Shaping the cavity of calix[4]arene using transition metals and binding alkali-metal cations inside the cavity: the relevance of the alkali-metal cation–arene interaction

Transition metals can be used for shaping and electronically enriching the calix[4]arene cavity; in this approach, the π-basic cavities can be adapted to alkali-metal cation complexation in a very hydrophobic environment and these cations can even be transferred into aliphatic hydrocarbons; the η 6 -arene–alkali-metal cation interaction is structurally elucidated.