Antimony V

Reactions of the antimony(V) ions Antimony(V) ions are derived from the amphoteric oxide Sb2Os. In acids this oxide dissolves under the formation of the antimony(V) cation Sb5+  

Sb2Os +1OH+ 2Sb5 + + 5H20 In acid solutions therefore we have the Sb5+ ion present. 

In alkalis, on the other hand, the antimonate Sb04 ion is formed  

In alkaline medium therefore we have the Sb04- present in solutions. Sb04 is a simplified expression of the composition of the antimonate ion in fact it exists in the hydrated form, which may be termed hexahydroxoantimonate(V). Its formation from Sb205 with alkalis may be described by the reaction  

For the study of these reactions, an acidified 0-2m solution of potassium hexahydroxoantimonate K[Sb(OH)6] can be used. Alternately, antimony pentoxide Sb2Os may be dissolved in concentrated hydrochloric acid. 

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Antimony(V) oxide can be prepared by treating antimony with concentrated nitric acid. It is an oxidising agent and when gently heated loses oxygen to form the trioxide. (The change in oxidation state stability shown by antimony should be noted since it corresponds to increasing metallic character.)... 

Unlike the amphoteric -i-3 oxide, the -i-5 oxide is acidic and dissolves only in alkalis to give hydroxoantimonates which contain the ion [SbfOH) ] . A third oxide, Sb204, is known but contains both antimony(III) and antimony(V), Sb (Sb 04), cf. Pb,04. 

The + 5 acid is known in solution and antimonates(V) can be obtained by dissolving antimony(V) oxide in alkalis. These salts contain the hexahydroxoantimonate(V) ion, [Sb(OH)(,] . 

Antimony(V) chloride is a fuming liquid, colourless when pure, m.p. 276 K. It is a powerful chlorinating agent. 

Organic fluorine compounds were first prepared in the latter part of the nineteenth century. Pioneer work by the Belgian chemist, F. Swarts, led to observations that antimony(Ill) fluoride reacts with organic compounds having activated carbon—chlorine bonds to form the corresponding carbon—fluorine bonds. Preparation of fluorinated compounds was faciUtated by fluorinations with antimony(Ill) fluoride containing antimony(V) haUdes as a reaction catalyst. 

Antimony Pentafluoride. Antimony(V) fluoride [7783-70-2], colorless, hygroscopic, viscous Hquid that has SbF units with... 

Antimony Pentachloride. Antimony(V) chloride [7647-18-9], SbQ, is a colorless, hygroscopic, oily Hquid that is frequently yeUow because of the presence of dissolved chlorine it caimot be distilled at atmospheric pressure without decomposition, but the extrapolated normal boiling point is 176°C. In the soHd, Hquid, and gaseous states it consists of trigonal bipyramidal molecules with the apical chlorines being somewhat further away than the... 

Chemical Designations - Synonyms Antimony (V) Chloride Antimony Perchloride Chemical Formula SbClj. 

Dipping solution Mix 2 ml antimony(V) chloride with 8 ml carbon tetrachloride. Storage The reagent solution should always be freshly prepared. 

Antimony(V) chloride forms colored Ji-complexes with double bond systems. 

Antimon-saure, /. antimonic acid, -saureanhy-drid, n. antimonic anhydride, antimony pent-oxide. -silber, n. antimonial silver, dyscrasite. -silberblende,/. pyrargyrite. -silberglanz, m. stephanite. -spiegel, m. antimony mirror, -sulfid, n. antimony sulfide, specif, antimony pentasulfide, antimony(V) sulfide, -sulfiir, n. antimony trisulfide, antimony(III) sulfide, -yerblndung,/. antimony compound, -wasser--stoff, m. antimony hydride, stibine. -weiss, n. antimony white (Sb Oa). -zinnober, m. kermes mineral. 

A similar procedure may also be used for the determination of antimony(V), whilst antimony (III) may be determined like arsenic(III) by direct titration with standard iodine solution (Section 10.113), but in the antimony titration it is necessary to include some tartaric acid in the solution this acts as complexing agent and prevents precipitation of antimony as hydroxide or as basic salt in alkaline solution. On the whole, however, the most satisfactory method for determining antimony is by titration with potassium bromate (Section 10.133). 

Discussion. In acid solution arsenic(III) can be oxidised to arsenic(V) and antimony(III) to antimony(V) by the well-established titration with a solution of potassium bromate and potassium bromide (Section 10.133). The end point for such determinations is usually observed indirectly, and very good results have been obtained by the spectrophotometric method of Sweetser and Bricker.23 No change in absorbance at 326 nm is obtained until all the arsenic)III) has been oxidised, the absorbance then decreases to a minimum at the antimony(III) end point at which it rises again as excess titrant is added. 

Recently an antimony(V) phthalocyanine was obtained by the oxidation of tluoroanti-mony(III) phthalocyanine.165... 

As an alternative to lithium enolates. silyl enolates or ketene acetals may be used in a complementary route to pentanedioates. The reaction requires Lewis acid catalysis, for example aluminum trifluoromethanesulfonate (modest diastereoselectivity with unsaturated esters)72 74 antimony(V) chloride/tin(II) trifluoromethanesulfonate (predominant formation of anti-adducts with the more reactive a,/5-unsaturated thioesters)75 montmorillonite clay (modest to good yields but poor diastereoselectivity with unsaturated esters)76 or high pressure77. 

Jain VK, Bohra R, Mehrotra RC (1982) Structure and Bonding in Organic Derivatives of Antimony(V). 52 147-196... 

The role of Lewis acids in the formation of oxazoles from diazocarbonyl compounds and nitriles has primarily been studied independently by two groups. Doyle et al. first reported the use of aluminium(III) chloride as a catalyst for the decomposition of diazoketones.<78TL2247> In a more detailed study, a range of Lewis acids was screened for catalytic activity, using diazoacetophenone la and acetonitrile as the test reaction.<80JOC3657> Of the catalysts employed, boron trifluoride etherate was found to be the catalyst of choice, due to the low yield of the 1-halogenated side-product 17 (X = Cl or F) compared to 2-methyI-5-phenyloxazole 18. Unfortunately, it was found that in the case of boron trifluoride etherate, the nitrile had to be used in a ten-fold excess, however the use of antimony(V) fluoride allowed the use of the nitrile in only a three fold excess (Table 1). 

Antimony(III) sulfide, Sb2S3 (stibnite) antimony(V) sulfide, Sb2S5 anti-mony(III) selenide, Sb2Se3 antimony(III) telluride, Sb2Te3 bismuth(III) selenide,... 

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