Single crystals of the mononuclear bis-oxamate nickel(II) complex [Ni(bipy)(H(2)edpba)].dmso (1) are obtained by reacting [Ni(bipy)Cl-2].H2O and the flexible K-2(H(2)edpba) ligand [bipy = 2,2'-bipyridine; H(4)edpba = N,N'-2,2'-ethylenediphenylenebis(oxamic acid)]. The reaction of 1 with copper(II) ions resulted in two products in which the replacement of the nickel(II) ion by copper(II) took place: the chain compound [Cu(bipy)(H(2)edpba)](n).3nH(2)O.ndmso [dmso = dimethyl sulfoxide] (2) and the analogous chain compound without dmso crystallization molecules [Cu(bipy)(H(2)edpba)](n).1.5nH(2)O (3a) in its polycrystalline form. The reaction of [Cu(bipy)Cl-2] and K-2(H(2)edpba) yielded single crystals of [Cu(bipy)(H(2)edpba)](n).1.5nH(2)O (3b). The H(2)edpba(2) ligand exhibits the anti conformation in 1, 2, and 3b, but it adopts different coordination modes: terminal bis-bidentate (1) and bridging bis-bidentate (2 and 3b) through the two pairs of carbonyl-oxygen atoms of the two oxamate arms. Magnetic susceptibility measurements carried out on a polycrystalline sample of 3b in the temperature range 1.9295 K showed the occurrence of very weak intrachain antiferromagnetic interactions [J = -0.40 cm(-1), the Hamiltonian being defined as H = -J Sigma S-i(i).Si+1], in agreement with the large values of the coppercopper separation [8.308(3) angstrom].