The anionic CdI(2)-type topological net, [Cu(2)(tci)(2)](2-), and the pentanuclear copper cluster cation [Cu(5)(tci)(2)(OH)(2)(H(2)O)(8)](2+) [tci = tris(2-carboxyethyl)isocyanurate] form a complementary 3D supramolecular framework. Interestingly, there exist centrosymmetric cyclic (H(2)O)(18) clusters in the cavities.