cryptand

Also known as cryptands

[[File:Cryptate of potassium cation.jpg|thumbnail|Structure of [[2.2.2-Cryptand|[2.2.2]cryptand]] encapsulating a potassium cation (purple). At crystalline state, obtained with an X-ray diffraction.]] [[File:Cryptand.svg|thumb|class=skin-invert-image|[2.2.2]Cryptand]]