scholarly journals STUDY OF DOUBLE PROTONS MIGRATION MECHANISM IN SUPRAMOLECULAR STRUCTURES OF ACETIC ACID-WATER AND ACETIC ACID-AMMONIA BY AB INITIO METHOD

2010 ◽  
Vol 3 (2) ◽  
pp. 102-110
Author(s):  
Karna Wijaya ◽  
Iqmal Tahir ◽  
Harnowo Harnowo
Keyword(s):  
Acetic Acid ◽  
Transition State ◽  
Ab Initio ◽  
Computational Study ◽  
Basis Set ◽  
Acid Water ◽  
Product Models ◽  
Migration Mechanism ◽  
Package Program ◽  
Acetic Acid Water

The theoretical study of double protons migration mechanism on acetic acid-water and acetic acid-ammonia associations has been carried out. The research covered determinations the reactant, transition state and product structures. To gain the goal, the research was conducted in three steps, i.e. (i) designing the reactant, transition state and product models, (ii) optimizing of structures, and (iii) calculating of their uncorrected total energy and frequencies with ab initio methods (basis set 6-31G**). All calculations were performed using Hyperchem ver 5.0 for Windows and Gaussian 94W package program. The computational study result showed that the calculated structures were in good agreement with the hypothetical structures.   Keywords: double protons migration, acetic acid, water, ammonia, molecular mechanics and ab-initio

scholarly journals Density Functional Theory and Complete Basis Set Ab Initio Computational Study of Five-, Six-, Seven- and Eight-hydrogen Coordinated Carbon Cations

1999 ◽  
Vol 23 (8) ◽  
pp. 502-503
Author(s):  
Branko S. Jursic
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Computational Study ◽  
Basis Set ◽  
Functional Theory ◽  
Complete Basis ◽  
Complete Basis Set ◽  
High Level

High level ab initio and density functional theory studies are performed on highly protonated methane species.

Liquid Structure of Acetic Acid−Water and Trifluoroacetic Acid−Water Mixtures Studied by Large-Angle X-ray Scattering and NMR

2007 ◽  
Vol 111 (31) ◽  
pp. 9270-9280 ◽  
Author(s):  
Toshiyuki Takamuku ◽  
Yasuhiro Kyoshoin ◽  
Hiroshi Noguchi ◽  
Shoji Kusano ◽  
Toshio Yamaguchi
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Large Angle ◽  
Liquid Structure ◽  
Acid Water ◽  
X Ray ◽  
X Ray Scattering ◽  
Acetic Acid Water ◽  
Ray Scattering

Acetic acid/water separation by pervaporation with silica filled PDMS membrane

2011 ◽  
Vol 51 (5) ◽  
pp. 819-825 ◽  
Author(s):  
Housheng Hong ◽  
Longxiang Chen ◽  
Qingwen Zhang ◽  
Zheran Zhang
Keyword(s):  
Acetic Acid ◽  
Acid Water ◽  
Pdms Membrane ◽  
Water Separation ◽  
Acetic Acid Water

Diagonal Chromatography for the Selective Purification of Tyrosyl Peptides

1974 ◽  
Vol 52 (11) ◽  
pp. 1013-1017 ◽  
Author(s):  
William H. Cruickshank ◽  
Barry L. Malchy ◽  
Harvey Kaplan
Keyword(s):  
Acetic Acid ◽  
Stationary Phase ◽  
Enzymatic Digestion ◽  
Acid Water ◽  
Chromatographic Purification ◽  
Amino Groups ◽  
Chromatographic System ◽  
Original Direction ◽  
Acetic Acid Water ◽  
Citraconic Anhydride

Thiolysis of an O-dinitrophenyl-tyrosyl peptide results in an increased solubility in the stationary phase of a n-butanol – acetic acid – water – pyridine (15:3:12:10) (BAWP) paper chromatographic system. It is shown that this property can be used to form the basis of a diagonal paper chromatographic purification of tyrosyl peptides from enzymatic digests of proteins. The amino groups of the protein are first reacted with citraconic anhydride and then the citraconyl protein is reacted with 1-fluoro-2,4-dinitrobenzene. The dinitrophenyl-citraconyl protein is subjected to enzymatic digestion, applied to a strip of Whatman 3 MM paper, thiolyzed with 5% 2-mercaptoethanol in acetone, and subjected to chromatography using BAWP as solvent. A guide strip is removed, thiolyzed with 5% 2-mercaptoethanol in 25% pyridine, and resubjected to chromatography in BAWP at right angles to the original direction of chromatography. The tyrosyl peptides are displaced off the diagonal towards the origin. The off-diagonal peptides are isolated from the original chromatogram by thiolysis and chromatography using the diagonal chromatogram to locate the positions of the dinitrophenyl-tyrosyl peptides.

scholarly journals Study of Regularities and Optimization of the Process of Fir Wood Peroxide Delignification in the Medium of “Acetic Acid – Water” in the Presence of Sulfuric Acid Catalyst

2019 ◽  
pp. 590-603
Author(s):  
Olga V. Yatsenkova ◽  
Andrei M. Skripnikov ◽  
Boris N. Kuznetsov
Keyword(s):  
Acetic Acid ◽  
Lignin Content ◽  
Reaction Medium ◽  
Acid Catalyst ◽  
Acid Water ◽  
High Yield ◽  
Process Conditions ◽  
Residual Lignin ◽  
Acetic Acid Water ◽  
Peroxide Delignification

The work describes a one-stage method of cellulose obtaining from fir wood based on peroxide delignification of wood under mild conditions (100 °C, atmospheric pressure) in the presence of acetic acid, water and catalyst of 2% wt. H2SO4. The possibility of obtaining cellulose with a residual lignin content <1% wt. at a low concentration of hydrogen peroxide (3% wt.) in the reaction medium was established. The optimal concentrations of reagents (Н2О2 – 3% wt., CH3COOH – 38.9% wt.) and the duration of the process (4 h) were determined by experimental and calculation methods. This conditions provide a high yield of cellulose product (≥45% wt.) with a low content of residual lignin (<1% wt.). The composition and structure of fir cellulose was studied by chemical analysis and by FTIR and SEM methods. The cellulosic product which was obtained in optimal process conditions is high-quality cellulose

Ternary liquid equilibria system: Acetic acid + water + toluene

2007 ◽  
Vol 23 (5) ◽  
pp. 323-328 ◽  
Author(s):  
P. Dakshinamurty ◽  
V. Subrahmanyam ◽  
M. Narsimha Rao
Keyword(s):  
Acetic Acid ◽  
Acid Water ◽  
Acetic Acid Water
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