Oxygen—antimony bonds

Exchange of antimony-carbon bonds with antimony-oxygen bonds is reported in a thorough study of the disproportionation of arylantimony oxides, RSbO (126, 127). At moderately elevated temperatures ( 100° C) in the solid state, the reaction of Eq. (157)... 

The v Sb-0 frequency shift has been correlated to the polarity of antimony oxygen bond and the add strength of the acceptor, which increases in the following order ... 

However, isomerization process has been found to be rapid and leads to an equilibrium mixture of both the tram and the cis isomers (Fig. 21. VI, VII)359,3645. The isomerization process proceeds via the twist mechanism and does not appear to involve an antimony-oxygen bond repture3645. 

Alkyl silyl ethers are cleaved by a variety of reagents Whether the silicon-oxygen or the carbon-oxygen bond is cleaved depends on the nature of the reagent used Treatment of alkoxysilanes with electrophilic reagents like antimony tri-fluonde, 40% hydrofluonc acid, or a boron tnfluonde-ether complex results in the cleavage of the silicon-oxygen bond to form mono-, di-, and tnfluorosiloxanes or silanes [19, 20, 21) (equations 18-20)... 

It is now possible to consider the ternary tin-antimony-oxygen system. It would be reasonable to expect that multiphase systems would predominate in antimony rich materials although there is little information about the solubility of tin in antimony oxide. Since the metal-oxygen bond lengths in tin(IV) and antimony(V) and (III) oxides are all similar 26, 29), it is reasonable to expect that mixed oxide formation by coprecipitation is feasible and would involve the replacement by antimony of tin in the tin(IV) oxide... 

Other Catalysts.—Copper(ii) alkoxides can be carbonylated, giving dialkyl carbonates, by insertion of carbon monoxide into the copper-alkoxide-oxygen bond. The first well-characterized copper(i)-carbonyl compounds are [CuCl(CO)(en)] and [(en)Cu(/i-CO)aCu(en)]Cl2. The effects of pH on rates of hydration of acetylene have been compared for the three catalysts CugSOi-CuSO, HgSOi, and PdS04-Fe2(S04)3. Alkyl and aryl halides can be carbonylated in the presence of ethanol, antimony pentachloride, and liquid sulphur dioxide ... 

Six elements are metalloids B, Si, Ge, As, Sb, and Te. Of these, silicon is by far the most abundant, making up over 27% of the Earth s crust, more than any other element except oxygen, hi fact, S1O2 and silicate minerals account for 80% of the atoms near the Earth s surface. Despite its great abundance, silicon was not discovered until 1824, probably because the strong bonds it forms with oxygen makes silicon difficult to isolate. Two much rarer metalloids, antimony (known to the ancients) and arsenic (discovered ca. 1250 ad) were isolated and identified long before silicon. 

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