Multiphoton ionization of acetone clusters: Metastable unimolecular decomposition of acetone cluster ions and the influence of solvation on intracluster ion-molecule reactions

Journal Article · Wed Aug 02 00:00:00 EDT 1989 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00198a010· OSTI ID:7071120

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

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1. Pennsylvania State Univ., University Park (USA)

A comprehensive investigation of the reactions of acetone ions in clusters was made to investigate and compare the similarities and differences in the ion reactions due to solvation effects. Neutral acetone clusters, prepared in a pulsed nozzle supersonic expansion, are ionized using multiphoton ionization and investigated using a time-of-flight reflectron technique. The observed major cluster ions resulting from prompt fragmentation following ionization are ((CH{sub 3}){sub 2}CO){sub m} {times} H{sup +} (m = 1-15), ((CH{sub 3}){sub 2}CO){sub m} {times} C{sub 2}H{sub 3}O{sup +} (m = 1-17), and ((CH{sub 3}){sub 2}CO){sub m} {times} CH{sub 3}{sup +} (m = 1-10). In a time window of a few tens of microseconds, all three classes of cluster ions unimolecularly decompose, losing only one acetone monomer. Interestingly, a reaction corresponding to the dehydration of ((CH{sub 3}){sub 2}CO){sub m} {times} H{sup +} and leading to the production of ((CH{sub 3}){sub 2}CO){sub m-2} {times} C{sub 6}H{sub 11}O{sup +} is observed for m = 2-6. The most striking finding of the present study is that the presence of water molecules in a cluster suppresses the dehydration reaction. This finding clarifies the discrepancy between earlier studies reported in the literature and, most importantly, provides further evidence for the influence of a solvent on ion reactions in clusters, and ion-molecule reactions in general.

• DOE Contract Number: FG02-88ER60648
• OSTI ID: 7071120
• Journal Information: Journal of the American Chemical Society; (USA), Vol. 111:16; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETONE
IONIZATION
CLUSTER MODEL
DATA ANALYSIS
DECOMPOSITION
EXPERIMENTAL DATA
ION-MOLECULE COLLISIONS
MEASURING INSTRUMENTS
MEASURING METHODS
PHOTOCHEMISTRY
SOLVENTS
CHEMICAL REACTIONS
CHEMISTRY
COLLISIONS
DATA
INFORMATION
ION COLLISIONS
KETONES
MATHEMATICAL MODELS
MOLECULE COLLISIONS
NUCLEAR MODELS
NUMERICAL DATA
ORGANIC COMPOUNDS
400201* - Chemical & Physicochemical Properties
400500 - Photochemistry