Slow photoelectron velocity-map imaging (sevi) spectroscopy of cryo-cooled anions

Weichman, Marissa L.

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https://hdl.handle.net/2142/100796 Copy

Description

Title

Slow photoelectron velocity-map imaging (sevi) spectroscopy of cryo-cooled anions

Author(s)

Weichman, Marissa L.

Contributor(s)

• Neumark, Daniel
• DeVine, Jessalyn A.
• Kim, Jongjin B.

Issue Date

2018-06-22

Keyword(s)

Comparing theory and experiment

Abstract

Slow photoelectron velocity-map imaging spectroscopy of cryogenically-cooled anions (cryo-SEVI) is a powerful technique for elucidating the vibrational and electronic structure of exotic neutral species. SEVI is a high-resolution variant of anion photoelectron imaging that yields spectra with energy resolution as high as 1 cm−1 . The preparation of cold anions eliminates hot bands and narrows rotational envelopes, enabling the acquisition of well-resolved photoelectron spectra for complex and spectroscopically challenging species.1,2 Recently, cryo-SEVI has been applied as a spectroscopic probe of transition state dynamics on neutral reactive surfaces, through photodetachment of a bound anion similar in geometry to the desired transition state. In the benchmark F + H2 reaction, we probe the transition state region through detachment of FH− 2 and directly observe new reactive resonances. Comparison to new theory allows for the assignment of resonances associated with quasi-bound states of the transition state and products.3 We also report spectra of the F + CH3OH hydrogen abstraction reaction through photodetachment of the CH3OHF− van der Waals cluster. We gain insight into the energetics and vibrational structure of transient complexes along the reaction coordinate of this complex polyatomic system.4 Finally, we report a new cryo-SEVI study of vinylidene (H2CC), a high energy isomer of acetylene, which is accessed directly through detachment of H2CC−. We find spectroscopic evidence that the isomerization of vinylidene to acetylene is highly state-specific, with excitation of the ν6 in-plane rocking mode resulting in appreciable tunneling-facilitated mixing with highly vibrationally excited states of acetylene.5

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100796

DOI

10.15278/isms.2018.FC04

Copyright and License Information

Copyright 2018 Marissa L. Weichman

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