Negative ion-molecule reactions with atomic hydrogen in the gas phase at 296 °K

Abstract

Gas phase reaction rates have been measured for the reactions of Cl−, I−, OH−, O2−, SF6, and some hydrates of Cl−, OH−, and O2− with atomic hydrogen in a flowing afterglow system at 296°K. In general, the reaction mechanism is associative detachment, X−+H→HX+e, and the rate constants are very large (∼ 10−9 cm3/sec). The reactivities of Cl−, OH−, and O2− are reduced by clustering with H2O. The reaction of I− with H is immeasurably slow, and SF6− reacts with H to form SF5− which does not react further.