15min:

THOMAS J. DOWD, LEANNE M. MILLER AND JAMES S. KELLER, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN, 46556.

A ground state population depletion grating was used to elucidate the effects of initial nuclear motion on the photodissociation dynamics of chlorine dioxide. The ultraviolet absorption of OClO occurs via the A²A₂ <- X²B₁ transition, but dissociation of OClO* proceeds on several different excited state surfaces leading to two distinct product channels. Since several excited bending states (₂) are populated at room temperature, a depletion grating can be formed involving these vibrational states by the interference of two degenerate pump beams tuned to transitions which lie below the predissociation threshold. A probe beam was tuned through the dissociation region to record the A<- X absorption spectra of specific vibrational states.