Accession Number:

ADA248043

Title:

Reaction of Br(-) with WF6: Competition between Charge Transfer and Association; Influence of Temperature, Pressure, and Vibrational Energy

Descriptive Note:

Corporate Author:

PHILLIPS LAB HANSCOM AFB MA

Personal Author(s):

Report Date:

1991-01-01

Pagination or Media Count:

5.0

Abstract:

The rate coefficient for the reaction of Br- with WF sub 6 was found to be 6 plus or minus 2 x 10 to the minus 10th cm cubed s to the minus 1st, independent of temperature and pressure over the ranges 243 to 433 K and 0. 2 to 1.2 Torr. The reaction proceeds by two channels association to form WF sub 6 Br- and charge transfer to form WF sub 6-. The association fraction was found to depend strongly on temperature and pressure, varying from more than 90 association at low temperatures and high pressures to less than 10 association at high temperatures and low pressures. The reaction as studied here is in the falloff regime of association reactions. A steep temperature dependence is observed in the association fraction at high temperatures. This steep temperature dependence is a consequence of WF sub 6 having many low frequency vibrational levels. Vibrational energy is here found to promote charge transfer more efficiently than does kinetic energy.

Subject Categories:

  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE