Mononuclear Cu(II) and Ni(II) complexes of bis(naphthalen-2-ol) Schiff base ligands

Abstract

With this work, we describe the synthesis and characterization of two new coordination complexes, a mononuclear Cu(II)L and a mononuclear Ni(II)L where the free base ligand is H2L = 1,1′-(((2-hydroxypropane-1,3-diyl)bis(azanylylidene)) bis(methanylylidene))bis(naphthalen-2-ol). In both metal complexes, the coordination environments are observed to be 4-coordinate square planar with two phenolic oxygens and two imine nitrogens coordinating the metal while the central pendant hydroxyl group was not observed to participate in coordination. In contrast to previously reported dinuclear complexes with similar ligand systems, the alkaline conditions presented in this work resulted in only the mononuclear coordination environments observed.