Comparing the spin density distribution in radical anions of several different oligomeric /spl pi/-chains

Summary form only given. We have studied the spin density distribution in a large number of radical ions, of oligomeric series of differently linked /spl pi/-systems as oligo-(ortho-, meta-, and paraphenylenevinylene)s la-c, oligoenes 2, -naphthylenes 3, -anthryienes 4, and -rylenos 5 by EPR/ENDOR and optical absorption spectroscopy. The results obtained show very different features depending on the geometry, the topology of the /spl pi/-systern, the chain ends and counter ion effects. Upon chain length extension both methods yield supplementary data allowing for a much deeper insight into characteristic molecular properties as limit of conjugation, bond length alternation patterns and structural reorganization upon charging.