Stannous bromide

Halides. The tin haUdes of the greatest commercial importance are stannous chloride, stannic chloride, and stannous fluoride. Tin hahdes of less commercial importance are stannic bromide [7789-67-5], stannic iodide [7790-47-8], stannous bromide [10031-24-0], and stannous iodide [10294-70-9] ( ) ... 

SiHcon tetrabromide [7789-66A], SiBr, and tribromosilane [7789-57-3], SiHBr, are used in a process to make high purity siHcon (40). Stannous bromide [10031 -24-0], SnBr2, is claimed as a catalyst in preparing a lubricant antioxidant (41). Stannic bromide [7789-67-5], SnBr, is used in the metallurgical separation of minerals (42). 

A very useful route to monoalkyltin trihalides involves the reaction of stannous bromide with alkyl bromides in the presence of 5 mol % of a trialkylantimony compound (47). A typical example is shown in the following equation. 

At ordinary temperature and under atmospheric pressure stannous bromide absorbs only 0-6 molecules of ammonia for every molecule of salt, even after standing for forty hours on lowering the temperature, however, to 0° C. and allowing the salt to remain in contact with ammonia gas for twenty-four hours, triammino-stannous bromide, [Sn(NH3)3]Br2, is formed as a yellow powder. At low temperatures stannous bromide and liquid ammonia react, and at —78° C. ammonia is rapidly absorbed, increase in bulk takes place, and addition compounds containing nine and five molecules of ammonia are produced. 

It is suggested that in the ammines of higher co-ordination number two shells of ammonia may surround the central metallic atom, and in the case of stannous bromide the co-ordination numbers are assumed to be 3+2 or 3+6, thus giving an explanation of the ammino-compounds containing nine or five molecules of ammonia.1... 

ALUMINUM BROMIDE (m.p. 97.5) Ammonium bromide Silver bromide (m.p. 434) Sodium bromide (m.p. 755) Stannous bromide (m.p. 215. BaBr0,CaBr0,KBr,PbBr0,HgBr, TIBr ... 

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 stannous bromide than with the chlorides. This reaction is also catalyzed by trialkylantimony 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 trihalides when catalyzed by organoantimony compounds (152). 

Iriniethoxyborohydridc. Stannous bromide. Stannous chloride. Teltamethylammonium borohydride. Thioglycolic acid. Tin. Titanium tetrachloride. Tri-/-butylaluminum. Tri-n-butyltin hydride. Triethylene glycol (see Zinc). Triethyl phosphite. Trimethylamine borane. Trimethylammonium formate. Trimethylsilane (indirect). Triphenyltin hydride. Tris-(tripbenylphosphine)chlor(X hodium. Zinc. Zinc amalgam. Zinc-Copper couple. Zinc hydrosulfide. 

Stannous bromide, 25% solution, obtained by dissolving tin in 40% solution of HBr. 

The procedure described in Note 6 gives a product that may contain more than 20 per cent of tw-chlorobenzaldehyde. This contamination can be avoided by using stannous bromide instead of the chloride as the reducing agent. 

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