NCNO → CN+NO: Complete NO(E, V, R) and CN(V, R) nascent population distributions from well‐characterized monoenergetic unimolecular reactions

We report detailed vibrational, rotational, and electronic (V, R, E) distributions of nascent NO(X 2Π) deriving from monoenergetic unimolecular reactions of jet‐cooled NCNO. Excitation is via the A 1A″ ← X 1A’ system above dissociation threshold (17 085±5 cm−1), and vibrational predissociation occurs following radiationless decay of the initially excited A 1A″ state. These results are combined with data on the corresponding CN(X 2Σ+) nascent V, R distributions, thereby providing a complete description of the energy partitioning into the various degrees of freedom of both products. The data presented here support our previous conclusion that dissociation is ‘‘statistical.’’ All the V, R distributions of both products can be predicted accurately using a modification of the phase space theory of unimolecular reactions (PST), which we call the separate statistical ensembles (SSE) method; it is expected that this method will have quite general applicability. NO spin‐orbit excitation is ‘‘cold’’ relative to ...