New property of the fullerenes:: the anomalously effective quenching of electronically excited states owing to energy transfer to the C70 and C60 molecules

The quenching of the electronically excited states of various energy donors-Tb3+; 9,10-anthracene dibromide; and adamantanone-by C-70 fullerene has been detected and analyzed. The quenching is characterized by anomalously high biomolecular quenching rate constants, which are obtained from the Stern-Volmer dependences of the energy-donor photoluminescence intensity on the concentration of the C-70 molecules. It has been shown that the high efficiency of quenching by the C-70 fullerene as compared to the C-60 fullerene is due to the higher polarizability of the C-70 molecule and large overlap integrals of the energy-donor photoluminescence spectra with the absorption spectrum of the C-70 fullerene.