Doctoral Dissertations

Date of Award

6-1982

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Chemistry

Major Professor

James Q. Chambers

Committee Members

Clifton Woods, Eldredge J. Kennedy

Abstract

Thiophosgene was reduced electrochemically in acetonitrile to a mixture of products which included an insoluble primarily carbon sulfur polymer and a soluble chlorine-rich oligomeric anion. The solid product, which precipitates during electrolyses, possesses spectral properties similar to those of a polymer realized from monomeric carbon sulfide in gas-phase reactions. Cyclic voltammograms showed one main reduction wave; this wave exhibited passivation behavior on repeat cycles at several types of solid electrodes. Various experiments designed to circumvent this phenomenon were attempted. The release of chloride ions during this reduction process was detected voltammetrically. Coulometric experiments in which reticulated vitreous carbon electrodes were employed yielded an n-value of about 1.0 F mol-1 for the main reduction process. A partial reduction mechanism which fits the results obtained in these experiments is proposed.

Further electrochemical and spectroscopic studies on tetramercaptotetrathiafulvalene have been pursued. The solid product isolated from the synthetic reaction was apparently partially oxidized or reacted upon workup. The results from these experiments are compared with an earlier study on this species. Electrochemical oxidation of this solid in N,N'-dimethylformamide resulted in the deposition of a film on the electrode surface. This film was studied with a variety of techniques. Evidence indicates that the film includes partially-oxidized tetrathiafulvalene units linked through disulfide bridges into an oligomeric structure. The original solid was also oxidized by air to yield a brown solid with properties different from those of the electrochemical oxidation product. The addition of oxygen to form sulfoxide moieties in the material is apparent. This material, when oxidized electrochemically, also formed a film on the electrode. Two very different films were obtained, according to voltammetric results. One sample produced a complex voltammogram; this result was not reproducible, however. In all other cases, the film was reduced to a soluble species which diffused away from the electrode surface.

Several unsuccessful experiments in which the synthesis of bimetallic complexes was attempted using Ru(bpy)2Cl2 and tetramercaptotetrathiafulvalene are also described.

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