Heterobinuclear complexes

THE DETERMINATION OF COPPER MICROAMOUNTS ON THE TERBIUM LUMINESCENCE SENSITIZED BY IT IN HETEROBINUCLEAR COMPLEX... 

A heterobinuclear complex of type PbMnL(NCS)4] containing the 24-membered macrocycle (187) ( = 5) has been synthesized. The X-ray structure shows a Pb—Mn separation of 4.857 A, with the metals bridged by two —NCS— groups." ... 

Advances in the chemistry of [M(CN)5L]" complexes, for M = Fe, Ru, and Os, have been reviewed.There has been rather little activity in the preparation of novel complexes, but considerable activity in studying the properties, especially solvatochromism and various aspects of kinetics of substitution, of known complexes. However there has been an attempted preparation of [Fe(CN)5(Ci2H25NH2)], in the hope of generating micelles or lyotropic liquid crystals. This preparation appeared to yield [Fe(CN)4(H20)(Ci2H25NH2)], whose alkali metal salts gave a hexagonal mesophase in water, but were also readily hydrolyzed to [Fe(CN)4(H20)2] . Heterobinuclear complexes of the form [(NC)5FeL ML 5] " " have been much studied, especially in relation to intramolecular electron transfer (see Section 5.4.2.2.5). 

Heterobinuclear complexes have been formed between PdCl(acac-Ci), bipy and Be(acac)2.271 The palladium compound retains an acid character and so replacement of an acac" from the Be(acac)2 gives a product which can be formulated as (50) from MW and NMR studies. 

Heterobinuclear complexes containing alkali or alkaline earth metal cations have been derived from mononuclear transition metal complexes of compartmental ligands (51).288 The molar conductivities of the (51)-CuLi2 series suggest that the complexes are uniunivalent electrolytes in water and so are present in solution as Li[(51b)CuLi]- H20 the corresponding di-sodium, -potassium or -cesium complexes are unibivalent electrolytes and so likely to be present in solution as M2[(51)Cu]- H20. 

As mentioned above, in the heterobinuclear preparations the presence of both mono- and homobi-nuclear V02+ complexes was detected 897 two alternative explanations were suggested (i) any HC1 present in the CHCI3 used for recrystallizing could strip the metals from the ligand and allow subsequent incorporation of V02+ into the outer compartment (ii) during the synthesis, the mechanism depicted in Scheme 23 could take place. These observations suggest that in solutions of the heterobinuclear complexes, several species are probably present and the product isolated is a function of the insolubility of the individual species. 

The heterobinuclear complex [PdPtCl2( -dppm)2] can also be prepared by treating the product from the reaction of dppm and [Pd(PPh3)4] with [PtCl2(NCBu,)2].76 The corresponding bromide, iodide and thiocyanate dipalladium and palladium-platinum complexes have been prepared by metathesis of the dichloride (9) with NaX.76... 

The heterobinuclear complex A,A-(H20)(en)2Cr(0H)Co(en)2(H20)5+ can be obtained similarly but has been characterized only in solution (215). (H20)5Cr(OH)Cr(H20)5+ has likewise been characterized only in solution, and can be made by acid hydrolysis of the dihydroxo-bridged complex (26). 

Iron-nickel compounds, into heterobinuclear complexes,... 

There is an interesting series of heterobinuclear complexes in which the Ru and Zr centers are connected by three different types of C2 bridges C-C, C=C, and C=C. 

Heterobinuclear complexes featuring the bridging germole dianion ligand have been described (equation 45)59,60. 

The macrocyclic Schiff base 5,9,14,18-tetramethyl-l,4,10,13-tetraazacyclo-octadeca-5,8,14,17-tetraene-7,16-dione (I) (H4daen) can serve as a precursor to the formation of either mononuclear macrocyclic complexes or mononuclear acyclic complexes, depending on the reaction conditions. The mononuclear complexes may then be used in the synthesis of homo- or heterobinuclear complexes. The synthetic procedures described have been extended to include Schiff bases derived from a range of symmetrical and nonsymmetrical tri-... 

The heterobinuclear complexes [MCo(/u,-FiCC2CF3)2(CO)3Cp] have been prepared by addition of octacarbonyldicobalt to the mononuclear alkyne complexes [M(F3CC2CF3)2(Cl)Cp] (M = Mo or W)24 demonstrating that cobalt-carbonyl fragments can coordinate to an alkyne already bound to another metal-ligand fragment see Eq. (5). 

Elements for the deposition of heterobinuclear complexes for preparing bimetallic catalysts have been reported by Ichikawa [48]. The use of heterobinuclear complexes as precursors for bimetallic catalysts was aimed at the fine-tuned control of a homogeneous composition in the nuclearity of bimetallic particles. As compared to catalysts prepared by NSD methods, mixed-metal cluster-derived catalysts should retain more bimetallic ensembles. However, the use of heterobinuclear complexes is limited by the availability of high-nuclearity clusters and by the narrow choice of metallic couples. The different types of interaction of these complexes with the support are the same as previously described for the NSD methods. 

Metal-metal bonds may be formed by irradiating metal hydrides or heterobinuclear complexs . 

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