Hydrolysis of ketene catalysed by nitric acid and water in the atmosphere

2020 ◽  
Vol 17 (6) ◽  
pp. 457
Author(s):  
Fang Xu ◽  
Xing-Feng Tan ◽  
Ze-Gang Dong ◽  
Da-Sen Ren ◽  
Bo Long
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Gas Phase ◽  
Energy Barrier ◽  
Reaction Rates ◽  
State Theory ◽  
Direct Reaction ◽  
Unimolecular Reaction ◽  
Atmospheric Water ◽  
Hydrolysis Of

Environmental contextThe detailed mechanism of hydrolysis of gas-phase ketene to form acetic acid is critical for understanding the formation of certain atmospheric contaminants. This study explores the effect of nitric acid and water on the hydrolysis of ketene in the atmosphere. The calculated results show that nitric acid is an effective catalyst in the hydrolysis of ketene to form acetic acid in atmospheric water-restricted environments. AbstractThe gas-phase hydrolysis of ketene and the unimolecular reaction of 1,1-enediol catalysed by nitric acid and water have been investigated using quantum chemical methods and conventional transition state theory with Eckart tunnelling. The theoretical calculation results show that nitric acid exerts a strong catalytic effect on the hydrolysis of ketene in the gas-phase. The calculated energy barrier for the direct reaction mechanistic pathway is reduced from 42.10kcal mol−1 in the reaction of ketene with water to 3.40kcal mol−1 in the reaction of ketene with water catalysed by HNO3. The catalytic ability of nitric acid is further proven in the hydrogen shift reaction of 1,1-enediol because the energy barrier of the unimolecular reaction of 1,1-enediol is decreased from 44.92kcal mol−1 to −4.51kcal mol−1. In addition, the calculated results indicate that there is competition between the direct and indirect mechanistic pathways with the increase of additional water molecules in the reaction of ketene with water catalysed by HNO3 and (H2O)n (n=1, 2). The calculated kinetics results show that the CH2=C=O+H2O+HNO3 reaction is significant in the gas phase of the atmosphere and the other reactions are negligible owing to the slow reaction rates. However, compared with the CH2=C=O+OH reaction, the CH2=C=O+H2O+HNO3 reaction is very slow and cannot compete with the CH2=C=O+OH reaction. CH2=C=O+OH is the main elimination pathway of ketene in the gas phase of the atmosphere. Our findings reveal that acetic acid may be formed through the hydrolysis of ketene in atmospheric water-restricted environments of the surfaces of aqueous, aerosol and cloud droplets.

New insights in atmospheric acid-catalyzed gas phase hydrolysis of formaldehyde: a theoretical study

RSC Advances ◽  
2015 ◽  
Vol 5 (42) ◽  
pp. 32941-32949 ◽  
Author(s):  
Fang-Yu Liu ◽  
Xing-Feng Tan ◽  
Zheng-Wen Long ◽  
Bo Long ◽  
Wei-Jun Zhang
Keyword(s):  
Nitric Acid ◽  
Gas Phase ◽  
Theoretical Study ◽  
Acid Catalyzed ◽  
Hydrolysis Of ◽  
Step Mechanism

A two-step mechanism of the gas phase hydrolysis of formaldehyde catalyzed by nitric acid.

Density Functional Calculations on the Alkaline Hydrolysis of Phosphate Triesters

2014 ◽  
Vol 900 ◽  
pp. 327-332
Author(s):  
Fu Ting Xia ◽  
Wen Yi Li ◽  
Zhi Yang ◽  
Hua Zhu
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Alkaline Hydrolysis ◽  
Energy Barrier ◽  
Density Functional ◽  
Stationary Points ◽  
Second Step ◽  
Free Energy Barrier ◽  
Triethyl Phosphate ◽  
Hydrolysis Of

We have performed density functional theory calculations on the alkaline hydrolysis of diethyl p-chlorophenyl phosphate and triethyl phosphate in the gas phase and in solution. It is found that the two hydrolysis reactions proceed through associative mechanism. The second step of hydrolysis reaction has a very low energy barrier fro diethyl p-chlorophenyl phosphate. For triethyl phosphate, the free energy barrier for the second step is higher both in the gas phase and in solution, indication the second step is the rate-determining step. The free energies of all stationary points and the free energy barrier for all the processes in solution are higher than those in the gas phase. Our calculations provide a comprehensive data set and allow re-interpretation of previous experimental and theoretical studies, and new experiment is proposed to trace reactions both in the gas phase and in solution.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

Organic material dissolved during oxygen-alkali pulping of hot water extracted birch sawdust

