| In this study, transition metal complexes have been covalently attached to a growing silica xerogel matrix by means of bifunctional ligands. Thermal decomposition of these silica xerogels has led to a wide variety of nanocomposites. When transition metal phosphine complexes are incorporated into a silica xerogel matrix, reductive thermal treatment of the xerogel in hydrogen yields transition metal phosphide nanoclusters in most cases. Alternatively, thermal oxidation of these molecularly doped silica xerogels in air yields nanocomposites containing metal oxide nanoclusters. When a combination of thermal air oxidation and reductive hydrogen treatment is utilized, elemental metal nanoclusters are produced. When transition metal thiolate complexes are incorporated into a silica xerogel, thermal decomposition of the silica xerogels under reducing conditions affords nanocomposites containing nanoclusters of elemental metal.;Using these techniques, we have prepared and characterized several metal, metal oxide, or transition metal phosphide nanocomposites. Specifically, the synthesis and characterization of five novel transition metal phosphide, two metal oxide, and seven metal nanocomposites have been reported in this dissertation. The preparation of these nanophase materials offers excellent opportunities to study the optical, catalytic, and magnetic properties of these new or rarely studied materials. |
