Interaction of Na(I), Ni(II) and Cu(II) with 2-cyano-2-(hydroxyimino)acetic acid: Spectroscopic and theoretical studies

Sodium(I), nickel(II) and copper(II) complexes of 2-cyano-2-(hydroxyimino)acetic acid have been characterized by vibrational and EPR spectra based on the DFT calculations. The bidentate ligand with the different protonation state of the oximic group chelates the transition metal ions through the oxime nitrogen and the carboxyl oxygen. However, two sodium ions are bonded to the deprotonated oximic as well as carboxylic groups.