Fluorescence Excitation Spectra of Photo-Fragmented Nitrobenzene Using a Picosecond Laser: Potential Evidence for NO Produced by Two Distinct Channels

Christopher J. Lue, Chakree Tanjaroon, J. B. Johnson, Scott W. Reeve, Susan D. Allen

Research output: Contribution to conferencePresentation

Abstract

Upon absorption of a UV photon, nitrobenzene can dissociate into C6 H5 O and NO through two different mechanisms. Evidence for these mechanisms was obtained from velocity map imaging (VMI) studies and theoretical calculations. VMI experiments showed NO produced with two distinct rotational distributions, which the calculations explained as a fast and a slow channel for NO production. We have recorded high resolution fluorescence excitation spectra of the NO resulting from photo-fragmented nitrobenzene using a pulsed picosecond tunable laser (pulse width ≈≈ 15 ps) by means of a two-color process. In the two-color process, photons of a particular energy dissociated the nitrobenzene while photons of a different energy probed the A2Σ+←X2Π(1/2,3/2) NO band system between 225-260 nm. This laser system allowed us to vary the delay between the photolysis and excitation pulses. At longer delays (>1 ns), we observed an increase in the population of NO, which may be evidence that at least two photolysis channels produce NO. We present the spectra we recorded at various photolysis/probe delays ranging from 0.025 to 1.5 ns. The spectral subtraction method we used to observe the production increase is introduced.
Original languageAmerican English
StatePublished - Jun 18 2013
Event68th International Symposium on Molecular Spectroscopy at OSU - Columbus, OH
Duration: Jun 18 2013 → …

Conference

Conference68th International Symposium on Molecular Spectroscopy at OSU
Period6/18/13 → …

Keywords

  • molecular spectrometry
  • nitrobenzene

Disciplines

  • Atomic, Molecular and Optical Physics

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