pH dependence of /sup 15/N NMR shifts and coupling constants in aqueous imidazole and 1-methylimidazole. Comments on estimation of tautomeric equilibrium constants for aqueous histidine

Journal Article · Wed Apr 23 00:00:00 EST 1980 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00529a002· OSTI ID:7141536

Alei, M Jr; Morgan, L O; Wageman, W E; Whaley, T W

/sup 15/N, /sup 1/H and /sup 13/C NMR spectra for (/sup 15/N/sub 2/)imidazole and (/sup 15/N/sub 2/)-1-methylimidazole in aqueous solution as functions of pH provide shift and coupling-constant information useful in characterizing the protonated and unprotonated forms of these compounds and as background for determining N binding to other species, such as metal ions. When combined with similar data for the imidazole-ring atoms in histidine, these data give more reliable estimates of tautomeric equilibrium constants for the amphionic and anionic forms of histidine than possible from the histidine data alone.

• Research Organization: Univ. of California, Los Alamos, NM
• OSTI ID: 7141536
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 102:9
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON 13
ISOTOPE EFFECTS
HISTIDINE
STRUCTURAL CHEMICAL ANALYSIS
HYDROGEN
IMIDAZOLES
NITROGEN 15
EXPERIMENTAL DATA
NUCLEAR MAGNETIC RESONANCE
AMINO ACIDS
AZOLES
CARBON ISOTOPES
CARBOXYLIC ACIDS
DATA
ELEMENTS
EVEN-ODD NUCLEI
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NITROGEN ISOTOPES
NONMETALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RESONANCE
STABLE ISOTOPES
400302* - Organic Chemistry- Isotope Effects- (-1987)