Photoinduced Ethane Formation from Reaction of Ethene with Matrix-Isolated Ti, V, or Nb Atoms

2005 ◽  
Vol 109 (42) ◽  
pp. 9465-9470 ◽  
Author(s):  
Matthew G. K. Thompson ◽  
J. Mark Parnis
Keyword(s):  
Ethane Formation

Superoxide-and Ethane-Formation in Subchloroplast Particles: Catalysis by Pyridinium Derivatives

1980 ◽  
Vol 35 (9-10) ◽  
pp. 770-775 ◽  
Author(s):  
E. F. Elstner ◽  
H. P. Fischer ◽  
W. Osswald ◽  
G. Kwiatkowski
Keyword(s):  
Electron Transport ◽  
Photosystem I ◽  
Photosynthetic Electron Transport ◽  
Redox Potentials ◽  
Light Reaction ◽  
Pyridinium Bromide ◽  
Superoxide Formation ◽  
Fatty Acid Peroxidation ◽  
Chlorophyll Bleaching ◽  
Ethane Formation

Abstract Oxygen reduction by chloroplast lamellae is catalyzed by low potential redox dyes with E′0 values between -0 .3 8 V and -0 .6 V. Compounds of E′0 values of -0 .6 7 V and lower are inactive. In subchloroplast particles with an active photosystem I but devoid of photosynthetic electron transport between the two photosystems, the active redox compounds enhance chlorophyll bleaching, superoxide formation and ethane production independent on exogenous substrates or electron donors. The activities of these compounds decrease with decreasing redox potential, with one exception: 1-methyl-4,4′-bipyridini urn bromide with an E′0 value of lower -1 V (and thus no electron acceptor of photosystem I in chloroplast lamellae with intact electron transport) stimulates light dependent superoxide formation and unsaturated fatty acid peroxidation in sub­ chloroplast particles, maximal rates appearing after almost complete chlorophyll bleaching. Since this activity is not visible with compounds with redox potentials below -0 .6 V lacking the nitrogen atom at the 1-position of the pyridinium substituent, we assume that 1 -methyl-4,4′-bi-pyridinium bromide is “activated” by a yet unknown light reaction.

Reactions of 1,2-Bis(1H-indol-2-yl)ethane: Formation of Indolo[2,3-c]carbazole and Cyclohept[1,2-b:5,4-b′]bisindole Derivatives

Tetrahedron ◽  
2000 ◽  
Vol 56 (13) ◽  
pp. 1911-1916 ◽  
Author(s):  
Jan Bergman ◽  
Tomasz Janosik ◽  
Larisa Yudina ◽  
Eric Desarbre ◽  
Göran Lidgren ◽  
...  
Keyword(s):  
Ethane Formation

Radiolysis of Ethyl Iodide in the Liquid Phase

1963 ◽  
Vol 2 (2) ◽  
Author(s):  
Ralph N. Schindler
Keyword(s):  
Steady State ◽  
Liquid Phase ◽  
Ethyl Iodide ◽  
Minor Importance ◽  
Ethylene Formation ◽  
Upper Limit ◽  
Diffusion Controlled ◽  
Ethane Formation

SummaryTheEthane formation in pure irradiated ethyl iodide occurs to only 50% by reactions under steady state conditions. The residual ethane results from diffusion controlled reactions in spurs. "Hot" processes are found to be of minor importance. Ethylene and butane production occurs in the spurs exclusively. The upper limit for ethylene formation via unimolecular elimination is estimated to G < 0.9.

Chlorophyll Photobleaching and Ethane Production in Dichlorophenyldimethylurea-(DCMU) or Paraquat-Treated Euglena gracilis Cells

1980 ◽  
Vol 35 (1-2) ◽  
pp. 129-135 ◽  
Author(s):  
Erich F. Elstner ◽  
W. Osswald
Keyword(s):  
Photosystem Ii ◽  
Photosystem I ◽  
Electron Acceptor ◽  
Euglena Gracilis ◽  
Acid Oxidation ◽  
Sensitive Material ◽  
Chlorophyll Bleaching ◽  
Ethane Formation

