Mixed-metal clusters listing

Examination of the methods that have been used in preparing the mixed-metal clusters listed in Table I reveals that the majority have been synthesized via four general types of reaction (1) pyrolysis, (2) addition... 

Thus far, dimensional reduction has not been applied in this way to any of the other parent solids listed in Table I. Of particular interest are systems that straddle the divide between the edge-bridged and face-centered octahedral geometries. Will reduced niobium-molybdenum halide mixtures simply disproportionate or will they lead to new mixed-metal clusters If the latter, then where does the crossover in cluster geometries occur An important factor in applying dimensional reduction is recognizing the variability in the stable electron counts within a particular cluster system. An extreme case occurs... 

In this review, we have attempted to compile a comprehensive listing of all of the mixed-metal clusters that have been prepared. It has been necessary to adhere to a specific definition of a mixed-metal cluster, and the following two criteria have been set by us for detailed coverage in this review. 

Mixed-metal clusters containing one ML fragment are very common. Table I lists the compounds of this type which have an edge-bridging ML... 

Mixed-Metal Clusters Containing Three ML (M = Cu or Au L = Two-Electron Donor Ligand) Units Which Do Not Belong to the Structural Classes Listed in Tables X-XII... 

A number of mixed-metal clusters which undergo metal core rearrangements have been reported since 1986, and these species are listed in Table XVII. The effect of the monodentate phosphine or phosphite ligands... 

Anions fig, where fi = Si, Ge, Sn, Pb, have 2n+A skeletal electrons and hence, according to PSEPT, should adopt nido stmctures, which has been confirmed experimentally, while their derivative clusters [(OC)3M(t) -E9)] (where M = Cr, Mo, W), have closo stmctures (bi-capped Archimedian antiprism) with 2 -I- 2 electrons [267]. Corbett [268] reviewed from the viewpoint of Wade s theory, the stmctures of these and many other mixed-metal clusters, a brief listing of which is given in Table 3.21 (compare with Table 3.20). 

Trl- and Higher Nuclearity Clusters.- Clusters structurally characterised by i ray diffraction are listed in Ted>le 2. Limitations of space for this article prevent a discussion of all these mixed metal cluster systems. 

The Ru/Os mixed-metal clusters with known structures reported within this reviewing period are listed in Tables 9-17. 

Mixed-metal clusters of Fe-Ru and Fe-Os will be surveyed in Ghapter 6.10, which is dedicated to iron organo-metallic compounds. Table 13 lists the Ru-Os mixed-metal clusters with known structures. 

In this body of catalysts, the metal cluster is said to be formed around the carbonyl precursor. According to SEM and TEM imaging, it appears that the carbonyl clusters are on the order of 1 pm in diameter when supported on carbon.192 Analysis with FTIR has shown that the carbonyl is present.189 190 198-200 203 Non-noble metals have also been studied along side the noble-metals in this group of catalysts. Table 4 lists the non-noble metal carbonyl catalysts studied.189-192 198-200 The non-noble metal carbonyl catalysts studied produced mixed results for the ORR activity. 

To underline the structural and bonding relationship between these mixed metal-carbon cluster species and carboranes, we list the formulae of representative examples in Table 4.1, classified according to the numbers of skeletal bonding electrons they contain and thus according to their structural type (closo, nido, or arachno ). 

A tabular listing of the Sn and Pb NMR data for the known Zintl complexes Sn4 , Sn/ , Pbg" ", and the mixed element analogs (i.e., Sng.xGox ) are given in Tables 1 and 2. Selected data for various counter cations (i.e., Na, K, etc.) are also given. Full listings can be found in [23, 28]. The spectra of the naked and Ei2 clusters have not been reported as they are only known in the gas phase or, in the case of Pbjo, only recently synthesized [29]. The transition metal derivatives of these clusters will be discussed in a later section. 

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