First example of the planar rectangular 18-nuclear nickel(II) hydroxo complex with n-(2-pyridylmethyl)iminodipropionic acid

Abstract

A planar rectangular cluster Ni18 (I) was obtained from N-(2-pyridylmethyl)iminodipropionic acid (II). The crystal structure of complex I was determined by X-ray diffraction. Complex I is built from the octanuclear planar framework (III) of the nickel(II) hydroxo complex (Ni...Ni 2.976–3.092 A), four nickel chelates with the corresponding acid (IV), which are coplanar with the framework and are on both its sides (Ni...Ni, 2.938–3.188 A), four hydroxo complexes, and two mixed chloro chelates V), which are not coplanar with the framework (Ni...Ni, 3.141 and 3.181 A). In the chelate parts of complex I, the organic ligand is hexadentate because of bridging bonds; the coordination polyhedroLn of the metal center is a distorted square bipyramid (4 + 2).