Photochemical processes of benzyltrimethylsilane at 77 K remarkable solvent effects and reaction mechanism

1996 ◽  
Vol 92 (17) ◽  
pp. 3035 ◽  
Author(s):  
Hiroshi Hiratsuka ◽  
Yukihiro Kadokura ◽  
Hiroyuki Chida ◽  
Mi�ko Tanaka ◽  
Satoshi Kobayashi ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Solvent Effects ◽  
Photochemical Processes

ChemInform Abstract: Photochemical Processes of Benzyltrimethylsilane at 77 K. Remarkable Solvent Effects and Reaction Mechanism

ChemInform ◽  
2010 ◽  
Vol 27 (49) ◽  
pp. no-no
Author(s):  
H. HIRATSUKA ◽  
Y. KADOKURA ◽  
H. CHIDA ◽  
M. TANAKA ◽  
S. KOBAYASHI ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Solvent Effects ◽  
Photochemical Processes

Catalyzed E/Z isomerization mechanism of stilbene using para-benzoquinone as a triplet sensitizer

2021 ◽  
Author(s):  
Kaho Nakatani ◽  
Hirofumi Sato ◽  
Ryoichi Fukuda
Keyword(s):  
Reaction Mechanism ◽  
Quantum Yield ◽  
Photochemical Reactions ◽  
Photochemical Processes ◽  
Isomerization Mechanism

Sensitizer molecules affect not only the quantum yield but also the selectivity of photochemical reactions. For an appropriate design of sensitized photochemical processes, we need to elucidate the reaction mechanism...

scholarly journals Solvent Effects and Reaction Mechanism

Nature ◽  
1957 ◽  
Vol 180 (4585) ◽  
pp. 534-535
Author(s):  
C. A. BUNTON
Keyword(s):  
Reaction Mechanism ◽  
Solvent Effects

A multilayered-representation, quantum mechanical/molecular mechanics study of the CH3Cl + F− reaction in aqueous solution: the reaction mechanism, solvent effects and potential of mean force

2014 ◽  
Vol 16 (16) ◽  
pp. 7611-7617 ◽  
Author(s):  
Jingxue Zhang ◽  
Yulong Xu ◽  
Jie Chen ◽  
Dunyou Wang
Keyword(s):  
Aqueous Solution ◽  
Reaction Mechanism ◽  
Molecular Mechanics ◽  
Solvent Effects ◽  
Potential Of Mean Force ◽  
Quantum Mechanical ◽  
Molecular Mechanics Method ◽  
Reaction In Water

A multi-layered representation, hybrid quantum mechanical and molecular mechanics method study of the CH3Cl + F− → CH3F + Cl− reaction in water.

Photoisomerization by Hula-twist. Photoactive biopigments

2002 ◽  
Vol 74 (8) ◽  
pp. 1391-1396 ◽  
Author(s):  
Robert S. H. Liu
Keyword(s):  
Reaction Mechanism ◽  
Triplet State ◽  
Food Industry ◽  
Photosynthetic Apparatus ◽  
Photoactive Yellow Protein ◽  
Review Of Literature ◽  
Food Colorants ◽  
Photochemical Processes ◽  
Naturally Occurring

A review of literature on photoisomerization of bilirubin and photoactive yellow protein suggests possible involvement of the volume-conserving Hula-twist (HT) reaction mechanism in their primary photochemical processes. Additional definitive experiments to verify their involvement are proposed. Information related to photoproducts of bacteriorhodopsin, rhodopsin, and phytochrome are reviewed. For carotenoids, because of participation of the longer lived triplet state in, for example, the photosynthetic apparatus, the involvement of HT is probably less likely. With the aim of extending the color fan of nature-identical food colorants offered by Roche and therefore offering a less critical colorant to the food industry, a project was initiated at Roche. The goal was to find a safer, naturally occurring pigment with a color hue similar to tartrazine. This paper discusses the process of how such a project is addressed in industry, as well as how promising candidates were selected from the wide variety of the naturally occurring carotenoids. The syntheses of some of these carotenoids will also be described.

scholarly journals Synthesis and evaluation of new guanidine-thiourea organocatalyst for the nitro-Michael reaction: Theoretical studies on mechanism and enantioselectivity

2012 ◽  
Vol 8 ◽  
pp. 1485-1498 ◽  
Author(s):  
Tatyana E Shubina ◽  
Matthias Freund ◽  
Sebastian Schenker ◽  
Timothy Clark ◽  
Svetlana B Tsogoeva
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Solvent Effects ◽  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Diethyl Malonate ◽  
Theoretical Studies ◽  
Michael Addition Reaction ◽  
The Michael Addition

A new guanidine-thiourea organocatalyst has been developed and applied as bifunctional organocatalyst in the Michael addition reaction of diethyl malonate to trans-β-nitrostyrene. Extensive DFT calculations, including solvent effects and dispersion corrections, as well as ab initio calculations provide a plausible description of the reaction mechanism.

REACTION MECHANISM STUDIES: 3. SOLVENT EFFECTS AND THE NATURE OF THE TRANSITION STATE IN THE DIAXIAL → DIEQUATORIAL REARRANGEMENT

1965 ◽  
Vol 43 (4) ◽  
pp. 847-861 ◽  
Author(s):  
J. F. King ◽  
R. G. Pews
Keyword(s):  
Reaction Mechanism ◽  
Transition State ◽  
Solvent Effects ◽  
Ion Pair ◽  
Polar Solvents ◽  
Concerted Mechanism ◽  
Opening Ratio ◽  
Mechanism Of The Reaction

The rates of the diaxial → diequatorial rearrangement of 2β,3α-dibromocholestane (Ia), and the analogous bromohydrin p-toluenesulfonates (Id and Ie) and anisates (If and Ig) have been measured in various solvents. The change in rate with variation in solvent was found to correlate with the change in the ionizing power of the solvents. The sensitivity of the rate of rearrangement to changes in solvent ionizing power, as measured by the ratio of the rate of rearrangement in nitromethane to that in decalin, was found to be smaller for the dibromide (Ia) than for the esters (Id to Ig). A detailed discussion of the mechanism of the reaction is presented. It is proposed that the following factors (either singly or simultaneously) could lead to the smaller sensitivity to solvent change shown by the dibromide (Ia) as compared with the esters (Id to Ig): (1) a difference in a postulated change of the axial: equatorial opening ratio with change in solvent, and (2) the development of a smaller charge in the transition state for the rearrangement of the dibromide (Ia) as compared with that in the rearrangement of the esters, when the reactions are carried out in the less polar solvents. It is argued that the operation of the latter factor would be most simply interpreted in terms of a merged ion-pair, cyclic-concerted mechanism, as initially suggested by Grob and Winstein.

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