Preparation unsupported mixed metals

Teraoka et al. [41, 42] have applied the amorphous citrate process to prepare unsupported (or neat) and supported perovskites of the type LaMn, LaCo, LaMnCu, LaCoFe, LaCaCo, LaCaMn, LaSrMn, LaSrCo, LaSrCoCu, and LaSrCoFe. The use of the citrate method for preparing atomically homogeneous oxides on supports has been a very important extension of the citrate method over the years. Nitrates of constituent metals of the required perovskite were dissolved in water and mixed with an aqueous solution of citric acid (molar ratio of citric acid to total metals 1 1). Water was evaporated from the mixed solution... 

The mixed-valent, square-planar cation [Rh (CO)2(CH3CN)2] was reported to form one-dimensional stack in the solid state. The chain is composed of the repeat unit [ Rh2 (02CCF3)2(C0)4 Rh2 °(02CCF3)4 Rh (02CCF3)2(C0)4 ] , in which an Rh",Rh" unit is connected with two dimeric Rh, Rh units. A linear chain composed of dirhodium units is not limited to acetonitriles and carbonyls. Metal chains of the type [ Rh2(OAc)2(LL)2 (BF4)] (LL = 1,10-phenanthroline 2,2 -bipyridyl) have been prepared by one-electron reduction of the corresponding dirhodium(II,II) precursors [Rh2(OAc)2 (LL)2] in aqueous ethanol. For the phen compound, three different Rh-Rh separations are noted in the Rh chain. The carboxylate bridged Rh-Rh distance is 2.652 A the unsupported interdimer Rh-Rh distance is 2.739 A and the resultant tetranuclear fragments are linked into an infinite chain by Rh-Rh... 

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