A Tetranuclear ?3-Alkoxo Cubane-Like Copper(II) Complex Containing 2-(ethylamino)ethanol and Acetate: Synthesis and Structural Characterization

Abstract

A tetranuclear cubane-like complex, [Cu<inf>4</inf>(μ-Etae) <inf>4</inf>(OAc)<inf>4</inf>]·H<inf>2</inf>O (1), with 2-(ethylamino)ethanol (EtaeH) and acetate (OAc)- ligands has been synthesized and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. Complex 1 crystallizes in the orthorhombic space group Pccn and consists of a tetranuclear [Cu<inf>4</inf>O<inf>4</inf>] 4+ cubane core in which four copper(II) ions are bridged by μ<inf>3</inf>-alkoxide oxygen atoms of the Etae- anion. The amine N atom of Etae-, and one of the O atom OAc also coordinate to the copper(II) ions forming a distorted square-pyramidal geometry with a CuO <inf>4</inf>N chromophore. The Cu⋯Cu separations with in the [Cu <inf>4</inf>O<inf>4</inf>]4+ cubane range from 2.905(2) to 3.377(2) Å, and these short Cu-Cu separations are responsible for the anti-ferromagnetic coupling between the copper centers. The cubane-like units are linked by N-H⋯O hydrogen bonds into one-dimensional supramolecular chains, which are further arranged in a two-dimensional array by van der Waal's interactions. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.