Degree Name

Master of Science (MS)

Semester of Degree Completion

1980

Thesis Director

Edward O. Sherman

Abstract

The catalytic activity of the compounds used in this study, Ru[P(C6H5)3]4 (η2-CH3CN)⋅CH3CN, Ru(CO)[P(C6H5)3]3CH3CN, Ru(CO)2[P(C6H5)3]3, Fe(CO)2[P(C6H5)3]3 was compared using the isomerization of allylbenzene to β-methylstyrene as the test reaction. The measured decreasing order of reactivity for these complexes is: Ru(CO)[P(C6H5)3]3CH3CN > Ru[P(C6H5)3]4 (η2-CH3CN)⋅CH3CN > Ru(CO)2[P(C6H5)3]3 > Fe(CO)2[P(C6H5)3]3. Mechanisms for the isomerization reaction using the different compounds have been proposed. An intermediate of the formula, Ru(CO)[P(C6H5)3]2 (C3H5C6H5), was isolated in the reaction of Ru(CO)[P(C6H5)3]3 (CH3CN) with a 400-fold excess of allylbenzene. The isolated complex supports a coordinatively-unsaturated ruthenium (0) species in the proposed mechanism for this complex.

The relative amounts of cis and trans β-methylstyrene produced in the reactions were measured and the data suggests that the two isomers of β-methylstyrene are not produced directly in the thermodynamic ratio. The interconversion of cis to trans β-methylstyrene is proposed to occur in a reaction that is simultaneous with the isomerization of allylbenzene to β-methylstyrene. Detection of this reaction had not been possible previously. The rate of interconversion of cis to trans β-methylstyrene appears to parallel the rate of olefin isomerization.

The compounds, Fe(CO)2[P(C6H5)3]3 and Ru(CO)2[P(C6H5)3]3, have been shown to oxidatively add to methyl iodide, producing Fe(CO)2[P(C6H5)]2(CH3)(I) and Ru(CO)2[P(C6H5)3]2(CH3)(I), respectively.

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