Journal
JOURNAL OF CHEMICAL PHYSICS
Volume 134, Issue 18, Pages -Publisher
AIP Publishing
DOI: 10.1063/1.3585606
Keywords
-
Funding
- National Science Foundation
- Air Force Office of Scientific Research
- (U.S.) Department of Energy, Office of Basic Energy Sciences, Chemical Sciences, Biosciences, and Geosciences Division
- JILA Visiting Fellowships
- UNR Foundation Professorship
- University of Nevada, Reno
Ask authors/readers for more resources
We report the 364-nm negative ion photoelectron spectra of CHX2- and CDX2-, where X = Cl, Br, and I. The pyramidal dihalomethyl anions undergo a large geometry change upon electron photodetachment to become nearly planar, resulting in multiple extended vibrational progressions in the photoelectron spectra. The normal mode analysis that successfully models photoelectron spectra when geometry changes are modest is unable to reproduce qualitatively the experimental data using physically reasonable parameters. Specifically, the harmonic normal mode analysis using Cartesian displacement coordinates results in much more C-H stretch excitation than is observed, leading to a simulated photoelectron spectrum that is much broader than that which is seen experimentally. A (2 + 1)-dimensional anharmonic coupled-mode analysis much better reproduces the observed vibrational structure. We obtain an estimate of the adiabatic electron affinity of each dihalomethyl radical studied. The electron affinity of CHCl2 and CDCl2 is 1.3(2) eV, of CHBr2 and CDBr2 is 1.9(2) eV, and of CHI2 and CDI2 is 1.9(2) eV. Analysis of the experimental spectra illustrates the limits of the conventional normal mode approach and shows the type of analysis required for substantial geometry changes when multiple modes are active upon photodetachment. (C) 2011 American Institute of Physics.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available