CONICET | Buscador de Institutos y Recursos Humanos

The thermal dissociation of the atmospheric constituent methyl formate was probedby coupling pyrolysis with imaging photoelectron photoion coincidence spectroscopy(iPEPICO) using synchrotron VUV radiation at the Swiss Light Source (SLS). iPEPICOallows threshold photoelectron spectra to be obtained for pyrolysis products, distinguishing isomers and separating ionic and neutral dissociation pathways. In thiswork, the pyrolysis products of dilute methyl formate, CH3OC(O)H, were elucidatedto be CH3OH + CO, 2 CH2O and CH4 + CO2 as in part distinct from the dissociation of the radical cation (CH3OH+? + CO and CH2OH+ + HCO). Density functionaltheory, CCSD(T), and CBS-QB3 calculations were used to describe the experimentally observed reaction mechanisms, and the thermal decomposition kinetics and thecompetition between the reaction channels are addressed in a statistical model. Oneresult of the theoretical model is that CH2O formation was predicted to comedirectly from methyl formate at temperatures below 1200 K, while above 1800 K, itis formed primarily from the thermal decomposition of methanol.