Magnetic and micellar effects on photoreactions. 1. /sup 13/C isotopic enrichment of dibenzyl ketone via photolysis in aqueous detergent solution

Journal Article · Wed Jul 01 04:00:00 EDT 1981 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00403a045· OSTI ID:6205989

Turro, N J ^[1]; Chow, M F; Chung, C J; Kraeutler, B

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1. Columbia Univ., New York, NY

The photolysis of dibenzyl ketone (DBK) in homogeneous organic solutions and in micelle-containing detergent solutions has been investigated from the standpoint of determining the extent and location of /sup 13/C enrichment that occurs. In a series of experiments it is established that for incomplete conversions the residual, recovered DBK is enriched in /sup 13/C relative to the initial unphotolyzed DBK. The efficiency of the /sup 13/C//sup 12/C separation is shown to be characterized by an isotope enrichment parameter, ..cap alpha.., which is independent of the extent of conversion. A combination of mass spectrometry and nuclear magnetic resonance spectroscopy provides support for the primary location of the /sup 13/C enrichment at C-1 (the carbonyl carbon) with a lesser but significant enrichment at C-2 (the methylene carbon). A very small but experimentally distinct enrichment of the aromatic rings is indicated by /sup 13/C NMR analysis. An isomer of DBK, 1-phenyl-4'-methylacetophenone (PMAP) is formed as a minor product of photolysis in micellar solutions. PMAP, like the recovered, residual DBK, is found to be substantially enriched in /sup 13/C relative to the starting DBK. The magnitude of ..cap alpha.. is found to be significantly influenced by the application of laboratory magnetic fields to the photolysis sample. The latter result, along with the unusually large magnitude of ..cap alpha.., suggests that the mechanism involved in isotopic enrichment is not dominated by kinetic mass isotope effects but rather by nuclear magnetic moment and/or magnetic spin isotope effects.

• OSTI ID: 6205989
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 103:13; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400303* -- Organic Chemistry-- Isotope Exchange & Isotope Separation-- (-1987)
400500 -- Photochemistry
ADDITIVES
AQUEOUS SOLUTIONS
AROMATICS
ARYL RADICALS
BENZYL RADICALS
CARBON 12
CARBON 13
CARBON ISOTOPES
CHEMICAL REACTIONS
DATA
DECOMPOSITION
DETERGENTS
DISPERSIONS
EMULSIFIERS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
INFORMATION
ISOTOPE SEPARATION
ISOTOPES
KETONES
LIGHT NUCLEI
MAGNETIC MOMENTS
MAGNETIC RESONANCE
MICELLAR SYSTEMS
MIXTURES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADICALS
RESONANCE
SEPARATION PROCESSES
SOLUTIONS
STABLE ISOTOPES
SURFACTANTS
WETTING AGENTS