Synthesis and properties of iron (II) quinoline-2-carboxylates, crystal structure of trans-diaquabis(quinoline-2-carboxylato)iron (II) bis(dichloromethane) solvate

• Published in: Polyhedron Vol. 24; no. 3; pp. 407 - 412
• Main Authors: Dobrzyńska, Danuta, Jerzykiewicz, Lucjan B., Duczmal, Marek
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 17-02-2005
• Subjects: Crystal structure; Hydrogen bonds; Iron (II) complexes; Magnetic properties; Hydrogen bonds; Iron (II) complexes; Crystal structure; Magnetic properties
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2004.11.026

Reaction between metallic iron and quinoline-2-carboxylic acid (Hquin-2-c) in dichloromethane yielded the amorphous Fe(quin-2-c)
2 (
1). In the presence of a small amount of water, X-ray suitable crystals of [Fe(quin-2-c)
2(H
2O)
2]
·
2CH
2Cl
2 (
2) were obtained. The structure of
2 is compared with the literature reported [Fe(quin-2-c)
2(H
2O)
2]
·
2EtOH 2H
2O (
3), a system of strong hydrogen bonds in
2 and
3 create the 2D framework. The spectral and magnetic properties of all compounds are reported.
Two mononuclear iron complexes with the quinoline-2-carboxylate ion (quin-2-c ion) have been obtained by the reaction of iron powder with quinoline-2-carboxylic acid in dichloromethane. The compounds [Fe(quin-2-c)
2] (
1), [Fe(quin-2-c)
2(H
2O)
2]
·
2CH
2Cl
2 (
2) and [Fe(quin-2-c)
2(H
2O)
2]
·
2EtOH
·
2H
2O (
3) have been investigated by IR and UV–Vis spectroscopy, magnetic susceptibility and field-dependent magnetization measurements. The structure of
2 has been characterised by X-ray diffraction. The 2D bilayered frameworks of
2 and
3 are constructed by extensive hydrogen bonding interactions between water and the organic ligand coordinated to iron (II). The magnetic properties of
2 and
3 were interpreted on the basis of a spin Hamiltonian that included axial and rhombic crystal field components. The weak antiferromagnetic (
2) and ferromagnetic (
3) interactions are evident in the low temperature data and possibly occur via strong hydrogen bonds.