One 3D and one 2D μ 1,5 -dicyanamide bridged Ni II complexes having molecular formula [Ni(L1)(dca) 2 ] (1) and [Ni 2 (L2) 2 (dca) 4 ]·0.5H 2 O (2) (L1=4-(2-aminoethyl)-morpholine, L2=1-(2-aminoethyl)-piperidine and dca=dicyanamide dianion) have been synthesized. X-ray single crystal analyses and low temperature magnetic measurements were used to characterize the complexes. Complex 1 represents a 3D structure where each metal ion is chelated by morpholine ligand (L1) and connected by four μ 1,5 -dca. Whereas complex 2 shows an undulated 2D structure with grid of (4,4) topology having two crystallographically independent Ni II centers in similar octahedral environment where each metal center is chelated by one piperidine ligand (L2) and coordinated by four μ 1,5 -dca. Magnetic measurements of both the complexes indicate weak antiferromagnetic interactions through the μ- 1,5 -dca bridging ligands.