FLUCTUATIONS IN THE UNIMOLECULAR DECOMPOSITION OF JET-COOLED NO2 - IMPLICATIONS FOR OVERLAPPING RESONANCES AND THE TRANSITION-STATE

We report a detailed examination of fluctuations in the internal state distributions of the NO ((II)-I-2) fragment formed in the monoenerget ic unimolecular decomposition of jet-cooled NO2, utilizing photofragme nt yield (PHOFRY) spectroscopy. The NO(upsilon,J,Omega,Lambda) PHOFRY spectra at E(dagger) < 3000 cm(-1) are highly structured, and we exami ne correlations among these spectra on the basis of the angular moment um, spin-orbit, parity, and vibrational labels of the monitored NO rov ibrational levels. We find that levels of similar total angular moment um in the same vibrational manifold are more strongly correlated with specific resonances in the activated molecule, as well as levels of th e same N in the two spin-orbit states of NO. The observed PHOFRY corre lations, as well as those found in the NO((IIOmega)-I-2; Omega = 1/2,3 /2) rotational state distributions, are interpreted in terms of projec tions of coherently excited overlapping molecular eigenstates onto the manifold of final states via levels of the transition state. The impl ications of the results to the transition state and the adiabatic evol ution of the NO degrees of freedom are discussed.