Polyoxometalate-based room-Temperature phosphorescent materials induced by anion-π interactions

Article abstract of DOI:10.1039/d0dt00159g

A series of host-guest materials containing polyoxometalate anions and lanthanide-organic layers have been synthesized and structurally characterized. By anion-π interactions between the anions and the π-Acidic naphthalenediimide moieties, the materials emit strong red room-Temperature phosphorescence and exhibit reversible photochromism.

Full text of DOI:10.1039/d0dt00159g

View Article Online
View Journal
Dalton
Transactions
An international journal of inorganic chemistry
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: X. Wu, H. Zhang,
S. Wang, W. Wu, L. Lin, X. Jiang and C. Lu, Dalton Trans., 2020, DOI: 10.1039/D0DT00159G.
Volume 46
Number 10
14 March 2017
Pages 3073-3412
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Dalton
Transactions
An international journal of inorganic chemistry
Accepted Manuscripts are published online shortly after acceptance,
before technical editing, formatting and proof reading. Using this free
rsc.li/dalton
service, authors can make their results available to the community, in
citable form, before we publish the edited article. We will replace this
Accepted Manuscript with the edited and formatted Advance Article as
soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes to the
text and/or graphics, which may alter content. The journal’s standard
Terms & Conditions and the Ethical guidelines still apply. In no event
ISSN 0306-0012
COMMUNICATION
Douglas W. Stephen et al.
shall the Royal Society of Chemistry be held responsible for any errors
N-Heterocyclic carbene stabilized parent sulfenyl, selenenyl,
and tellurenyl cations (XH+, X = S, Se, Te)
or omissions in this Accepted Manuscript or any consequences arising
from the use of any information it contains.
rsc.li/dalton

Please do not adjust margins
Page 1 of 6
Dalton Transactions
View Article Online
DOI: 10.1039/D0DT00159G
COMMUNICATION
Polyoxometalate-based Room-Temperature Phosphorescent
Materials Induced by Anion-π Interaction
Xiao-Yuan Wu a, Hai-Long Zhang a,b, Sa-Sa Wang a, Wei-Ming Wu a, Lang Lin c, Xiao-Yu Jiang c, Can-
Received 00th January 20xx,
Accepted 00th January 20xx
Zhong Lu*a,b
DOI: 10.1039/x0xx00000x
A series of host-guest materials containing polyoxomatalate anions between the luminophores. Moreover, POMs have a widely
and lanthanide-organic layers have been synthesized and applications in electrochemistry, optics, magnetism, medicine,
structurally characterized. By anion-π interaction between the and catalysis.[10] Introducing POMs into the luminescent
anions and the π-acidic naphthalenediimide moieties, the materials materials, more multifunctional systems will be developed. So
emit strong red room-temperature phosphorescence and exhibit design and syntheses of versatile POMs-based luminescent
reversible photochromism.
materials have become attractive and challenging branch.[11]
Naphthalenediimide (NDI) derivatives have been widely used
as light-harvesting chromophore in solar cells and molecular
probes, due to their intense absorption in the visible region or
high fluorescence quantum yield.[12] Interacting with suitable
electron donor, NDI derivatives not only show tunable color
luminescence,[13] but also exhibit π-localized RTP owing to the
intramolecular charge-transfer states bridging the relatively
large energy gap between the NDI-localized π–π* and π–π*
states.[14] Furthermore, due to the long π-conjugation plane and
the strong π-acidity, NDI derivatives can easily form charge
transfer complexes with anions, such as fluorion, chloridion,
and high negative-charge POMs.[15] More recently, our research
group reported a series of photochromic materials based on
POMs and pyridine-substituted NDI derivatives, which show the
strong anion-π interactions and hydrogen bonding
interactions.[16] Herein, carboxyphenyl-substituted NDIs (3,3’-
(1,3,6,8-tetraoxobenzol[lmn][3,8]-phenanthroline-2,7(1H,3H,
6H,8H)diyl)-di-benzoic acid, abbreviated as H2L[17]) as organic O-
donor ligand was applied to assemble a novel host-guest
materials with Ln and POM ions. By charge transfer between the
POMs and NDIs, the materials emit strong red RTP. Meanwhile,
the charge-transfer-induced NDI radicals and the variation of
the tungsten valence state lead to significant photochromism.
