Boron atom reactions. II. Rate constants with O2, SO2, CO2, and N2O

The gas phase reactions of atomic boron with O2, SO2, CO2, and N2O have been studied using a new flow tube apparatus. Boron atoms were produced in a microwave discharge of a 0.02% mixture of diborane in argon. The bimolecular rate constants at 300 °K were obtained by measuring the density of boron down the flow tube as a function of reactant density. The rate constants for the O2, SO2, CO2, and N2O reactions are, in units of cm3 molecule−1 sec−1, 4.6±1.8×10−11, 1.1±0.4×10−10, 7.0±2.8×10−14, and 2.1±0.8×10−14, respectively. These results are compared with the rates measured for the reactions of the group IIA and IVA atoms. The patterns observed in the data are noted and a possible mechanism is discussed.