Degree Name

Master of Science (MS)

Semester of Degree Completion

1983

Thesis Director

Edward O. Sherman

Abstract

Dichlorocarbonyltris(triphenylphosphine)ruthenium (II), Ru(CO)(Cl)2(Ph3P)3, was prepared by modification of a procedure reported to yield the dimer, (Ru(CO)(Cl)2(Ph3P)2)2. Dissolution of Ru(CO)(Cl)2(Ph3P)3 in acetonitrile resulted in loss of triphenylphosphine and dimer formation.

Metathesis of Ru(CO)(Cl)2(Ph3P)3 in hexane with excess tertiary phosphine yielded complexes of the type Ru(CO)(Cl)2-(R2R′P)3 where R2R′P is Ph2MeP or PhMe2P. 1H and 31p nmr spectra of these materials showed that two phosphines are mutually trans and cis to the remaining phosphine ligand. This metathesis reaction could not be used with tertiary alkyl phosphine to prepare analogous compounds.

Potentiostatic reduction of Ru(CO)(Cl)2(Ph3P)3 in acetonitrile with excess Ph3P at a platinum cathode gave the zero valent complex, Ru(CO)(CH3CN)(Ph3P)3, in high yield. This compound has also been synthesized by electrolysis of the dimer mentioned above. The enhanced solubility of Ru(CO)(Cl)2(Ph3P)3 relative to the dimer results in shorter electrolysis times.

Attempts to metathesize Ru(CO)(CH3CN)(Ph3P)3 with Ph2MeP, PhMe2P or Et3P in acetonitrile yielded only mixtures of compounds as intractable oils.

Polarographic and voltammetric studies of Ru(CO)(Cl)2(Ph2MeP)3 and Ru(CO)(Cl)2(PhMe2P)3 in acetonitrile indicates that these materials are reduced irreversibly with the uptake of two electrons. Two electroactive species are formed in acetonitrile solutions of these compounds. These species arise from tertiary phosphine/acetonitrile exchange. Mass transport of the electroactive speciesis controlled by both kinetics and diffusion.

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