Room-temperature phosphorescent (RTP) materials with
persistent luminescence have attracted enormous attention
due to their important applications in biological imaging,[1] light-
emitting devices,[2] information storage and encryption,[3]
chemical sensing,[4] etc.. There are two key strategies for
yielding efficient RTP materials: promoting intersystem crossing
(ISC) and suppressing the non-radiative decay processes.[5] It
has been proofed that introducing heavy-atom or electron
donor into an intraligand charge-transfer state could lead to
more efficient ISC, and result in fluorescence/RTP dual
emission.[6] Polyoxometalates (POMs), a large family of nano-
sized inorganic clusters with oxygen-rich surfaces, are promising
candidates for architecting efficient fluorescence/RTP materials
with photoactive organic molecules because they hold several
advantages including strong capacity to undergo multi-electron
redox processes, tunable structure and strong electrostatic, H-
bonding, charge-transfer interactions with organic molecules.[7]
Dessapt et. al. successfully tuned the emission color of an
archetypal Ir(III) complex from green to red through controlling
the crystal packing mode with different POMs.[8] Recently, they
reported two new supramolecular fluorescent materials
through combining POM anions with an “aggregation-induced
emission”-active phospholium.[9] In these materials, the
nucleophilic oxygen-rich POM anions exalt the solid-state
luminescence through strengthening the rigidity of the
phospholium and preventing the π-π stacking interactions
1
3
The
solvothermal
reaction
of
H4SiW12O40·xH2O,
Ln(NO3)3·6H2O/LNCl3·6H2O, H2L and Tetramethylammonium
hydroxide in the solvent mixture of N,N-dimethylformamide
(DMF) and water at 80 °C for 48h yielded yellowish block-
shaped
crystals
of
[(CH3)4N]4[Ln(L)1.5(H2O)3](SiW12O40)·4H2O·3DMF (1, Ln= Lu, Yb,
Tm, Er, Ho, Dy, Tb, Gd, Eu).
a. CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and
Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the
Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
E-mail: czlu@fjirsm.ac.cn.
X-ray single-crystal analysis reveals that the nine compounds
are isostructural and crystallize in the P-1 space group. The
compounds consist of {LnL1.5(H2O)3}n layers, Keggin-type anions
{SiW12O40}4-, tetramethylammonium [(CH3)4N]+ counter cations,
as well as several lattice water and DMF molecules. Herein, only
b. University of Chinese Academy of Sciences, Bejing 100049, China.
c. Fujian University of Technology, Fuzhou, Fujian 350108, PR China
Electronic Supplementary Information (ESI) available: [details of any supplementary
information available should be included here]. See DOI: 10.1039/x0xx00000x
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 2 of 6
COMMUNICATION
Journal Name
the crystal structure of 1-Lu is intensively described. The Lu3+
cation is coordinated to eight oxygen atoms. Among them, five
come from three carboxyl groups of three ligands, and the other
three belong to water molecules. Totally deprotonated ligand L
adopts two coordinated types. In type-I, each carboxylate group
of the ligand bridges one Lu3+ cation with the μ1–η1:η1
coordination mode. In type-II, each carboxylate group is in the
μ1–η1:η0 coordination mode to link one Lu3+ cation. The dihedral
angles between the NDI core and two benzoate rings are 61.71˚,
70.51˚ (for type-I) and 77.71˚ (for type-II), respectively.
Remarkably, neighbouring Lu3+ cations are connected into a
wave-like chain by the ligand in type-I configuration. Such
chains are arranged in ABAB-type to form a square-window
about 20.4 × 21.0 Å. Furthermore, the ligands in type-II model
link the neighbouring chains into two-dimensional layer, and
divide the square-window into triangle-grid. Along the a axis,
such layers arrange in a line to form one-dimensional channels.
The POM anions locate in the channels suitably (Fig. 1a). It is
noteworthy that each POM anion is surrounded by three NDI
tectons in bowl-like. Meanwhile, each NDI tecton is sandwiched
by two POM anions (Fig. 1b). The trinuclear subunit {W3O13} and
the NDI rings arrange in face-to-face manner, while the dihedral
angles are 1.56°, 2.18° and 6.75°, respectively. The distances
between the oxygen atom of the POM anions and the NDI
tectons are range from 2.790 Å to 3.638 Å, which exhibit
typically anion-π interactions.[16]. These anion-π interactions
offer effective pathways for the charge transfer and play an
important role in the progress of photochromism and
photoluminescence. Additionally, there are two types of
hydrogen bonds between the Ln-L layers and the POM anions.
One is the O-H···O (2.818 Å) hydrogen bonds between the
coordinated water molecules and the POMs. The other is the C-
H···O (3.334 Å) hydrogen bonds between the benzoate rings and
the POMs. These hydrogen bonds further stabilize the crystal
frameworks.
View Article Online
DOI: 10.1039/D0DT00159G
Fig 2. The in situ UV/Vis spectra (a) and the in situ EPR spectra
(b) show the changes of 1-Lu after irradiation with simulated
sunlight light (red line) and kept in dark for 1 day (blue line); the
inset shows the photochromic images of 1-Lu.
