Formation of Vibrationally Excited OH by the Reaction H + O_3

Abstract

An earlier study [Chem. Phys. Lett. 1, 619 (1968)] concluded that the reaction H + O(3) ? OH + O(2) forms OH predominantly in the highest accessible vibrational levels, upsilon = 8 and 9. We have extended this earlier work (1) by using fourier transform spectroscopy which is capable of giving more precise values for the relative vibrational populations at low intensities, (2) by recording emission down to lower background pressures (1 x 10(-4) Torr), and (3) by treating the vessel walls so as to remove OHdagger (vibrationally excited OH in it ground (2)II electronic state) more effectively. This involved using a room temperature vessel coated with silica gel. Under these conditions (provided that the values available for the radiational lifetime of OHdagger are correct) vibrational relaxation of OHdagger should have been largely arrested. We conclude that the relative rate constants for formation of OHdagger in levels upsilon are k(upsilon = 6) < 0.4, k(upsilon = 7) asymptotically equal to 0.4, k(upsilon = 8) asymptotically equal to 0.8, and k(upsilon = 9) = 1.00.