Clusters heterometallic

For heterometallic clusters with [Fe3S4] couples, the order potentials can be summarized as follows ... 

CODH from acetogens found to catalyze acetyl-CoA synthesis and nickel proposed to be the active site of CO oxidation and acetyl-CoA synthesis. CODH found to contain a heterometallic cluster consisting of nickel and iron that binds CO and proposed to be the active site of acetyl-CoA synthesis. Growth of acetogens on nitrate disables the acetyl-CoA pathway. ... 

Ligand activation and transformation at heterometallic clusters have been reviewed, but few examples of very mixed -metal clusters effecting these... 

Reactions of clusters with mononuclear or dinuclear metal complexes frequently provide a method of expanding the metal core nuclearity under controlled conditions. The majority of medium- and high-nuclearity homometallic clusters has been prepared from lower-nuclearity cluster precursors by thermolyses ("heat-it-and-hope ) reactions. This is less true of the heterometallic clusters in this... 

The electrochemical behavior of heterometallic clusters has been reviewed clsewbcre."" The interest in examining clusters stems from their potential to act as "electron sinks " in principle, an aggregate of several metal atoms may be capable of multiple redox state changes. The incorporation of heterometals provides the opportunity to tune the electrochemical response, effects which should be maximized in very mixed"-metal clusters. Few very mixed -metal clusters have been subjected to detailed electrochemical studies the majority of reports deal with cyclic voltammetry only. Table XII contains a summary of electrochemical investigations of "very mixed"-metal clusters. 

In the second cluster, the two Ru6 octahedra are linked through two palladium atoms. The third cluster contains two additional palladium atoms. The Pd4 skeleton adopts the form of a bent square. The two Ru6 octahedra have local structures similar to those in the second cluster, but their relative orientation is now twisted. Apparently, formation of these heterometallic cluster complexes does not result from a simple combination reaction between cationic and anionic complexes but is accompanied by partial redox reactions.900... 

Although the self-assembly process is easy and convenient to operate, success in obtaining the expected object is still a challenge for chemists. The aims of this article are to summarize the coordination chemistry of amino acids, to review our recent work on 3d-4f heterometallic clusters bearing amino acid ligands, and to expound the effects of several factors of influence on self-assembly, such as presence of a secondary ligand, lanthanides, crystallization conditions, the ratio of Cu2+ to amino acids, and transition metal ions. We hope that our systematic researches on the 3d-4f amino acid clusters can provide a useful framework of reference for the study of other self-assembly systems. 

Cyclopentadienyl rhodium silyl derivatives include Cp Rh(H)2(SiEt3)2, which has been used as a precursor to heterometallic clusters.257 The photolysis of CpRh(PPh3)(7]2-C2H4) with SiHR3 (R = Et, Pr1) results in oxidative... 

Braunstein, P. and Rose, J. (1998) Heterometallic clusters for heterogeneous catalysis, in Catalysis hy Di- and Polynuclear Metal Cluster Complexes (eds R.D. Adams and... 

Perrhenate and related building blocks are constituents of several cluster compounds where they act as terminal groups in organometallic rhenium oxides such as in [(cp Re)3(//2-0)3(/U3-0)3Re03]+ (49)21 Qj. jjj heterometallic clusters such as the structurally related [(Re)3(//f dppm)3(/u -0)3Re03]+ (dppm = bis(diphenylphosphino)methane) and Pt4 P(C6H 11)3)4 (//-C0)2(Re04)2]. A series of platinum-rhenium and platinum-rhenium-mercury clusters with Pt-Re multiple bonds has been isolated from reactions of Pt3 precursors with Rc207 or perrhenate. " ... 

N NMR spectroscopy, 32 364-365 heterometallic cluster synthesis by nitrosylation of performed heterometallic aggregates, 32 350-351 from sulfur-rich metal complexes, 32 352-353... 

Unusual Compositions. Three series of compounds deserve special consideration because they have developed from laboratory curiosities into classes of their own. These are the heterometallic clusters, the carbide clusters, and the tetranuclear cu-bane clusters. 

Rearrangements of clusters, i.e. changes of cluster shape and increase and decrease of the number of cluster metal atoms, have already been mentioned with pyrolysis reactions and heterometallic cluster synthesis in chapter 2.4. Furthermore, cluster rearrangements can occur under conditions which are similar to those used to form simple clusters, e.g. simple redox reactions interconvert four to fifteen atom rhodium clusters (12,14, 280). Hard-base-induced disproportionation reactions lead to many atom clusters of rhenium (17), ruthenium and osmium (233), iron (108), rhodium (22, 88, 277), and iridium (28). And the interaction of metal carbonyl anions and clusters produces bigger clusters of iron (102, 367), ruthenium, and osmium (249). 

Heterometallic clusters from thiometalate ligands by unit construction and the possibility of... 

Binding energy, pentacarbonyliron, 6, 3 Binuclear complexes bis-Cp titanium halides, 4, 522 with Ni-M and Ni-C cr-bonds heterometallic clusters, 8, 115 homometallic clusters, 8, 111 Binuclear dicarbonyl(cyclopentadienyl)hydridoiron complexes, with rand C5 ligands, 6, 178 Binuclear iridium hydrides, characteristics, 7, 410 Binuclear monoindenyl complexes, with Ti(IV), 4, 397 Binuclear nickel(I) carbonyl complexes, characteristics, 8, 13 Binuclear osmium compounds, with hydrocarbon bridges without M-M bonds, 6, 619... 

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... 

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