Volume 122, Issue 10, 08 March 2005
Index of content:
122(2005); http://dx.doi.org/10.1063/1.1869497View Description Hide Description
Nonadiabatic dynamics in the title reaction have been investigated by REMPI detection of the and products. Reaction was initiated by photodissociation of at within a single expansion of a dilute mixture of and HCl in argon, giving a mean collision energy of in the center-of-mass frame. Significant production of was observed, with careful checks made to ensure that no additional photochemical or inelastic scattering sources of perturbed the measurements. The fraction of the total yield of atoms formed in the level at this collision energy was , and must arise from nonadiabatic dynamics because the ground potential energy surface correlates to products.
122(2005); http://dx.doi.org/10.1063/1.1871894View Description Hide Description
The title reaction has been under extensive experimental and theoretical investigations. Presented here is the experimental evidence suggesting a reactive resonance in this reaction—an intriguing possibility that has been hitherto unsuspected. The initial speculation was inferred from theoretical works in the literature, and subsequent confirmation came from the observed pattern of the angular distributions of the product pair, when plotted in the angle-collision energy plane. This characteristic pattern proves particularly incisive and universal in revealing the imprint of reactive resonance in experimental observable. The nature of the proposed resonance in this reaction is also elucidated.
122(2005); http://dx.doi.org/10.1063/1.1871912View Description Hide Description
Betaine is a permanent zwitterion. The molecular betaine anion has been generated in a hybrid, infrared desorption-electron photoemission source and its photoelectron spectrum recorded. The photoelectron spectrum of the betaine anion is characteristic of a dipole bound anion, and its vertical detachment energy was measured to be . Calculations by Rak, Skurski, and Gutowski [J. Chem. Phys.114, 10673 (2001)] had found the betaine anion to be a dipole bound anion with a vertical detachment energy of 0.28 eV. We also measured the vertical detachment energy of deprotonated betaine to be .