Reaction of formamide with Ni(NO3)2{\textperiodcentered}6H 2O under hydrothermal condition in a mixture of MeOH/H2O forms a two-dimensional formate bridged sheet Ni(HCOO)2(MeOH) 2 (1). X-ray structure analysis reveals the conversion of formamide to formate which acts as a bridging ligand in complex 1 where the axial sites of Ni(II) are occupied by methanol used as a solvent. An analogous reaction in presence of 4,4′-bipyridyl (4,4′-bipy) yielded a three-dimensional structure Ni(HCOO)2(4,4′-bpy) (2). DC magnetic measurements as a function of temperature and field established the presence of spontaneous magnetization with Tc (Curie temperature) = 17 and 20.8 K in 1 and 2, respectively, which can be attributed due to spin-canting. DFT calculations were performed to corroborate the magnetic results of 1 and 2. {\textcopyright} 2010 Elsevier Ltd. All rights reserved.