Synthesis and Crystal Structure of a Heptanuclear and an Octanuclear Copper(II) Complex Derived from α-D-Glucofuranoses

CuII complexes of different 6‐(β‐keto‐enamino)‐6‐deoxy‐1,2‐O‐isopropylidene‐α‐D‐glucofuranoses 3a–f have a high tendency to build up oligonuclear clusters. Two new oligonuclear copper(II) complexes could be synthesised, crystallised and their structures determined. The complex Cu(3a) was found to consist of a heptanuclear cluster in which two β‐cubane like substructures share one copper ion. The structure is highly asymmetric and in the cluster every CuII ion has a different coordination geometry. Variation of the residues of the β‐ketoenaminic unit leads to the formation of the octanuclear copper(II) complex Cu(3e). Similarly, this has two β‐cubane subunits consisting of a heptanuclear structure with an additionally attached copper ion. In the crystal, two Cu8 cluster molecules are found differing in their geometries due to intermolecular interactions responsible for the formation of a supramolecular network. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)