Iodine Complexes in Inert Solvents. II. Complexes of Iodine with Some Aromatic Ethers and Biphenyl in Carbon Tetrachloride

Abstract

Characteristic constants and absorption spectra are given for anisole, p-dimethoxy-benzene, o- and p-methoxy-biphenyl, and biphenyl complexes with iodine, as determined in carbon tetrachloride solution near room temperature. Three absorption maxima are found for the anisole-iodine complex: at 4900 A, 3450 A, and 2950 A. The band near 4900 A is attributed to a modified iodine transition, while the two ultraviolet bands are attributed to the formation of two isomeric charge-transfer complexes. The two non-degenerate anisole donor orbitals, with different ionization potentials, are supposed to correspond to the degenerate pair of benzene e1g molecular orbitals. The ultraviolet absorption spectra found for the other iodine complexes are interpreted similarly. A method for estimating the two equilibrium constants and the two extinction curves for such complexes, having isomeric forms, is suggested.