Transient ISEELS: a new probe of chemical reactions

An inner shell electron energy loss spectrometer (ISEELS) has been adapted as a probe of chemical reactions by coupling its gas phase interaction regi on to the output of a variety of chemical reactors including thermolysis, g as phase reaction, and heterogeneous reaction systems. Three examples of tr ansient ISEELS studies are presented: in situ generation of a reactive carb ene by thermolysis of its stable dimer, reaction of a silylene with N2O in the gas phase, and the heterogeneous reactions of H2S and H2O with crystall ine boron in a heated quartz tube. In the latter example, temperature depen dent inner shell excitation spectra, mass spectrometry and ab initio calcul ations were used to show that in the high temperature limit the reaction of H2S (g) and B (s) over SiO2 (s) gives rise to borine (HBO), a species prev iously un-detected from this reaction chemistry. (C) 2001 Elsevier Science B.V. All rights reserved.