Three new polyamine Ni(II) complexes, namely [Ni(trien)(phen)](BF 4 ) 2 1, [Ni(trien)(bipy)](ClO 4 ) 2 2 and [Ni(trien)(en)](ClO 4 ) 2 3 [trine = triethylenetetramine, phen = 1,10-phenanthroline, bipy = 2,2 0 -bipyridyl, en = ethylenediamine] have been synthesized and characterized by physicochemical and spectroscopic methods. Complexes 1 and 2 crystallize in monoclinic space group P21/c, and possess a distorted octahedral geometry. Significant hydrogen bonding interactions are found in both complexes.