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Acid Halogenides

Very different problems

Organic acid halogenides

Since the reactivity may be very different, you will find here only some general hints. There are three possibilities:

  1. Dispose in a separate bottle. Advantage: Very easy, but it may be more expensive.
  2. Dispose as solvent waste. To avoid that all the waste will fly past your ears, you may add the acid halogenide only in very small portions. It is not needed that you spend hours or even days standing at the waste container, but only add a little bit from time to time, where it is best to do this with a proper filled waste container since in an empty waste container there is at the moment nothing wich will dectivate the acid halogenide and then you will have a desaster without any warning if the container is later on filled with other chemicals. This method is more effort but it will be cheaper. The safety is very enhanced if the mixture is stirred on adding the compound.
  3. Deactivation with water or alcohol. But even if you use "gratuitous" water the amount of waste increases and makes the disposing more expensive. A deactivation is only meaningful, if the mixture then may be disposed as organic solvent waste.

Phosphoroxychloride:

A deactivation is only meaningful if the quantity is so small that the resulting mixture may be flushed down the drain. Otherwise disposing the untreated compound in a separate bottle is more profitable.

On hydrolysis in pure water an explosive reaction may occur with a perfidous time delay! It is better to use hydrochloric acid from the beginning as described below:

To a three necked flask equipped with dropping funnel and gas outlet pipe a little bit of hydrochloric acid is added. Then a little bit of phosphoroxychloride is added with stirring until the mixture is warmed up. Then ice and phosphoroxychloride is alternating added in a way the solution remains constantly slightly warmed and will not boil. The acidic gas is absorbed. Carefully ensure that the phosphoroxychloride will react instantaneously and never will form a separate layer! If you see a second layer, immediately stop adding the phosphoroxychloride and wait until the layer has disappeared. If the reaction is running propperly even larger amounts of the phosphoroxychloride may be deactivated quickly. If necessary you may additionally cool the flask in a bath.

Since the resulting mixture is very acidic, it should be neutralised. The salt solution may then be flushed down the drain.

Phosphortribromide, Sulfurylchloride:

A deactivation is only meaningful if the quantity is so small that the resulting mixture may be flushed down the drain. Otherwise disposing the untreated compound in a separate bottle is more profitable.

These kind of acid chlorides may be deactivated with diluted sodium hydroxide solution. If the reaction is too vigorous, add ice to the mixture. The resulting mixture may be flushed down the drain.