Bismuth oxide halides

Bismuthonium ylides, 4 34 Bismuth(III) oxide, 4 23-24 Bismuth oxide(l l), 4 23 Bismuth oxide(l 2), 4 23 Bismuth oxide(2 4), 4 23 Bismuth oxide(3 5), 4 23 Bismuth oxide(4 9), 4 23 Bismuth oxide halides, 4 23 Bismuth oxides, 4 23-24 Bismuth oxybromide, 4 23 Bismuth oxychloride, 4 23 physical properties of, 4 20t pigment used in makeups, 7 836t Bismuth oxyfluoride, 4 23 Bismuth oxyiodide, 4 23 Bismuth pentafluoride, 4 22 physical properties of, 4 20t Bismuth phosphate, 4 25... 

Bismuth oxide halides BiOX are readily formed as insoluble precipitates by the partial hydrolysis of the trihalides (e.g. by dilution of solutions in concentrated aqueous HX). BiOF and BiOI can also be made by heating the corresponding BiX3 in air. BiOI, which itself decomposes above 300°, is brick-red in colour the other 3 BiOX arc white. All have complex layer-lattice slructurcs. When BiOCl or BiOBr arc heated above 600° oxide halides of composition Bi2403l Xio arc formed, i.e. replacement of 5 O atoms by 10 X in Bi240j6. (Bi203>. 

The bismuth(lll) halides are moisture sensitive and are readily converted into the oxyhalides BiOX (equation 1). Addition of acid to aqueous suspensions of the oxyhalides will regenerate BiX3, which exist as complex halo anions in solution. Addition of ammonium hydroxide to such solutions results in the formation of insoluble Bi(OH)3, which is easily dehydrated to the oxide. 

Saturated hydrocarbons may also be oxidized by bismuth oxide catalysts. For example, methane is converted to CO2 and a mixture of higher hydrocarbons over bismuth oxide catalysts that also contain sodium, calcium, cesium, and/or halide... 

Reaction of elemental bismuth with the halogens at elevated temperatures leads to the production of 61X3. Properties of the trihalides are summarized in Table 2. Bismuth is first oxidized by p2(g) to BiF3, with conversion to BiFg occuring above 600 °C. The latter is the only known homoleptic bismuth(V) halide, although organic derivatives of the form... 

Only one halide - the white bismuth chloride oxide q.v) - appears to have been used significantly as a pigment. However, Salter (1869) describes a purple compound (bismuth purple) prepared by passing chlorine through a bismuth oxide hydrate suspension in aqueous potash the precise composition is unknown. 

A number of other metallic halide salts have been found to condense with ethylene oxide, propylene oxide, or epichlorohydrin in a similar fashion (Eq. 662). Among them are phosphorus trichloride/ 7- a 17 bismuth trichloride,1SM arsenic trichloride,1000 silicon tetrachloride/7 1 titanium tetrachloride/ 09 16,7 beryllium chlorido/189 and Won trifluoride.401 Depending on their reactivity, on the reactant ratio, and... 

Bismuth is an important element in many of the new high-temperature, oxide superconductors and in a variety of heterogeneous mixed oxide catalysts. Some of the methods employed in the preparation of these materials, namely sol-gel and chemical vapor deposition processes, require bismuth alkoxides as precursors and a number of papers on these compounds have recently been published.1 One synthetic route to bismuth alkoxides, which avoids the more commonly used trihalide starting materials and the often troublesome separation of alkali metal halides, involves the reaction between a bismuth amide and an alcohol according to the following equation ... 

The M—M bonds in R3MMR3, R3M(R2M) MR3 or (R2M) for M = Sn, Pb are cleaved by water, alcoholic solution of AgN03, alkyl iodides, mercury and bismuth halides and are oxidized by air. In contrast, these compounds with M = Si, Ge are stable under similar reaction conditions. The stability of the highly reactive R2M=MR2, as well as the tendency of R2M to dimerize, diminish as the atomic number of M increases160-162. 

In our investigation we have used BiOHal electrodes obtained by the exhaustive anodic oxidation of a bismuth layer with a thickness of about 200 nm on a platinum substrate in aqueous solutions of potassium halides (KHal) using the method previously reported in full details [93]. The resulted BiOHal films exhibited porous structure (according to the BET data, the surface area was 47, 25, and 6 m2/g for BiOCl, BiOBr, and... 

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