Two bimetallic assemblies, [Ni(tn)(2)](2)[Cr(CN)(5)(NO)]OH .H2O (1) and [Ni(tn)(2)](2)[Co(CN)(6)]NO3-2H(2)O (2) (tn = 1,3-diaminopropane), have been prepared and structurally and magnetically characterized. Crystal data for 1 (2): space group P (1) over bar (P (1) over bar), a = 8.698(3) (8.937(2)) Angstrom, b = 10.001(2) (9.863(1)) Angstrom, c = 10.158(2) (10.064(1)) Angstrom, alpha = 87.40(2) (86.064(10))degrees,beta = 65.10(2) (65.489(10))degrees, gamma = 81.63(2) (81.572(12))degrees and Z = 1 (1). Both structures consist of two-dimensional grid-like polycations containing Ni-N equivalent toC-M linkages (M = Cr or Co) and counteranions (OH, NO3). Magnetic studies of 1 showed that the complex displays a metamagnetic behavior originating from intralayer ferromagnetic and interlayer antiferromagnetic interactions. Long-range antiferromagnetic ordering was observed at T-N = 3.3 K. Complex 2 exhibits intramolecular ferromagnetic interactions through the diamagnetic N equivalent toC-Co-N equivalent toC bridges, owing to superexchange involving the empty d(sigma), orbital of the diamagnetic Co(III) ion.