Structural analysis and magnetic properties of the 1D [Fe(dca)(2)bipy(H2O)]center dot 1/2H(2)O and the 3D [Ni(dca)(2)bipy] (dca = dicyanamide; bipy=4,4 '-bipyridine)

The combined use of bipy (4,4'-bipyridine) and dca (dicyanamide) has led to the preparation of two polymeric compounds of formulae [Fe(dca)(2)bipy(H2O)].1/2H(2)O (1) and [Ni(dca)(2)bipy] (2). Both have been synthesised and characterised through IR and UV-Vis spectroscopies, thermal analysis, X-ray difracction and measurements of the molar magnetic susceptibility. Compound 1 is 1D and exhibits weak antiferromagnetic interactions. Compound 2 consists of two interpenetrated 3D networks giving rise to weak ferromagnetic interactions. The formation of both types of structure can be related to the different Pearson acidities of Fe-II and Ni-II ions.