ON THE SPIN DISTRIBUTION IN BRIDGED ANTHRACENE VIOLOGEN MOLECULES - AN ELECTRON NUCLEAR DOUBLE-RESONANCE STUDY

Studies on the spin distribution in the radical state of anthracene-sigma-bridge-viologen supermolecules with different bridge units are reported. Electron-nuclear double resonance experiments (ENDOR) were performed on electro-chemically reduced molecules. Proton hyperfine coupling constants at different molecular sites were obtained and are discussed in detail. The experimentally determined values are compared with quantum chemical calculations of the INDO type. The observed spin distribution depends significantly on the type of the bridging unit. The relevance of the spin distribution for electron transfer in donor-bridge-acceptor molecular complexes is discussed.