Blue species dinuclear

The dinuclear ironflll) complex [Fe20(Ll)2(0Ac)2] (LI = N,N -bis(3,4,5-tri-methoxybenzyl)ethylenediamine-N,N -diacetate) (Fig. 6), in a reaction with 3 equiv. of H2O2 reacts to form a new deep-blue species with a maximum absorption at 560 nm. As indicated by the spectroscopic studies, the new... 

Treffry A, Zhao Z, Quail MA, Guest JR, Harrison PM. 1995. Iron(ll) oxidation by H-chain ferritin evidence from site-directed mutagenesis that a transient blue species is formed at the dinuclear iron center. Biochemistry 34 15204-15213. 

The blue dinuclear species in Eq. (13) can be obtained using oxidants other than 02. It is obtained pure and in quantitative yield when the... 

The compound loses a chlorine to give M0NCI3 when heated in CC14 at 100°C, and water produces dinitrogen, ammonia, and molybdenum blue. It is superficially analogous to the tantalum dinuclear species discussed above, but its paramagnetism is still a puzzle. 

A comparison of aliphatic amides, cyclic amides, cyclic imides and 2,4-dioxopyrimidines (uracils) in their deprotonated and diplatinated form (Scheme 4) reveals an increasing steric shielding of the V-bonded Pt ion (Ptx). With respect to formation of stacked and partially oxidized dinuclear species, it is evident that application of the binding principles seen in the blues of cyclic amides to the uracils and imides allows for tetranuclear species only. On the other hand, the presence of an additional O-donor in the imides and uracils (and likewise the cytosines, vide infra) provides an... 

Since it is known that the tetranuclear mixed-valent platinum blue and tan complexes such as 1 and 2 undergo disproportionation and reduction by water as Eqns. 1-3 and 7-9 show [54] [66], all the species appearing in Eqns. 1-3 and 7-9 are present in the solution. However, only one or several of the four species in the solution may in fact be active during catalytic olefin oxidation. To clarify this point, the effects of the Pt oxidation state in the platinum complexes were compared. The results are summarized in Table 2. It clearly shows that the dinuclear Pt111 complex is most effective, and is likely to be a true catalyst. Compound 1 also exhibits high activity, whereas the dinuclear Pt11 complex is ineffective. All other factors expected to affect the catalytic efficiency, including the presence of 02, the surfactant and the choice of solvent, have been examined and the results are summarized... 

The dinuclear species [Ni2L] (L = 21) has also been demonstrated to exist as an equilibrium mixture of yellow (low-spin) and blue (high-spin) forms in aqueous solution, further demonstrating the parallel between the metal-ion chemistry of the present binuclear species relative to that of cyclam. 

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