Time-resolved infrared study on the photochemistry of O-fluoroformyl- and O-chlorooxalyl-9-fluorenone oxime: the reactivity of the fluoroformyl radical in acetonitrile solution.
This note describes the photochemistry of O-chlorooxalyl- and O-fluoroformyl-9-fluorenone oxime. The solution photochemistry of both precursors was investigated by time-resolved step/scan FTIR spectroscopy. Experiments on O-chlorooxalyl-9-fluorenone oxime only allowed for detection of CO2 and bleaching of the precursor, indicating predominant N-O cleavage. The chlorocarbonyl radical, ClCO*, was not detected. In contrast, TRIR investigations on fluoroformyl oxime 2 gave evidence for formation of the fluoroformyl radical FCO* (3), which rapidly adds to the solvent acetonitrile, yielding a fluoroformyl-functionalized iminyl radical 4. Its reaction with triplet molecular oxygen, on the other hand, is impeded by an activation enthalpy that has been calculated as deltaH# = 3.2 kcal/mol.
Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum, Germany. goetz.bucher@rub.de
Götz
G
Bucher
Christoph
C
Kolano
Olaf
O
Schade
Wolfram
W
Sander