Fading of organic artists' colorants by atmospheric nitric acid: reaction products and mechanisms

1992 ◽  
Vol 26 (5) ◽  
pp. 952-959 ◽  
Author(s):  
Daniel Grosjean ◽  
Lynn G. Salmon ◽  
Glen R. Cass
Keyword(s):  
Nitric Acid ◽  
Reaction Products ◽  
Acid Reaction

Interactions ofStreptomyces griseus aminopeptidase with amino acid reaction products and their implications toward a catalytic mechanism

2001 ◽  
Vol 44 (4) ◽  
pp. 490-504 ◽  
Author(s):  
R. Gilboa ◽  
A. Spungin-Bialik ◽  
G. Wohlfahrt ◽  
D. Schomburg ◽  
S. Blumberg ◽  
...  
Keyword(s):  
Amino Acid ◽  
Catalytic Mechanism ◽  
Reaction Products ◽  
Acid Reaction

Effect of Oxidized Lipid/Amino Acid Reaction Products on the Antioxidative Activity of Common Antioxidants

1998 ◽  
Vol 46 (9) ◽  
pp. 3768-3771 ◽  
Author(s):  
Ishtiaque Ahmad ◽  
Manuel Alaiz ◽  
Rosario Zamora ◽  
Francisco J. Hidalgo
Keyword(s):  
Amino Acid ◽  
Antioxidative Activity ◽  
Reaction Products ◽  
Acid Reaction

Vibration-spectral studies of compounds formed by the combination of methylformamide and dimethylformamide with some strong acids

1966 ◽  
Vol 19 (11) ◽  
pp. 2091 ◽  
Author(s):  
E Spinner
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Infrared Spectra ◽  
Spectral Studies ◽  
Ionic Form ◽  
Reaction Products ◽  
Unknown Structure ◽  
Acid Reaction ◽  
Strong Acids

A determination of the infrared spectra of the solid hydrochlorides of methylformamide and dimethylformamide and of the Raman spectra of their aqueous solutions showed that certain spectral features change with the medium used. The infrared spectra of the two amides in concentrated and in aqueous sulphuric acid, and in concentrated hydrochloric acid (HCl and DCl), are consistent with the existence of two amide/acid reaction products for each amide: one (certainly ionic) form predominates in sulphuric acid solutions; a second form, of unknown structure, is present in the solid hydrochlorides, and in hydrochloric acid the two forms coexist in equilibrium.

Reaction products of diorganotin(IV) oxides, R2SnO, with nitric acid. Part 2 – R = n-butyl and t-butyl

2014 ◽  
Vol 92 (6) ◽  
pp. 484-495 ◽  
Author(s):  
Hans Reuter ◽  
Martin Reichelt
Keyword(s):  
Nitric Acid ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Primary Reaction ◽  
Dimeric Molecule ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Solvent Molecules ◽  
Hydroxide Hydrate ◽  
Hydrogen Bonded

The reaction of diorganotin(IV) oxides, R2SnO with R = n-butyl and t-butyl, with nitric acid in different stoichiometric ratios resulted in the formation of different products depending on the organic groups attached to the tin atom: the diorganotin(IV) dinitrate dihydrates, n-Bu2Sn(NO3)2·2H2O (2d) and t-Bu2Sn(NO3)2·2H2O (2e), the mixed diorganotin(IV) nitrate methoxide oxide n-Bu2Sn(NO3)(n-Bu2SnOMe)O (6), and the diorganotin(IV) nitrate hydroxide hydrate t-Bu2Sn(NO3)(OH)·H2O = [t-Bu2Sn(OH)(H2O)][NO3] (7). On examination of the solubility of the primary reaction products in different solvents, the three additional compounds t-Bu2Sn(NO3)(OH)·DMSO (8), t-Bu2Sn(NO3)(OH)·THF, and 2-t-Bu2Sn(NO3)(OH)·DMF = [t-Bu2Sn(OH)dmf]2[NO3]2·[t-Bu2Sn(NO3)OH]2 (9) could be isolated. All compounds have been structurally characterized by single crystal X-ray diffraction (primary results for 7) with special attention paid to dimensionality (2d and 2c = monomeric, hydrogen bonded molecules; 6 = dimeric molecules of ladder-type structure; 7 = dimeric cation; 8 = dimeric molecule with hydrogen bonded solvent molecules; 9 = both components dimeric), tin coordination (6, 7, 8, and 9 = trigonal bipyramidal; 2d and 2e = eightfold), and nitrate bonding modes (7 and 9 = isolated, hydrogen bonded; 6, 8, and 9 (component 2) = monodentate; 2d and 2e = symmetrical bidentate), the latter one being analyzed using both Sn–O and N–O distances.

