Synthesis of FeBr 3-cyclodextrin complexes in non-aqueous solution

Abstract

Mixing FeBr 3 either solid or dissolved in ethyl ether, in acetonitrile or in dichloromethane with solid β-cyclodextrin, form different type of FeBr 3-cyclodextrin complexes as indicated by their stoichiometric composition and thermal and spectroscopic properties. The complexes are stable under usual atmospheric conditions. Water solutions of FeBr 3 at pH 12 containing cyclodextrin are stable over 24 h. The solid complexes were characterized by DSC and TGA analysis as well as by IR spectroscopy. It is shown that the complexes obtained from the reaction of solid cyclodextrin with FeBr 3 dissolved in ethyl ether, acetonitrile, or dichloromethane catalyze the oxidation of methyl phenyl sulfide to methyl phenyl sulfoxide although in different yields. The best complex for this purpose is the one prepared in CH 2Cl 2 which afforded the sulfoxide in good yield.