Steady-state and laser flash photolysis studies of bridgehead-substituted dibenzobarrelenes

Journal Article · Mon Dec 31 23:00:00 EST 1984 · J. Org. Chem.; (United States)

DOI:https://doi.org/10.1021/jo00214a026· OSTI ID:6444296

Murty, B A.R.C.; Pratapan, S; Kumar, C V; Das, P K; George, M V

The photochemistry of bridgehead-substituted dibenzobarrelenes has been investigated by steady-state photolysis, product analysis, and time-resolved laser flash photolysis. 4b-Substituted dibenzosemibullvalenes are formed as major photoproducts from dibenzobarrelenes, bearing acetoxy, formyl, ethyl, and methoxy 9-bridgehead substitutents, whereas 8b-substituted dibenzosemibullvalenes (or products derived from them) are formed from 9-hydroxy- and 9-cyano-substituted dibenzobarrelenes. Laser flash photolysis gives rise to transient phenomena attributable to the triplets of dibenzobarrelenes (phi/sub T/ = 0.2-0.7 in benzene). These are characterized by broad and diffuse absorption spectra, short lifetimes (0.07-11 /sup +/s), and varying degrees of quenchability by azulene, ferrocene, ..beta..-cartene, and p-methoxyphenol. The rate constants for triplet quenching by the latter quenchers as well as oxygen and di-tert-butylnitroxy radicals are presented.

• Research Organization: Indian Institute of Tech., Kanpur
• OSTI ID: 6444296
• Journal Information: J. Org. Chem.; (United States), Journal Name: J. Org. Chem.; (United States) Journal Issue: 14 Vol. 50:14; ISSN JOCEA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400500* -- Photochemistry
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
LASER RADIATION
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATIONS