Unusual metal coordination chemistry from an amino-amide derivative of 4-nitrophenol, a surprising ligand.

The simple ligand N-(2-aminoethyl)-2-hydroxy-5-nitrobenzamide () exhibits several coordination modes depending on the reaction conditions, acting as a zwitterion on its own or being ionic in the presence of acid and depending on the concentration of metal present in a reaction, it can coordinate to the metal in either a 1:1 or a 1:2 metal:ligand mode. Furthermore, the role of solvent plays an important role in these complexation reactions with both four and six coordinate copper complexes being obtained using water as solvent but only six coordinate copper complexes obtained using acetonitrile as solvent.