The square-planar structure of bis[N-(i-propyl)-3-oxy-2-naphthaldiminato]copper(II)

The stepped square-planar Schiff base copper(II) complex bis[N-(i-propyl)-3-oxy-2-naphthaldiminato]copper(II) (1) is presented. This compound was synthesized and characterized by chemical analysis, mass spectrometry, UV–visible, IR, far-IR, and X-ray crystallography. In addition, EPR studies were carried out for 1. In this complex, the geometry around the copper ion is stepped square planar. EPR spectra in toluene, chloroform, and DMF solutions at 77 K suggest that the geometry of 1 is similar to that observed in the solid state by X-ray crystallography. Kohn–Sham geometry optimizations on this complex are in good agreement with the experimental data. Additionally, we show that a square planar structure for the bis-(N-i-Pr-3-oxy-2-naphthaldiminato)copper(II) complex can also be found in gas phase and not only in the solid state, result that challenges the hypothesis that packing effects are crucial for obtaining this structure.