ADSORPTIVE AND CATALYTIC PROPERTIES OF ISOLATED UNITS OF [FE4S4(SR)4]2-

Reaction of 3-mercaptopropyltrimethoxysilane with wide pore silica gel produced a gel with surface ≡ SiCH2CH2CH2SH groups. Exchange between RS- groups occurred when this material was exposed to [Fe4S4(S-t-Bu)4]-[(n-Bu)4N]2 in acetonitrile, to produce a silica gel containing the Fe4S4 unit bound to the surface with accompanying n-Bu4N+ counterions. Since the n-Bu4N+ ion decomposed at about 1 10 °C, a gel in which this ion had been replaced by Ca2+ was also prepared. These Fe4S4-attached gels exhibited no catalytic activity for the hydrogenation of carbon monoxide, ethylene, propylene, 1, 3-butadiene, or acetylene at 25-250 °C nor for the oxidation of hydrogen, carbon monoxide, ethylene, or 1.3-butadiene at 25-100 °C. Significant adsorption of carbon monoxide and hydrogen appeared only at subzero temperatures and it was not clear whether such adsorption should be characterized as strong physisorption or very weak chemisorption. Copyright © 1979, American Chemical Society. All rights reserved.