Infrared action spectroscopy of the OD stretch fundamental and overtone transitions of the DOOO radical

J Phys Chem A. 2008 Oct 2;112(39):9269-76. doi: 10.1021/jp801232a. Epub 2008 May 29.

Abstract

The DOOO radical has been produced by three-body association between OD and O2 in a supersonic free-jet expansion and investigated using action spectroscopy, an IR-UV double-resonance technique. Partially rotationally structured bands observed at 2635.06 and 5182.42 cm(-1) are assigned to the OD stretch fundamental (nu(OD)) and overtone (2nu(OD)), respectively, of the trans-DOOO radical. Unstructured bands observed in both spectral regions are assigned to cis-DOOO. Nascent OD X(2)Pi product state distributions following vibrational predissociation appear to be nearly statistical with respect to the degree of rotational excitation, but display a marked propensity for Pi(A') Lambda-doublets, which is interpreted as a signature of a planar dissociation. The energetically highest open OD X(2)Pi product channel implies an upper limit dissociation energy D0 < or = 1856 cm(-1) or 5.31 kcal mol(-1). This value allows refinement of the upper limit D0 of the atmospherically important HOOO isotopomer, suggesting that it is marginally less stable than previously thought.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Deuterium*
  • Energy Transfer
  • Hydroxyl Radical / chemistry*
  • Oxygen / chemistry*
  • Spectrophotometry, Infrared
  • Spectroscopy, Fourier Transform Infrared
  • Stereoisomerism

Substances

  • Hydroxyl Radical
  • Deuterium
  • Oxygen