scholarly journals GAS PHASE MEASUREMENTS OF MONO-FLUORO-BENZOIC ACIDS AND THE DIMER OF 3-FLUORO-BENZOIC ACID

2016 ◽  
Author(s):  
Kexin Li ◽  
Stephen Kukolich ◽  
Lu Kang ◽  
Aaron Pejlovas ◽  
Spencer Carey ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Gas Phase ◽  
Benzoic Acids ◽  
Phase Measurements

scholarly journals Gas phase measurements of mono-fluoro-benzoic acids and the dimer of 3-fluoro-benzoic acid

2015 ◽  
Vol 142 (14) ◽  
pp. 144303 ◽  
Author(s):  
Adam M. Daly ◽  
Spencer J. Carey ◽  
Aaron M. Pejlovas ◽  
Kexin Li ◽  
Lu Kang ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Gas Phase ◽  
Benzoic Acids ◽  
Phase Measurements

Application of the Hammett equation in the esterification of substituted benzoic acids, catalyzed by AlPO4 in the gas phase

1983 ◽  
Vol 61 (2) ◽  
pp. 230-234 ◽  
Author(s):  
J. V. Sinisterra ◽  
J. M. Marinas ◽  
A. Llobera
Keyword(s):  
Benzoic Acid ◽  
Gas Phase ◽  
Surface Reaction ◽  
Adsorption Process ◽  
Positive Charge ◽  
Kinetic Constant ◽  
Benzoic Acids ◽  
Hammett Equation ◽  
Substituted Benzoic Acids ◽  
First Time

The Hammett equation has for the first time been applied to the esterification in the gas phase of m-MeO, p-MeO, m-Me, p-Me, H, m-NO2, m-Cl, and m-Br benzoic acids, catalyzed by AlPO4 of the F type. It is shown that the Hammett equation could be applied to the adsorption equilibrium constant, KA, and to the apparent kinetic constant, [Formula: see text] The KA and [Formula: see text] values used in this paper have been taken from a study by the same authors. The m-NO2 benzoic acid is in disagreement with the general behavior of the other acids in the application of the Hammett equation to the adsorption process. The p-MeO benzoic acid is in disagreement with the behavior of the acids in the application of the equation to the surface reaction. In these cases, the ρ values were negative. It can be deduced that a positive charge is generated in the adsorption process and in the surface reaction. The AAc2 mechanism is discussed according to the values of ρ, and a more detailed mechanism is proposed. The separation of the enthalpic and entropic contributions to the substituent effect is carried out. [Formula: see text] and[Formula: see text] are nearly 50% in the adsorption process. In the surface reaction, the entropie contribution is greater (72.5%) than the enthalpic (27.5%).

scholarly journals Hydrogenation of benzoic acid derivatives over Pt/TiO2 under mild conditions

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Miao Guo ◽  
Xiangtao Kong ◽  
Chunzhi Li ◽  
Qihua Yang
Keyword(s):  
Electron Transfer ◽  
Benzoic Acid ◽  
High Efficiency ◽  
Carboxyl Groups ◽  
Carboxyl Group ◽  
Benzoic Acids ◽  
Catalyst Poisoning ◽  
Benzoic Acid Derivatives ◽  
Mild Conditions ◽  
Transfer Direction

AbstractHydrogenation of benzoic acid (BA) to cyclohexanecarboxylic acid (CCA) has important industrial and academic significance, however, the electron deficient aromatic ring and catalyst poisoning by carboxyl groups make BA hydrogenation a challenging transformation. Herein, we report that Pt/TiO2 is very effective for BA hydrogenation with, to our knowledge, a record TOF of 4490 h−1 at 80 °C and 50 bar H2, one order higher than previously reported results. Pt/TiO2 catalysts with electron-deficient and electron-enriched Pt sites are obtained by modifying the electron transfer direction between Pt and TiO2. Electron-deficient Pt sites interact with BA more strongly than electron-rich Pt sites, helping the dissociated H of the carboxyl group to participate in BA hydrogenation, thus enhancing its activity. The wide substrate scope, including bi- and tri-benzoic acids, further demonstrates the high efficiency of Pt/TiO2 for hydrogenation of BA derivatives.

