Iodine Complexes in Inert Solvents. III. Iodine Complexes with Methanol, Ethanol, or Diethyl Ether in Carbon Tetrachloride

Abstract

Thermodynamic and spectroscopic constants, obtained by a spectrophotometric method, are reported for complexes of methanol, ethanol, and diethyl ether with iodine in carbon tetrachloride. It is shown that the heats of formation of the complexes are nearly identical with values obtained by a nonspectroscopic method. From the spectroscopic and nonspectroscopic data for solutions of methanol, ethanol, and diethyl ether with iodine or with iodine and carbon tetrachloride, it is concluded that the activity coefficients for the iodine and the alcohols are independent of their concentrations and that in these cases the alcohols do not solvate the complexes even at concentrations of nearly one hundred percent alcohol. Exact molar extinction coefficients for iodine in n‐heptane and in carbon tetrachloride are given in Table I, and related data in Fig. 2. There is a detailed discussion of errors due to the neglect of temperature effects, underlying bands, and volume changes on mixing the solvents. Evidence in support of ``Liquid Lattice Penetration Complex'' theory, in which it is assumed that the stabilizing forces arise from ``donor‐acceptor'' interaction, is also discussed. It is found that Andrews and Keefer's linear relations between ΔF and ΔH or ΔS, for the aromatic complexes of iodine, do not hold for all iodine complexes.