Centres bound

A polymer containing [Ru(bpy)3]2+—like centres bound has been prepared by copolymerisation of [Ru (bpy)2(MVbpy)]2+ and sodium styrenesulphonate (1 20 molar ratio) in the presence of3—cyclodextrin (O Connell 1983). This sample is quenched by PVS with a rate constant (1.0xl09dm3mol l) rather similar... 

Alkynyl ligands are only modest 7i-acids however, this can allow electronic communication between metal centres bound to bis(alkynyl)diyl bridging ligands, e.g. the diruthenium butadiyne-l,4-diyl complex shown (Figure 4.19) undergoes four single 1VE oxidations. If the metals were not in electronic communication, oxidation of one iron centre would not significantly affect the redox potential of the second, i.e. both would oxidize at the same potential. 

It is interesting to note that the rather rigid pyridazine bridge of 36 results in an inversion of chirality for the two metal centres bound to it, whereas the more flexible bridges in the other parts of the molecule and in 37 lead to homochirality. 

Cyanide-bridged linkage isomers with catecholateruthenium(II) centres bound to Mn(I) or M(alkyne) units... 

Figure 7 Synthesis of a tricyclic compound, involving a CpCo centre bound to a dithiolene group substituted onto a tetrahydropyran ring ...

Prussian Blue, Fe4[Fe(CN)6]3-14H20, has been known for three centuries, and its crystal structure (Buser et al., 1977) incorporates octahedral Fe(II) centres bound to six cyanide ligands in a [Fe(CN)6] moiety. The terminal N-donors of the cyanide ligands point to additional Fe(III) centres and a charge-balance of four Fe(IIl) centres with three [Fe(CN)6]" anions is achieved. Six of the 14 water molecules are bound to Fe(lll) and the remaining 8 fill the void in the framework structure and can be removed by heat treatment in vacuo. A wide variety of Prussian Blue analogues M c[MXCN)6]3,-zH20 [M... 

The structure of the oxidised form showed basically a four-coordinate Cu centre bound by two histidines, a deprotonated cysteine and a methionine in a distorted tetrahedral arrangement with the [Cu(his)2(cys)] fragment forming a trigonal unit with an axial methionine residue weakly bound at about 2.8 A (Fig. 2). 

Spectroscopic studies have demonstrated that a palladium catalyst for the asymmetric rearrangement of allylic trifluoroacetimidates possesses in the activated oxidized form a Pd(III) centre bound to a ferrocene core that remains unchanged (Fe(II)) during the oxidative activation. ... 

The mean degree of hydrolysis is dependent upon the degree of hydroxylation of the surface. Higher support dehydration temperatures reduce both the quantity of complex bound on the surface and also the degree of hydrolysis for those titanium centres bound. Titanium(IIl) centres can be produced in a variety of ways, most effectively by ultraviolet photolysis under hydrogen. However, these reduced metal ions seem to adopt a range of coordination spheres. 

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