Some slightly decomposed crystals of 4-methoxyphenyl-diazonium-tetrafluoroborate.

Diazonium salts are tricky compounds, since most of them are not stable enough to isolate them in pure form, because they decompose easily. Old reports say that diazonium perchlorates (ClO4) could easily explode when they are stored in pure form, but tetrafluoroborates (BF4) are mostly stable. To test it’s stability the easiest thing is to mix a small amount of the pure salt with 10x weight of sand and heat it up. If it explodes it is not stable, but if it melts and decomposes slowly, it is safe to use.

The Balz–Schiemann reaction is a chemical reaction in which aniline [1] are transformed to aryl fluorides [3] via diazonium fluoroborates [2] (on the picture). It is named after the German chemists Günther Schiemann and Günther Balz, this reaction is the preferred route to fluorobenzene and some related derivatives.

How this works?

9:30 pm • 20 November 2015 • 401 notes • View comments