Basicities Bismuth compounds

The Dragendorjf reagent is available in different compositions, and it mainly stains nitrogen-containing compounds, producing colored zones on a white background. For solntion a 1.7 g of basic bismuth nitrate and 20 g of tartaric acid are dissolved in 80 ml of water. For solution b 16 g of potassium iodide are dissolved in 40 ml of water. The final spray reagent is mixed from solution a and b in the... 

Scarpignato C, Pelosini I Bismuth compounds for eradication of Helicobacter pylori Pharmacology and safety. Progr Basic Clin Pharmacol 1999 11 87-126. 

Several bismuth compounds that can be used in aqueous media have been introduced. Due to increasing demand of water as a solvent in organic synthesis, catalysts that can be used in aqueous media are becoming more and more important. Although bismuth Lewis acids are not very stable in water, it has been shown that they can be stabilized by basic ligands. Chiral amine and related basic ligands combined with bismuth Lewis acids are particularly useful in asymmetric catalysis in aqueous media. On the other hand, Bi(OH)3 is stable in water and works as an efficient catalyst in water. Because of the unique characteristics of bismuth compounds, other chiral and achiral bismuth catalysts will be focused on and developed rapidly in the field of synthetic organic chemistry. 

Tellurium oxide, Te02, is found in rhombic crystals as the mineral tellurite, whilst ferrotellurite is probably an iron tellurate, emmonsite and dividensite being similar compounds. Other naturally occurring tellurates are montanite, a basic bismuth tellurate, and magmlite, a... 

The only well-established oxide of bismuth is Bi203, a yellow powder soluble in acids to give bismuth salts. It lacks acidic character and is insoluble in alkalis. From solutions of bismuth salts, alkali, or ammonium hydroxide precipitates a hydroxide, Bi(OH)3. Like the oxide, this compound is completely basic. Bismuth(V) oxide is extremely unstable and has never been obtained in pure form. The action of extremely powerful oxidizing agents on Bi203 gives a red-brown powder that rapidly loses oxygen at 100°C. 

Lewis acidity, basicity, H-bonding and compiexing of organic arsenic, antimony and bismuth compounds ... 

Lange, K. C. H. Klapoetke, T. M. Lewis acidity, basicity, H-bonding and complexing of organic arsenic antimony and bismuth compounds. Chem. Org. Arsenic, Antimony Bismuth Compd. Patai, S., Ed., Wiley New York, 1994, 66-315. 

Bismuth oxychloride (BiOCl) is a colorless fine powder, which melts at 232°C and boils at 447°C. It is practically insoluble in water and alcohols, but readily soluble in hydrochloric acid and nitric acid. Above 570°C, it liberates BiCb to be transformed into a Bi405Cl3 compound. Among bismuth oxyha-lides, only the oxychloride is available commercially at a cost of US 30.00 ( 7500) for a sample of 99% purity and US 98.60 ( 24 400) for a sample of 99.99% purity per 50 g. However, other oxyhalides can readily be prepared by partial hydrolysis of trivalent bismuth halides or by the interaction of basic bismuth nitrate (BiO(N03)) with the corresponding sodium halide in aqueous... 

Bismuth compounds are added more and more to special polymers for bone implants and dental prothetic devices in order to make them detectable to X-rays. Diagnostic devices for medical purpose have been using the bismuth-germanium oxide crystals to neutralize lethal gamma rays and improve overall imaging. Basic bismuth salicylate is used to impart a pearly surface to polystyrene and phenol-formaldehyde resins. 

The chloride was also sold as blanc de Perle or pearl white when it was prepared by precipitation of aqneous bismutii nitrate with hydrochloric acid and blanc cTEspagm, where aqueous bismuth nitrate was mixed with brine Colour Index, 1971). Other terms apparently associated with this compound are flake white and bismuth white (qq.v.). The Colour Index identifies two white bismuth compounds used as pigments Cl 77163/Pigment White 14, which is listed as bismuth chloride oxide (BiClO), and Cl 77169/Pigment White 17, which is described as basic bismuth nitrate . 

