Solvent isotope effects in the acidolysis and other electrophilic substitution reactions of penta-aquaorganochromium(III) ions in aqueous solution

1981 ◽  
pp. 2452 ◽  
Author(s):  
Victor Gold ◽  
David L. Wood
Keyword(s):  
Aqueous Solution ◽  
Electrophilic Substitution ◽  
Isotope Effects ◽  
Substitution Reactions ◽  
Electrophilic Substitution Reactions ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

Ketonization of the unusually acidic elongated enol generated by flash photolytic decarboxylation of p-formylphenylacetic acid in aqueous solution

2008 ◽  
Vol 86 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Yvonne Chiang ◽  
Kirill Kolmakov ◽  
A Jerry Kresge
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Perchloric Acid ◽  
Flash Photolysis ◽  
Isotope Effects ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

Rates of photolysis of p-formylphenylacetic acid were measured flash photoytically in perchloric acid and sodium hydroxide solutions, and also in acetic acid, biphosphate ion, and tris-(hydroxymethyl)methaneammonium ion buffers, using H2O and D2O as solvents. The results provide rate profiles and solvent isotope effects, which indicate that photolysis occurs through an elongated enol intermediate. This enol is unusually strongly acidic, by some two to three pQa units, when compared with simple non-elongated enols.Key words: flash photolysis, elongated enols, rate profiles, solvent isotope effects.

Generation of 6-methylene-2,4-cyclohexadienylidene ketene by flash photolysis of benzocyclobutenone in aqueous solution and study of the reactions of this ketene in that medium

2003 ◽  
Vol 81 (6) ◽  
pp. 607-611 ◽  
Author(s):  
Y Chiang ◽  
A J Kresge ◽  
H -Q Zhan
Keyword(s):  
Aqueous Solution ◽  
Ring Opening ◽  
Flash Photolysis ◽  
Isotope Effects ◽  
Buffer Solutions ◽  
Product Identification ◽  
Rate Profile ◽  
Solvent Isotope ◽  
Rates Of Decay ◽  
Solvent Isotope Effects

Flash photolysis of benzocyclobutenone in aqueous solution produced a transient species with a microsecond lifetime whose rates of decay were measured in perchloric acid, sodium hydroxide, and buffer solutions over the acidity range [H+] 1 × 10–13 – 100 M. This produced a rate profile, isotope effects, and buffer behaviour typical of ketene reactions, and that, together with product identification, served to identify this transient as 6-methylene-2,4-cyclohexadienylidene ketene, formed by electrocyclic opening of the four-membered ring of benzocyclobutenone. Comparison of rates of reaction of this ketene with those of its saturated analog, pentamethyleneketene, produced some expected as well as some unexpected results. Key words: cyclobutenone chemistry, electrocyclic ring opening, ketene hydration, rate profile, solvent isotope effects.

Photoredox chemistry of nitrobenzyl alcohols in aqueous solution. Acid and base catalysis of reaction

1986 ◽  
Vol 64 (10) ◽  
pp. 2076-2086 ◽  
Author(s):  
Peter Wan ◽  
Keith Yates
Keyword(s):  
Aqueous Solution ◽  
Isotope Effects ◽  
Base Catalysis ◽  
Quantum Yields ◽  
Hydronium Ion ◽  
Acid And Base ◽  
New Type ◽  
Solvent Isotope ◽  
Catalytic Effects ◽  
Solvent Isotope Effects

The photochemistry of several m- and p-nitrobenzyl alcohols (1–5) has been studied in aqueous solution. These compounds react via an intramolecular photoredox pathway to give reduced and oxidized moieties of the substituent groups. The reaction is an example of a new type of photoreaction of nitro-substituted aromatic derivatives that is not observed in organic solvents, the presence of water being essential. This effect is exemplified by measuring the quantum efficiency as a function of mol% water in aqueous acetonitrile, methanol, and formamide: the reaction efficiency decreases rapidly as water is depleted in the mixture. Catalytic effects due to the hydronium and hydroxide ions were studied: the para derivatives exhibited hydroxide ion catalysis; the meta derivatives exhibited hydronium ion catalysis. Quantum yields, solvent isotope effects, and α-deuterium isotope effects are reported for the parent derivatives.

Solvent isotope effects on the solubility of argon and pair interactions in aqueous solution of hexamethylenetetramine

2000 ◽  
Vol 49 (8) ◽  
pp. 1383-1388 ◽  
Author(s):  
V. K. Abrosimov ◽  
E. V. Ivanov ◽  
L. S. Efremova ◽  
Yu. P. Pankratov
Keyword(s):  
Aqueous Solution ◽  
Isotope Effects ◽  
Solvent Isotope ◽  
Solvent Isotope Effects ◽  
Pair Interactions
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