Super selective liquid phases:

Certain liquid phases might be said to be super associative. A few of these liquids depend on the formation of loose chemical adducts with particular solutes to effect separation. Silver ions form loose adducts along with olefins of the categories shown below

Saturated solutions of silver nitrate within ethylene glycol, glycerol and triethylene glycol or in benzyl cyanide have been used as selective solvent for olefins. Benzyl cyanide has an advantage over the glycols because it is non-hygroscopic and does not needs moisture free carrier gas. Parafins are not retained and pass rapidly through the column while alkynes react to form siliver acetylides and remain on the column. Temperature should be below 40°C, above this limit adducts with AgNO₃ are not created and solutions are unstable. Mercuric perchlorate has been used to remove unsaturated through π- complexes along with olefins, alkynes and aromatics. The tetracyanoethylated pentaerythritol (TCEPE) is highly selective for aromatics.