The reaction of M(S2O6) (M = Cu-II, Ni-II, and Co-II) with 4,4'-bipyridine-N,N'-dioxide (bpdo) results in the formation of novel 3D, 2D, and mononuclear complexes. Complex 1, {[Cu(H2O)(bpdo)(2)](S2O6)(H2O)}(n), is a 2-D wavelike polymer with the Cull ion located on a 2-fold axis and having a distorted square-pyramidal coordination sphere. With Co-II and Ni-II, 3-D complexes, {[M(bpdo)(3)](S2O6)(C2H5OH)(7)}(n) [M = Co-II (2), Ni-II (3)], were obtained. The metal atoms are situated on centers of symmetry and have octahedral environments coordinated to six bpdo molecules. The same reaction in aqueous solution with a metal/ligand ratio of 1:1 results in the formation of mononuclear complexes, {[M(bpdo)(H2O)(5)](SO4)(H2O)(2)} [M = Co-II (4), Ni-II (5)], accompanied by the decomposition of the dithionate S2O62- to sulfate anions SO42-.