Issue 5, 1997

Syntheses, crystal structures and magnetic properties of [Ni2(C2O4)(tren)2][ClO 4]2 and [Ni2(C4O4)(tren)2(H2 O)2][ClO4]2 [tren = tris(2-aminoethyl)amine]

Abstract

Two dinuclear nickel(II) complexes [Ni 2 (C 2 O 4 )(tren) 2 ][ClO 4 ] 2 1 and [Ni 2 (C 4 O 4 )(tren) 2 (H 2 O) 2 ][ClO 4 ] 2 2 [tren = tris(2-aminoethyl)amine, C 2 O 4 2- = oxalate dianion and C 4 O 4 2- = dianion of 3,4-dihydroxycyclobut-3-en-1,2-dione (squaric acid)] have been synthesized and characterized by single-crystal X-ray diffraction. Their structures consist of dinuclear nickel(II) cations and unco-ordinated perchlorate anions. The nickel environment is distorted octahedral NiN 4 O 2 in both complexes: four nitrogen atoms of the tren group acting as a tetradentate ligand and two oxygen atoms of oxalate (1) or a water molecule and a squarate oxygen (2) comprise the co-ordination. The oxalate acts as a bis(chelating) ligand whereas the squarate adopts a µ-1,2-bis(monodentate) co-ordination mode. The intradimer metal–metal separation is 5.413(1) and 6.224(1) Å in 1 and 2, respectively. The co-ordinated water molecule in 2 forms an intramolecular hydrogen bond to an unco-ordinated squarate-oxygen atom. Variable-temperature susceptibility measurements revealed the occurrence of relatively strong (1) and weak (2) intramolecular antiferromagnetic coupling, the relevant parameters being J = -28.8 cm -1 and g = 2.16 for 1 and J = -0.4 cm -1 and g = 2.15 for 2 (J being the exchange parameter in the isotropic spin Hamiltonian [H with combining macron] = -J[S with combining macron] A ·[S with combining macron] B ). A comparative study of the ability of oxalate and squarate groups to mediate electronic interactions in the structurally characterized oxalato- and squarato-bridged nickel(II) complexes was carried out.

Article information

Article type
Paper

J. Chem. Soc., Dalton Trans., 1997, 811-818

Syntheses, crystal structures and magnetic properties of [Ni2(C2O4)(tren)2][ClO 4]2 and [Ni2(C4O4)(tren)2(H2 O)2][ClO4]2 [tren = tris(2-aminoethyl)amine]

I. Castro, M. Luisa Calatayud, J. Sletten, F. Lloret and M. Julve, J. Chem. Soc., Dalton Trans., 1997, 811 DOI: 10.1039/A606105B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements