Open Chemistry Journal


ISSN: 1874-8422 ― Volume 8, 2021

Dinuclear Copper(II) 3,4,5-Tri-O-benzylgallate

Masahiro Mikuriya1, *, Chihiro Yamakawa1, Naoyuki Masuda1, Daisuke Yoshioka1, Sayuri Yamaguchi2, Hidetoshi Yamada2, Tsutomu Mizuta3, Naomi Kawata4, Hidekazu Tanaka5, Makoto Handa5
1 Department of Applied Chemistry for Environment and Research Center for Coordination Molecule-based Devices, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda 669-1337, Japan
2 Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda 669-1337, Japan
3 Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526, Japan
4 Natural Science Center for Basic Research and Development, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526, Japan
5 Department of Chemistry, Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan



Ellagitannins have attracted much attention because of the biological and pharmacological activities. In the total synthesis of ellagitannins, 3,4,5-tri-O-benzylgallic acid has been a key compound to introduce the protected galloyl group. From the perspective of coordination chemistry, 3,4,5-tri-O-benzylgallic acid is an interesting carboxylate ligand which might be capable of dinuclear carboxylate complex. Such a dinuclear carboxylate complex might be interesting as a new example of copper acetate type complexes.


The objective of the work is to synthesize a copper acetate type complex by using 3,4,5-tri-O-benzylgallic acid and to see a new feature of copper acetate compounds, by elucidating the crystal structure, magnetic property, and adsorption property for N2 gas.


Copper(II) 3,4,5-tri-O-benzylgallate has been synthesized by a reaction of 3,4,5-tri-O-benzylgallic acid and copper(II) nitrate at pH=9 condition. The isolated complex was characterized using single-crystal X-ray structure analysis, XRD analysis, UV-visible spectroscopy, IR spectroscopy, and temperature dependence of magnetic susceptibility.


The crystal structure shows a crystallographically centrosymmetric dinuclear molecule with four carboxylato-bridges and axial dimethylformamide molecules and crystal dmf molecules [Cu···Cu 2.6345(12) Å]. In the crystal, 1D supramolecular assembly by π-π interaction between the benzyl aromatic rings of dinuclear molecules was observed. Temperature dependence of magnetic susceptibilities showed a considerable antiferromagnetic interaction between the two copper(II) ions (2J = –214 cm–1). Type-II gas-adsorption property was observed for N2.


A key-compound for the total synthesis of ellagitannins, 3,4,5-tri-O-benzylgallic acid (Htbng), was shown to be a new ligand for the synthesis of dinuclear copper acetate analogue with a lantern-type core, extending the realm of copper acetate clusters.

Keywords: Copper acetate, Crystal structure, Magnetic property, 3,4,5-Tri-O-benzylgallic Acid, Ellagitannins, Magnetic susceptibility.

Article Information

Identifiers and Pagination:

Year: 2019
Volume: 6
Issue: Suppl-1, M3
First Page: 19
Last Page: 26
Publisher Id: CHEM-6-19
DOI: 10.2174/1874842201906010019

Article History:

Received Date: 15/01/2018
Revision Received Date: 27/03/2018
Acceptance Date: 02/02/2019
Electronic publication date: 22/03/2019
Collection year: 2019

© 2019 Mikuriya et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Applied Chemistry for Environment, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, 669-1337, Japan; Tel: +81-79-565-8365; Fax: +81-79-565-9729; E-mail:

Track Your Manuscript:


I am completely satisfied with the service I received from Bentham Science Publishers, right from the submission of our research paper in ‘Open Chemistry’ to its publication in the journal. The reviewers' and editor's comments were very helpful in improving the paper.

I take this opportunity to express my appreciation to the whole team of BSP!

Dr. Arun Kumar Sharma
Govt. P.G. College,

Browse Contents

Webmaster Contact:
Copyright © 2022 Bentham Open