Dissociation dynamics: Measurements of decay fractions of metastable ammonia cluster ions

Journal Article · Wed Aug 15 04:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459033· OSTI ID:6635251

Wei, S; Tzeng, W B; Castleman, Jr, A W ^[1]

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1. The Pennsylvania State University, Department of Chemistry, University Park, Pennsylvania 16802 (USA)

The decay fractions of metastable ammonia cluster ions which undergo unimolecular (evaporative) dissociation in a time window of 1--40 {mu}s were measured by using a reflection time-of-flight mass spectrometer. Corrections concerning instrumental artifacts and ion trajectory of parents and daughters are made to imporve the precision of the measurements. The data are used to derive the Gspann parameter and heat capacity of clusters as described in evaporative ensemble model of metastable dissociation. Using the dissociation fractions measured in the present studies, in conjunction with kinetic energy release values previously measured in our laboratory, we apply Klots' evaporative ensemble model to obtain binding energies of ammonia cluster ions (NH{sub 3}){sub {ital n}}H{sup +}, 4{le}{ital n}{le}17. The deduced binding energy values are found to be in very good agreement with both thermochemical data and Engelking's modified statistical theory.

• DOE Contract Number: FG02-88ER60648
• OSTI ID: 6635251
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 93:4; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMMONIA
BINDING ENERGY
CHARGED PARTICLES
COMPLEXES
DISSOCIATION
ENERGY
ENERGY LEVELS
EXCITED STATES
HYDRIDES
HYDROGEN COMPLEXES
HYDROGEN COMPOUNDS
IONS
MASS SPECTROSCOPY
METASTABLE STATES
MOLECULAR IONS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
SPECTROSCOPY
TIME-OF-FLIGHT METHOD