Cage oxide

The formulation [Ag radical] can be considered as existing in a solvent cage. Oxidation then proceeds when the radical diffuses out of the cage to be further oxidized to acetone by a second mole of Ag . The rate data show that the oxidative reactivity of AgOH+ towards propan-2-ol is much less than that of Ag +. Comparison of activation parameters with those for propan-2-ol oxidations by other oxidants reveals no relation to the standard redox potential. 

Aside from their extensive use in metaHacarborane chemistry, the dicarboUide anions are important intermediates in the synthesis of other carborane compounds. For example, aqueous ferric chloride oxidation of the 1 anion results in the 10-vertex cage nido- b ()-(Z, 2 (H8) and the... 

A particularly elegant route to metallacarbor-anes is the direct oxidative insertion of a metal centre into a c/oso-carborane cluster the reaction uses zero-valent derivatives of Ni, Pd and Pt in a concerted process which involves a nett transfer of electrons from the nucleophilic metal centre to the cage ... 

Data are given in Table 10-7 to illustrate certain facets of the Marcus cross relation. They refer to six reactions in which the cage complex Mn(sar)3+ is reduced or Mn(sar)2+ oxidized.34 These data were used to calculate the EE rate constant for this pair. The results of the calculation, also tabulated, show that there is a reasonably self-consistent value of fcEE for Mn(sar)3+/Mn(sar)2+ lying in the range 3-51 L mol-1 s-1. When values34 for an additional 13 reactions were included the authors found an average value of kEE = 17 L mol 1 s l. 

Vanadium borophosphates 107-109 that contain cluster anions with different ring sizes can be synthesized by hydrothermal reactions of vanadium(III) oxide, boric acid and an appropriate phosphate salt [145,146]. The ring size of the cluster anion with the composition [(VO)2BP20iol 4-6 is determined by the size of the cation that is, however, included only in the interior of the cages with n = 5 and 6 (Fig. 28). 

Metal deactivators—Organic compounds capable of forming coordination complexes with metals are known to be useful in inhibiting metal-activated oxidation. These compounds have multiple coordination sites and are capable of forming cyclic strucmres, which cage the pro-oxidant metal ions. EDTA and its various salts are examples of this type of metal chelating compounds. 

Zeolites form a unique class of oxides, consisting of microporous, crystalline aluminosilicates that can either be found in nature or synthesized artificially [J.M. Thomas, R.G. Bell and C.R.A. Catlow in Handbook of Heterogeneous Catalysis (Ed. G. Ertl, H. Knbzinger and J. Weitkamp) (1997), Vol. 1, p. 206, VCH, Weinheim.]. The zeolite framework is very open and contains channels and cages where cations, water and adsorbed molecules may reside and react. The specific absorption properties of zeolites are used in detergents, toothpaste, and desiccants, whereas their acidity makes them attractive catalysts. 

A subsequent detailed analysis of the permanganate oxidation of the tertiary hydrogen atom of 4-phenylvaleric acid in 2.5 M potassium hydroxide solution supports the caged radical mechanism. The reaction order is two overall, A h/ d is ca. 11.5, ring substitution has little elfect on the rate (p 0) and the oxidation proceeds with a net 30-40 % retention of optical configuration. 

Zeolite Y modified with (+/-)-l,3-dithiane-l-oxide, 1 molecule per super cage... 

Walter, M. and Hakkinen, H. (2006) A hollow tetrahedral cage of hexadecagold dianion provides a robust backbone for a tuneable sub-nanometer oxidation and reduction agent via endohedral doping. Physical Chemistry Chemical Physics, 8, 5407-5411. 

The dispiro compound A reacts with 2 cage molecules B to form the complex molecule 77 displayed in Fig. 13. The intermediate in brackets cannot be isolated. In contrast to the reaction of the same stannylene with sulfur (Eq. (26)) the dispiro compound A cannot be isolated seperately. The mechanism of reaction (34) may of course be more complicated. The cage molecule B is discussed in more detail in Section 6.5. It should be noted that in 77 six tin atoms of two different oxidation states are combined. 

The remarkable physical properties exhibited by the divalent macrobicyclic cage complex [Co(sep)]2+ (29) are unparalleled in Co chemistry.219 The complex, characterized structurally, is inert to ligand substitution in its optically pure form and resists racemization in stark contrast to its [Co(en)3]2+ parent. The encapsulating nature of the sep ligand ensures outer sphere electron transfer in all redox reactions. For example, unlike most divalent Co amines, the aerial oxidation of (29) does not involve a peroxo-bound intermediate. 

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