Dinuclear organometallics

As an illustrative example taken from the current literature, consider the variation of C-C and C-O bond lengths in the deltate species CsO2- held within a dinuclear organometallic uranium(IV) complex. In a remarkable synthesis, this cyclic aromatic oxocarbon dianion is generated by the metal-mediated reductive cyclotrimerization of carbon monoxide, as indicated in the reaction scheme... 

Carbonyl Complexes of the Transition Metals Cluster Compounds Inorganometalhc Compounds Containing Transition Metal Main Group Elements Cyanide Complexes of the Transition Metals Dinuclear Organometallic Cluster Complexes Gold Inorganic Coordination Chemistry. 

Dihydrogen Complexes Related Sigma Complexes Dinuclear Organometallic Cluster Complexes Hydrogenation Isomerization of Alkenes Polynuclear Organometallic Cluster Complexes. 

Because of the great strength of iridium-iridium bonds, there is a wealth of information on polynuclear metal-carbonyl cluster compounds of iridium (see Dinuclear Organometallic Cluster Complexes mA Polynuclear Organometallic Cluster Complexes). It4(CO)i2 (45) may be synthesized from... 

Substitution reactions on metal-carbonyl dimers (see Dinuclear Organometallic Cluster Complexes) and clusters see Polynuclear Organometallic Cluster Complexes) occur by replacement of a CO with an entering ligand ... 

In a number of cases, dinuclear (see Dinuclear and Dinuclear Organometallic Cluster Complexes) reductive elimination, in which two metal centers participate in the reaction, has been observed ... 

Finally, dinuclear Pd complexes can be prepared, which contain bridging cyclopentadienyl ligands (see Dinuclear Organometallic Cluster Complexes). WheuPdl/j -CsHsK ) -2-MeC3Hs) is reacted with two equivalents of phosphines or phosphites, dinuclear species Pd2(/r-C5H5)(/u,-2-MeC3H5)L2 are formed (equation 50). 

In general, high-oxidation state complexes have far fewer than 18 electrons becanse extreme steric crowding would result if enough ligands were bonded to the metal center to form either a 17- or 19-electron species. Similarly, dimerization to generate cluster-type complexes is often prevented for steric reasons see Dinuclear Organometallic Cluster Complexes). 

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