Formation of a Nanocomposite Containing Particles of C0₃C from a Single-Source Precursor Bound to a Silica Xerogel Host Matrix

Addition of the alkylidynetricobalt nonacarbonyl complex (HO)₃SiCo₃C(CO)₉ to a conventional sol-gel recipe for silica xerogel formation leads to apparent covalent incorporation of this cluster into the skeletal 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 °C affords a black xerogel nanocomposite containing particles of diameter 10-46 nm. TEM, EDS, XRD, and electron diffraction data indicate that the nanostructured material is predominantly C0₃C with some C0₃O₄ also being present. Formation of C0₃C as the sole cobalt carbide substance detected demonstrates synthetic control of nanoparticle composition through the proper choice of core composition of a molecular precursor.