Synthesis, Crystal Structures and Magnetism of a Series of Heptanuclear Rare‐Earth‐Centered Trigonal Prism Clusters

Abstract

Abstract A series of heptanuclear rare‐earth‐centered trigonal prism clusters [LnCu 6 (μ‐OH) 3 (HL) 2 (L) 4 ]·(ClO 4 ) 2 ·25H 2 O (Ln = La−Ho and Y; H 2 L = iminodiacetic acid) was synthesized and their crystal structures were determined by X‐ray diffraction. The rare‐earth center and the copper ions are bridged by three μ 3 ‐OH and six μ 2 ‐O moieties from the carboxyl groups of six different ligands. The rare earth ion is nine‐coordinate and the coordination polyhedron is an unusual, highly symmetrical tricapped trigonal prism (C 3h ). The cluster has an interesting, highly symmetrical eclipsed structure (C 3h ) which utilizes the central rare earth cation as a template. The temperature‐dependence of the magnetic susceptibility of the cluster series was investigated and was found to vary with the central rare‐earth ions. The magnitude of the antiferromagnetic interaction constants J between Cu 2+ ions in [LaCu 6 ] and [YCu 6 ] were compared and estimated to be −24 cm −1 and −7 cm −1 , respectively, indicating a significant effect of the central diamagnetic ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)