Homologation reactions, metal clusters

Several mixed-metal clusters containing platinum and cobalt are known and some of them have been employed as methanol homologation catalysts.1 Among them, the title compound2 was first prepared unambiguously from the reaction of dichloro[l,2-ethanediylbis(diphenylphosphine)]platinum with sodium tetracarbonylcobaltate, Na[CO(CO)4]. The compound also may be prepared by the reaction of [l,2-ethanediylbis(diphenyl-phosphine)]bis(phenylethynyl)pIatinum with Co COJg.1... 

The metal catalysts derived from the zeolite-entrapped metal cluster complexes have been studied because of the interest in a uniform distribution and a high degree of metal dispersion through the zeolite frameworks. Nevertheless, little information is available on the structural and chemical behavior of the entrapped metal cluster complexes, particularly on the retention of the cluster character under the reaction conditions, e.g., CO + H2, alkane hydrogenolysis and methane homologation re-... 

In some other cases, the intermetal electron transfer does not occur even during hour-long irradiations. The initial simultaneous reduction reactions of and M are followed by mixed coalescence and association of atoms and clusters with ions, homolog or not. Besides the dimerization of atoms of the same metal into M2 and M 2, coalescence of both types of atoms occurs twice more frequently. Subsequently, mixed coalescence and reduction reactions progressively build bimetallic alloyed clusters according to the statistics of encounters, therefore to the relative initial ion abundance [53]. 

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