Reaction of N-Acetyl-2,3-diphenylindole with Nitric Acid

1972 ◽  
Vol 50 (20) ◽  
pp. 3392-3396 ◽  
Author(s):  
Vinod Dave ◽  
E. W. Warnhoff
Keyword(s):  
Nitric Acid ◽  
Acid Reaction ◽  
Acid Catalyzed ◽  
Chemical Evidence

Based on spectroscopic and chemical evidence the 3-hydroxy-6-nitro-2,3-diphenylindolenine structure 8 is assigned to the previously reported N-acetyl-2,3-diphenylindole–nitric acid reaction product. The product from the acid-catalyzed rearrangement of 8 is assigned the oxindole structure 12.

Acid reaction products of indole-3-carbinol and their effects on cytochrome P450 and phase II enzymes in rat and monkey hepatocytes

1992 ◽  
Vol 43 (7) ◽  
pp. 1439-1447 ◽  
Author(s):  
H.M. Wortelboer ◽  
C.A. De Kruif ◽  
A.A.J. Van Iersel ◽  
H.E. Falke ◽  
J. Noordhoek ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Phase Ii ◽  
Reaction Products ◽  
Phase Ii Enzymes ◽  
Acid Reaction

scholarly journals Direct observations of the atmospheric processing of Asian mineral dust

2007 ◽  
Vol 7 (5) ◽  
pp. 1213-1236 ◽  
Author(s):  
R. C. Sullivan ◽  
S. A. Guazzotti ◽  
D. A. Sodeman ◽  
K. A. Prather
Keyword(s):  
Mineral Dust ◽  
Heterogeneous Reaction ◽  
Field Studies ◽  
Dust Particles ◽  
Reaction Products ◽  
Transport Pathway ◽  
Air Masses ◽  
Atmospheric Processing ◽  
Acid Reaction ◽  
The Individual

Abstract. The accumulation of secondary acids and ammonium on individual mineral dust particles during ACE-Asia has been measured with an online single-particle mass spectrometer, the ATOFMS. Changes in the amounts of sulphate, nitrate, and chloride mixed with dust particles correlate with air masses from different source regions. The uptake of secondary acids depended on the individual dust particle mineralogy; high amounts of nitrate accumulated on calcium-rich dust while high amounts of sulphate accumulated on aluminosilicate-rich dust. Oxidation of S(IV) to S(VI) by iron in the aluminosilicate dust is a possible explanation for this enrichment of sulphate, which has important consequences for the fertilization of remote oceans by soluble iron. This study shows the segregation of sulphate from nitrate and chloride in individual aged dust particles for the first time. A transport and aging timeline provides an explanation for the observed segregation. Our data suggests that sulphate became mixed with the dust first. This implies that the transport pathway is more important than the reaction kinetics in determining which species accumulate on mineral dust. Early in the study, dust particles in volcanically influenced air masses were mixed predominately with sulphate. Dust mixed with chloride then dominated over sulphate and nitrate when a major dust front reached the R. V. Ronald Brown. We hypothesize that the rapid increase in chloride on dust was due to mixing with HCl(g) released from acidified sea salt particles induced by heterogeneous reaction with volcanic SO2(g), prior to the arrival of the dust front. The amount of ammonium mixed with dust correlated strongly with the total amount of secondary acid reaction products in the dust. Submicron dust and ammonium sulphate were internally mixed, contrary to frequent reports that they exist as external mixtures. The size distribution of the mixing state of dust with these secondary species validates previous mechanisms of the atmospheric processing of dust and generally agrees with simulated aerosol chemistry from the STEM-2K3 model. This series of novel results has important implications for improving the treatment of dust in global chemistry models and highlights a number of key processes that merit further investigation through laboratory and field studies.

Polymetallic Ore Concentration Middlings Nitric Acid Leaching Kinetics

2017 ◽  
Vol 265 ◽  
pp. 1065-1070 ◽  
Author(s):  
D.A. Rogozhnikov ◽  
B.V. Kolmachikhin
Keyword(s):  
Nitric Acid ◽  
Nitric Acid Concentration ◽  
Acid Leaching ◽  
Numerical Differentiation ◽  
Phase Reaction ◽  
Leaching Kinetics ◽  
Reaction Products ◽  
Mathematical Methods ◽  
Kinetic Evaluation ◽  
Nitric Acid Leaching

The purpose of this work is the kinetic evaluation of reactions occurring during nitric acid leaching of pollymetallic sulfide middlings, for the most complete translation of copper, zinc and sulfur in solution and concentration of precious metals in residue. Methodology is pollymetallic sulfide middlings nitric acid leaching kinetics were studied using mathematical methods such as the experimental data numerical differentiation. Relevance/value is the main sulfide minerals kinetic characteristics were obtained for the studied materials, including the rate of the process, order of reaction, the rate constant for the forward and reverse reaction. Findings are the rate of the process is limited by kinetics. The calculated values of kinetic parameters showed that the process kinetics are influenced by such factors as the nature of leachable sulfide, nitric acid concentration, the surface area of the solid sulfide, the system approaches equilibrium at saturation of the liquid phase reaction products.

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