Kinetics of isotopic hydrogen exchange in 3-hydroxypyridine N-oxide
Journal Article
·
· Bull. Acad. Sci. USSR, Div. Chem. Sci. (Engl. Transl.); (United States)
OSTI ID:6576190
This study investigated the isotopic exchange of H/D in 3-hydroxypyridine N-oxide (3-HPO), working at 160/sup 0/C over the pD range from 1.0 to 9.5. The effect of temperature on the protonation (K/sub C/) and ionization (K/sub N) constants of the compound and the pH of aqueous solutions of the compound at 24-90/sup 0/C were also examined. The experimental data were used to develop the expressions which could be used to estimate ..delta..pH(24-t/sup 0/C) values over the 24-t/sup 0/C temperature interval and the 1.0-9.5 pH range. The protonation and ionization constants, pK/sub C/ and pK/sub N/, and their dependence on the pH of the medium, were determined from the measured chemical shifts of the 3-HPO ring protons, using a previously described method. The value of the pH of each solution was measured at 24/sup 0/C, and the value of the additive ..delta..pH(24-t /sup 0/C) term was calculated. The variation of pK/sub C/ and pK/sub N/ over the 24-90/sup 0/C interval could be described satisfactorily by equations of the pK = C/T + D + ET form. Analysis of the kinetics of H/D exchange in 3-hydroxypyridine N-oxide at 160/sup 0/C and pD 1.9-9.5 showed electrophilic substitution at high pD to involve the D/sub 3/O/sup +/ ion and the anion form of 3-hydroxypyridine N-oxide; at pD <6H/D exchange involves the OD/sup -/ ion and the cation and neutral forms of the compound.
- Research Organization:
- Academy of Sciences of the USSR, Moscow
- OSTI ID:
- 6576190
- Journal Information:
- Bull. Acad. Sci. USSR, Div. Chem. Sci. (Engl. Transl.); (United States), Journal Name: Bull. Acad. Sci. USSR, Div. Chem. Sci. (Engl. Transl.); (United States) Vol. 30:9; ISSN BACCA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thiazolium C(2)-proton exchange: structure-reactivity correlations and the pK/sub a/ of thiamin C(2)-H revisited
Equilibrium behavior and proton transfer kinetics of the dioxotetracyanometalate complexes of molybdenum(IV), tungsten(IV), technetium(V), and rhenium(V): Carbon-13 and oxygen-17 NMR study
Isotopic and stereochemical probes of the mechanism of bovine plasma amine oxidase
Journal Article
·
Tue Jul 12 00:00:00 EDT 1988
· Biochemistry; (United States)
·
OSTI ID:6901515
Equilibrium behavior and proton transfer kinetics of the dioxotetracyanometalate complexes of molybdenum(IV), tungsten(IV), technetium(V), and rhenium(V): Carbon-13 and oxygen-17 NMR study
Journal Article
·
Tue Jan 04 23:00:00 EST 1994
· Inorganic Chemistry; (United States)
·
OSTI ID:5088430
Isotopic and stereochemical probes of the mechanism of bovine plasma amine oxidase
Thesis/Dissertation
·
Tue Dec 31 23:00:00 EST 1985
·
OSTI ID:6974617
Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400303* -- Organic Chemistry-- Isotope Exchange & Isotope Separation-- (-1987)
AZINES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
DATA
DEUTERIUM
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
INFORMATION
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PYRIDINES
REACTION KINETICS
STABLE ISOTOPES
TEMPERATURE EFFECTS
400303* -- Organic Chemistry-- Isotope Exchange & Isotope Separation-- (-1987)
AZINES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
DATA
DEUTERIUM
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
INFORMATION
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PYRIDINES
REACTION KINETICS
STABLE ISOTOPES
TEMPERATURE EFFECTS