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6257648 
Journal Article 
Anion and cation chemistry of phosphoryl chloride as an electron scavenger in a fuel-rich, methane—oxygen flame 
Crovisier, PN; Goodings, JM; Hugh Horton, J 
1992 
114 
1 
99-121 
A premixed, fuel-rich, methane—oxygen flame at atmospheric pressure was doped with 0.05 mol. % of phosphoryl chloride, POCl3. The phosphorus anions and cations produced by chemical ionization were observed by sampling the flame through a nozzle into a mass spectrometer. The POCl3 additive was a very effective scavenger of free electrons by negative ion formation in the burnt gas of the hydrocarbon flame, even more so than trimethylphosphate, TMP, studied previously under similar conditions. The kinetic breakdown of POCl3 is faster, yielding the major anions PO−2 and PO−2; the role of electronegative chlorine is relatively minor. To a remarkable degree, the ion chemistry observed with both additives is very similar, stemming from a common series of neutral phosphorus intermediates. In addition to PO−2 and PO−3, common anions include PO−, PO2(OH)−2 and PO2(CH2)−; common cations have the general form PO+n · xH2O(n=1−3, x=0−3). New phosphorus anions observed with POCl3 include: PO2(OH)(CH3)−; the disphosphorus species P2O5H−, P2O5CH−3, P2O5 · OH− and P2O5H− · H2O; and the chlorinated anions POx(OH)yCl−z formed by nucleophilic substitution of POCl3, as well as Cl−. New cations include POCl3 · H+ and the series PO+4, PO+5 · H2O, showing the extraordinary affinity of phosphorus for oxygen. The ion chemistry is discussed in detail, mainly involving proton transfer, nucleophilic substitution (SN2) and three-body association (e.g. hydration). 
phosphoryl chloride; electron scavenging; flame chemistry.