Photochemistry of a-diketones. I. Some photochemical reactions of 1,1,4,4-Tetramethyl-2,3-dioxotetralin

1967 ◽  
Vol 20 (8) ◽  
pp. 1671 ◽  
Author(s):  
GE Gream ◽  
JC Paice ◽  
CCR Ramsay
Keyword(s):  
Carbon Monoxide ◽  
Acetic Acid ◽  
Carbonyl Group ◽  
Methyl Formate ◽  
Photochemical Reactions ◽  
Hydroxy Ketones ◽  
Competing Reactions

The photochemical reactions (at λ > 3000 A) of the non-enolizable α- diketone (XIV) have been investigated in the solvents methanol, isopropanol. cyclohexane, toluene, n-butyraldehyde, methyl formate, acetic acid, dioxan, and benzene. In general, selective 1,2-addition of solvent to one carbonyl group to give a-hydroxy ketones is the predominant reaction. Competing reactions include reduction to the acyloin (XXI) and loss of carbon monoxide to give 1,1,3,3- tetramethylindanone (XVII). In methanol, two isomeric diols (XXIII) and (XXIV) were unexpectedly formed.

scholarly journals Observations of air composition in Brazil between the Equator and 20°s during the dry season.

1985 ◽  
Vol 15 (1-2) ◽  
pp. 77-120 ◽  
Author(s):  
P.J. Crutzen ◽  
M.T. Coffey ◽  
A.C. Delany ◽  
J. Greenberg ◽  
P. Haagenson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Carbon Monoxide ◽  
Tropical Forests ◽  
Air Pollutants ◽  
Trace Gases ◽  
Dry Season ◽  
Photochemical Reactions ◽  
Ozone Concentrations ◽  
Air Chemistry ◽  
High Concentrations

Field measurement programs in Brazil during the dry season months of August and September in 1979 and 1980 have demonstrated the great importance of the continental tropics in global air chemistry. Especially in the mixed layer, the air composition over land is much different from that over the ocean and the land areas are clearly longe scale sources of many inportant trace gases. During the dry season much biomass, burning takes place especially in the cerrado regions leading to substantial emission of air pollutants, such as CO, NOx, N2O, CH4 and other hydrocarbons. Ozone concentrations are alsoenhanced due to photochemical reactions. Biogenic organic emissions from tropical forests play likewise an important role in the photochemistry of the atmosphere. Carbon monoxide was found to be present in high concentrations in the boundary layer of the tropical forest, but ozone concentrations were much lower than in the cerrado.

scholarly journals Interstellar Glycolaldehyde, Methyl Formate, and Acetic Acid. I. A Bimodal Abundance Pattern in Star-forming Regions

2019 ◽  
Vol 883 (2) ◽  
pp. 129 ◽  
Author(s):  
Samer J. El-Abd ◽  
Crystal L. Brogan ◽  
Todd R. Hunter ◽  
Eric R. Willis ◽  
Robin T. Garrod ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Methyl Formate ◽  
Abundance Pattern ◽  
Star Forming ◽  
Star Forming Regions

scholarly journals Metal-free carbon monoxide-releasing micelles undergo tandem photochemical reactions for cutaneous wound healing

2020 ◽  
Vol 11 (17) ◽  
pp. 4499-4507 ◽  
Author(s):  
Jian Cheng ◽  
Bin Zheng ◽  
Sheng Cheng ◽  
Guoying Zhang ◽  
Jinming Hu
Keyword(s):  
Carbon Monoxide ◽  
Wound Healing ◽  
Photochemical Reactions ◽  
Free Carbon ◽  
Cutaneous Wound Healing ◽  
Cutaneous Wound ◽  
Metal Free ◽  
Improved Stability

Metal-free carbon monoxide-releasing polymers (CORPs) are synthesized via a direct polymerization approach, exhibiting not only improved stability but also accelerated wound healing performance as compared to CORM-3.

