Spectral manifestation of the vibronic shift and occurrence of the C60− anion in stable single crystals of (Ph4P)2C60Y, YCl, Br or I, and (Ph4As)2C60Cl

Electronic and vibrational spectroscopy were used to study the electronic processes in charge-transfer complexes of fullerene and tetraphenylphosphornium or tetraphenylarsenium halides. These fully ionic crystalline complexes feature the occurrence of C60 monoanions and the onset of charged phonon behavior, all of which were observed and discussed. The large downshift, the strong enhancement of the linewidth and of the oscillator strength were observed for the highest frequency F1u mode of C60 in solid state complexes of fullerene and organic donors.