A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
Research output: Journal Publications and Reviews (RGC: 21, 22, 62) › 21_Publication in refereed journal › peer-review
Author(s)
Detail(s)
Original language | English |
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Pages (from-to) | 3799-3803 |
Journal / Publication | Journal of the Chemical Society - Dalton Transactions |
Issue number | 19 |
Online published | 1 Jan 1996 |
Publication status | Published - 7 Oct 1996 |
Externally published | Yes |
Link(s)
Abstract
A new pyrazolate-bridged tetranuclear copper(II) complex [{CuL(H2O)}4]·12H2O (H2L = 5-methoxycarbonylpyrazole-3-carboxylic acid) was synthesized and its crystal structure determined. The molecule has C2 symmetry and consists of four copper atoms bridged by four planar L ligands through the nitrogen atoms of the pyrazole groups to form a (-Cu-N-N-)4 12-membered ring. The co-ordination of each copper is distorted square planar. The basal plane of each copper atom is nearly parallel to a neighbouring pyrazole plane and perpendicular to another neighbouring pyrazole plane. In the crystal there is a hydrogen-bond network between water molecules and carboxylate groups which may control the packing. The magnetic properties of the complex have also been investigated down to 5 K. The fitting of the experimental data using a Heisenberg Hamiltonian shows that the exchange interaction between the copper atoms propagated through the monopyrazolate bridge is antiferromagnetic with J = -12.34 cm-1. The reason for this small value relative to those in di-μ-pyrazolato-dicopper(II) complexes is discussed.
Citation Format(s)
A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties. / Zhang, Hua; Fu, Degang; Ji, Feng et al.
In: Journal of the Chemical Society - Dalton Transactions, No. 19, 07.10.1996, p. 3799-3803.Research output: Journal Publications and Reviews (RGC: 21, 22, 62) › 21_Publication in refereed journal › peer-review