INORGANIC GRIGNARD-REAGENTS - PREPARATION AND THEIR APPLICATION FOR THE SYNTHESIS OF HIGHLY-ACTIVE METALS, INTERMETALLICS, AND ALLOYS

NiCl2, FeCl2, PdCl2, PtCl2, RuCl3, RhCl3, and IrCl3 react with excess amounts of ''active magnesium'' (Mg*) or diethylmagnesium (Et(2)Mg) in THF generating soluble bimetallic species with the generalized formula [M(1)(MgCl)(m) . (MgCl2)(p)], m = 1-3, p = 0-1 (''inorganic Grignard reagents''). In the Ru- and Ir-Mg-Cl systems, it appears that two different metal Grignard reagents, [Ru(MgCl)(2) . 0.5MgCl(2)] (8a) or [IrMgCl . MgCl2] (10a) and [M'(MgCl)(3)], M' = Ru (8b) or Ir (10b), can be prepared through application of Et(2)Mg and Mg* respectively. Hydrolysis or alcoholysis of THF solutions containing the inorganic Grignard reagents deliver finely divided, X-ray amorphous metals M(1) (usually) hydrogen gas and the corresponding Mg salts. The inorganic Grignard reagents in THF react with metal chlorides M(2)Cl(n) in the molar ratio of n:m with the precipitation of nanoparticulate intermetallics or alloys M(n)(1)M(m)(2) according to equation n[M(1)(MgC1)(m) . (MgCl2)(p)] + mM(2)Cl(n) --> M(n)(1)M(m)(2) down arrow + (mn + p)MgCl2. The isolated X-ray amorphous intermetallics or alloys were characterized by Fe-57 Mossbauer spectroscopy (where M(2) = Fe), DSC and high resolution TEM. Thermal annealing of the X-ray amorphous bimetallic solids leads in most cases to micro- or nanocrystalline intermetallics or alloys which can then be identified through X-ray powder diffraction. Thus the preparation of highly active, nanocrystalline metals, intermetallics, and alloys is possible through solution chemistry via a controlled two-step process.