Dissociation dynamics and multiphoton ionization mechanism of ammonia clusters

Journal Article · Thu Oct 05 04:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100357a002· OSTI ID:6971872

Misaizu, F; Houston, P L; Nishi, N ^[1]; Shinohara, H ^[2]; Kondow, T; Kinoshita, M ^[3]

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1. Institute for Molecular Science, Okazaki (Japan)
2. Mie Univ. (Japan)
3. Univ. of Tokyo (Japan)

Two-color, two-photon ionization of ammonia has been used to investigate the ionization and dissociation mechanisms of ammonia clusters. By observing the ion signals in a reflectron time-of-flight mass spectrometer as a function of the delay time between the two laser pulses, it is found that the lifetime of the intermediate to formation of (NH{sub 3}){sub 2}H{sup +} and higher mass cluster ions is at least 500 times longer than that to formation of NH{sub 4}{sup +} and (NH{sub 3}){sub 2}{sup +}. Similar results are found for deuterated ammonia. The intermediate is formed by one-photon excitation in the energy range accessing the A {sup 1}A{sub 2} state of ammonia. This observation confirms that the mechanism of ionization of the dimer in this energy region is two-photon ionization followed by the rapid intracluster proton-transfer reaction (NH{sub 3}){sub 2}{sup +} {yields} NH{sub 4}{sup +} + NH{sub 2}. The mechanism for ionization of larger clusters is discussed.

• OSTI ID: 6971872
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:20; ISSN JPCHA; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMMONIA
CHEMICAL REACTION KINETICS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
DATA ANALYSIS
DISLOCATIONS
EXPERIMENTAL DATA
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
IONIZATION
KINETICS
LINE DEFECTS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
MEASURING METHODS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUMERICAL DATA
REACTION KINETICS
SPECTROSCOPY