σ-Bond Metathesis Reactions of Sc(CH_3)_2^+ with Secondary C−H Bonds: Reactivity with Cyclohexane and Cyclopentane
Abstract
Fourier transform ion cyclotron resonance mass spectrometry has been used to examine the σ-bond metathesis reactions of Sc(CH_3)_2^+ with the secondary C−H bonds of cyclohexane and cyclopentane. Methane elimination, accompanied by further dehydrogenation, is the initial and dominant reaction observed. These processes are facile at room temperature and involve little or no activation energy. Measured total bimolecular rate constants for the reaction of Sc(CH_3)_2^+ with cyclohexane and cyclopentane are 6.2 × 10^(-10) and 5.1 × 10^(-10) cm^3 s^(-1) molecule^(-1), respectively. The total bimolecular rate constant for the reaction of Sc(CD_3)_2^+ with cyclohexane is measured to be 6.6 × 10^(-10) cm^3 s^(-1) molecule^(-1). In accordance with earlier theoretical predictions these metathesis reactions appear to proceed via an allowed four-center mechanism similar to that of a 2_σ + 2_σ cycloaddition. The observed gas phase reactivity is also compared to the liquid phase reactivity of similar complexes and the implications are discussed.
Additional Information
© 1996 American Chemical Society. Received June 18, 1996. This work was supported by the National Science Foundation under Grant CHE-9108318 and by a grant from AMOCO. We also wish to acknowledge the Beckman Foundation and Institute for continuing support of the FT-ICR research facility.Additional details
- Alternative title
- σ-Bond Metathesis Reactions of Sc(CH3)2+ with Secondary C−H Bonds: Reactivity with Cyclohexane and Cyclopentane
- Eprint ID
- 86480
- Resolver ID
- CaltechAUTHORS:20180518-162114141
- NSF
- CHE-9108318
- Amoco
- Arnold and Mabel Beckman Foundation
- Caltech Beckman Institute
- Created
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2018-05-21Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field