FORMATION OF A NANOCOMPOSITE CONTAINING PARTICLES OF CO3C FROM A SINGLE-SOURCE PRECURSOR POUND TO A SILICA XEROGEL HOST MATRIX

Addition of the alkylidynetricobalt nonacarbonyl complex (HO)(3)SiCo3C (CO)(9) to a conventional sol-gel recipe for silica xerogel formation leads to apparent covalent incorporation of this cluster into the skel etal backbone of the xerogel matrix through the heterocondensation of Si-OH groups. Subsequent thermolysis of this purple, molecularly doped xerogel in a hydrogen atmosphere at 500 degrees C affords a black xer ogel nanocomposite containing particles of diameter 10-46 nm. TEM, EDS , XRD, and electron diffraction data indicate that the nanostructured material is predominantly Co3C with some Co3O4 also being present. For mation of Co3C as the sole cobalt carbide substance detected demonstra tes synthetic control of nanoparticle composition through the proper c hoice of core composition of a molecular precursor.