Fluorene-fullerene dyads: Modulation of interaction

Two new fullerene[C60]-fluorene dyads, N-methyl-2-(9-fluorenyl)-3,4-fulleropyrrolydine and N-methyl-2-(2-fluorenyl)-3,4-fulleropyrrolydine, were synthesized and investigated. Cyclic voltammetry, fluorescence experiments, electronic spectra and Density Functional Theory (DFT) calculations, all indicate ground and excited state interactions when fluorene is linked at carbon 9, whereas linkage through position 2 does not affect the ground and excited state of the fulleropyrrolidine moiety. As a consequence, only changing the position of the fluorene chromophore linkage, opens the way to modulate interactions, choosing between a simple spacer and an active unit.