The spectroscopic and structural properties of copper(II) complexes of the novel tridentate (ONO) pyridine N-oxide ligand Hpoxap

• Published in: Polyhedron 2002-07, Vol.21 (16), p.1561-1571
• Main Authors: Baran, Peter, Boča, Roman, Breza, Martin, Elias, Horst, Fuess, Hartmut, Jorı́k, Vladimı́r, Klement, Róbert, Svoboda, Ingrid
• Format: Article
• Language: English
• Subjects: Hydrogen bonding; Magnetism; Pyridine N-oxide ligands, copper(II) complexes; X-ray structures
• ISSN: 0277-5387
• DOI: 10.1016/S0277-5387(02)01020-3

A tridentate ligand (Hpoxap=2-( o-hydroxyphenyliminomethyl)pyridine N-oxide) has been synthesised by the Schiff condensation of 2-pyridinecarboxaldehyde N-oxide with 2-aminophenol. A series of copper(II) complexes with this ONO-donor ligand has been prepared and their spectroscopic properties (electron, vibration, ESR) were studied. The structures for two complexes have been determined by X-ray analysis. The structure of [Cu(poxap)(OAc)] consists of isolated neutral molecules in which the copper(II) atom is situated in a slightly distorted square-planar surrounding. The structure of [Cu(poxap)(H 2O)(NO 3)] consists of neutral molecules which are interconnected by hydrogen bonds giving rise to a ladder structure of copper(II) ions with two different Cu⋯Cu distances of 5.27 and 7.41 Å. The copper atoms are in a slightly distorted square-pyramidal environment with the tridentate ligand poxap − and the water molecule in the basal plane; the apical position being occupied by an oxygen atom of the nitrate anion. Magnetic susceptibility studies were undertaken and these confirm predominantly a dimeric character of the complex. A tridentate ligand (Hpoxap=2-( o-hydroxyphenyliminomethyl)pyridine N-oxide) has been synthesised by the Schiff condensation of the 2-pyridinecarboxaldehyde N-oxide with 2-aminophenol. A series of the copper(II) complexes with this ONO-donor ligand has been prepared and their spectroscopic properties (electron, vibration, ESR) were studied; the structures of [Cu(poxap)(OAc)] and [Cu(poxap)(H 2O)(NO 3)] have been determined by X-ray analysis and magnetic properties were studied.