Fragmentation Dynamics of Small Molecules under Nonlinear Short-Pulse UV Excitation in the Gas Phase.

Abstract

Picosecond excitation and subnanosecond time resolution were used to distinguish prompt and delayed emission in the CN B bands from compounds XCN (X=Cl, CN, CH3). The prompt component originates from unimolecular dissociation of excited valence states of ClCN and (CN)2. From a detailed kinetic analysis of the dependence of CN B emission on initial pressure, the existence of a long-lived (ca. 24-136 ns) precursor (probably vitonically excited positive parent ions) has been postulated. Ion-molecule collisions appear essential for the delayed formation of Cbr B. The collisions appear essential for the delayed formation of CN-B. The kinetic studies, in toto, have yielded a comprehensive mechanistic picture of the molecular processes subsequent to the impulse excitation and have emphasized the importance of ion-molecule collision processes. Keywords: Chemiluminescence; Acetonitrile; Cyanogen; Chlorocyanogen.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1985
Accession Number
ADA166157

Entities

People

  • Richard G. Weiss

Organizations

  • Georgetown University

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • B Band
  • Chemical Compounds
  • Chemistry
  • Classification
  • Collisions
  • Dissociation
  • Electric Fields
  • Emission
  • Fragmentation
  • High Pressure
  • Ionization
  • Molecules
  • Precursors
  • Production
  • Security
  • Small Molecules
  • Waveforms

Readers

  • Molecular Photonics/Laser Physics