ANOMALOUSLY LARGE ISOTOPE EFFECT IN THE CHEMILUMINESCENCE FROM N(S-4)-3) RECOMBINATION(O(P)

The effect of isotopic substitution on the chemiluminescence that occu rs during the recombination of the N(S-4) and O(P-3) atoms has been st udied for the following isotope combinations: N-14 + O-16, N-15 + O-16 , N-14 + O-18, N-15 + O-18. Emissions in the NO delta, gamma, beta and Ogawa bands were identified in the spectra. Isotopic substitution cau sed remarkable changes in the vibrational distribution and intensity o f the emission from the NO(B (2) Pi) state (beta bands). This effect c an be explained by the isotopic shift of those vibrational levels of t he B state relative to the a (4) Pi state which are populated via the gateway mechanism.