scholarly journals Band Gap Modulation in Zirconium-Based Metal-Organic Frameworks by Defect Engineering

2019 ◽  
Author(s):  
Marco Taddei ◽  
Giulia M. Schukraft ◽  
Michael E. A. Warwick ◽  
Davide Tiana ◽  
Matthew McPherson ◽  
...  
Keyword(s):  
Band Gap ◽  
Gas Phase ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Benzoic Acids ◽  
Defect Engineering ◽  
Metal Organic ◽  
Band Gap Modulation ◽  
Valence Band Energy ◽  
Defective Sites

We report a defect-engineering approach to modulate the band gap of zirconium-based metal-organic framework UiO-66, enabled by grafting of a range of amino-functionalised benzoic acids at defective sites. Defect engineered MOFs were obtained by both post-synthetic exchange and modulated synthesis, featuring band gap in the 4.1-3.3 eV range. Ab-initio calculations suggest that shrinking of the band gap is mainly due to an upward shift of the valence band energy, as a result of the presence of light-absorbing monocarboxylates. The photocatalytic properties of defect-engineered MOFs towards CO<sub>2</sub> reduction to CO in the gas phase and degradation of Rhodamine B in water were tested, observing improved activity in both cases, in comparison to a defective UiO-66 bearing formic acid as the defect-compensating species.

scholarly journals Raman-Matrixspektrum von As4/ Raman Matrix Spectrum of As4

1982 ◽  
Vol 37 (9) ◽  
pp. 1127-1128 ◽  
Author(s):  
Klaus Manzel ◽  
Wilfried Schulze ◽  
Volker Wölfel ◽  
Rolf Minkwitz
Keyword(s):  
Raman Spectrum ◽  
Gas Phase ◽  
Phase Measurements ◽  
Laser Raman ◽  
Matrix Spectrum

AbstractThe laser Raman spectrum of matrix-isolated As4-tetrahodra is reported. The frequencies are different to former data obtained by gas-phase measurements.

Antibacterial Activities of Phenolic Benzaldehydes and Benzoic Acids against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica

2003 ◽  
Vol 66 (10) ◽  
pp. 1811-1821 ◽  
Author(s):  
MENDEL FRIEDMAN ◽  
PHILIP R. HENIKA ◽  
ROBERT E. MANDRELL
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Benzoic Acid ◽  
Benzene Ring ◽  
Campylobacter Jejuni ◽  
Salmonella Enterica ◽  
Acid Methyl Ester ◽  
Benzoic Acids ◽  
Oh Groups ◽  
Chemical Structures

We evaluated the bactericidal activities of 35 benzaldehydes, 34 benzoic acids, and 1 benzoic acid methyl ester against Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica when these compounds were substituted on the benzene ring with 0, 1, 2, or 3 hydroxy (OH) and/or methoxy (OCH3) groups in a pH 7.0 buffer. Dose-response plots were used to determine the percentage of the sample that induced a 50% decrease in CFU after 60 min (BA50). Of the 70 compounds tested, 24 were found to be active against all four pathogens, and additional 4, 10, and 12 were found to be active against three, two, and one of the pathogens, respectively. C. jejuni was ~100 times as sensitive as the other three pathogens. The 10 compounds that were most active against the four pathogens (with average BA50 values ranging from 0.026 to 0.166) and are candidates for studies of activity in foods or for disinfections were 2,4,6-trihydroxybenzaldehyde, 2,5-dihydroxybenzaldehyde, 2,3,4-trihydroxybenzaldehyde, 2-hydroxy-5-methoxybenzaldehyde, 2,3-dihydroxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, 4-hydroxy-2,6-dimethoxybenzaldehyde, 2,5-dihydroxybenzaldehyde, 2,4-dihydroxyben-zaldehyde, and 2-hydroxybenzaldehyde. Comparison of the chemical structures of the test compounds and their activities revealed that (i) the aldehyde (CHO) group was more active than the carboxyl (COOH) group whether or not OH groups were present; (ii) compounds were most active with trisubstituted OH &gt; disubstituted OH &gt; monosubstituted OH; (iii) for disubstituted derivatives, 2-OH enhanced activities were exhibited by benzaldehyde but not by benzoic acid; (iv) compounds were more active with OH than with OCH3, irrespective of the position of substitution on the benzene ring; (v) compounds with mixed OH and OCH3 groups exhibited variable results, i.e., in some cases OCH3 groups enhanced activity and in other cases they did not; (vi) methoxybenzoic acids were largely inactive; and (vii) gallic acid was 20 times as active against S. enterica at pH 7.0 as it was at pH 3.7, suggesting that the ionization of its OH groups may enhance bactericidal activity.