scholarly journals Photochemical reactions in the fluorite region II─Photochemical decomposition of formaldehyde vapour

1937 ◽  
Vol 163 (913) ◽  
pp. 221-227 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Absorption Spectrum ◽  
Ground State ◽  
Wave Length ◽  
Ultra Violet ◽  
Photochemical Reactions ◽  
Photochemical Decomposition ◽  
The Subject ◽  
Region Ii ◽  
Formaldehyde Vapour

The photochemical decomposition of formaldehyde in the near ultra­-violet has been the subject of several investigations. It is known (Norrish and Kirkbride 1932) that the products are chiefly carbon monoxide and hydrogen, and that neither the composition of the products nor the quantum yield depends appreciably on wave-length. Recently Price (1935) has investigated the far ultra-violet absorption spectrum of formaldehyde. The first band observed in this region occurs at about 1745 A and is very diffuse, whereas the first bands in acetaldehyde (Price 1935) and acetone (Noyes, Duncan and Manning 1934) occur at longer wave-lengths and are relatively much sharper. Price ascribes this diffuseness to a predissociation resulting from the interaction of the upper state in formaldehyde with the ground state and assumes that the primary dissociation at about 1745 A should be CH 2 O → hv 1745 A CH 2 + O.

Destruction of C2H4O2 isomers in ice-phase by X-rays: Implication on the abundance of acetic acid and methyl formate in the interstellar medium

2017 ◽  
Vol 13 (S332) ◽  
pp. 418-424
Author(s):  
Marina G. Rachid ◽  
K. Faquine ◽  
S. Pilling
Keyword(s):  
Acetic Acid ◽  
Cross Sections ◽  
Methyl Formate ◽  
X Rays ◽  
Formation Cross Section ◽  
X Ray ◽  
Synchrotron Light ◽  
The Difference ◽  
Astrophysical Ices

AbstractC2H4O2 isomers, methyl formate (HCOOCH3), acetic acid (CH3COOH) and glycoaldehyde (HOCH2CHO), have been detected in a lot of sources in ISM. However, their abundances are very different, with methyl formate much more abundant than the other two isomers. This fact may be related to the different destruction by ionizing radiation of these molecules. The goal of this work is experimentally study the photodissociation processes of methyl formate and acetic acid ices when exposed to broadband soft X-ray from 6 up to 2000 eV. The experiments were performed coupled to the SGM beamline in the Brazilian Synchrotron Light Source (LNLS/CNPEM) at Campinas, Brazil. The simulated astrophysical ices (12K) were monitored throughout the experiment using infrared vibrational spectroscopy. The analysis of processed ices allowed the determination of the effective destruction cross sections of the parent molecules as well as the effective formation cross section of daughter molecular species. The relative abundance between acetic acid and methyl formate (NCH3COOH/NHCOOCH3) in different astronomical scenarios and their column density evolution in the presence of X-rays were calculated and our results suggests that such radiation field can be one of the factors that explain the difference in the isomers C2H4O2 abundances. We also quantified the daugther species after the establishment of a chemical equilibrium in the samples.

Catalysis by hydrogen halides in the gas phase. XVIII. Methyl formate and hydrogen bromide

1968 ◽  
Vol 21 (7) ◽  
pp. 1711
Author(s):  
DA Kairaitis ◽  
VR Stimson
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Decomposition Product ◽  
Methyl Formate ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Radical Chain ◽  
Hydrogen Halides ◽  
Chain Decomposition ◽  
First Order

Hydrogen bromide catalyses the decomposition of methyl formate into carbon monoxide and methanol at 390-460�. The radical chain decomposition product, methane, is formed in only a small amount that is further reduced by the addition of inhibitor. The reaction is homogeneous and molecular, is first order in each reactant, and follows the Arrhenius equation: k2 = 1012.50exp(-32200/RT)sec-1 ml mole-1 It is not reversed by added methanol.

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