Synthesis and magnetism of Nickel(II) binuclear complexes with oxamide-N,N'-diacetic acid

Three novel mu-oxamidato binuclear complexes have been synthesized, namely [Ni(oxaa)Ni(L)(2)(H2O)(2)]. XH2O, where oxaa is oxamide-N,N'-diacetic acid tetraanion and L denotes 2,2'-bipyridyl (bpy), 4,4'-dimethyl-2,2'-bipyridyl (Me(2)bpy) or 1,10-phenanthroline (phen). The temperature dependences of t he magnetic susceptibilities of [Ni(oxaa)Ni(bpy)(2)(H2O)(2)] and [Ni(oxaa)N i(phen)(2)(H2O)(2)]. H2O have been investigated in the 4.2-300 K range, giv ing the exchange parameters J =-25.3 cm(-1) for bpy and J = -26.4 cm(-1) fo r phen, respectively. These results are commensurate with antiferromagnetic interaction between the adjacent metal ions.