TY  - JOUR
A1  - Jankunas, Justin
A1  - Zare, Richard N.
A1  - Bouakline, Foudhil
A1  - Althorpe, Stuart C.
A1  - Herraez-Aguilar, Diego
A1  - Aoiz, F. Javier
T1  - Seemingly anomalous angular distributions in H+D-2 reactive scattering
JF  - Science
N2  - When a hydrogen (H) atom approaches a deuterium (D-2) molecule, the minimum-energy path is for the three nuclei to line up. Consequently, nearly collinear collisions cause HD reaction products to be backscattered with low rotational excitation, whereas more glancing collisions yield sideways-scattered HD products with higher rotational excitation. Here we report that measured cross sections for the H + D-2 -> HD(v' = 4, j') + D reaction at a collision energy of 1.97 electron volts contradict this behavior. The anomalous angular distributions match closely fully quantum mechanical calculations, and for the most part quasiclassical trajectory calculations. As the energy available in product recoil is reduced, a rotational barrier to reaction cuts off contributions from glancing collisions, causing high-j' HD products to become backward scattered.
Y1  - 2012
U6  - https://doi.org/10.1126/science.1221329
SN  - 0036-8075
VL  - 336
IS  - 6089
SP  - 1687
EP  - 1690
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  -