Antimony compounds using

Antimony Compounds. The greatest use of antimony compounds is in flame retardants (qv) for plastics, paints, textiles, and mbber. Antimony compounds used in flame retardants are antimony pentoxide, sodium antimonate [15593-75-6] Na[Sb(OH) ], and, most importantly, antimony trioxide. These compounds, when used alone, are poor flame retardants however, when combined with halogen compounds, they produce mixtures that are effective. 

Table 22 Some Antimony Compounds Used in Medicine...

Haas, K., Feldmann, J., Wennrich, R., and Stark, K. J. (2001) Species-specific isotope-ratio measurements of volatile tin and antimony compounds using capillary GC-ICP-time-of-flight-MS. Fresenius J. Anal. Chem., 370, 587-96. 

Health and Safety Aspects. The U.S. EPA has significantly reduced the aHowed levels of antimony compounds in drinking water causing a toxicity cloud over the viabHity of this class of stabilizers. Presently, antimony products are no longer aHowed for use as potable water pipe stabilizers pending completion of NSE International s review (28). Eor these reasons, the future of this stabilizer technology appears limited. 

Two methods are used to measure pH electrometric and chemical indicator (1 7). The most common is electrometric and uses the commercial pH meter with a glass electrode. This procedure is based on the measurement of the difference between the pH of an unknown or test solution and that of a standard solution. The instmment measures the emf developed between the glass electrode and a reference electrode of constant potential. The difference in emf when the electrodes are removed from the standard solution and placed in the test solution is converted to a difference in pH. Electrodes based on metal—metal oxides, eg, antimony—antimony oxide (see Antimony AND ANTIMONY ALLOYS Antimony COMPOUNDS), have also found use as pH sensors (8), especially for industrial appHcations where superior mechanical stabiUty is needed (see Sensors). However, because of the presence of the metallic element, these electrodes suffer from interferences by oxidation—reduction systems in the test solution. 

This reaction gives fair-to-good yields of monoorganotin tribromides and trichlorides when quaternary ammonium or phosphonium catalysts are used (149). Better yields are obtained with organic bromides and staimous bromide than with the chlorides. This reaction is also catalyzed by tri alkyl antimony compounds at 100—160°C, bromides are more reactive than chlorides in this preparation (150,151). a,C0-Dihaloalkanes also react in good yield giving CO-haloalkyltin trihaHdes when catalyzed by organoantimony compounds (152). 

Praziijuantel. This drug (1), C H24N202, can be used to treat schistosomiasis caused by any one of the three major species. Pra2iquantel is an acylated pyta2ino—isoquinoline derivative that has replaced the traditional (and more toxic) trivalent antimonial compounds. 

Antimony compounds have been used to treat leishmaniasis ever since tartar emetic (antimony potassium tartrate) was discovered early in the 20th century to have efficacy against the mucocutaneous form of the disease. The cutaneous form has been treated with tartar emetic formulated in an ointment. Many side effects have been seen with this trivalent antimonial, some of which can be ascribed to the difficulty of obtaining pure antimony for its manufacture. These side effects include toxicity to the heart, Hver, and kidneys. Other promising trivalent antimonials have been abandoned in favor of pentavalent antimonials with lower toxicity. 

Additive inhibitors have been developed to reduce the contaminant coke produced through nickel-cataly2ed reactions. These inhibitors are injected into the feed stream going to the catalytic cracker. The additive forms a nickel complex that deposits the nickel on the catalyst in a less catalyticaHy active state. The first such additive was an antimony compound developed and first used in 1976 by Phillips Petroleum. The use of the antimony additive reportedly reduced coke yields by 15% in a commercial trial (17). 

Xenon difluoride has been used to oxidize a number of antimony compounds [102, 109] in yields ranging from 73 to 98%. Elemental fluorine oxidized tris(pen-tafluorophenyl)stibine to tris(pentafluorophenyl)stibine difluoride in 98% yield [706]. Oxidative fluonnation of stibines has also been accomplished with iodine pentafluoride [707]. 

In situations such as the acid pickling of steel or the use of steel pipes to handle sour oil streams, the use of suitable inhibitors can give a significant reduction in hydrogen entry. In this context it is important to emphasise that the efficiency of an inhibitor in reducing hydrogen entry is not the same as its efficiency in reducing corrosion. Thus arsenic and antimony compounds... 

A comparison of bromine and phosphorus compounds on the flammability of PET fiber shows phosphorus (as phosphine oxide) to be 3.7 times more effective than bromine (Table 1). No synergy was observed. Nevertheless, phosphorus was shown to be more effective than antimony normally used as a synergist, resulting in a higher oxygen index at a lower concentration (Table 2). 

There remains an urgent need for new effective antiparasitic agents, an area of drug development that has languished because of poor economic return. The spread of resistance to chloroquine (an antimalaria treatment) is one reason for attention to be paid to this area, as well as the sheer numbers of people affected. Antimony compounds (43) and (44) (Figure 20) are used to treat... 

The transesterification and glycolysis reactions proceed via the Aac2 mechanism described above in Section 2.1. The reactions are acid catalyzed as demonstrated by Chegolya el al. [27], who added TPA to the polycondensation of PET and observed a significant increase of the apparent reaction rate. The industrial polycondensation process is accelerated by the use of metal catalysts, with these being mainly antimony compounds. 

An antagonism can occur between phosphorus flame retardants and antimony compounds when used in combination. 

Antimony was known in the days of alchemy (500 BCE to 1600 ce) when it was associated with other metals and minerals such as arsenic, sulfides, and lead used as medications. It is possible that an alchemist, Basilus Valentinus (fi. 1450), knew about antimony and some of its minerals and compounds sometime around the mid-fifteenth century ce. Physicians of this period—and earlier periods—used elements such as mercury and antimony to cure diseases, although they knew that these elements were toxic in larger doses. Antimony was used to treat depression, as a laxative, and as an emetic for over two thousand years. Despite the elements poisonous nature, physicians of that early era considered both mercury and antimony good medicines. 

Nicolas Lemery (1645—1715), a French chemist, studied and analyTed antimony and its compounds in detail. He published his findings in 1707. Antimony was used primarily as a treatment for diseases, but as a chemical element it was neglected it until modern days, when it was used to produce low-melting-point alloys. 

Antimonypentoxide (Sb Oj) is used as a flame retardant for textile materials and as a source to prepare other antimony compounds. 

What about the applicability of organolithium compounds of type 29 with heavy organoelement groups in organic synthesis At present we can realize three modes of use (Scheme 39). The antimony compound is suitable as a reagent for nucleophilic halomethylation Nucleophilic lithiomethylation and carbonyl olefination, two other modes of application, are the objects of Sects. 4.4,4.5, and Chap. 5. 

Sodium stibogluconate is a pentavalent antimo-nial compound. It is a prodrug as the pentavalent an-timonial has to be reduced to a divalent antimony compound. Sodium stibogluconate is used to deal leishmaniasis and is only available for adminisda-tion by injection. It is excreted in the urine. In general it is tolerated fairly well. Adverse effects include pain at the injection site and gasdointestinal complaints. Cardiac arrhythmias can occur and renal and hepatic function should be monitored. 

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