Magnetic and Structural Studies of Copper–Lanthanoid Complexes; the Synthesis and Structures of New Cu3Ln Complexes of 6‐chloro‐2‐Pyridone (Ln = Gd, Dy and Er) and Magnetic Studies on Cu2Gd2, Cu4Gd2 and Cu3Gd Complexes

Abstract

AbstractThe synthesis and structural characterisation of three copper–lanthanoid complexes are reported. The compounds, of general formula [Cu3M(chp)8(NO3)(S)] [M = Gd, S = H2O in 2; M = Dy, S = H2O in 3; M = Er, S = (H2O)0.5(MeOH)0.5 in 4; chp = anion of 6‐chloro‐2‐pyridone], are made by reaction of [Cu2(chp)4] (1) with the hydrated lanthanoid nitrate salt in methanol. Structural studies reveal the three copper atoms lie in an approximate hemisphere about a central lanthanoid atom. Magnetic studies on 2 and two further Cu–Gd complexes show ferromagnetic coupling between the 3d and 4f metals. Consideration of these results along with magnetic data previously reported for Cu–Gd compounds leads to a correlation between the magnitude of this exchange coupling and the exponential of the Cu…Gd distance. This is the first magneto‐structural correlation reported for mixed d‐block/f‐block metal complexes.