Cation-anion combination reactions. II. Reactions of p-nitrobenzenediazonium ion with hydroxide ion in aqueous solution

1971 ◽  
Vol 93 (10) ◽  
pp. 2425-2428 ◽  
Author(s):  
Calvin D. Ritchie ◽  
David J. Wright
Keyword(s):  
Aqueous Solution ◽  
Hydroxide Ion

Deamination of n-octylamine in aqueous solution: the substitution/elimination ratio is not altered by a change of 108 in hydroxide ion concentration

1989 ◽  
Vol 54 (23) ◽  
pp. 5424-5426 ◽  
Author(s):  
Oscar D. Monera ◽  
Min Kun Chang ◽  
Gary E. Means
Keyword(s):  
Aqueous Solution ◽  
Ion Concentration ◽  
Hydroxide Ion

Rate–acidity profiles for exchange of the 4-methyl protons in amino, imino, and keto pyrimidines

1979 ◽  
Vol 57 (20) ◽  
pp. 2783-2789 ◽  
Author(s):  
Ross Stewart ◽  
Stewart J. Gumbley ◽  
R. Srinivasan
Keyword(s):  
Aqueous Solution ◽  
Carbonyl Group ◽  
Principal Components ◽  
Kinetic Isotope Effect ◽  
Activation Parameters ◽  
Methyl Groups ◽  
Imino Group ◽  
Hydroxide Ion ◽  
Kinetic Isotope ◽  
Amino Pyrimidine

The rate of exchange of deuterium for protium in the 4-methyl groups of 2-imino-1,4-dimethyl-1,2-dihydropyrimidine (1), 1,4-dimethyl-2-pyrimidone (2), and 4-methyl-2-amino-pyrimidine (3) has been determined in aqueous solution over an acidity range of some 21 pH(H0) units. The various exchange routes involve attack by base (water, hydroxide ion, buffer anion) on substrate (neutral, singly protonated, doubly protonated) and the identities of the principal components across the acidity spectrum have been established for all three compounds. The Brønsted slope, kinetic isotope effect, and activation parameters for 1 have also been determined. Protonating 1 activates it toward exchange by a factor of 103; addition of a second proton has a further effect of >105. The activating effects of the imino group, the carbonyl group, and the protonated imino group in these compounds are in the ratio 10−1:1:102.

High-Pressure Stopped-Flow Study of the Kinetics of Base Hydrolysis of the Dichromate Ion by Hydroxide Ion, Ammonia, Water, and 2,6-Lutidine in Aqueous Solution

1983 ◽  
Vol 66 (8) ◽  
pp. 2445-2448 ◽  
Author(s):  
Peter Moore ◽  
Yves Ducommun ◽  
Peter J. Nichols ◽  
Andr� E. Merbach
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Base Hydrolysis ◽  
Stopped Flow ◽  
Hydroxide Ion ◽  
Ammonia Water ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Flow Study

ChemInform Abstract: VIBRATIONAL ANALYSIS OF A MODEL FOR THE HYDROXIDE ION IN AQUEOUS SOLUTION

1981 ◽  
Vol 12 (12) ◽  
Author(s):  
R. A. MORE O'FERRALL ◽  
A. J. KRESGE
Keyword(s):  
Aqueous Solution ◽  
Vibrational Analysis ◽  
Hydroxide Ion

Meisenheimer complexes: a kinetic study of water and hydroxide ion attacks on 4,6-dinitrobenzofuroxan in aqueous solution

1976 ◽  
Vol 98 (19) ◽  
pp. 5883-5890 ◽  
Author(s):  
Francois Terrier ◽  
Francois Millot ◽  
William P. Norris
Keyword(s):  
Aqueous Solution ◽  
Kinetic Study ◽  
Hydroxide Ion ◽  
Meisenheimer Complexes

