Syntheses, crystal structures and magnetic properties of two novel layeredcompounds: [Fe-3(C2O4)(3)(4,4 '-bpy)(4)] and [Co(C2O4)-(4,4 '-bpy)] (4,4 '-bpy=4,4 '-bipyridine)

The combination of 4,4'-bipyridine (4,4'-bpy) and oxalate ligands has resul ted in the formation of two novel layered compounds [Fe-3(C2O4)(3)(4,4'-bpy )(4)] 1 and [Co(C2O4)(4,4'-bpy)] 2. Both compounds exhibit two-dimensional layer structures. That of 1 consists of iron(II) oxalate chains, with the t erminal and the bridging 4,4'-bpy stacking alternately between the chains. The structure of 2 contains linear chains of cobalt(II) oxalate which are c ross-linked by 4,4'-bpy molecules in a perpendicular manner, leading to squ are grid sheets with rectangular windows. Magnetic measurements reveal that weak antiferromagnetic interactions are mediated in both compounds.