Donor-pi-Acceptor systems containing extended TTF derivatives with quinonoid structures have been synthesized and characterized. Their properties as second order NLO chromophores have been studied by experimental (EFISH) and theoretical methods. (C) 1998 Elsevier Science Ltd. All rights reserved.
New π-extended tetrathiafulvalene-containing fulleropyrrolidine dyads endowed with vinyl spacers
The synthesis of novel C-60-donor dyads in which the fulleropyrrolidine moiety is covalently attached to an pi-extended tetrathiafulvalene analogue through an ethylenic spacer is described. The cyclic voltammetry confirms the redox reactivity of both donor and acceptor chromophores and the semiempirical PM3 theoretical calculations predict the existence of two conformational isomers. In the ground state, no evidence of charge transfer interaction was observed in solution. Upon excitation, the fullerene singlet excited state in C-60-donor dyads is subject to a solvent-dependent, rapid fluorescence quenching, suggesting an intramolecular electron transfer. (C) 2000 Elsevier Science S.A. All rights reserved.