Study of the magnetic exchange within the cluster polymer [NaCu6(gly)8(ClO4)3(H2O)]n(ClO4)2n

The synthesis and structure of a new member of the family of complexes containing the [NaCu6(aa)8]5+ (aa = amino-acid) cage moiety are presented. The formula of this new compound is [NaCu6(gly)8(ClO4)3(H2O)]n(ClO4)2n (1); it is formed by hexanuclear clusters linked into chains through axial-equatorial CuII–O–CuII coordination links along the crystallographic a axis and connected via  ClO4- ligands in the b direction. Magnetic susceptibility measurements have revealed intra-cluster ferromagnetic interactions leading to and ST = 3 ground state for each hexanuclear unit, and the presence of weak inter-cluster ferromagnetic exchange. The coupling within the hexanuclear moieties has been investigated by means of DFT calculations that have corroborated the interpretation of the experimental results.

Graphical abstractIn the cluster polymer [NaCu6(gly)8(ClO4)3(H2O)]n (ClO4)2n (1), the hexanuclear cages organize as extended sheets. The magnetic interaction between Cu(II) ions within the clusters is ferromagnetic leading to S = 3 units that in turn exhibit ferromagnetic interactions between them. DFT calculations suggest that the magnetic coupling changes with the temperature.Figure optionsDownload full-size imageDownload as PowerPoint slide