Fig.6.1 depicts the Ebsworth diagram of N and P in acidic solution as well as N in basic solution. The top two elements in this group N and P are typical non-metals. The metallic character, which appears in the heavier elements, increases down the group, although the conductivity of solid Bi is not high. The typical oxidation numbers of all the members of the group are +3 and +5 but the stability of the +3 state in Bi is greater than the +S state (inert pair effect). The chemistry of N and P is dominated by covalent bond formation. On the other hand, ionic compounds of Bi(III) are the common bismuth compounds. The oxides of N and P are acidic in nature (except the neutral N2O and NO), the amphoteric nature becomes apparent in the oxides of the heavier elements. 

Bismuth trioxide may be prepared by the following methods (/) the oxidation of bismuth metal by oxygen at temperatures between 750 and 800°C (2) the thermal decomposition of compounds such as the basic carbonate, the carbonate, or the nitrate (700—800°C) (J) precipitation of hydrated bismuth trioxide upon addition of an alkah metal hydroxide to a solution of a bismuth salt and removal of the water by ignition. The gelatinous precipitate initially formed becomes crystalline on standing it has been represented by the formula Bi(OH)2 and called bismuth hydroxide [10361 -43-0]. However, no definite compound has been isolated. 

The brittle, silvery, shiny metal was long considered the last stable element of the Periodic Table. In 2003 it was unmasked as an extremely weak alpha emitter (half-life 20 billion years). Like thulium, there is only one isotope. Bismuth alloys have low melting points (fuses, fire sprinklers). As an additive in tiny amounts, it imparts special properties on a range of metals. Applied in electronics and optoelectronics. The oxichloride (BiOCl) gives rise to pearlescent pigments (cosmetics). As bismuth is practically nontoxic, its compounds have medical applications. The basic oxide neutralizes stomach acids. A multitalented element. Crystallizes with an impressive layering effect (see right). 

The addition of isocyanates to hydroxy compoimds is inhibited by acid compounds (e.g., hydrogen chloride orp-toluenesulfonic acid) on the other hand, it can be accelerated by basic compounds (e.g., tertiary amines like triethylamine, N,hl-dimethylbenzylamine, and especially l,4-diazabicyclo[2.2.2]octane) and by certain metal salts or organometallic compounds (e.g., dibutyltin dilaurate, bismuth nitrate). These catalysts are often effective in amounts of much less than 1 wt%. 

Trivalent Compounds.—In trivalent vanadium compounds the basic character of the element is well developed, and both normal and oxy-salts of the sesquioxide V203 are well defined, e.g. vanadous sulphate, V2(S04)3, and vanadium oxymonochloride, VOC1. It has been previously mentioned that resemblances between the elements of the A and B Subdivisions of Group V. are mainly restricted to the pentavalent compounds it is of interest to note that the oxychloride has analogues in the trivalent antimony and bismuth basic chlorides, SbOCl and BiOCl. Trivalent vanadium also displays considerable analogy, however, with other trivalent transitional elements, as shown by the following —... 

BASIC SALT. A compound belonging to the categories of both salts and bases, because it contains OH (hydroxyl) or O (oxide) as well as the usual positive and negative radicals of normal salts. Among the best examples are bismuth subnitrate, often written BiONO, and basic copper carbonate, Cu2 (OH)2CO.). Most basic salts arc insoluble in water and many arc of vaiiable composition. 

Bismuth(III) oxide, Bi O is the compound produced by heating the metal, or its carbonate, in air. It is definitely a basic oxide, dissolving readily 111 acid solutions, and unlike the arsenic or antimony compounds, not amphiprotic in solution, although it forms stoichiometric addition compounds on heating with oxides of a number of other metals. It exists in three modifications, white rhombohedral, yellow rhombohedral, and gray-black cubical, Bismuth(II) oxide. BiO, has been produced by heating die basic oxalate. 

Bismuth forms a number of complex compounds, including the sulfa-tobismuthates. e.g., NaBi(S04)2 and N i. Ill [ SO .. and the Ihiocyanato-bismuthates, e.g., Na3Bi(SCN)e, by the interaction of sodium thiocyanate and BnSCN )2. The salts of bismuth tend to lose part of their acid readily, especially on liealiug, to fomt basic salts. 

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