Crystal structure and photoluminescence properties of a new monomeric copper(II) complex: bis(3-{[(3-hydroxypropyl)imino]methyl}-4-nitrophenolato-κ3 O,N,O′)copper(II)

Abstract

Copper(II)–Schiff base complexes have attracted extensive interest due to their structural, electronic, magnetic and luminescence properties. The title novel monomeric CuII complex, [Cu(C10H11N2O4)2], has been synthesized by the reaction of 3-{[(3-hydroxypropyl)imino]methyl}-4-nitrophenol (H2 L) and copper(II) acetate monohydrate in methanol, and was characterized by elemental analysis, UV and IR spectroscopies, single-crystal X-ray diffraction analysis and a photoluminescence study. The CuII atom is located on a centre of inversion and is coordinated by two imine N atoms, two phenoxy O atoms in a mutual trans disposition and two hydroxy O atoms in axial positions, forming an elongated octahedral geometry. In the crystal, intermolecular O—H...O hydrogen bonds link the molecules to form a one-dimensional chain structure and π–π contacts also connect the molecules to form a three-dimensional structure. The solid-state photoluminescence properties of the complex and free H2 L have been investigated at room temperature in the visible region. When the complex and H2 L are excited under UV light at 349 nm, the complex displays a strong green emission at 520 nm and H2 L displays a blue emission at 480 nm.