studies. 7 and 8 exhibited emission peaks at 510 and 460 nm, respectively, in the solid-state photoluminescence (PL) spectra. The temperature variable magnetic properties of 1–12 revealed the presence of antiferromagnetic (in 1–3 and 7–11) or ferromagnetic interactions (in 4–6 and 12) with Curie constants C = 0.24 (7), 0.28 (8) or 0.35 cm3 K mol−1 (9) and Weiss constants θ = −0.34 (7), −0.32 (8) or −0.40 (9) K for the mononuclear complexes. The dinuclear complexes demonstrated J values of −89.2(2) (1), −71.1(3) (2), −59.6(1) (3), 98(1) (4), 79.1(2) (5), −85.4(2) (10) and −89.5(2) (11) cm−1. Strong ferromagnetic interactions were observed in the case of 6 (J = 172(3) cm−1 and zJ′ = 2.3(2) cm−1), which were comparable with those of 12 (J12 = 197(2) cm−1, J13 = −9.3(3) cm−1). A correlation exists between the Cu–O–Cu angle and magnetic coupling in di- and trinuclear Cu(II) complexes. Moreover, 4–6 were active catalysts for the oxidation of 3,5-DTBC to 3,5-DTBQ and showed catecholase activity in the order 4 > 5 > 6 (Kcat = 943 (4), 698 (5) and 553 h−1 (6)). This order can be rationalized in terms of the electron density on the ligand, which neutralizes the effective positive charge on Cu(II), thus forming the less or more stable intermediate. The order of catecholase activity and the electronic spectral properties of 4–6 were also investigated by DFT and TDDFT studies, respectively.

Journal ArticleDOI
Yueling Cao1, Minghui Tang1, Mingming Li1, Jiang Deng1, Fan Xu1, Lei Xie1, Yong Wang1 
TL;DR: In this article, a novel N-doped carbon supported Rh catalyst was developed via one-pot pyrolysis of chitin and (NH4)3RhCl6.
Abstract: A novel N-doped carbon supported Rh catalyst was developed via one-pot pyrolysis of chitin and (NH4)3RhCl6. The catalyst exhibited excellent catalytic activity and recyclability for the hydrogenation of benzoic acid to cyclohexane carboxylic acid. Characterization indicated that the high catalytic performance of Rh/N–C-700 is mainly attributed to the proportion of Rh0 to Rh3+ and Rh particle size. More importantly, this novel synthesis strategy significantly increased the interaction between Rh nanoparticles and N-doped carbon in contrast with the conventional impregnation and NaBH4 reduction methods, thus preventing the Rh nanoparticles from migration, aggregation, and leaching from the support surface and therefore improving the reusability of the catalyst. This synthetic method may pave a new way for producing N-doped carbon supported metal catalysts from chitin on a large scale, which is attractive for industrial applications.

Journal ArticleDOI
TL;DR: This study isolated Bacillus licheniformis MH48 from rhizosphere soil and demonstrated that this strain shows significant antifungal activity against Rhizoctonia solani, Colletotrichum gloeosporioides, and Phytophile capsici.

Journal ArticleDOI
TL;DR: In this paper, an electrostatic attraction between positively charged polyethylenimine (PEI)-capped gold nanoparticles and the negatively charged external surfaces of halloysite nanotubes was investigated.

Journal ArticleDOI
TL;DR: In this paper, a density functional theory was used to study the mechanism and kinetics of benzoic acid with hydroxyl radicals in both gas and aqueous phases.
Abstract: Density functional theory was used to study the mechanism and kinetics of benzoic acid with hydroxyl radicals in both gas and aqueous phases as well as benzoate with hydroxyl radicals in the aqueous phase at the M06-2X/6-311+G(d,p) level of theory. The results show that all reaction pathways involved the formation of pre-reactive complexes which in turn alter reaction energy barriers. The reaction rate constants, calculated based on classical transitional theory, followed the order of meta addition > para addition > ortho addition for the reaction of benzoic acid and hydroxyl radicals in both gas and aqueous media. The energy barrier analysis reveals that the ortho adducts were also less vulnerable to subsequent reaction. In addition, the rate constants for the addition reactions were highest for benzoate in the aqueous phase, followed by benzoic acid in the aqueous phase, then by benzoic acid in the gas phase, consistent with electrostatic potential analysis. However, the rate constants of hydrogen abstraction in the aqueous phase were much lower than that in the gas phase and thus, gas phase reactions are preferred. The incorporation of one explicit water molecule, for addition reactions between benzoic acid and hydroxyl radicals, lowered reaction rates in the aqueous phase by increasing the bond length between the oxygen and reacting carbon in the benzene ring.

Journal ArticleDOI
TL;DR: The newly synthesized coumarin derivative showed a strong one-photon absorption band (ε ≈ 29000 cm-1 M-1) in the visible region (>∼400 nm) and time-dependent density functional theory calculations predicted a sizable TP absorption cross-section with a maximum at ∼650 nm significantly lager than that related to the OP absorption band.

Journal ArticleDOI
TL;DR: This approach provides polycyclic imidazolidinone derivatives in typically good yields of α-Ketoamides through redox-annulations with cyclic secondary amines.