ChemInform Abstract: SIMULATION OF FORMAMIDE HYDROLYSIS BY HYDROXIDE ION IN THE GAS PHASE AND IN AQUEOUS SOLUTION

1985 ◽  
Vol 16 (34) ◽  
Author(s):  
S. J. WEINER ◽  
U. C. SINGH ◽  
P. A. KOLLMAN
Keyword(s):  
Aqueous Solution ◽  
Gas Phase ◽  
Hydroxide Ion

Rate and equilibrium constants for formation and hydrolysis of 9-formylfluorene oxime: diffusion-controlled trapping of a protonated aldehyde by hydroxylamine

2000 ◽  
Vol 78 (12) ◽  
pp. 1594-1612 ◽  
Author(s):  
RA More O'Ferrall ◽  
D M O'Brien ◽  
D G Murphy
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Reaction Pathway ◽  
Equilibrium Constants ◽  
Diffusion Control ◽  
General Measure ◽  
Hydroxide Ion ◽  
Diffusion Controlled ◽  
Enol Tautomer ◽  
Hydrolysis Of

Equilibrium constants Kadd = 440 and Kox = 3.0 × 108 for formation of a carbinolamine adduct and oxime, respectively from 9-formylfluorene and hydroxylamine, and pKa = –1.62 for protonation of the oxime, have been evaluated at 25°C in aqueous solution, based on measurements in hydroxylamine buffers, acetic acid buffers, and dilute HCl. Rate constants for hydrolysis of the oxime have been measured in the acidity range pH 4–12 M HClO4. At the highest acidities, a reaction pathway via protonated carbinolamine has been identified: evidence is presented that the reverse of this reaction involves rate-determining attack of hydroxylamine upon protonated 9-formylfluorene. By assuming that the attack of hydroxylamine is diffusion-controlled, with rate constant 3 × 109 M –1 s–1, a pKa for O-protonation of the aldehyde (–4.5) is derived. Taking account of the equilibrium constant for enolization of 9-formylfluorene (KE = 16.6), a pKa for for C-protonation of the enol tautomer ((–5.7) may also be obtained. Comparison of this pKa with that of the enol of acetophenone shows that the enol of 9-formylfluorene is less basic by a factor of 1010. By combining pKas for protonation of the aldehyde and oxime with measured or estimated equilibrium constants for addition of water, hydroxide ion, and hydroxylamine to 9-formylfluorene, it is also possible to obtain values of pKR = –5.3, 4.1, and 12.25 for the protonated 9-formylfluorene, protonated oxime, and 9-formylfluorene, respectively. The usefulness of pKR in providing a general measure of equilibrium constants for electrophile-nucleophile combination reactions is discussed.Key words: oxime, formyfluorene, hydrolysis, protonation, diffusion-control.

On the Determination and Use of Reduction Potentials of Short-Lived Radicals. A Review

2000 ◽  
Vol 65 (6) ◽  
pp. 829-843 ◽  
Author(s):  
Henning Lund ◽  
Karen Skov ◽  
Steen Uttrup Pedersen ◽  
Torben Lund ◽  
Kim Daasbjerg
Keyword(s):  
Aqueous Solution ◽  
Electron Transfer ◽  
Reaction Mechanisms ◽  
Nucleophilic Attack ◽  
Grignard Reaction ◽  
Hydroxide Ion ◽  
Reduction Sequence ◽  
Reduction Potentials ◽  
Srn1 Reaction

A method, the "competition method", for the determination of reduction potentials and estimation of standard potentials for short-lived radicals is reviewed. Applications of the reduction potentials of radicals as arguments for reaction mechanisms are presented for the Grignard reaction, the photoreduction of ketones with alcohols, and the SRN1 reaction. Reductions induced by hydroxide ions are discussed in more detail, and the classic reaction between nitrosobenzene and hydroxide ion in aqueous solution is used as an example of such a reaction. A nucleophilic attack by hydroxide ion rather than an electron transfer initiates the reduction sequence. A review with 26 references.

Sign in / Sign up

Export Citation Format

Share Document