title: Photolysis of a Benzyne Precursor Studied by Time-Resolved FTIR Spectroscopy.
abstract: The 266 nm laser flash photolysis of phtaloyl peroxide (2) in liquid acetonitrile solution at room temperature has been investigated. Upon 266 nm laser irradiation, 2 is effectively photodecarboxylated leading to the formation of o-benzyne (1) and two equivalents of CO2, yet a small fraction of photolyzed 2 follows a different pathway leading to 6-oxocyclohexa-2,4-dienylideneketene (3) and one equivalent of CO2. Compound 3 is kinetically reactive and reacts in the microsecond time scale following a first-order kinetic law. The presence of 1 in the photolysis experiment is confirmed by trapping experiments with methyl 1-methylpyrrole-2-carboxylate (6). The Diels-Alder reaction between 1 and 6 occurs under the selected experimental conditions on a time scale shorter than 100 ms.
authors.affiliation: Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universtität , Wegelerstraße 12, 53115 Bonn, Germany.
authors.forename: Joel
authors.initials: J
authors.lastname: Torres-Alacan