Structure of aqua-bis(ethylenediamine)copper(II) bis(2,6-dimethylphenolate)

The single-crystal X-ray structure of [Cu(en)2(H2O)](dmp)2 (en=1,2-diaminoethane and dmp=2,6-dimethylphenolate) shows the copper(II) ion in a quite regular square pyramidal N4O environment. The phenolate is not coordinated to the metal ion. Instead, the oxygen atom of each of the phenolate anions participates in three hydrogen bonds to the H atoms of the coordinated water and ethylenediamine ligands. These hydrogen atoms connect the cations and the anions in infinite polymeric chains, thereby apparently preventing the copper ions from reduction by dmp.