Multiphoton gas phase dissociation of methyl and ethyl formates

Abstract

Abstract The IR-multiphoton-initiated decomposition of methyl and ethyl formates is reported. Experiments were carried out by 9.6 μm irradiation under mildly focused conditions, with fluences of about 10 J cm −2 . CO, CH 4 , CO 2 , C 2 H 6 and CH 3 OH were detected for HCOOCH 3 while CO, CH 4 , C 2 H 4 , C 2 H 2 and traces of CO 2 were observed for HCOOC 2 H 5 . The product yields were measured by quantitative gas chromatographic analyses. In HCOOC 2 H 5 , the dominant process is the reaction producing ethylene and CO (already observed in pyrolysis and UV photolysis). In HCOOCH 3 two presumably unimolecular reactions seem to occur, one producing CO and CH 3 OH and the other producing CH 4 and CO 2 , in contrast with the assumed mechanisms for pyrolysis and photolysis. The product yields can be interpreted in terms of secondary thermal or radical reactions. The effects of inert gases were studied. Luminescence in the focal region originating from OH·, CH·, C 2 and H 2 O(113) excited species was observed and its temporal behavior studied.