Oligomeric tetrathiafulvalenes in supramolecular chemistry
A range of highly ordered dendritic and oligomeric macromolecules, functionalised with tetrathiafulvalene (TTF) derivatives as a redox-active sub-unit were assembled. In particular, the first dendritic macromolecules incorporating TTF were constructed by the reaction of poly-acid chlorides and alcohol functionalities. Electrochemical techniques showed the novel redox-superstructures to be efficient π-electron donors that are able to undergo two reversible, multi-electron-on oxidations. The TTF-units were established to be acting independently, and the extent to which the redox groups could be oxidised was evaluated. UV studies demonstrated the redox- assemblies to be capable of forming charge-transfer complexes m solution and showed potential for the formation of conducting charge-transfer complexes. Preliminary studies showed the precursors to these compounds to be suitable for use as electrochemical detectors for dopamine. Structural variation of the core units increased the air and thermal stability of the dendritic materials, whilst retaining the characteristics of the multi-redox system. These systems formed stable aggregates of the radical cation and afforded conducting charge- transfer complexes with TCNQ. The new precursors to multi-TTF systems were then used in attempts to impart redox characteristics on pseudorotaxanes and rotaxanes. Preliminary attempts were made to assemble multi-TTF systems using a TTF derivative as a core and at the periphery.