A QUANTITATIVE SPECTROPHOTOMETRIC STUDY OF INTERACTIONS BETWEEN IODINE AND ARYL METHYL SULFIDES IN CARBON TETRACHLORIDE,

Mixtures of aryl methyl sulfides and iodine in carbon tetrachloride have two charge-transfer absorption bands with maxima located near 3050 A and between 3380 and 3525 A respectively. Computer analysis of spectrophotometric data for these systems at 20 and 45 C showed that 1 data collected between 3300 and 3600 A are con sistent with the simultaneous reversible forma tion of two isomeric oneone complexes between the sulfide and iodine, and that 2 data between 2900 and 3100 A the region where the sulfides absorb cannot be explained by the simultaneous reversible formation of two isomeric oneone complexes. Only for the o-tolyl methyl sulfide iodine complex do the mean molar absorptivities in the long wavelength band increases as the temperature is increased. Thermodynamic and spectroscopic constants for the iodine complexes with thioanisole and with o-, m-, and p-tolyl methyl sulfides in carbon tetrachloride are given. Contact charge-transfer and charge transfer theories are considered. Author