ISOTOPIC EFFECTS DURING CATALYTIC HYDROGENATION

Journal Article · Wed Jan 01 00:00:00 EST 1964 · J. Am. Oil Chemists' Soc.

DOI:https://doi.org/10.1007/BF02661890· OSTI ID:4055595

Bitner, E D; Selke, E; Rohwedder, W K; Dutton, H J

The validity of tracer experiments, particularly for the isotopes of H, depends on a knowledge of the magnitude of the isotopic discrimination. The isotopic effect on rate con stants for H over T is a factor of 60 and, for H over D, 18. Attempts were made to estimate the magnitude of isotope effects involving T and D by measuremert of the isotopic discrimination of T and D during catalytic hydrogenation of methyl oleate with a mixture of H and T and with a mixture of H, D, and T. The catalytic hydrogenation of a Tlabeled compound, methyl 9- octadecenoate -9, 10-T, and the description of various specialized equipment and methods of analyses are included. No isotopic discrimination was observed during catalytic reduction of methyl oleate with H--T gas mixtures. One explanation offered is that at atmospheric pressure and 40 deg C the isotopic effect on solubility is small and the concentration of the dissolved H isotopes is rate limiting. Tritium in methyl 9-octadecenoate-9, 10-T was not released during saturation of the double bond but appears in the gaseous phase upon completion of hydrogenation, as indicated by an ion chamber. No isotopic discrimination was observed in the reduction of methyl oleate with mixtures of H, D, and T,; however, mass spectrometry indicated an increase in the H --D ratio during hydrogenation. Under the conditions described, T and D may be used to study the mechanism of hydrogenation without significant isotopic effects. An automatic manometric apparatus used to perform all hydrogenations is illustrated. (BBB)

• Research Organization: Northern Regional Research Lab., Peoria, Ill.
• Sponsoring Organization: USDOE
• NSA Number: NSA-18-017860
• OSTI ID: 4055595
• Journal Information: J. Am. Oil Chemists' Soc., Vol. Vol: 41; Other Information: Orig. Receipt Date: 31-DEC-64
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
ALKENES
CATALYSIS
CHEMICAL REACTIONS
CONFIGURATION
DEUTERIUM
GASES
HYDROGEN
HYDROGENATION
IONIZATION CHAMBERS
ISOTOPE EFFECTS
LABELLED COMPOUNDS
LABORATORY EQUIPMENT
MASS SPECTROMETERS
MEASURED VALUES
METHYL RADICALS
MIXING
MOLECULES
OLEIC ACID
OPERATION
ORGANIC ACIDS
PLANNING
PREPARATION
PRESSURE
QUALITATIVE ANALYSIS
QUANTITY RATIO
REACTION KINETICS
RECORDING SYSTEMS
REDUCTION
SOLUBILITY
TRACER TECHNIQUES
TRITIUM