All of the compounds exhibit the photochromic
transformation from yellowish to light brown while they are
irradiated by simulated sunlight light (Xenon Lamp, 300W, PLS-
SXE 300/300UV, 320-780nm) for 30 minutes. Then keeping in
the dark under ambient conditions, all of the compounds return
to yellowish slowly. The UV/Vis spectra were carried out for 1-
Lu samples before and after light irradiation to support photo-
induced transformation. As shown in Fig. 2a, in the range of
200-400 nm, the spectral shapes and intensities are almost
unchanged after irradiation, which can mainly be assigned to
the π-π* transitions of NDIs tectons ( 350 – 400 nm ) and the
ligand-to-metal charge transfer (LMCT) transitions (Ob,c → W)
within the POMs anions ( 200 -350 nm ).[8, 18] It’s notabl that the
absorbance intensity of the broad band above 400nm is
obviously increased after irradiation. The two shoulder peaks at
438nm and 485nm may be attributed to the organic radicals,
which formed by the intermolecular charge-transfer between
the electron-deficient naphthalenic rings and the electron-rich
POM anions.[16b, 19] In the UV-vis spectra, the weak peak in the
range of 400 nm and 500 nm is already present before
irradiation, indicating that the material is very sensitive to light.
The absorbance between 600-2000 nm can be mainly assigned
to the variation of the tungsten valence state by photoinduced
charge-transfer transition through the bridging oxygen bonds in
POMs. In the POM structure, the lowest unoccupied molecular
orbitals (LUMO) is mainly localized on the W atoms, and the
highest occupied molecular orbital is mainly localized on the
bridging oxygen atoms. The fact of the charge transfer between
WVI and WV through the bridging oxygen bonds in POM is known
to be the origin of the typical NIR absorption of POMs.[20]
Fig 1. (a) The framework of 1-Lu viewed along the a axis. (b) The
anion–π interactions between adjacent POMs and NDI moieties
(
all the coordinated DMA/water molecules and hydrogen atoms are
omitted for clarity).
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 6
Dalton Transactions
Please do not adjust margins
Journal Name
COMMUNICATION
Keeping irradiated sample in dark for one day, the two shoulder interactions result in the donor to acceptor chVaierwgeA-rtticrlaenOsnfliener
DOI: 10.1039/D0DT00159G
peaks show negligible decrease, while the absorbance intensity states which has reduced EST and enhanced ISC processes,
above 800nm is almost decreased to the original. It is consequently leading to RTP. [14, 16a] In the nine compounds, the
demonstrated that the organic radicals are stable under special emission peaks for the lanthanides couldn’t be found.
ambient conditions, while the reduced tungsten are oxidized in
Moreover, to further insight into the photophysical
air.[21] The generation of organic radical and WV species has properties and excited-state information on the emissions for
been confirmed by the signals at g = 2.0039 and g = 1.9249 in these compounds, the lifetime were measured under the
the EPR spectra (Fig. 2b), respectively.
strongest emission at 621 nm and the excitation at 410 nm. The
corresponding emission decay curves were fitted to a double
exponential function [I = A1 exp(-t/τ1) + A2 exp(-t/τ2)][23] (Fig.
S6). The average emission lifetimes (τav) of the nine compounds
are in the range of 0.60 - 9.94 ms (Table S1). These results
The as-synthesized bulk samples of 1-Ln show a PXRD pattern
basically identical to the simulated one from the single-crystal
X-ray data but with the weakening of some diffraction peaks,
which confirming the phase purity of the samples (Fig. S2 in the
ESI†). The crystal structure of 1-Lu after irradiation is identical
to that before irradiation (Fig. S3). The results of FT-IR spectra
(Fig. S4, S5) also correspond well with the above conclusion.
Therefore, the photochromic phenomenon arises from
photoinduced charge transfer process rather than structural
transformation or photolysis.
indicate that the photoluminescence of 1-Ln is
a
photoluminescence emission resulting from the excited
electronic charge-transfer states of the crystals.[16a, 19b]
Fig 4. The emission spectra of 1-Gd at room temperature after
irradiation with simulated sunlight (300 W) at 0, 2, 4, 6, 8, 10,
12 min. The inset shows the time-dependent phosphorescence
intensity upon irradiation.
Fig 3. The emission spectra of H2L and 1-LN (LN = Eu, Gd, Tb, Dy,
Ho, Er, Tm, Yb, Lu) under the excitation at 410 nm at room
temperature. The inset shows the excitation spectrum.
Interestingly, while irradiated under the ultraviolet visible
light, the phosphorescence intensity decreases with unchanged
emission peak positions. As shown in Fig.4, the phosphorescent
intensity of the 1-Gd sample decreases gradually to 12% of the
initial intensity after irradiation for 12 minutes. Considering the
close distance (2.790-3.638 Å) between the POMs and the NDIs,
the quenching of the luminescence should originated from the
fluorescence resonant energy transfer (FRET) effect, [24] which
produced based on the substantial overlap of the emission
bands of the luminophore (NDIs) and the significantly increased
photogenerated absorption bands of the WV at 600-800 nm
wavelength region. Besides, the variation of the energy levels
for the bridging intermolecular charge-transfer states occurs
accompanied irradiation, which may lead to lower efficiencies
of ISC processes and weaker RTP.
