Electron absorption spectroscopy study of the iodine intercalated charge transfer complexes of C-60 with organic donors

Electronic absorption spectroscopy was applied to study the electron processes in the iodine doped charge transfer (CT) complexes of C-60 With two different organic donors, i.e., tetramethylenedithiodimethyl-tetrathiafulvalene (TMDTDM-TTF) and 2,2',6,6'-tetraphenyldipyranilydene (TPDP). Evolution of the electronic absorption spectra for the progressively iodine intercalated complexes has been investigated and discussed. It was shown that the iodine can intercalate the crystalline CT complexes of the fullerene under mild conditions as opposed to intercalation of the solid fullerite. The role of the charge transfer processes between the donor and C-60, as well as between iodine and the organic donor, is discussed. Extensive doping with iodine of a C-60 complex leads to the increase of separation of the fullerene molecules.