Gas phase recoil phosphorus reactions—IV Effect of moderators on the abstraction reactions

Abstract The use of helium, neon and argon as moderators in recoil 32 P systems has shown that the F-abstraction from PF 3 to give 32 PF 3 is not diminished by moderation while the H-abstraction from PH 3 to give 32 PH 3 decreases to as low as 27% of the unmoderated value with the addition of 98% neon. These results are consistent with the supposition that the H-abstraction from PH 3 by 32 P atoms has a reaction cross section curve covering a wide energy range with a rather low threshold. The corresponding F-abstraction appears to involve thermal reactions of 32 P with a much narrower energy range for its reaction cross section curve.