The Kinetics of Coordinate Bond Formation

A novel method has been developed for determining the rates of very fast gas-phase bimolecular reactions, which is based on interpretation of the temperature gradients in a flow system similar to that used for the study of the reactions of sodium vapor and alkyl halides. The kinetics of the reactions between boron tri-fluoride and tri-, di-, and monomethylamine to form the corresponding coordinately bonded compounds have been studied. These reactions appear to have negligibly small activation energies, and their rates show a pressure dependence consistent with a mechanism: y+z⇌yz*yz*+m→yz+m*in which the long-lived intermediate yz* must be stabilized by loss of energy in a collision. The random scatter of individual rate constants is about 20 percent.