Chloride-bridged, defect-dicubane {Ln4} core clusters: syntheses, crystal structures and magnetic properties

Abstract

Three chloride-bridged lanthanide compounds, [Ln₄Cl₆(CH₃OH)₁₂(OH)₂]·4Cl·2CH₃OH [Ln = Gd (1), Dy (2) and Er (3)], have been unexpectedly isolated by the reactions of LnCl₃·6H₂O and N,N′-bis(salicylidene)-1,2-(phenylene-diamine) (H₂L). X-ray crystallographic analysis reveals a triclinic cell with a unique defect-dicubane {Ln₄} core and the structure across this series is nominally isomorphic. Measurements of direct current magnetic susceptibility and isothermal magnetization give insight into the relevant cluster Hamiltonians for 1, 2, and 3, and alternating current susceptibility shows slow relaxation in 2, but not in 1 or 3 down to 2 K and up to 1 kHz.