Free radical production and thermal decomposition mechanisms of small molecules by flash pyrolysis

Flash pyrolysis coupled with single photon vacuum-ultraviolet photoionization time-of-flight mass spectrometry was used to investigate (1) the feasibility of gas-phase free radical production upon thermal decomposition of appropriate precursors, and (2) mechanisms of thermal decomposition of chemical species involved in combustion processes and microelectronics manufacture. Production of radicals such as CH3 from CH3I and C2H 5 from C2H5I was attained. Combustion research included the discovery of a new free radical pathway involved in the pyrolysis of methyl-t-butyl ether, an investigation into the contribution of acetylene and vinylacetylene as a precursor to soot formation, and the isomerization/decomposition mechanism of 1,3-butadiene and its isomers. Study of pyrolysis mechanisms of SiH4, Si2H6 and GeH4 by direct detection of their products (radicals, nanoparticles) was carried out. A greater understanding of the thermal decomposition processes involved in these systems will allow (1) optimization of free radical production for further studies of free radicals, (2) reduction of pollution and soot production, and (3) greater control of chemical vapor deposition of semiconductor films.