Abstract Light dependent (35 Klux) chlorophyll bleaching in autotrophically grown Euglena gracilis cells at slightly acidic pH (6.5-5.4) is stimulated by the photosystem II blockers DCMU and DBMIB (both 10-5 м) as well as by the autooxidizable photosystem I electron acceptor, paraquat (10-3 м).Chlorophyll photobleaching is accompanied by the formation of thiobarbituric acid - sensitive material (“malondialdehyde”) and ethane.Both chlorophyll photobleaching and light dependent ethane formation are partially prevented by higher concentrations (10-4 м) of the autooxidizable photosystem II electron acceptor DBMIB or by sodium bicarbonate (25 mм).In vitro studies with cell free extracts (homogenates) from E. gracilis suggest that α-linolenic acid oxidation by excited (reaction center II) chlorophyll represents the driving force for both ethane formation and chlorophyll bleaching.Ethane formation thus appears to be a sensitive and non-destructive “in vivo” marker for both restricted energy dissipation in photosystem II and, conditions yielding reactive oxygen species at the reducing side of photosystem I.

KINETIC AND REACTIVE PROPERTIES OF ETHYLENE ON CLEAN AND HYDROGEN-COVERED Pd(111)

2003 ◽  
Vol 10 (06) ◽  
pp. 909-916 ◽  
Author(s):  
L. BURKHOLDER ◽  
D. STACCHIOLA ◽  
W. T. TYSOE
Keyword(s):  
Activation Energy ◽  
Infrared Spectroscopy ◽  
Temperature Programmed Desorption ◽  
Molecular Adsorption ◽  
Lateral Interactions ◽  
Ethylene Adsorption ◽  
Reflection Absorption Infrared Spectroscopy ◽  
Temperature Programmed ◽  
Ethane Formation ◽  
Reactive Properties

Several molecular adsorption states are identified following ethylene adsorption on clean and hydrogen-covered Pd(111) using temperature-programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS). Di-σ-bonded ethylene forms on clean Pd(111) desorbing with an activation energy of 80 kJ/mol at low coverages. The strong intermolecular lateral interactions considerably reduce the desorption temperature at higher coverages. Π-bonded ethylene is formed on hydrogen-covered Pd(111), where the proportion of π-bonded species increases with hydrogen coverage. This species converts to the more stable di-σ-bonded species on heating. Ethane formation is detected in TPD from hydrogen-precovered Pd(111), which is predominantly formed by reaction with π-bonded ethylene.

ChemInform Abstract: FLASH PHOTOLYSIS OF ACETONE IN GAS PHASE, KINETICS OF ETHANE FORMATION FROM METHYL RADICALS

1975 ◽  
Vol 6 (13) ◽  
Author(s):  
MARJA-LIISA POHJONEN ◽  
LEILA LEINONEN ◽  
HELGE LEMMETYINEN ◽  
JOUKO KOSKIKALLIO
Keyword(s):  
Gas Phase ◽  
Flash Photolysis ◽  
Methyl Radicals ◽  
Gas Phase Kinetics ◽  
Ethane Formation ◽  
Kinetics Of

KINETICS AND MECHANISMS OF THE THERMAL DECOMPOSITION OF ACETALDEHYDE: I. THE UNINHIBITED REACTION

1964 ◽  
Vol 42 (8) ◽  
pp. 1851-1860 ◽  
Author(s):  
M. Eusuf ◽  
K. J. Laidler
Keyword(s):  
Order Reaction ◽  
Second Order ◽  
Small Extent ◽  
Kinetic Behavior ◽  
Third Order ◽  
The Third ◽  
Rate Of Reaction ◽  
Ethane Formation ◽  
Kinetics Of ◽  
Initial Process

The kinetics of the uninhibited decomposition of acetaldehyde have been reexamined. The initial rates of the decomposition of pure acetaldehyde show strict three-halves-order dependence at temperatures from 480 to 525 °C, and the activation energy is 47.6 kcal per mole. Foreign gases, which decrease the rate of reaction, cause a significant increase in order. The rate of ethane formation is second order in acetaldehyde, and Trenwith has found the hydrogen formation to be second order in acetaldehyde. The results are shown to be consistent only with a mechanism involving second-order initiation and the third-order reaction 2CH3 + M → C2H6 + M as the terminating step. The rate of the initiation process is increased only to a small extent by the addition of inert foreign gases; it is suggested that the initial process may be CH3CHO + CH3CHO → CH3CHOH + CH3CO, with a subsequent breakdown of CH3CHOH into CH3CHO + H. The mechanism is shown to account for the overall kinetic behavior and for the formation of the minor products.

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