A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties

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...

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Main Authors: Zhang, Hua, Fu, Degang, Ji, Feng, Wang, Guoxiong, Yu, Kaibe, Yao, Tianyang
Other Authors: School of Materials Science & Engineering
Format: Article
Language:English
Published: 2012
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Online Access:https://hdl.handle.net/10356/95681
http://hdl.handle.net/10220/8334
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-956812023-07-14T15:46:44Z A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties Zhang, Hua Fu, Degang Ji, Feng Wang, Guoxiong Yu, Kaibe Yao, Tianyang School of Materials Science & Engineering DRNTU::Science::Chemistry::Inorganic chemistry::Synthesis 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. Accepted version 2012-07-13T04:39:23Z 2019-12-06T19:19:44Z 2012-07-13T04:39:23Z 2019-12-06T19:19:44Z 1996 1996 Journal Article Zhang, H., Fu, D., Ji, F., Wang, G., Yu, K., & Yao, T. (1996). A Pyrazolate-bridged Cyclic Tetranuclear Copper(II) Complex : Synthesis, Crystal Structure and Magnetic Properties. Journal of the Chemical Society, Dalton Transactions, (19), 3799-3803. https://hdl.handle.net/10356/95681 http://hdl.handle.net/10220/8334 10.1039/DT9960003799 en Journal of the Chemical Society, Dalton Transactions © 1996 The Royal Society of Chemistry. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of the Chemical Society, Dalton Transactions, The Royal Society of Chemistry. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: http://dx.doi.org/10.1039/DT9960003799. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Science::Chemistry::Inorganic chemistry::Synthesis
spellingShingle DRNTU::Science::Chemistry::Inorganic chemistry::Synthesis
Zhang, Hua
Fu, Degang
Ji, Feng
Wang, Guoxiong
Yu, Kaibe
Yao, Tianyang
A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
description 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.
author2 School of Materials Science & Engineering
author_facet School of Materials Science & Engineering
Zhang, Hua
Fu, Degang
Ji, Feng
Wang, Guoxiong
Yu, Kaibe
Yao, Tianyang
format Article
author Zhang, Hua
Fu, Degang
Ji, Feng
Wang, Guoxiong
Yu, Kaibe
Yao, Tianyang
author_sort Zhang, Hua
title A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
title_short A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
title_full A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
title_fullStr A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
title_full_unstemmed A pyrazolate-bridged cyclic tetranuclear copper(II) complex : synthesis, crystal structure and magnetic properties
title_sort pyrazolate-bridged cyclic tetranuclear copper(ii) complex : synthesis, crystal structure and magnetic properties
publishDate 2012
url https://hdl.handle.net/10356/95681
http://hdl.handle.net/10220/8334
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