Oxides double

However, compounds known to be double oxides in the solid state are named as such for example, Cr2Cu04 (actually Cr203 CuO) is chromium(III) copper(II) oxide (and not copper chromite). 

Several compounds of the CaO—P2O3—H2O system are given in Table 8. The common names for the mono-, di-, and tricalcium phosphates arise from the traditional double-oxide formulas, CaO 2i5p T2O3, 2CaO H2O +205, and 3CaO +205, respectively. These terms are routinely used in industry. With the exception of the monocalcium salt, the calcium phosphates are all sparingly soluble. 

In summary for non-metal transfer situations chemical thermodynamics is a useful guide to probable behaviour. The transfer of a non-metal, X, dissolved in a molten metal, M to another metal M", will depend on the relative free energies of formation of M X and M X (see Section 7.6). Thus sodium will give up oxygen to Zr, Nb, Ti and U, as the free energy of oxide formation of these metals is greater than that for sodium on the other hand, sodium will remove oxygen from oxides of Fe, Mo and Cu unless double oxides are formed. 

Table 21.18 Structures, thermal data, and molar volumes of metal oxides and hydroxides, and of some double oxides ...

An alternative approach, which has only been applied to heteroaromatic thiepins, is provided by the Pummerer reaction.70,71 The careful double oxidation of hetarenothicpancs to the corresponding S-oxides, followed by brief treatment with acetic anhydride at 150 °C in the absence of oxygen, gives the heteroaromatic thiepins in moderate yield. 

Other sources of Ru(0) can also be used for this synthesis. For example, it was recently demonstrated that [Ru(arene)(diene)] complexes such as 39 undergo double oxidative addition of heterosubstituted dihalo compounds 40 in the presence of phosphine ligands (Eq. 5) [21]. 

The trimeric platinum(O) complex [Pt3(CNBu )6] undergoes a double oxidative addition reaction with 2,2-bis(disilanyl)dithiane to give tetrakis(organosilyl)bis(/-butylisocyanide)platinum(IV) complexes.53 The Si—Ge bonds in bis(silylgermyl)dithiane are also cleaved by [Pt3(CNBu )6] giving analogous platinum(IV) complexes with Pt—Si and Pt—Ge bonds.53... 

The ozonolysis of carotenoids was employed in order to obtain oxygenated cleavage products for biological tests, for example, for lycopene. In this case, among a series of products, one product formed by a double oxidative cleavage was purified and characterized as ( , ,/ )- 4 - methyl - 8 -oxo-2,4,6-nonatrienal, and it was shown to be active in the induction of apoptosis in HL-60 cells (Zhang et al. 2003). 

On the very basic level, kinetic stability of 1,2-dications can be explained by molecular orbital (MO) theory. When loss of two electrons leading to the formation of a dication (double oxidation) occurs from an antibonding MO, it results in the formation of a normal (two-electron/two-center) chemical bond (Scheme 1). 

Megaw, H. D. Crystal stmcture of double oxides of the perovskite type. The Proc. Phys. Soc., 1946, Voulme 58, 133-152. 

Complexes with a double oxide bridged core, [Fe2(/u-0)2], are known. ... 

New functional groups can arise as a result of oxidation of the compounds mentioned above. For example, the oxidation of a thiol yields a disulfide (R-S-S-R). Double oxidation of a primary alcohol (R-CH2-OH) gives rise initially to an aldehyde (R-C(O)-H), and then to a carboxylic acid (R-C(O)-OH). In contrast, the oxidation of a secondary alcohol yields a ketone (R-C(O)-R). The carbonyl group (C=0) is characteristic of aldehydes and ketones. 

A double oxidation at the 5,6-carbon-carbon double bond and N-9 by 2equiv of OT-chloroperbenzoic acid (MCPBA) was postulated as the mechanism for the oxidative rearrangement of 8-dialkylaminoxanthines to novel l-oxo-2,4,7,9-tetraazaspiro[4,5]dec-2-ene-6,8,10-triones <1999EJ02419>. The presence of an electron-donating 8-amino substituent was essential for this reaction to occur. Further oxidation of the products gave 1,3-dimethylpara-benic acid 45, which was also produced directly when selenium dioxide or hydrogen peroxide were used (Scheme 11). 

Next, 15-LOX oxidizes both 15-HPETE and 5-HPETE to LTA4 (Figure 26.4). Rat peritoneal monocytes and human leukocytes are also able to oxidize AA into the dihydroxy derivative, 5(S), 15(,V)-dihydroxy-6,l 3-/ran.v-8,11 -c/.v-cicosatctracnoic acid (5,15-DiHETE). It has been shown [18] that 5,15-DiHETE was formed by a double oxidation of AA catalyzed by both 5-LOX and 15-LOX lipoxygenases (Figure 26.5). It is interesting that the... 

The common feature of the internal reactions discussed so far is the participation of electronic defects. In other words, we have been dealing with either oxidation or reduction. We now show that reactions of the type A+B = AB can take place in a solvent crystal matrix as, for example, the formation of double oxides (CaO +Ti02 = CaTi03) in which atomic (ionic) but no electronic point defects are involved. Although many different solvent crystal matrices can be thought of (e.g., metals, semiconductors, glasses, and even viscous melts and surfaces), we will deal here mainly with ionic crystal matrices in order to illustrate the basic features of this type of solid state reaction. 

Figures 12a and 12b illustrate the ESR spectra at —180°C and 25°C, respectively, of Nb(7r-allyl)4 after reaction with Manosil VN3 previously dried at 200°C. Figure 12b is complex and shows a mixture of at least two species present in the system. The major peaks are present in the system. The major peaks are also present in the frozen solution spectrum (Figure 10a) indicating that they arise from a rigidly held surface species. This species arises from the reaction of Nb(7r-allyl)4 with two adjacent hydroxyl groups and is therefore the double oxide bridge configuration (Reaction 3). Upon further addition of Nb(7r-allyl)4 to the silica, the pseudo isotropic spectrum (Figure lib) becomes more evident. This suggests that Nb(7r-allyl)4 reacts preferentially with the paired hydroxyl groups, an observation in accord with the literature (63).

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