FORMATION OF CRYSTALLINE NANOCLUSTERS OF FE2P, RUP, CO2P, RH2P, NI2P,PD5P2, OR PTP2 IN A SILICA XEROGEL MATRIX FROM SINGLE-SOURCE MOLECULAR PRECURSORS

Metal complexes containing bifunctional phosphine ligands that possess alkoxysilyl functional groups have been prepared for seven metals of the first, second, or third transition metal series. Incorporation of these single-source precursors into silica xerogel matrixes using sol- gel chemistry affords molecularly doped xerogels. Subsequent thermal t reatment of these doped xerogels under solely reducing conditions sele ctively affords nanoclusters of Fe2P, RuP, Co2P, Rh2P, Ni2P, Pd5P2, or PtP2 which are highly dispersed throughout the bulk of the xerogel ma trix. Characterization of these nanocomposite materials by transmissio n electron microscopy, energy-dispersive spectrometry, X-ray diffracti on, and electron diffraction indicates that the metal phosphide nanocl usters are highly crystalline with some exhibiting nonspherical morpho logy.