Heterometallic cubane clusters

Fig. 3. Ground state spin (S) and valence delocalization schemes for the known oxidation states of [Fe3S4] clusters. Discrete [Fe3S4] clusters have not been observed in siny protein, but they have been identified as fragments in heterometallic cubane clusters. Reduction of the [Fe3S4]+ cluster by three electrons, to yield a putative aU-ferrous cluster, occurs with the concomitant addition of three protons. Key S , grey Fe +, black Fe +, white Fe, white with central black dot.

Heterometallic cubane clusters, 47 63 Heterometallic polymeric cluster compounds, 46 258-259... 

These studies of protein-bound heterometallic cubanes have amply demonstrated that the heterometal site is redox active and able to bind small molecules. Although they have yet to be identified as intrinsic components of any protein or enzyme (except as part of the nitrogenase FeMo cofactor cluster (254)), they are clearly attractive candidates for the active sites of redox enzymes. 

Trinuclear Cuboidal and Heterometallic Cubane-Type Iron-Sulfur Clusters New Structural and Reacticity Themes in Chemistry and Biology R. H. Holm... 

B7.13 Trinuclear cuboidal and heterometallic cubane-type iron-sulfur clusters new structural and reactivity themes in chemistry and biology... 

An Ru-Re mixed-metal cluster anion with the formula [RuRe6G(GO)2i] was created from a photochemical reaction between the [Re6G(GO)i9] anion and Ru3(GO)i2- Heterometallic sulfide clusters of Ru-Re with open or cubane structures are also known. 

The mercurial Hg[Fe(CO)3NO]2 reacts with elemental sulfur S8 to yield the cubane-type cluster [Fe4S4(N0)4] (36, 37) it is not therefore entirely unexpected that metal complexes rich in sulfur can likewise react with this mercurial to produce novel heterometallic nitrosyls. 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

Two homometallic octanuclear clusters, [FegS CNBu1) ] [37] and [Fe8S8 (PCy 3)61 [37,38], have been isolated (see earlier discussion), as has the related heterometallic cluster [Mo2Fe6S8(PEt3)6(tccat)2] [70], The latter cluster is the first example of an Fe—S edge-linked, reduced MoFe3S4 double-cubane with Mo atoms at the periphery of each cuboid subunit. The reduced double-cubane core is stabilized by triethylphosphane coordinated to the Fe atoms. The utility of such materials as precursors to potential cofactor models, both structural and functional, has yet to be explored. 

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