The preparation and crystal structures of five cyano-bridged Fe - Mn complexes, [(bipy)(2)Fe-II(CN)(2)Mn-II(bipy)(2)](2)(ClO4)(4) ( 1), [(bipy)(2)Fe-II(CN)(2)Mn-II(DMF)(3)(H2O)](2)(ClO4)(4) ( 2), {[(Tp) Fe-III(CN)(3)](2)Mn-II(DMF)(2)(H2O)}(2) ( 3), {[(Tp) Fe-III(CN)(3)](2)Mn-II( DMF)(2)}(n) ( 4), and Na-2[(MnFeII)-Fe-II(CN)(6)] ( 5) (bipy = 2,2'-bipyridine, Tp = tris(pyrazolyl) hydroborate), are reported here. Compounds 1 - 4 contain the basic Fe-2(CN)(4)Mn-2 square building units, of which 1 - 3 show the motif of discrete molecular squares of Fe-2(CN)(4)Mn-2 and 4 possesses a 1D double-zigzag chainlike structure, while compound 5 is a 3D cubic framework analogous to that of Prussian blue. Compounds 1 and 2 show weak ferromagnetic interactions between two Mn(II) ions through the bent - NC - Fe(II) - CN - bridges. Compound 3 shows weak antiferromagnetic coupling between the Fe(III) and Mn(II) ions, while compound 4 displays a metamagnetic-like behavior with T-N = 5.2 K and H-c = 10.5 kOe. Compound 5 exhibits a ferromagnetic ordering with T-c = 3.5 K, coercive field, H-c, = 330 G, and a remnant magnetization of 503 cm(3) Oe mol(-1).