title: Oxalate/hydrogen peroxide chemiluminescence reaction. A 19F NMR probe of the reaction mechanism.
abstract: The mechanism of the oxalate/hydrogen peroxide chemiluminescence reaction has been examined by magnetic resonance techniques. Investigation of the reactive intermediates involved in chemiluminescence was carried out with bis(2,6-difluorophenyl)oxalate (DFPO) using 19F NMR to probe its reactions with aqueous hydrogen peroxide. Formation and reactions of the intermediate hydroperoxy oxalate ester B along with the formation of the half ester product C and difluorophenol D were monitored by 19F NMR. When the reaction of DFPO and aqueous hydrogen peroxide was carried out in the presence of dansylphenylalanine, a typical fluorescent analyte, the intensity of the resonance due to the intermediate B was diminished in direct proportion to the concentration of the analyte. Comparison of the time/intensity profile of the chemiluminescence emission with that of the 19F NMR transient suggests that the hydroperoxy oxalate ester B is the likely 'reactive' intermediate, capable of participating in a chemically initiated electron exchange luminescence mechanism.
authors.affiliation: Center for Bioanalytical Research, University of Kansas, Lawrence 66045-0046.
authors.forename: H P
authors.initials: HP
authors.lastname: Chokshi
authors.forename: M
authors.initials: M
authors.lastname: Barbush
authors.forename: R G
authors.initials: RG
authors.lastname: Carlson
authors.forename: R S
authors.initials: RS
authors.lastname: Givens
authors.forename: T
authors.initials: T
authors.lastname: Kuwana
authors.forename: R L
authors.initials: RL
authors.lastname: Schowen
mesh_terms: D005461:Fluorine; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism*; D008163:Luminescent Measurements; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010070:Oxalates / Q000032:analysis / Q000378:metabolism*
chemical_list: D010070:Oxalates; D005461:Fluorine; D006861:Hydrogen Peroxide