A series of tetranuclear lanthanide complexes comprising two edge-sharing triangular units with field-induced slow magnetic relaxation for Dy4 species

Abstract

The syntheses, crystal structures and magnetic studies are reported for a series of Ln₄ clusters formulated as Ln₄(μ₃-OH)₂(php)₂(OAc)₆(H₂O)₂]·4MeOH·nH₂O (Ln = Gd (1), Tb (2), Dy (3) (n = 2) and Ho (4) (n = 0); H₂php = 2,6-(picolinoylhydrazone)pyridine). The overall metal core of each cluster is comprised of two edge-sharing triangular Ln₃ units linked by μ₃-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.