Oxime Analogs of Amino Acids and Peptides Are Efficient Ligands for Ni(II) Ions

Abstract

Oxime derivatives of amino acids, amides, and peptides are very efficient ligands for NiII ions forming very stable water-soluble complexes. Oxime of amino acids amides forms octahedral and square-planar complexes with the same 4N coordination mode. The spectroscopic and X-ray diffraction studies indicate an unusual role for the hydrogen bond in NiH−1L2 species, which stabilizes the cis coordination of two ligands in a planar complex. Oxime analogs of natural amino acid can be much more efficient ligands than the parent molecules.