Photoprocesses associated with the complexation of a pyridine-functionalized C60 fullerene derivative to ruthenium- and zinc-tetraphenylporphyrins (tpp) have been studied by time-resolved optical and transient EPR spectroscopies. It has been found that upon irradiation in toluene, a highly efficient triplet-triplet energy transfer governs the deactivation of the photoexcited [Ru(tpp)], while electron transfer (ET) from the porphyrin to the fullerene prevails in polar solvents. Complexation of [Zn(tpp)] by the fullerene derivative is reversible and, following excitation of the [Zn(tpp)], gives rise to very efficient charge separation. In fluid polar solvents such as THF and benzonitrile, radical-ion pairs (RPs) are generated both by intramolecular ET inside the complex and by intermolecular ET in the uncomplexed form. Charge-separated states have lifetimes of about 10 micros in THF and several hundred of microseconds in benzonitrile at room temperature.

Transient EPR spectroscopy has been applied to measure the spectra of excited triplet states in two series of fullerene bisadducts. Eight different bisadducts of C60 with bis(ethoxycarbonyl)methylene and five bis-N-methylpyrrolidines have been analyzed. The D and E parameters of electron dipolar interaction and the populations of the zero field triplet sublevels, accounting for spin polarization, have been determined by spectrum simulation. They appear peculiar for each bisadduct. It is shown that triplet EPR technique represents a useful spectroscopic tool that allows structural assignments to bisadducts of C60.

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The formation of high-quality Langmuir-Blodgett films of copper and nickel phthalocyanine derivatives substituted with short branched chains is reported. Ellipsometric and polarized optical absorption measurements suggest that the phthalocyanine molecules have a preferred orientation, with their large faces perpendicular to the dipping direction and to the substrate plane. Electrochromic effects are also noted in these multilayer films.