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

The DOOO radical has been produced by three-body association between OD and 02 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 (V-OD) and overtone (2V(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') A-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 Do <= 1856 cm(-1) or 5.31 kcal mol(-1). This value allows refinement of the upper limit D-0 of the atmospherically important HOOO isotopomer, suggesting that it is marginally less stable than previously thought.