Ruthenium-platinum cluster preparation

Cobaltocenium calix[4]arene receptors, characteristics, 12,475 Cobaltocenium-metallacarborane salts, preparation, 3, 23 Cobaltocenium receptors, characteristics, 12, 474 Cobalt phosphines, as supports, 12, 683 Cobalt-platinum nanoparticles, preparation, 12, 74 Cobalt-ruthenium clusters, as heterogeneous catalyst precursors, 12, 768... 

Platinum nanoparticles, preparation, 12, 78 Platinum-nitrogen bonds, in platinacycles, 8, 508 Platinum-osmium carbonyl clusters, characteristics, 8, 420 Platinum-oxygen bonds, in platinacycles, 8, 505 Platinum particles, surface reactivity, 12, 542 Platinum-phosphorus bonds, in platinacycles, 8, 508 Platinum-rhenium carbonyl clusters, characteristics, 8, 420 Platinum(II)-ruthenium(II) binary complexes, preparation,... 

Monomethoxycarbonyl ruthenium complexes have been obtained by reaction of mthenium(O) clusters with methoxide anion in methanol [67]. Hydroxyl-carbonyl complexes of platinum were prepared by nucleophilic attack of OH on a carbonyl ligand [68] or by insertion of CO into a hydroxy platinum complex [69]. Hydroxycarbonyl-bpy complexes of ruthenium [21], iridium and rhodium [21] have been proposed as... 

Watanabe, M., Uchida, M. Motoo, S. Preparation ofhighly dispersed platinum 4-ruthenium alloy clusters and the activity for the electrooxidation of methanol. J. Electroanal. Chem. Interfacial Electrochem. 229 (1987), pp. 395 06. 

Non-ionic thiourea derivatives have been used as ligands for metal complexes [63,64] as well as anionic thioureas and, in both cases, coordination in metal clusters has also been described [65,66]. Examples of mononuclear complexes of simple alkyl- or aryl-substituted thiourea monoanions, containing N,S-chelating ligands (Scheme 11), have been reported for rhodium(III) [67,68], iridium and many other transition metals, such as chromium(III), technetium(III), rhenium(V), aluminium, ruthenium, osmium, platinum [69] and palladium [70]. Many complexes with N,S-chelating monothioureas were prepared with two triphenylphosphines as substituents. 

Fig. 1 shows clearly that only one hydrogen consumption peak was found for the bimetallic precursor prepared by coadsorption, which has been assigned to hydrogen conjointly consumed during the reduction of both metals due to the formation of a kind of alloy between platinum and ruthenium. The bimetallic clusters thus formed will be richer in platinum for the CAD series than for the CAC series, due to the metal contents shown in Table 1. 

Pt(NH3) ions since the molecular dimensions of these metal complexes exceed the pore apertures. Platinum was incorporated during the synthesis of the zeo-hte by mixing solutions of K2PtCl4 with solutions of sodium metasiUcate and sodium aluminate in the required amounts. More recently, Davis et al. [129,130] prepared intrazeoHtic 2-5 nm ruthenium particles in NaA and CaA zeoHtes by addition of [Ru(NH3)5Cl] CI2 to the hydrothermal synthesis mix of zeolite A. This technique of metal loading has never been widely used to prepare metal clusters in zeolites but is frequently employed to substitute lattice aluminum in zeoHtes or aluminophosphates by metal ions. 

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