Mixed-dimer formation in binary systems of 4-substituted benzoic acids and structure considerations

2008 ◽  
Vol 86 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Maren Roman ◽  
Annett Kaeding-Koppers ◽  
Peter Zugenmaier
Keyword(s):  
Benzoic Acid ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Binary Systems ◽  
Benzoic Acids ◽  
Dimer Formation ◽  
Crystalline Phases ◽  
Cholesteric Phase ◽  
Liquid Crystalline Phases ◽  
Substituted Benzoic Acids

The phase behavior of binary systems of 4-substituted benzoic acids is governed by the formation of mixed dimers. This study was conducted to determine the effect of the components’ structural difference on mixed-dimer formation in crystalline and liquid-crystalline phases. The phase diagrams of two systems, with 4-[(S)-(–)-2-methylbutoxy]benzoic acid (MBOBA) as one component and 4-(hex-5-enoxy)benzoic acid (HOBA) and 4-(dec-9-enoxy)benzoic acid (DOBA), respectively, as the second component, were determined by differential scanning calorimetry, polarized-light microscopy, and X-ray diffraction. The MBOBA-HOBA system exhibited a cholesteric phase, two solid solutions, and above 58 °C for compositions between 40 and 80 mol% HOBA a crystalline phase of mixed dimers. The MBOBA-DOBA system showed a crystalline phase of mixed dimers at all compositions, a cholesteric phase, and a twisted smectic C phase, which was dominated by mixed dimers at 60 and 70 mol% DOBA. We conclude that liquid-crystalline phases are generally dominated by mixed dimers, but in crystalline phases the formation of mixed dimers is promoted by a greater difference in molecular structure. The crystal structure of two of the pure compounds MBOBA and DOBA and comparable compounds have been determined for an evaluation of the arrangements of the molecules in the crystal and liquid-crystalline state.Key words: benzoic acid, crystal arrangement, phase diagrams, liquid crystal.

Biosynthese von p-Hydroxybenzoesäure und anderer Benzoesäuren in höheren Pflanzen

1964 ◽  
Vol 19 (5) ◽  
pp. 398-405 ◽  
Author(s):  
M. H. Zenk ◽  
G. Müller
Keyword(s):  
Benzoic Acid ◽  
Protocatechuic Acid ◽  
Higher Plants ◽  
Side Chain ◽  
Hydroxybenzoic Acid ◽  
Benzoic Acids ◽  
Coumaric Acid ◽  
Cinnamic Acids ◽  
Feeding Experiments ◽  
Catalpa Ovata

Feeding experiments with glucose- (2-14C), phenylalanine- (3-14C), tyrosine- (3-14C) and p-coumaric acid- (3-14C) showed that the latter three substances are incorporated in good yields into p-hydroxybenzoic acid in leaves of Catalpa ovata. Kinetic experiments showed that p-hydroxybenzoic acid is formed from phenylalanine via p-coumaric acid and the subsequent β-oxidation of the side chain. p-Hydroxybenzoic acid can also be synthetised by hydroxylation of benzoic acid, but this does not seem to be the biosynthetic route in Catalpa.Phenylalanine- (3-14C) is also incorporated into benzoic acid, protocatechuic acid, and vanillic acid by different plants; the radioactivity of the β-C atom of the amino acid was found in each case to be located in the carboxyl group of the C6 — C1 acid. This suggests that in higher plants the benzoic acids are formed from the corresponding cinnamic acids via β-oxidation.

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