TAPPI Journal ◽  
2015 ◽  
Vol 14 (4) ◽  
pp. 237-244 ◽  
Author(s):  
JONI LEHTO ◽  
RAIMO ALÉN
Keyword(s):  
Acetic Acid ◽  
Betula Pendula ◽  
Cooking Time ◽  
Hot Water ◽  
Partial Hydrolysis ◽  
Chemical Pulping ◽  
Black Liquors ◽  
Aliphatic Carboxylic Acids ◽  
Hydrolysis Of ◽  
Cooking Conditions

Untreated and hot water-treated birch (Betula pendula) sawdust were cooked by the oxygen-alkali method under the same cooking conditions (temperature = 170°C, liquor-to-wood ratio = 5 L/kg, and 19% sodium hydroxide charge on the ovendry sawdust). The pretreatment of feedstock clearly facilitated delignification. After a cooking time of 90 min, the kappa numbers were 47.6 for the untreated birch and 10.3 for the hot water-treated birch. Additionally, the amounts of hydroxy acids in black liquors based on the pretreated sawdust were higher (19.5-22.5g/L) than those in the untreated sawdust black liquors (14.8-15.5 g/L). In contrast, in the former case, the amounts of acetic acid were lower in the pretreated sawdust (13.3-14.8 g/L vs. 16.9-19.1 g/L) because the partial hydrolysis of the acetyl groups in xylan already took place during the hot water extraction of feedstock. The sulfur-free fractions in the pretreatment hydrolysates (mainly carbohydrates and acetic acid) and in black liquors (mainly lignin and aliphatic carboxylic acids) were considered as attractive novel byproducts of chemical pulping.

Synthesis and properties of 1,3-bis(4-nitrophenyl)-1-butene

1980 ◽  
Vol 45 (7) ◽  
pp. 2120-2124 ◽  
Author(s):  
Gabriel Čík ◽  
Anton Blažej ◽  
Kamil Antoš ◽  
Igor Hrušovský
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Double Bond ◽  
Fuming Nitric Acid

1,3-Bis(4-nitrophenyl)-1-butene was prepared by nitration of 1,3-diphenyl-1-butene (I) with fuming nitric acid in acetic acid. The double bond in I was protected by addition of bromine which was eliminated after the nitration. The UV, IR and 1H- spectra of the synthesized compounds are interpreted.

DFT study on the hydrolysis of metsulfuron-methyl: A sulfonylurea herbicide

2018 ◽  
Vol 17 (08) ◽  
pp. 1850050 ◽  
Author(s):  
Qiuhan Luo ◽  
Gang Li ◽  
Junping Xiao ◽  
Chunhui Yin ◽  
Yahui He ◽  
...  
Keyword(s):  
Free Energy ◽  
Water Molecule ◽  
Carbonyl Group ◽  
Energy Barrier ◽  
Density Functional ◽  
Free Energy Barrier ◽  
Functional Theory ◽  
Metsulfuron Methyl ◽  
Catalytic Role ◽  
Hydrolysis Of

Sulfonylureas are an important group of herbicides widely used for a range of weeds and grasses control particularly in cereals. However, some of them tend to persist for years in environments. Hydrolysis is the primary pathway for their degradation. To understand the hydrolysis behavior of sulfonylurea herbicides, the hydrolysis mechanism of metsulfuron-methyl, a typical sulfonylurea, was investigated using density functional theory (DFT) at the B3LYP/6-31[Formula: see text]G(d,p) level. The hydrolysis of metsulfuron-methyl resembles nucleophilic substitution by a water molecule attacking the carbonyl group from aryl side (pathway a) or from heterocycle side (pathway b). In the direct hydrolysis, the carbonyl group is directly attacked by one water molecule to form benzene sulfonamide or heterocyclic amine; the free energy barrier is about 52–58[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. In the autocatalytic hydrolysis, with the second water molecule acting as a catalyst, the free energy barrier, which is about 43–45[Formula: see text]kcal[Formula: see text]mol[Formula: see text], is remarkably reduced by about 11[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. It is obvious that water molecules play a significant catalytic role during the hydrolysis of sulfonylureas.

scholarly journals Nitration of Jharia basin coals, India: a study of structural modifications by XRD and FTIR techniques

2021 ◽  
Author(s):  
Prabal Boral ◽  
Atul K. Varma ◽  
Sudip Maity
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Linear Relationship ◽  
Glacial Acetic Acid ◽  
Vitrinite Reflectance ◽  
Aqueous Media ◽  
Interlayer Spacing ◽  
Acetic Acid Medium ◽  
X Ray ◽  
The Media

