Velocity map imaging of HBr photodissociation in large rare gas clusters

Journal Article · Thu Apr 21 04:00:00 EDT 2011 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3578610· OSTI ID:21560157

Fedor, J; Kocisek, J; Poterya, V; Votava, O; Pysanenko, A; Farnik, M ^[1]; Lipciuc, M L ^[2]; Kitsopoulos, T N ^[3]

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1. J. Heyrovsky Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, 18223 Prague (Czech Republic)
2. Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA (United Kingdom)
3. Department of Chemistry, University of Crete, Heraklion (Greece) and Institute of Electronic Structure and Lasers, Foundation for Research and Technology, Hellas, P.O. Box 1527, 71110 Heraklion (Greece)

We have implemented the velocity map imaging technique to study clustering in the pulsed supersonic expansions of hydrogen bromide in helium, argon, and xenon. The expansions are characterized by direct imaging of the beam velocity distributions. We have investigated the cluster generation by means of UV photodissociation and photoionization of HBr molecules. Two distinct features appear in the hydrogen atom photofragment images in the clustering regime: (i) photofragments with near zero kinetic energies and (ii) ''hot'' photofragments originating from vibrationally excited HBr molecules. The origin of both features is attributed to the fragment caging by the cluster. We discuss the nature of the formed clusters based on the change of the photofragment images with the expansion parameters and on the photoionization mass spectra and conclude that single HBr molecule encompassed with rare gas ''snowball'' is consistent with the experimental observations.

• OSTI ID: 21560157
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 15 Vol. 134; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOMS
BROMINE COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
COLLISIONS
DECOMPOSITION
DISSOCIATION
DISTRIBUTION
ELEMENTS
ENERGY
ENERGY LEVELS
EXCITED STATES
EXPANSION
FLUIDS
GASES
HALOGEN COMPOUNDS
HELIUM
HYDROBROMIC ACID
HYDROGEN
HYDROGEN COMPOUNDS
IMAGES
INORGANIC ACIDS
INORGANIC COMPOUNDS
IONIZATION
KINETIC ENERGY
MASS SPECTRA
MOLECULAR CLUSTERS
MOLECULE COLLISIONS
MOLECULES
NONMETALS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOIONIZATION
PHOTOLYSIS
PHOTON COLLISIONS
PHOTON-MOLECULE COLLISIONS
RARE GASES
SPECTRA
VELOCITY
VIBRATIONAL STATES
XENON