溴化钾，Potassium bromide；anhydrous, powder, free-flowing, Redi-Dri™, 99.999% trace metals basis

Potassium bromide is a white salt that crystallizes in the cubic rock salt structure, like sodium chloride. KBr is hygroscopic, deliquescent, highly soluble in water, and soluble in some polar organic solvents like glycerol, ethylene glycol, liquid ammonia, and hot ethanol, but insoluble in acetone. When dissolved, KBr dissociates completely into its ions, making it a useful source of bromine ions in double displacement reactions or salt metathesis reactions. For example, this property was used in the production photographic films of silver bromide: KBr was reacted with silver nitrate to precipitate silver bromide, a salt that decomposes on exposure to light.

 

Potassium bromide is widely used in optics because KBr has a low refractive index and a wide spectral range into the infrared with nearly no absorption. As a result, KBr is widely used as infrared optical windows, as infrared beamsplitters, and as substrates for interferometers. Commonly KBr is used in transmission infrared spectroscopy as a media for powder samples. The KBr and powder are ground together and pressed, using a die, into a thin disc under vacuum. The disc suspends the sample without contributing to the transmitted signal. Potassium bromide has also been used in synthesis, commonly as a source of bromide ions. For example, double displacement of KBr and bismuth nitrate yielded nanosheets of bismuth oxybromide.[1] [2] Solutions of KBr have also been found to be useful shape-control agents or crystal-habit modifiers in formation of metal nanocrystals, including palladium nanorods[3] and bimetallic platinum-paladium nanocrystals.[4] [5] KBr is a common source of bromide ions used as nucleophiles in organic chemistry.

可用于除去外周膜蛋白。

 

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