AbstractFour coal samples from Jharia basin, India are treated with nitric acid in glacial acetic acid and aqueous media to find out the chemical, petrographic and spatial structure of the organic mass by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. X-ray parameters of coal like interlayer spacing (d002), crystallite size (Lc), aroamticity (fa), average number of aromatic layers (Nc), and coal rank (I26/I20) have been determined using profile-fitting software. Considerable variation is observed in treated coals in comparison to the demineralized coals. The d002 values of treated coals have increased in both the media showing increase in disordering of organic moieties. A linear relationship has been observed between d002 values with the volatile matter of the coals. Similarly, the d002 values show linear relationship with Cdmf contents for demineralized as well as for the treated coals in both the media. The Lc and Nc values have decreased in treated coals corresponding to demineralized coals. The present study shows that nitration in both the media is capable of removing the aliphatic side chains from the coals and aromaticity (fa) increases with increase in rank and shows a linear relationship with the vitrinite reflectance. The corresponding I26/I20 values are least for treated coals in glacial acetic acid medium followed by raw and then to treated coals in aqueous medium. FTIR studies show that coal arenes of the raw coals are converted into nitro-arenes in structurally modified coals (SMCs) in both the media, the corresponding bands at 1550–1490 and 1355–1315 cm−1 respectively. FTIR study confirms that nitration is the predominant phenomenon, though, oxidation and nitration phenomena takes place simultaneously during treatment with nitric acid to form SMCs. In comparison to raw coals, the SMCs show higher aromaticity and may be easily converted to coal derived products like activated carbon and specialty carbon materials.

The synthesis of norbornanes with functionalized carbon substituents at a bridgehead. 1-(3-Oxonorborn-1-yl)ethanone and 1-(3-oxonorborn-1-yl)-2-propanone

1992 ◽  
Vol 70 (5) ◽  
pp. 1492-1505 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bromide ◽  
Tertiary Alcohol ◽  
Ethyl Bromoacetate ◽  
Second Molar ◽  
Molar Equivalent ◽  
Acid Lactone ◽  
Basic Hydrolysis ◽  
Hydrolysis Of

Treatment of 2-norobornene-1-carboxylic acid (7) with one equivalent of methyllithium in ether followed by a second molar equivalent after dilution with tetrahydrofuran gave 1-(norborn-2-en-lyl)ethanone (10) and only a trace of the tertiary alcohol 11. Reaction of 7 with formic acid followed by hydrolysis gave a 4:3 mixture of exo-3- and exo-2-hydroxynorbornane-1-carboxylic acid (16 and 17), whereas oxymercuration–demercuration gave only the exo-3-hydroxy isomer 16. Oxidation of 16 and 17 gave 3- and 2-oxonorbornane-1-carboxylic acid (27 and 29), respectively. Oxymercuration–demercuration of 10 gave exclusively 1-(exo-3-hydroxynorborn-1-yl)ethanone (30), which was also prepared by treatment of 16 with methyllithium in analogous fashion to that used for the conversion of 7 to 10. Oxidation of 30 gave 1-(3-oxonorborn-1-yl)ethanone (1). Dehydrobromination of exo-2-bromonorbornane-1-acetic acid and dehydration of 2-hydroxy-norbornane-2-acetic acid derivatives gave 1-(norborn-2-ylidene) acetic acid derivatives to the exclusion of norborn-2-ene-1 -acetic acid derivatives. Treatment of exo-5-acetyloxy-2-norobornanone (52) with ethyl bromoacetate and zinc gave ethyl exo-5-acetyloxy-2-hydroxynorbornane-(exo- and endo-2-acetate (53 and 54). Reaction of 53 with hydrogen bromide gave initially ethyl endo-3-acetyloxy-exo-6-bromonorbornane-1-acetate (59), which was subsequently converted to a mixture of 59 and its exo-3-acetyloxy epimer 61. Catalytic hydrogenation of this mixture gave a mixture of ethyl endo- and exo-3-acetyloxynorbornane-1 -acetate (62 and 63). Basic hydrolysis of this gave a mixture of the corresponding hydroxy acids, 70 and 71; the former was slowly converted to the latter at pH 5. Oxidation of the mixture of 70 and 71 gave 3-oxonorbornane-1-acetic acid (72). Treatment of the mixture with methyllithium as for 16 gave a mixture of 1-(endo- and exo-3-hydroxynorborn-1-yl)-2-propanone (73 and 74), which was oxidized to 1-(3-oxo-norborn-1-yl)-2-propanone (2). Reaction of exo-2-hydroxynorbornane-1-acetic acid lactone (75) with methyllithium in ether gave (1-(exo-2-hydroxynorborn-1-yl)-2-propanone (76), which on oxidation gave the 2-oxo isomer 78 of 2.

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