Synthesis and characterization of a novel iron (III) silsesquioxane compound

A new iron (III) containing silsesquioxane compound, [Bu4N][((CH3)2CHCH2)7Si7O12FeCl] (4) was prepared by reacting [Bu4N][FeCl4] (3) with the isobutyl substituted silsesquioxane trisilanol, ((CH3)2CHCH2)7Si7O12H3, (1) in the presence of three equivalents of triethylamine, Et3N (2). The magnetic susceptibility of 4 was measured by Evans method, and the effective magnetic moment, μeff, is consistent with a high spin Fe (III) center. The composition and molecular structure of 4 was fully determined by IR, elemental analysis, APCI mass spec, and X-ray crystal analyses, and its potential as a precursor to a model of the structure and chemistry of the Fe-ZSM-5 catalyst is discussed.