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 [NaCu(6)(aa)(8)](5+) (aa = amino-acid) cage moiety are presented. The formula of this new compound is [NaCu(6)(gly)(8)(ClO(4))(3)(H(2)O)](n)(ClO(4))(2n) (1); it is formed by hexanuclear clusters linked into chains through axial-equatorial Cu(II)-O-Cu(II) coordination links along the crystallographic a axis and connected via ClO(4)(-) ligands in the b direction. Magnetic susceptibility measurements have revealed intra-cluster ferromagnetic interactions leading to and S(T) = 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. (C) 2008 Elsevier B. V. All rights reserved.