Dinuclear metal complex bridging

Oxidative-addition reactions have been widely studied with bridged dinuclear metal complexes [1,2,5, 32]. Earlier work with the ylides and sulfur bonded ligands... 

Numerous dinucleating macrocyclic and macrobicyclic ligands have been synthesized, in particular by the versatile amine + carbonyl — imine reaction they form dinuclear metal complexes as well as cascade complexes with bridging groups [2.58-2.63, 3.24-3.27, 4.1-4.4], for instance in dicobalt complexes that are oxygen carriers [3.26]. 

Several dinuclear metal complexes with the ligand system 53 as bridging unit are now known, where steric constraints are much less pronounced and where fold angles are much greater or nearly 180°. These complexes belong to the structure types 60-63, where the metal fragments reside in fraws-configuration, i.e. on different sides of the... 

Giuffrida, G. and Campagna, S. (1994) Influence of peripheral ligands on the metal-metal interaction in dinuclear metal complexes with V-heterocyclic bridging ligands, Coord. Chem. Rev. 135/136, 517-531. 

Floris B, Donzello MP, Ercolani C (2003) Single-atom bridged dinuclear metal complexes with emphasis on phthalocyanine systems. In Kadish KM, Smith KM, Guilard R (eds) The porphyrin handbook, vol 18. Academic Press, San Diego, p 1... 

Phosphates bridge dinuclear metal centers in the active sites of some phosphoes-terases [1-3]. Dinuclear metal complexes should be able to provide double Lewis acid activation for hydrolyzing phosphates. To quantify double Lewis acid activation for cleaving phosphate diesters, we studied the reaction of 24 (Figure 6.16), which has... 

DINUCLEAR METAL COMPLEXES WITH BRIDGING M—H—SI INTERACTIONS... 

The cations 97 and 98 are examples of dinuclear metal complexes in which a methyl group attached by a normal metal-carbon bond to one metal atom leans over toward the second metal atom to allow C—H—Fe bonding to occur. This ensures that each iron atom in each complex has the full complement of 18 electrons required for coordinative saturation. A similar phenomenon is observed in the dicationic mixed Rh-Os complex 99. The methyl group in this complex, involved in the agostic bridged interaction, is surprisingly symmetrical. In fact, the Rh-C distance (2.29 A) is slightly shorter than the Os-C distance (2.32 A). 

Figure 7 Splitting of metal

With the purpose to design alkoxy bridged dinuclear metal complexes in which the presence of five and six coordinated metal centers is enforced by the ligand in the assembly process, new routes to multidentate ligands were developed. The first method (scheme 8) is based on sequential aromatic Mannich reactions of para-substituted phenols. In this way dinucleating ligand 22, which can bind two metal atoms in chemical or geometrical distinct environments, is accessible. 

The SiH-functionalized metallo-siloxanes, especially, of Eq. 1 exhibit high synthetic potential due to oxidative addition to electronically unsaturated metal centers giving easy access to Si-O-Si bridged dinuclear metal complexes, like la,b and 2 (Fig. 1) [4,6b]. 

Kim aud coworkers explored a known receptor 2,6-bis(bis(2-pyridylmethyl)aminomelhyl)-4-meihyl-phenol (H-bpmp) for naked-eye detection of phosphate anion in aqueous solution." Zn + coordination with bis(2-picolyl)amine (Dpa) together with the formation of a phenoxo-bridged dinuclear metal complex (32) affords the anion binding pocket The pH-sensitive dye pyrocatechol violet (8) was chosen as the indicator for the competition assay. When [Zn2(H-bpmp)] + was titrated into a solution of 8 at pH 7.0, the solution color changed from yellow (444 nm) to blue... 

A. L. Balch, Adv. Chem. Ser, 1982, 196, 243-255. Novel Reactions of Dinuclear Metal Complexes. Reactions and Structures of Palladium Complexes Containing Is(diphenylphosphino)methane as a Bridging Ligand. 

The catalytic cleavage of phosphodiesters is an area of intense investigation due to the potential for the site-directed cleavage of these esters in DN A and RNA. Dinuclear metal complexes are currently among the best catalysts for phosphodiester hydrolysis. One motif fhaf has been found to be successful is the bridging of two metals with hydroxide ligands, such as in i. This bis(cobalt) complex has X-phenylmethylphosphate in its coordination sphere, where X can be different substituents. A... 

Chloro-bridged dipalladium(ii) resolving agents R,R)- and (dinuclear metal complex as the corresponding mono-solvate in a typical second-order asymmetric transformation. 

Rather many homo- and hetero-dinuclear metal complexes containing mixed ( -H)(/i-X) bridges have been studied. Among recent examples are... 

The reaction of the coordinatively unsaturated ruthenium amidinates with [Cp RuCl]4 tetramer or [CpRufMeCNlsJPFg provides access to novel amidinate-bridged dinuclear ruthenium complexes (Scheme 146), which in turn can be transformed into cationic complexes or hydride derivatives. In these complexes, a bridging amidinate ligand perpendicular to the metal-metal axis effectively stabilizes the highly reactive cationic diruthenium species. 

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