A series of tetranuclear lanthanide complexes comprising two edge-sharing triangular units with field-induced slow magnetic relaxation for Dy-4 species

The syntheses, crystal structures and magnetic studies are reported for a series of Ln(4) clusters formulated as Ln(4)(mu(3)-OH)(2)(php)(2)(OAc)(6)(H2O)(2)]center dot 4MeOH center dot nH(2)O (Ln = Gd (1), Tb (2), Dy (3) (n = 2) and Ho (4) (n = 0); H(2)php = 2,6-(picolinoylhydrazone)pyridine). The overall metal core of each cluster is comprised of two edge-sharing triangular Ln(3) units linked by mu(3)-OH bridges. Direct-current (dc) magnetic susceptibility studies reveal that the Ln(III) ions are very weakly coupled in all four compounds. Alternating-current (ac) magnetic susceptibility studies for 3 indicate that field-induced slow relaxation phenomenon occurs for this compound.