The spin density distribution in the radical anions of naphthalene-mono-, di- and -tetra-carboxylic esters is determined from the proton hfs coupling constants as measured by EPR spectroscopy and discussed in terms of semi-empirical MO calculations.

O-Alkyl naphthalenecarbothioates and bis-carbothioates are prepared by the reaction of the corresponding esters by use of Lawesson's reagent. The related naphthalenecarbodithioates are obtained (a) from methylnaphthalenes via bromination with NBS, subsequent methoxide-promoted reaction with sulfur, and finally alkylation of the carbodithioate salts with alkyl halides or (b) lithiation of bromonaphthalenes, reaction with carbon disulfide, and alkylation. The thiono- and dithioesters were transformed into persistent radical anions by in situ electroreduction. Spin density distributions were determined by EPR spectroscopy and MO calculations.