Crystal structure of hexa-μ-chlorido-μ₄-oxido-tetrakis{[1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole-κN ³]copper(II)} containing short NO₂...NO₂ contacts

Abstract

The title tetranuclear copper complex, [Cu4Cl6O(C6H9N3O3)4] or [Cu4Cl6O(MET)4] [MET is 1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole or metronidazole], contains a tetrahedral arrangement of copper(II) ions. Each copper atom is also linked to the other three copper atoms in the tetrahedron via bridging chloride ions. A fifth coordination position on each metal atom is occupied by a nitrogen atom of the monodentate MET ligand. The result is a distorted CuCl3NO trigonal–bipyramidal coordination polyhedron with the axial positions occupied by oxygen and nitrogen atoms. The extended structure displays O—H...O hydrogen bonding, as well as unusual short O...N interactions [2.775 (4) Å] between the nitro groups of adjacent clusters that are oriented perpendicular to each other. The scattering contribution of disordered water and methanol solvent molecules was removed using the SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–16] in PLATON [Spek (2009). Acta Cryst. D65, 148–155].

Adamantane-type clusters: compounds with a ubiquitous architecture but a wide variety of compositions and unexpected materials properties

“…They were isolated after an addition of simple CuCl x to L in the presence of ambient air, hydroxide or CuO. 385–436 In some of those cases, the oxygen source could not be determined and is most likely a H 2 O or O 2 impurity in the reaction, or stems from decomposition of the solvent. A deviating synthetic strategy uses oligomeric [LCuCl] x complexes already containing the desired ligand, which rearrange to the desired product.…”