Crystal structure of poly[hexa-μ-bro-mido-bis{2-[1-(py-ri-din-2-yl)ethyl-idene-amino]ethanol-ato}tetracopper(II)]

Abstract

The reaction of the Schiff base 2-[1-(pyridin-2-yl)ethyl-idene-amino]-ethanol (HL), which is formed by reaction of 2-amino-ethanol and 2-acetyl-pyridine with CuBr₂ in ethanol results in the isolation of the new polymeric complex poly[hexa-μ-bromido-bis-{2-[1-(pyridin-2-yl)ethyl-idene-amino]-ethano-lato}tetra-copper(II)], [Cu₄Br₆(C₉H₁₁N₂O)₂]_n or [Cu₄Br₆ L ₂]_n. The asymmetric unit of the crystal structure of the polymeric [Cu₄Br₆ L ₂]_n complex is composed by four copper (II) cations, two monodeprotonated mol-ecules of the ligand, and six bromide anions, which act as bridges. The ligand mol-ecules act in a tridentate fashion through their azomethine nitro-gen atoms, their pyridine nitro-gen atoms, and their alcoholate O atoms. The crystal structure shows two types of geometries in the coordination polyhedrons around Cu²⁺ ions. Two copper cations are situated in a square-based pyramidal environment, while the two other copper cations adopt a tetra-hedral geometry. Bromides anions acting as bridges between two metal ions connect the units, resulting in a tetra-nuclear polymer compound.

Keywords: 2-(1-((2-hyroxyeth­yl)imino)­acetyl­pyridine); 2-amino­ethanol; acetyl­pyridine; crystal structure; square pyramidal; tetra­hedral.