Oligofluorene molecular wires in donor-acceptor conjugates

The molecular wire behaviour of oligofluorenes has been investigated by the synthesis of novel covalently bound fluorene-C(_60) derivatives. Firstly, oligofluorene derivatives containing one or two pyrrolidinofullerene units at their termini (51 and 53) were synthesized and their electronic properties investigated. This was followed up by the preparation of donor-acceptor conjugates - using C(_60) as acceptor - whereby fluorene is utilised as connecting unit. Triads containing different electron donors such as p-quinonoid π-extended tetrathiafulvalene (exTTF), zinc(II) porphyrin (ZnP) and ferrocene (Fc) were synthesised, i.e. 57, 68, 74 and 80 respectively. The electrochemical and photophysical behaviour of 57 has been discussed, together with the electrochemical studies of 68, 74 and 80. Photophysical studies for the latter three are currently being undertaken. Additionally, we herein report the investigation of novel DTPY- C(_60) dyad 88 and the synthesis of two thiol terminated fluorene-pyrrolidinofullerene derivatives 96a,b.