Accession Number:

ADA218410

Title:

Threshold Photodetachment Spectroscopy of the I + HI Transition State Region

Descriptive Note:

Interim technical rept. Nov-Dec 1989,

Corporate Author:

CALIFORNIA UNIV BERKELEY DEPT OF CHEMISTRY

Report Date:

1990-01-01

Pagination or Media Count:

18.0

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 HIv0 asymptote. AW

Subject Categories:

  • Physical Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE