Journal of Alloys and Compounds
A family of polyoxometalate-resorcin[4]arene-based metal–organic
materials: Assemblies, structures and lithium ion battery properties
Ming-Yue Yu1, Jin-Hua Liu1, Jin Yang⁎, Jian-Fang Ma⁎
Key Lab for Polyoxometalate Science, Department of Chemistry, Northeast Normal University, Changchun 130024, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Polyoxometalates (POMs) are alternative anode materials of lithium ion batteries (LIBs) for their reversible
electrochemical redox behaviors and electron storage functions. To overcome the low conductivity and poor
stability of the POMs, embedment of POMs into metal–organic hybrid complexes is a promising synthetic
strategy. Here, we designed a family of copper-containing POM-resorcin[4]arene-based complexes supported
by a resorcin[4]arene ligand (TPTR4A), copper cations and Keggin-type POMs, namely, [Cu4(TPTR4A)2]
Received 12 November 2020
Received in revised form 7 January 2021
Accepted 30 January 2021
Available online 10 February 2021
[PMo12O40](OH)·2DMA·H2O (1a), [Cu4(TPTR4A)2][SiW12O40]·2.5DMA (1b) and [Cu4(TPTR4A)2][PW12O40
]
Keywords:
(OH)·0.5DMA·5H2O (1c) (DMA = N,N’-dimethylacetamide). To improve the conductivity of the complexes,
composites 1a@GO-1c@GO were obtained through mechanical grinding of the complexes and graphene
oxide (GO). Strikingly, they show high initial specific capacity and stability for LIBs. This work offered a
strategy for application of the POM-based complexes as LIBs via combining POM-based complexes and RGO.
© 2021 Elsevier B.V. All rights reserved.
Polyoxometalate
Resorcin[4]arene
Crystal structure
Lithium-ion batteries
1. Introduction
groups are excellent candidate ligands for this purpose [38,39]. Thus,
the proper combination of POMs with calix[4]arenes will produce
Lithium ion batteries (LIBs) have gained considerable attention
owing to their potential application in energy storage systems [1–5].
In this aspect, traditional graphites, as the most common commer-
cial electrode materials, impede their development in LIBs due to the
limited theoretical capacity [6–10]. Thus, the exploration of new
electrode materials has become a hotspot for energy storage. Poly-
oxometalates (POMs), a class of nanoscale metal-oxo clusters, are
ideal candidates for anode materials of LIBs owing to their attractive
physical and chemical properties [11–17], including tunable com-
positions, electron storage functions and reversible electrochemical
redox behaviors [18,19]. Nevertheless, poor conductivity and in-
stability in electrolyte hinder their further development as anode
materials [20–23]. Self-assembly of POMs and proper substrates to
form POM-based hybrid complexes is a promising synthetic ap-
proach owing to the structural diversity and increased stability of
inorganic–organic complexes with tunable structures, high stability
and potential applications [40–42]. However, the examples that
POM-calixarene-based hybrid complexes applied in LIBs have been
In this work, we synthesized a new resorcin[4]arene-based li-
gand with four chelating 4-(pyridin-2-yl)pyrimidine-2-thiolate
groups (TPTR4A) (Scheme 1). The multidentate TPTR4A ligand is
easy to chelate with metal ions to generate attractive structures and
improved stability of the obtained complexes [5,43]. In this work, a
family of stable POM-resorcin[4]arene-based complexes, namely,
[Cu4(TPTR4A)2][PMo12O40](OH)·2DMA·H2O (1a), [Cu4(TPTR4A)2]
[SiW12O40]·2.5DMA (1b) and [Cu4(TPTR4A)2][PW12O40](OH)·0.5D-
MA·5H2O (1c) (DMA = N,N’-dimethylacetamide), were achieved by
assembly of TPTR4A, copper cations and Keggin-type POMs. To im-
prove the conductivity and capacity of these complexes, such POM-
resorcin[4]arene-based materials were anchored to the surface of
reduced graphene oxide (RGO) through mechanical grinding of the
As a consequence, the resulting composites show much better
electrochemical behaviors than the POM-resorcin[4]arene-based
complexes.
In this facet, functionalized calix[4]arenes are potential macro-
cyclic ligands for constructing inorganic–organic complexes [32–37].
Particularly, the functionalized calix[4]arenes with multi-chelating
⁎
Corresponding authors.
1
These authors contributed equally to this work.
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