FLUORESCENCE OF C60 IN SOLUTIONS AT ROOM TEMPERATURE

Abstract: Strong, medium and weak fluorescence spectra for C60 in different solutions at room temperature are reported for the first time, which indicate that intensity of fluorescence is dependent on the interaction between C60 and solvent. It is shown that the solvents of effective electron donors could make a comparatively strong interaction with fullerenes due to the formation of the charge transfer adduct, which could greatly distort the molecular symmetry and lead to the strong fluorescence. Since the discovery of fullerene, the photophysical properties of C60 have been extensively studied [1-3]. However, the low-lying electronic transitions in C60 are weakly allowed due to the high icosahedral symmetry of C60, which leads to the small fluorescence radiative. The environmental effects, the rare gas matrix perturbation effect and the low-temperature effect, for example, could relax the selection rules of C60 and lead to a high fluorescence radiation rate [4-5]. However, few reports about fluorescence spectra of fullerenes at room-temperature solutions have been reported, and only weak and broad fluorescence spectra for C60 were observed [6-7]. At room temperature, in commonly employed solutions such as toluene, benzene, CCl4 et al, the fullerenes tend to preserve highly molecular symmetry