Studies in materials chemistry: I. Fluorine substitution in tetrathiafulvalenes and macrocycles. II. A new 1,2-dithiolene complex as a precursor to conductive materials

This research project consisted of two parts. First, the effect of fluorine substitution in the area of materials chemistry was investigated. A novel tetrathiafulvalene (TTF) derivative, octafluorodibenzotetrathiafulvalene (F{dollar}sb8{dollar}-DBTTF), was synthesized. It is unique because it is the first TTF derivative with fluorine directly attached to the {dollar}pi{dollar} system of the TTF moiety, allowing for an investigation of the {dollar}pi{dollar}-donating ability of fluorine on the TTF system. It was found that the oxidation potentials of the TTF donor were increased by fluorine substitution, but the positive charge on the oxidized form of the donor was not destabilized by the presence of these fluorine atoms, relative to hydrogen. Attempts to isolate a charge-transfer salt gave no product, as any products resulting from the oxidation of F{dollar}sb8{dollar}-DBTTF failed to form a crystalline product.; Also, the effects of fluorine substitution were examined in a macrocyclic system. The effects of the substitution of two trifluoromethyl groups in a tetraaza (14) annulene macrocycle were studied. It was found that the fluorinated macrocycle was more resistant to oxidation, as expected. In addition, it was found that the fluorinated macrocycle was able to electrocatalytically reduce CO{dollar}sb2{dollar} at a potential of {dollar}-{dollar}1.06 V vs. S.C.E. This represents a tremendous advance, as this is some 0.60 V more positive than in the case of the parent macrocycle.; The second part of this project, the nickel(III) complex of a new 1,2-dithiolene was synthesized as a precursor to conductive materials. This dithiolene, 1,3-dithiole-4,5-dithiolate (MDDT{dollar}sp{lcub}2-{rcub}{dollar}) is structurally related to the ligand DDDT{dollar}sp{lcub}2-{rcub}{dollar}, with MDDT{dollar}sp{lcub}2-{rcub}{dollar} containing one less carbon in the backbone ring. The complex Ni(MDDT){dollar}sb2sp-{dollar} exhibits an irreversible oxidation at +0.72 V and an irreversible reduction at {dollar}-{dollar}1.13 V.