Resonance fluorene anion

INDO and McLachlan-modified HMO calculations have been conducted to help interpret the electron spin resonance (ESR) spectrum of cation radical (120) <78JPC1181> which is generated by protonation of (98) in TFA followed by reduction with zinc of the resultant dication (119) (Scheme 1) <63TL95>. The calculated energy level of the HOMO for (120) is of lower energy than that of the isoelectronic fluorene anion radical in both the INDO and HMO approximations. Similar calculations have been conducted to explain the ENDOR spectrum of (120) <84CPL398>. 

The electropolymerization of fluorene (Fig. 26) produces a polymer with a conductivity of 10 S cm. By functionalizing carbon 9 of the five-membered ring, substituted fluorenes have also been oxidized to form polymers of 9-methylfluorene, 9,9 -dimethylfluorene, and 9-phenylfluorene. These polymers gave comparable voltammograms, which seems to indicate that the substituents are not directly involved in the polymerizations. The doped polymers contained tetrafluoroborate anions, but their conductivities were very low [382,383]. The samples were analyzed by elemental analysis, infrared spectroscopy, electron spin resonance, and scanning electron microscopy. 

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