Tetrairon cluster

Examples of O-alkylation have also been demonstrated for triruthenium and triosmium anionic clusters, as well as the tetrairon cluster Fe CO)] - (31-33). This reaction has considerable promise as an entry into many different methylidyne complexes through the replacement of the OR" group, eq. 20 (38). 

The electrochemical properties of the two types of iron-cluster-derivatized AuNPs resemble that of the monomeric tetrairon cluster, except that they additionally show adsorption due to their large size, and evidence that all the Fe4 clusters are active at about the same potential, thereby indicating that they are sufficiently remote from one another to behave independently. The changes in the cyclic voltammetric pattern caused by the addition of H2P04 and ATP2- oxoanions evidence recognition features that are very different from those obtained with dendritic ferrocene exoreceptors. In particular, the results show that with these iron-cluster-derivatized AuNPs... 

Some striking demonstrations of metal-metal bond lability are provided by cluster rearrangements due to protonation. This is the case for some anionic osmium clusters (cf. Section VI). It involves ligand activation for some tetrairon clusters (51-53). Thus, the clusters 9 and 11 open up upon protonation, and compensation for the lost iron - iron bonds in the products 10 and 12 comes from the bonding between one iron atom and a carbonyl oxygen. The relation of these unusual nucleophile-electrophile interactions to cluster-induced CO transformations is obvious. 

Astruc and co-workers have also isolated dendrimers using a tetrairon cluster [ CpFe(p,3-CO) 4], 302.355 Dendrimer 303, with nine organoiron clusters at the peripheries, was prepared via the reaction of the tetrairon cluster with dendrimer 301 (Scheme 2.78). These types of dendrimers were air-stable, and electrochemistry studies showed that the iron clusters were separated enough from each other to prevent any electrostatic interaction. These dendrimers are potential exoreceptors, which are generally confined to dendrimers containing metallocene units.355... 

Sedney D, Rieff WM (1979) A Mossbauer spectroscopy investigation of iron chromophore equivalence in three tetrairon clusters. Inorg Chun Acta 34 231-236... 

Iron-sulfur-nitrosyl complexes (continued) from tetranuclear precursors, 32 343 tellurium analogs, 32 350 tetrairon complexes, N NMR spectroscopy, 32 365 x-ray crystallography [Fe(NO)(S2CNR2)2 and related clusters, 32 359-361... 

Poly(propylene amine) dendrimers carrying at their periphery 9, 16, and 27 (compound 8 in Fig. 6.8) tetrairon [ CpFe(p3-CO) 4] clusters have been recently prepared... 

The recent upsurge of interest in iron-sulfur-nitrosyl complexes has been stimulated in part by the reported isolation of [Fe2(SMe)2(NO)4] from natural sources (12), by the obvious resemblances between these complexes and the naturally occurring [2Fe-2S] and [4Fe-4S] clusters of iron sulfur proteins (23, 14), and by the connections between tetrairon-sulfur-nitrosyls and cubane-type clusters (15). Most of the work in this area has been published in the past 5 years or so, and no review has previously been made. However, a number of excellent reviews of the wider aspects of metal-nitrosyl chemistry have appeared (16 19). 

Finally, we note a number of higher nuclearity iron-containing clusters. Hieber (74) reported a complex formulated as [Sn2Fe5(CO)2o], 62, although no structural details were presented. Hieber also described a complex formulated as [PbFe3(CO)12], but later work by Whitmire (71) indicates that this compound is probably the tetrairon species, 56. Mackay and Nicholson (75) have described the synthesis and structures of three polynuclear species [Fe2(CO)7 //-E(Fe2(CO)8) 2] (63, E = Ge 64, E = Sn) and [Fe3(CO)10- //-Ge(Fe2(CO)8) 2], 65, from reactions involving germanium or tin... 

Further examples of Bi2 clusters in this class are the anionic and dianionic complexes [Bi2Fe3(CO)9], 2 (130 and 131), reported by Whitmire (128) as resulting from sequential one-electron reduction of 126 with sodium amalgam, and the dibismuth-tetrairon dianion [Bi2Fe4(CO)I3]2 (132) obtained from... 

Dicarboxypyridine, with trinuclear Os clusters, 6, 747 Dichalcogenides, addition to alkynes, 10, 752 Di(/i4-chalcogenido)tetrairon complexes, preparation, 6, 277... 

Botar, B., Kogerler, P. and Hill, C. (2007). Tetrairon and Hexairon Hydroxo/Acetato Clusters Stabilized by Multiple Polyoxometalate Scaffolds. Structures, Magnetic Properties, and Chemistry of a Dimer and a Trimer, Inorg. Chem., 46, pp. 5398-5403. 

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