FORMATION OF CRYSTALLINE NANOCLUSTERS OF AG, CU, OS, PD, PT, RE, OR RU IN A SILICA XEROGEL MATRIX FROM SINGLE-SOURCE MOLECULAR PRECURSORS

Metal complexes containing bifunctional ligands which possess alkoxysi lyl functional groups have been prepared for seven metals of the first , second, or third transition metal series. Incorporation of these sin gle-source precursors into silica xerogel matrixes using sol-gel chemi stry affords molecularly doped xerogels. Subsequent thermal treatment of these doped xerogels under reducing or oxidizing-then-reducing cond itions affords nanoclusters of Ag, Cu, Os, Pd, Pt, Re, or Ru which are highly dispersed throughout the bulk of the xerogel matrix. Character ization of these nanocomposite materials by TEM, EDS, XRD, and electro n diffraction indicates that the metal nanoclusters are highly crystal line. A visible spectrum of the silver nanocomposite shows the expecte d surface plasmon resonance near 415 nm.