A New Mixed‐Valent Copper Cyanido Complex and a New Copper(II) Acetato Complex, Prepared with an Ionic Liquid

When copper(II) acetate is treated with the ionic liquid n ‐butylmethylimidazolium cyanide (BMIm‐CN), in ethanol solution, two new copper coordination compounds are obtained. (BMIm) 2 [Cu 4 (CN) 7 ] comprises a 3D coordination polymer of cyanide bridged copper ions. This anionic coordination polymer contains Cu I as well as Cu II ions, i.e. it is a mixed‐valent compound. The polymer can be described as honeycomb structure with the BMIm + cation being located in the cages. The second compound obtained from the chemical reaction is (BMIm)[Cu 2 (OAc) 5 ][Cu(OAc) 2 (H 2 O)] 2 · C 2 H 5 OH, which can be described as double‐salt. The first unit (BMIm)[Cu 2 (OAc) 5 ] contains paddle wheel copper(II) acetato moieties, which are bridged by additional acetato ligands and form infinite chains. The second part of the double salt is the neutral, [Cu(OAc) 2 (H 2 O)] 2 complex. These two parts as well as the co‐crystallized ethanol molecule are connected through a network of hydrogen bridges.