A supramolecular copper-aqua-crown ether complex, (Cu ''(H2O)(4)-(dibenzo-24-crown-8](2+) (1C) is stabilized with a Lindqvist-type polyoxometalate anion, [(Mo6O19)-O-VI](2-) (1a), in an ion-pair compound [Cu ''(H2O)(4)(dibenzo-24-crown-8][(Mo6O19)-O-VI] &3bond; [1c][1a] &3bond; 1. In the crystal, 1c and la assemble to a chainlike structure in which each polyoxoanion la is sandwiched by two 1c cations. 1c is a structurally characterized dibenzo-24-crown-8 (a larger-cavity crown ether) supramolecular complex that shows encapsulation of a small cation at the center of its internal cavity, and compound 1 represents a unique example of a first-row transition metal-crown ether inclusion complex that interacts with a polyoxometalate anion.