THERMOCHEMISTRY OF MOLECULAR-COMPLEXES .5. MOLECULAR-COMPLEXES OF I-2 WITH ETHYLBENZENES AND N-ALKYLBENZENES

The enthalpies of formation and equilibrium constants are reported for molecular complexes of I-2 with five ethylbenzene and nine n-alkylbenzene donor molecules in CCl4. The wavelength of maximum absorbance for each complex is also reported. For ethylbenzene donor molecules, the formation enthalpy and equilibrium constant for the complexes depend strongly on the number of ethyl groups attached to the benzene ring, but only weakly on the position of the groups. For the n-alkylbenzene donor molecules, both the formation enthalpy and equilibrium constant for complex formation are independent of the length of the alkyl chain. These results are consistent with previous observations on weak complexes of I-2 with substituted benzene donors.