Two 1D coordination polymers composed of DyZn2(salen)(2) units and pyridin-N-oxide-4-carboxylate have been prepared by solvothermal reactions. Complex 1 with the formula {[DyZn2(L-a)(2)(POC)](OH)(ClO4)}center dot H2O center dot MeOH [H2La] = N,N'-bis (3-meth oxysalicylidene)-1,3-diaminopropane, POC- = pyridin-N-oxide-4-carboxylate] is composed of a zigzag chain cation [DyZn2 (L-a)(2) (POC](n)(2n+ )as well as isolated hydroxide and perchlorate anions. Complex 2 with the formula {[Dy3Zn7(L-b)(6)(POC)(6)](OH)(3)(ClO4)(2)}.9H(2)O [H2Lb] = N,N'-bis(3-methoxysalicylidene)-1,2-diaminoethane] is also an ionic compound containing isolated hydroxide and perchlorate anions, but its cation shows a novel nanowire structure, in which six-coordinate zinc(II) ions with C-3 symmetry act as the axis and [DyZn2(L-b)(2)(POC)](2+) structural units as spiral leaves. Complex 1 shows good single-molecule magnet performance with an U-eff /k value of 235.3(3.1) K (H-dc = 0 Oe), one of the largest values for coordination polymers. A butterfly-shaped magnetic hysteresis loop can be monitored at as high as 3.8 K for 1, while a dc field is necessary for complex 2 to display slow magnet relaxation owing to the quantum-tunneling effect, with a much smaller U-eff/k value of 14.6(0.2) K (H-dc = 1000 Oe). The difference of magnetic properties has been explained using detailed ab initio calculations.