C60-based dumbbells:: connecting C60 cages through electroactive bridges

Recent examples of C-60 dumbbells covalently linked by different electron-donor fragments (porphyrins, pi-conjugated oligomers, TTFs, etc.) are summarized and their main properties highlighted. Although, similarly to the related C-60-donor dyads, no significant electronic interaction has been observed between the three electroactive components in the ground state, namely two C-60 units and the electron-donor fragment, the presence of a second C-60 cage provides enhanced photophysical properties to the final triads in comparison to the related dyads. These findings suggest the presence of a cooperative effect. Some of these C-60 dumbbell triads have been applied in the construction of photovoltaic devices and the results obtained indicate that they can play a very active role in the emerging field of optoelectronic devices.