OligomerConjugation length and charge distribution in radical anions of one- and two-dimensional oligo (a) rylenes
Review articleOpen access
1993/04/19 Full-length article DOI: 10.1016/0379-6779(93)90821-D
Journal: Synthetic Metals
AbstractThe distribution of charge (spin) density over two-dimensional planar conjugated oligorylenes (1) is studied herein and compared to the results from one-dimensional oligoarylenes. The radical anions have been characterized by EPR/ENDOR and optical absorption spectroscopy. The spin density in the oligorylene anions tends to be partially localized at both ends of the two-dimensional π-band.It is also shown that the largest 1H hyperfine-coupling constants for all homologues show a similar convergence behaviour as found for the optical transition (λmax) at longest wavelength.In the singly bridged napthylenes and perylenes, the π-overlap between the subunits is drastically reduced and the intramolecular electron transfer in the monoanions depends sensitively upon the conditions of radical generation.A novel approach to soluble high molecular weight material with perylene subunits is described which can either be cyclized to conjugated polyrylenes or electronically decoupled by steric hindrance with nearly orthogonal alignment opening the possibility to yield high spin molecules.
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