Multiphoton ionization of ammonia clusters and the dissociation dynamics of protonated cluster ions

Journal Article · Wed May 01 04:00:00 EDT 1985 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.448849· OSTI ID:5818963

Echt, O; Dao, P D; Morgan, S; Castleman, Jr, A W

Ammonia clusters, produced via supersonic expansion, are subjected to multiphoton ionization using a tunable pulsed laser. The products of ionization and subsequent dissociation processes are investigated using a time-of-flight mass spectrometer equipped with a reflectron (reflecting electric field). Cluster ions containing more than 65 ammonia molecules were formed via internal ion molecule reactions taking place within the initially ionized aggregate. The proton transfer reaction which ensues leads to substantial excess internal energy and subsequent cluster decomposition. Dissociation due to both collisional and unimolecular processes was identified in the field-free region. Studies of the dynamics of dissociation were made for species up to the protonated 16-mer; the loss of up to at least five monomer units following cluster ion formation was observed. Results of an investigation of the influence of laser fluence and the energy of the ionizing photons are also presented.

• Research Organization: Department of Chemistry, 152 Davey Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802
• OSTI ID: 5818963
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 82:9; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ADDUCTS
AGGLOMERATION
AMMONIA
DISSOCIATION
ELECTROMAGNETIC RADIATION
HYDRIDES
HYDROGEN COMPOUNDS
IONIZATION
LASER RADIATION
MULTI-PHOTON PROCESSES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PHOTOIONIZATION
RADIATIONS