Absolute Rate Expressions for Hydrogen Atom Abstraction from Molybdenum Hydrides by Carbon-Centered Radicals
| Autor: | Jerome C. Birnbaum, Mikhail S. Alnajjar, Kenneth W. Hicks, John C. Linehan, James A. Franz |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
chemistry.chemical_classification
Dodecane Hydride chemistry.chemical_element Absolute rate General Chemistry Hydrogen atom abstraction Photochemistry Biochemistry Medicinal chemistry Catalysis chemistry.chemical_compound Colloid and Surface Chemistry Reaction rate constant chemistry Molybdenum Benzene Alkyl |
| Zdroj: | Journal of the American Chemical Society. 121:9824-9830 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja991412e |
| Popis: | A new family of basis rate expressions for hydrogen atom abstraction by primary, secondary, and tertiary alkyl radicals in dodecane and benzyl radical in benzene from the molybdenum hydride Cp*Mo(CO)3H and for reactions of a primary alkyl radical with CpMo(CO)3H in dodecane are reported (Cp* = η5-pentamethylcyclopentadienyl, Cp = η5-cyclopentadienyl). Rate expressions for reaction of primary, secondary, and tertiary radical clocks with Cp*Mo(CO)3H were as follow: for hex-5-enyl, log(k/M-1 s-1) = (9.27 ± 0.13) − (1.36 ± 0.22)/θ, θ = 2.303RT kcal/mol; for hept-6-en-2-yl, log(k/M-1 s-1) = (9.12 ± 0.42) − (1.91 ± 0.74)/θ; and for 2-methylhept-6-en-2-yl, log(k/M-1 s-1) = (9.36 ± 0.18) − (3.19 ± 0.30)/θ (errors are 2σ). Hydrogen atom abstraction from CpMo(CO)3H by hex-5-enyl is described by log(k/M-1 s-1) = (9.53 ± 0.34) − (1.24 ± 0.62)/θ. Relative rate constants for 1°:2°:3° alkyl radicals were found to be 26:7:1 at 298 K. Benzyl radical was found to react 1.4 times faster than tertiary alkyl radical. The muc... |
| Databáze: | OpenAIRE |
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