Threshold Photodetachment Spectroscopy of the I + HI Transition State Region
Abstract
We have developed a method for probing the transition state region of a neutral bimolecular reaction via photodetachment of a stable negative ion similar in structure to the neutral transition state. In several cases, we have found that the photoelectron spectrum of the hydrogen-bonded anion AHB(-) exhibits resolved vibrational structure which can be assigned to an unstable (AHB) complex located near the transition state for the hydrogen transfer reaction A + HB yields HA + B. The results described previously were obtained with a fixed-frequency negative ion photoelectron spectrometer. Here we report considerably higher resolution results for IHI(-) obtained on a recently constructed threshold photodetachment spectrometer. In this experiment, mass- selected ions are photodetached with a tunable pulsed laser, and only those photoelectrons produced with nearly zero kinetic energy are detected as a function of laser wavelength. The threshold photodetachment spectrum of IHI(-) shows considerably more structure than was observed in the lower resolution photoelectron spectrum. In particular, we observe narrow (30 cm) peaks due to long-lived states of the (IHI) complex which lie well above the I + HI(v=0) asymptote. (AW)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1990
- Accession Number
- ADA218410
Entities
People
- D. M. Neumark
- I. M. Waller
- T. N. Kitsopoulos
Organizations
- University of California, Berkeley