Buckyball as an Electron Donor in a Dyad of C60 and Xanthene Dye

We successfully achieved the synthesis of C-60-xanthlium, X60_NTf2, where fullerene is an electron donor and xanthlium is an electron acceptor. When the precursor compound X60-OH was excited at 550 nm, the C-60 emission was observed at 715 nm. On the other hand, the fluorescence of X60_NTf2 was completely quenched under the same conditions, suggesting that photo-induced intramolecular electron transfer (ET) occurred from the singlet excited state of C-60. The electrochemical measurement proved that the X60_NTf2 is exothermically possible of ET reaction from C-1(60)* to xanthylium to form C-60(.+). Density functional theory (DFT) calculations support the acceptor ability of the xanthylium by showing that the coefficients of the lowest unoccupied molecular orbital (LUMO) were on xanthene moiety. This is a well-arranged model compound to investigate the properties of transiently generated fullerene radical cations.

Automated summary

The study successfully synthesized C-60-xanthlium, X60_NTf2, with fullerene as an electron donor and xanthlium as an electron acceptor. Experimental results showed photo-induced intramolecular electron transfer from the singlet excited state of C-60 to xanthlium. Additionally, electrochemical measurements and DFT calculations supported the acceptor ability of xanthene moiety in X60_NTf2. This model compound is useful for investigating properties of transiently generated fullerene radical cations.