Bis-cation salt complexation by meso-octamethylcalix[4]pyrrole: linking complexes in solution and in the solid state.

Pyridinium and imidazolium bis-cations are shown to link calix[4]pyrrole anion complexes both in solution and in the solid state. This is accomplished by binding of the bis-cations to the electron-rich bowl shaped cavities formed by two separate calixpyrrole-anion complexes. These resulting sandwich-type structures provide a new way of organising calix[4]pyrrole anion complexes in space.