Abstract:
Macrocyclic oligothiophenes are attractive synthetic targets for their appealing -conjugation and as potential candidates for applications in organic electronics. The framework also serves as model systems to explore the effect of delocalization in large macrocycles. This thesis will describe the first one pot synthesis of macrocyclic oligothiophenes bearing 4n, (4n+2) and (4n+1) from commercially available precursors. The isolation of a free-radical with 25 electrons and its amphoteric behaviour has been discovered under ambient conditions. The details of characterizion in solution and solid states along with photo-physical properties and redox activity were discussed in detail. The ability of 4n macrocyclic systems (32 and 48) to undergo reversible two electron redox between antiaromatic and aromatic states has been explored for the first time. Both (32 and 48) undergo reversible oxidation to form 30 and 46 aromatic dication. Depending on the size of the macrocycle, the dicationic species were found to be either diamagnetic or paramagnetic in nature.
