UV laser photochemistry: triplet biradical trapping efficiencies and lifetimes

Journal Article · Tue Mar 04 23:00:00 EST 1986 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00265a015· OSTI ID:5895097

Adam, W; Hannemann, K; Wilson, R M

The trapping of triplet 1,3-cyclopentadiyl (1) and the triplet 1,4-biradical 2-(2-ethyl)cyclopent-2-enyl (2) with molecular oxygen has been studied quantitatively. The lifetime of 1 has been found to range between 720 and 900 ns and that of 2 between 53 and 94 ns depending on the solvent. The biradical 1 was found to be trapped in essentially quantitative yield with no indication of oxygen-catalyzed intersystem crossing. In contrast, 2 was found to be trapped in 54-79% yield with the residual biradical quenching being due to oxygen-catalyzed intersystem crossing. These and other biradical trapping data have been correlated with 1,3-biradical geometries and found to be in accord with Salem's rules for spin-orbit coupling in triplet biradicals. 28 references, 7 figures, 2 tables.

• Research Organization: Universitaet Wuerzburg, Wuerzburg/Am Hubland, West Germany
• OSTI ID: 5895097
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 108:5; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
BOND ANGLE
CHEMISTRY
DATA
DIENES
ELECTROMAGNETIC RADIATION
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
LASERS
LIFETIME
METASTABLE STATES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN
PENTADIENES
PHOTOCHEMISTRY
POLYENES
RADIATIONS
RADICALS
SPECTROSCOPY
ULTRAVIOLET RADIATION