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Ferrocene-centered reagents can be bound to the surface of high surface area (400 m2/g) silica by reaction of the silica with alkane solutions of (1,1 '-ferrocenediyl)dichlorosiIane (la), (1,1 '-ferrocenediyl)dimethylsilane (lb), or (l.l'-ferrocenediyl)diphenylsilane (Ic). Derivatization is not found when ferrocene itself is used as the derivatization reagent; ferrocene is easily washed from the silica powder by solvents which do not affect the ferrocene centers bound upon reaction of the silica with la-c. As determined by photoacoustic spectroscopy, derivatization with Ia-c results in ring opening of the strained C-Si-C linkage bridging the two cyclopentadienyl rings to yield a simple, monosubstituted ferrocene center attached to the surface. Surface -OH functionality apparently reacts in a manner analogous to homogeneous solution sources of -OH such as MeOH. Reaction of lb with MeOD yields [Fe(p5-C5H4D)(t;5-C5H4Si(OMe)Me2)]. Optical absorption spectral changes accompanying reaction of Ia-c with solution sources of -OH are consistent with the differences found in the photoacoustic spectra of the pure powders of Ia-c compared to the silica powders derivatized with these reagents. Reaction of silica powders derivatized with Ia-c with acidic solutions of benzoquinone results in the oxidation of the surface-confined ferrocene centers to ferricenium centers giving photoacoustic spectra nearly the same as that from an authentic sample of a pure ferricenium salt. The surfaceconfined ferricenium can be used to oxidize Ar,A',A",A,-tetramethyl-p-phenylenediamine (TMPD) to TMPD+• in solution; this reaction allows an estimate of the surface coverage at 10"11 mol/cm2.

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