One- and two-photon processes in the photochemistry of 1,3-bis(1-naphythyl)-2-propanone: an example of a reluctant Norrish Type I reaction

Journal Article · Wed Sep 02 00:00:00 EDT 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00252a030· OSTI ID:6085594

Johnston, L J; Scaiano, J C

Photoexcitation of 1,3-bis(1-naphthyl)-2-propanone in the carbonyl or naphthalene chromophore leads to the formation of a carbonyl-localized singlet state in the subnanosecond time scale. This singlet decays (tau/sub s/ = 1.4 ns in isooctane), presumably to yield the carbonyl triplet, which rapidly populates the naphthalene-localized triplet state. This intermediate can be readily detected by laser flash photolysis and shows typical naphthalene-like characteristics (TT absorption, lambda/sub max/ = 430 nm). Product and quenching studies indicate that the Norrish Type I cleavage occurs from the singlet state with Phi approx. = 0.002. Excitation of the triplet state with the pulses from a dye laser (430 nm) leads to cleavage of the CH/sub 2/-CO bond to yield 1-naphthylmethyl radicals in a process that the authors describe as a reluctant Norrish Type I reaction. The quantum yield for this process is approx.0.06. The structural features required for this type of process to occur are discussed.

• Research Organization: National Research Council of Canada, Ottawa, Ontario
• OSTI ID: 6085594
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 109:18
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETONE
PHOTOCHEMICAL REACTIONS
CARBONYLS
DYE LASERS
EXCITED STATES
EXPERIMENTAL DATA
PHOTOCHEMISTRY
QUANTUM EFFICIENCY
REACTION INTERMEDIATES
TRIPLETS
CHEMICAL REACTIONS
CHEMISTRY
DATA
EFFICIENCY
ENERGY LEVELS
INFORMATION
KETONES
LASERS
LIQUID LASERS
MULTIPLETS
NUMERICAL DATA
ORGANIC COMPOUNDS
400500* - Photochemistry