Document Type

Dissertation - Open Access

Award Date

1975

Degree Name

Doctor of Philosophy (PhD)

Department / School

Chemistry

First Advisor

Henry Gehrke, Jr.

Abstract

The purpose of this study was to examine the solution interactions of rhenium(V) chloride and oxotrichlorobis(triphenylphosphine)rhenium(V) in a continuation of studies of rhenium(V) chemistry. These goals were accomplished using vacuum line and Schlenk tube techniques. As a result of this work, rhenium(V) chloride was found to dissolve with reaction in 1, 4-dioxane, diethyl ether and acetone. There was only a very small amount of rhenium(V) chloride which dissolved in carbon tetrachloride, chloroform and cyclohexane. Part of what did dissolve was shown by electronic and infrared spectroscopy to be oxotetrachlororhenium(VI) which was present as an impurity in small amounts. Oxotetrachlororhenium(VI) reacts with triphenylphosphine in carbon tetrachloride to form tetrachloro(triphenylphosphinetriphenylphosphine oxide) rhenium(IV). The infrared spectra of rhenium(V) chloride was found to differ from reports in the literature. Supported by good correlations between x-ray powder data and calculated d- spacings from the crystal structure, the infrared spectrum in this study was more representative of rhenium(V) chloride than those reported. An examination of "aged" rhenium(V) chloride was made, which indicated that the differences in reactions of "aged" rheniun(V) chloride, and fresh rhenium{V) chloride are due to partial hydrolysis of rhenium(V) chloride. The reaction of rhenium(V) chloride, in acetone, with pyridine was examined, It was found that a stoichiometric amount of pyridine was required to obtain µ-oxodioxotetrachlorotetrakis(pyridine) dirhenium(V) from either ''aged" rhenium(V) chloride or fresh rheniun(V) chloride. An excess of pyridine caused the formation of dioxotetrakis(pyridine)­ rhenium(V) chloride dihydrate with either "aged” or fresh rhenium(V) chloride. Sealed tube reactions of oxotrichlorobis(triphenylphosphine)­ rhenium(V) with chloroform produced a variety of products which depended on the purity of the chloroform and the presence of excess triphenylphosphine. Tetrachlorobis(triphenylphosphine oxide)rhenium(IV) and tetrachlorobis(triphenylphosphine) were produced when stock chloroform was used. When stock chloroform and excess triphenylphosphine were used, bis(methyltriphenylphosphonium) hexachlororhenate was formed. Pure chloroform, excess triphenylphosphine and oxotrichlorobis(triphenylphosphine)rhenium(V) reacted, producing three products. Tentative formulations were suggested but required further work before a more positive formulation could be made. A proposed sequence of reactions based on the reaction of bromoform with triphenylphosphine was examined and was found to correlate much of the observed data from sealed tube reactions of oxotrichlorobis­ (triphenylphosphine)rhenium(V) with chloroform.

Library of Congress Subject Headings

Rhenium
Solvents

Format

application/pdf

Publisher

South Dakota State University

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Chemistry Commons

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