Bridged compounds clusters

Chelation of ixo-maleonitriledithiolate (imdt) has been structurally characterized in the octahedral cobalt(III) complex trmw-[Co(imdt)2(P(ra-Bu)3)2], formed via reaction of cobalt(II) ion with K2(imdt) in the presence of the phosphine.1037 Simple chelating thiolates such as SCH2CH2S not only form mononuclear compounds, but participate in bridging in clusters such as [Co3(SCH2CH2S)3(PEt3)3]3+ (243).1038... 

The only apparent exception to this rule is the hydrido-bridged osmium cluster (/u-CHjX/u-H lOsalCOhol (75) (Table IV). The alkanediyl derivatives (type G) may even be distinguished from the closely related metal alkyls. The chemical shifts of the latter compounds typically cover the... 

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... 

Iron-only hydrogenase, dithiolate-bridged compounds as biomimetic models, 6, 239 Iron oxide films, synthesis, 12, 51 Iron-palladium nanoparticles, preparation, 12, 74 Iron-platinum bimetallic clusters, with isocyanide clustes,... 

In the N3 bridged compounds, there is a stronger electron-electron interaction through the N/ bridging molecule between two adjacent Ni spins, than between the NO2 bridged compounds. A cluster model constructed on the basis of the accurate structure determined by X-ray diffraction is used in the DV-Xa calculation for NINAZ, NDMAZ, and NDMAP. These are typical Haldane gap materials, which include the N3-bridging ligand. 

Figure 6.19 (a) Crystal structure of [Eu4(S02calix[4]arene)2(iX3-0H)4(Ac0)4] (b) the structure of one of its dinuclear building units and (c) the hydroxo bridged tetranuclear cluster core (d) the molecular structure of the ligand in its neutral form is shown [25]. (Reproduced from Z.P. Zheng, Cluster compounds of the f-elements, in K.A. Gschneidner, Jr., J.C.G. Biinzli, and V.K. Pecharsky (eds.). Handbook on the Physics and Chemistry of Rare Earths, volume 40, 2010, with permission from Elsevier.)... 

The labile cluster Os3(NCMe)2(CO),g adds HCl or HBr to form the hydride- and halide-bridged compound OSjHXfCOjg under mild conditions. ... 

The labile cluster Os3(NCMe)2(CO),g adds HCl or HBr to form the hydride- and halide-bridged compound Os3HX(CO),q under mild conditions. A similar cluster, Os3(NCMe)(CO)i, adds HCl and HBr to afford first OSjHXCCO), in 50% yields and then, with further loss of CO, HOs3X(CO)jq. When HI is passed through Os,(NCMe)(CO), in CH,CL, HOs,I(CO), is isolated. ... 

Our discussion will comprise separately the mononitrosyl, polynitrosyl, bridging, and cluster nitrosyl complexes, with emphasis on the first group. We present different types of MNO compounds, without attempting to collect all available structures. Examples with either classical coligands (amines, cyanides, water, polypyridines, etc.) or porphyrin compounds have been chosen, in an attempt to illustrate recent developments in the field. Apart from the information contained in the previous Comprehensive Coordination Chemistry (CCC, 1987)17 a comprehensive review on structures... 

Sometimes ligands themselves may fragment. For example, the electron impact spectrum of the dithiolate-bridged compound illustrated on the next page exhibits only a trace of a parent molecular ion cluster centered at tn/z 534, but has an intense cluster at 478 corresponding to loss of ethylenes (mass of 28 each)... 

In the last 10 years, considerable amount of research has been devoted to the development of heterodinuclear cyano-bridged cubic cluster based on the [Feni(Tp)(CN)3]- synthon which directs the formation of cyanide-bridged compounds with interesting structures and magnetic properties. 

NO binds covalently to transition metals M forming a diversity of structural types comprising mononuclear, NO bridging, and cluster compounds.8-10 Within the first class, main coordination numbers are 6,5, and 4, as sketched in Table 7.1, revealing an important structural result, namely, the adoption of linear or bent geometries of the MNO fragments. 

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