title: Observation of a Reactive Rainbow in F + CH3D → CH2D(v = 0) + HF(v = 3)?
abstract: Rainbow structures in the scattering angular distribution play an important role in deepening our understanding about the elastic and rotationally inelastic collisions of atoms/molecules. Reported here is the discovery of a rainbow in a chemical reaction. At Ec = 4.3 kcal mol(-1) one of the correlated product pairs in the F + CH3D reaction, (vHF, vCH2D) = (3, 00), displays a distinct bulge in angular distribution. We showed that the bulge originates predominantly from the low-j states of the HF(v = 3) products. Heuristic considerations led us to propose that such a bulge could be regarded as a signature for rainbow scattering. The underlying mechanism for its occurrence in this nearly thermoneutral product pair is ascribed to a delicate interplay of the attractive and repulsive parts of interactions in the vicinity of the transition state. In a sense, the situation bears striking similarity to the more familiar elastic rainbow, thus coined "reactive rainbow".
authors: Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica , P.O. Box 23-166, Taipei, Taiwan 10617.
authors: Huilin
authors: H
authors: Pan
authors: Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica , P.O. Box 23-166, Taipei, Taiwan 10617.|Department of Physics, National Taiwan University , Taipei, Taiwan 10617.
authors: Kopin
authors: K
authors: Liu