A QUANTITATIVE-ANALYSIS OF THE UV-VISIBLE ABSORPTION-SPECTRA OF THE PRODUCTS DERIVED FROM THE NONALTERNANT HYDROCARBON FLUORANTHENE VIA ELECTROLYSIS OR ALKALI-METAL REDUCTION IN THE SOLVENTS HMPA AND THF

The non-alternant aromatic hydrocarbon fluoranthene has been reduced i n the solvents HMPA (Hexamethylphosphoric triamide) and THF (tetrahydr ofuran), either by electrolysis or by reaction with Na or Li. The spec ies thus produced have been characterized by UV-visible absorption spe ctroscopy. In both solvents and regardless the synthetic preparation m ethod used, the radical anion Ar- displays almost identical absorption s. The species formed by further reduction show highly different optic al transitions in HMPA and in THF. This is rationalized in terms of a normal dianion in THF. The exact nature of the second species (hereaft er ''X'') obtained in HMPA is still debatable. Indeed, ''X'' reacts wi th aqueous HCl to yield ArH4 and ArH3-ArH3 as expected for a dianion b ut on the other hand, the addition of an excess of fluoranthene to a s olution of ''X'' does not lead to the aromatic monoanion by dismutatio n.