KINETIC AND THERMODYNAMIC STUDIES OF GASEOUS METALLO-ORGANIC CATIONIC COMPLEXES
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Date
2009
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Journal ISSN
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Publisher
Ohio State University
Abstract
The construction of a custom fabricated photodissociation spectrometer permits the determination of thermodynamic properties (activation energies), reaction rates, and mechanistic details of bare metal cation mediated $\sigma $-bond activation in the gas phase. Specifically, the products and rates resulting from the unimolecular decomposition of the Ni$^+$Acetaldehyde adduct are monitored after absorption of a known amount of energy. The two dissociative products which are observed in high yield are Ni$^+$ and Ni$^+$CO. The Ni$^+$CO fragment ion could result from the activation of a C-C $\sigma$-bond or from the activation of a C-H $\sigma$-bond. The rate constant for the decarbonylation of Ni$^+$Acetaldehyde was approximately 30 percent greater than that of the rate constant for the decarbonylation of Ni$^+$Acetone. For the decarbonylation of Ni$^+$Acetone, there needs to be a methide shift, whereas in the decarbonylation of Ni$^+$Acetaldehyde one could have C-C insertion followed by an aldhyde H-shift. The rate-limiting step of the decarbonylation process will be discussed.
Description
Author Institution: Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798