SUPRAMOLECULAR COMPLEXES OF PHOTOEXCITED FUNCTIONALIZED FULLERENES AND SPIN LABELED ALKYL AMMONIUM DERIVATIVES

摘要

The formation of host-guest complexes of triplet excited fullerene derivatives and nitroxide radicals was monitored by TR-EPR. C_(60) functionalized with crown ethers and nitroxide radicals bearing an ammonium group have been investigated. The TR-EPR spectra of these systems, which are able to form host-guest complexes have been compared with those obtained with different fullerene derivatives and nitroxide radicals not expected to associate. The spectra of the host-guest complexes showed features peculiar of the quartet state of the coupled radical triplet system. The species with no supramolecular association gave the simple superposition of the triplet and the nitroxide radical spectra. For both cases simulations have been performed on the spectra obtained at different temperatures. The spectral changes have been related to the kinetics of the association-dissociation process.