dioxide a t this wave length it is 5100. If one makes the extreme assumption that anthracene which is interacting with the solvent is completely transpare n t a t this wave length, then it must be concluded that no more than ti455 of the anthracene is free Thus no less than 3Gyo of the hydrocarbon is iii\olved in the interaction. I n view of the agreetnent of the spectral data for this compound with Heer's law, this holds at all concentrations. From these considerations it must be concluded that, coiltrarp t o the suggestion of M-eiss,ll the interaction between anthracene and sulfur dioxide cannot consist of coinplete electron transfer to yield the (radical) ion pair (C14HII))(SO, J . Such an ion pair would dissociate to about the same extent'? as the pair triphenylcarboniuni chloride which has been ihown' to have a dissociation constant in sulfur clrciuitie no smaller than 10 a t 0". It would yield cBriorniously greater conductances than those ob vmetl. T u the extent that the anthracene T N H ,ind anthracene-sulfur dioxide interactions are sitriilar, doubt is cast on 11-eiss' picture of the former < I \ well Acknowledgment. -One of us (K. E. \T.) gratefully d~-knowledgessupport of the spectrophotoinetric work by the Office of Kava1 Research (Coiitrdct No. N5ori-TB Task XX, with Harvard Uni1 ersity). The conductivity study was made possible by 3 Frederick Gardner Cottrell Grant made to Boston University by the Research Corpor,y the Shell Dr\rlopmcnt Cu.,b;ineryvill?, Calif. (in isouctane:; ' , t i l ref. ,;. p . 2lj4 (in carbon tetrachloride,: ic: \\-. V, XIayneord and l i . 1'. 11. Roe, Proc. 1 2 0 ~ ..Sue. ( 7 , i i r i d i i n l . 8 1 6 2 , l l g s j j (in ethanol), I!,]) K . J,:iuer .rl:d 1 1 . f l w i c , . ) ) I \ i T
