MICROWAVE-DISCHARGE IN POLYHALOGENATED METHANES - INVESTIGATION OF THE RESULTING SPECIES USING ION-MOLECULE REACTIONS

The species resulting from a microwave discharge in polyhalogenated me thanes were investigated using their reactivity with Ar+, Cl-, and FeC O+ probe ions. With discharge off, reaction of FeCO+ with most of thes e substrates led mainly to halomethyl cations along with a (XFeCO) neu tral species in which the CO molecule probably remains bound to the me tal. With discharge on, completely different products were observed: f or fluorinated substrates Pyrex etching yielded silicon and boron fluo rides, with COBr2 formation in the case of CF3Br. Molecular chlorine o r bromine were formed from chlorine- or bromine-containing halomethane s, along with hydrogen halides in the case of hydrogen-containing subs trates. Discharge mixtures from CFCl3 or CHCl3 contained CCl4. No reco mbination by carbon-carbon bond formation leading to dimers or oligome rs was detected.