A novel 3D heteropolymetallic coordination polymer, {[Na5Cu8Sm4(NTA)(8)(ClO4)(8)(H2O)(22)] center dot ClO4 center dot 8H(2)O}(n) (H(3)NTA = nitrilotriacetic acid), based on the metalloligand [Cu(NTA)](-), has been prepared and characterized by X-ray crystal diffraction. The single-crystal structure shows that the complex forms a 3D framework with interpenetrating 1 D channels along the a and b axes, respectively. These channels construct 2D "tube net" layers in the ab plane. The temperature-dependent magnetic properties have been studied and showed the presence of antiferromagnetic couplings between Cull ions. The investigation of ion exchange reveals that the uncoordinated perchlorate anions that filled in the channels can be exchanged by anions of tetrafluoroborate.