Intermolecular interactions between new bismacrocyclic donors and a series of accepters (such as quinone, TCNQ, or toluene) have been studied by crystallography in the solid state and by voltammetry in solution. The bismacrocyclic molecules functioning as receptors contain well-defined flexible cavities which accommodate molecules of appropriate size and can adjust to the guest molecules. This brings together transition metal ions and organic substrates within the same supramolecular structure. The host-guest interactions decrease the energy gap between the HOMO of the donor species and the LUMO of accepters, thus leading to the observed nonadditive CT properties.