Methyl fluoride formation from thermal fluorine-18 reaction with dimethylmercury

The attack of fluorine atoms (F) on dimethylmercury [(CH3)2Hg] with the formation of methylfluoride (CH3F) has been observed in the gas phase by using radioactive 18F thermalized by multiple collisions with sulfur hexafluoride(SF6). Ca 9.6% of thermal 18F atoms are found as CH318F, with the remainder reacting with (CH3)2Hg to form other products, mainly, H18F. The rate constant k5 for this substitution reaction has been measured at 2870K to be 0.68 times as fast for thermal 18F as hydrogen abstraction from methane and 1.67 times as fast as hydrogen abstraction from hydrogen. These relative rates correspond to an absolute rate constant k5 = (4.6 +- 0.4) x 10-11 cm3 molecule-1s-1. The total rate constant for all reactions with (CH3)2 Hg is 4.7 +- 0.5) x 10-10cm3 molecule-1s-1. 3 figures, 4 tables