The solid photoluminescence properties of 1-Ln have been
measured with their crystalline samples under the excitation of
unfocused UV light at room temperature in air. In the excitation
spectrum, the excitation peak at 410 nm was detected and kept
its position after irradiation (Fig. S8). Consequently, the POMs
do not participate to the excitation processes because their
absorption is localized at higher energies (200-350 nm). As
shown in Fig 3, the sample of the organic ligand is almost non-
fluorescent, probably due to the large singlet-triplet energy gap
that is intrinsic to π-π* transitions. Notably, compared to the
traditional
POMs-based
hybrid
materials
with
[22]
photoluminescence reduced or quenched,
all of these
samples exhibit the identical strong red photoluminescence
with two main peaks separately. One of the monomer emission
peaks is at 621 nm, and the other is a broad peak at around 680
nm. The highest photoluminescence quantum yield (OLQY) of
these solid sample is 2.0% for Gd (Table S1). The interesting and
practically important photoluminescence properties of these
crystals may be ascribed to the interactions between the NDIs
and the POMs. In 1-Ln, POM anions act as the electron donor
to modify the NDIs rings. The obvious intermolecular anion-π
Conclusions
In conclusion, we have utilized a carboxyphenyl-substituted
NDI ligand for successfully synthesizing a serials of host-guest
materials based on POMs and Ln-organic layers, which exhibits
distinct room-temperature phosphorescence as well as
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 4 of 6
COMMUNICATION
Journal Name
5699. (f) S. S. Wang and G. Y. Yang, Chem. Rev. 2015, 115,
reversible photochromism upon simulated sunlight light
irradiation. The single-crystal structural analysis clearly
indicates that the significant intermolecular anion–π
interactions between the POMs and NDIs provide efficient
charge-transfer pathways between the POMs and the π-acidic
NDI, resulting in additional intermolecular charge-transfer
states that serve to bridge the large EST between the lowest
local-excited states and thus trigger efficient RTP. Clearly, this
new strategy extends the scope of anion-π engineering to
develop solid-state emitters. Finally, as POMs can also exhibit
intrinsic photoactive, redox or magnetic properties, this work
opens the way towards the design of novel multifunctional
hybrid systems.
4893-4962. (g) D. D. Li, P. T. Ma, J. Y. Niu and J. P.VWiewanArgti,clCeoOonrlinde.
DOI: 10.1039/D0DT00159G
Chem. Rev. 2019, 392, 49-80. (h) X. X. Li, D. Zhao and S. T.
Zheng, Coord. Chem. Rev. 2019, 397, 220-240. (i) D. Y. Du, J.
S. Qin, S. L. Li, Z. M. Su, and Y. Q. Lan, Chem. Soc. Rev. 2014,
43, 4615-4632.
P. Bolle, H. Serier-Brault, R. Génois, E. Faulques, A. Boulmier,
O. Oms, M. Lepeltier, J. Marrot, A. Dolbecq, P. Mialane and R.
Dessapt, J. Mater. Chem. C 2016, 4, 11392-11395.
P. Bolle, Y. Chéret, C. Roiland, L. Sanguinet, E. Faulques, H.
Serier-Brault, P.-A. Bouit, M. Hissler and R. Dessapt, Chem
Asian J. 2019, 14, 1642-1646.
8
9
10 (a) Q. Han, C. He, M. Zhao, B. Qi, J. Niu, and C. Duan, J. Am.
Chem. Soc. 2013, 135, 10186-10189. (b) J. S. Qin, D. Y. Du, W.
Guan, X. J. Bo, Y. F. Li, L. P. Guo, Z. M. Su, Y. Y. Wang, Y. Q. Lan,
and H. C. Zhou, J. Am. Chem. Soc. 2015, 137, 7169-7177. (c) Q.
Han, B. Qi, W. Ren, C. He, J. Niu, and C. Duan, Nat. Commun.
2015, 6, 10007. (d) M. Zhao, X. W. Zhang, and C. D. Wu, ACS
Catal. 2017, 7, 6573-6580. (e) Y. R. Wang, Q. Huang, C. T. He,
Y. Chen, J. Liu, F. C. Shen and Y. Q. Lan, Nat. Commun. 2018,
9, 4466. (f) H. Zhang, W. Liu, A. Li, D. Zhang, X. Li, F. Zhai, L.
Chen, L. Chen, Y. Wang and S. Wang, Angew. Chem. Int. Ed.
2019, 58, 16110-16114. (g) S. L. Xie, J. Liu, L. Z. Dong, S. L. Li,
Y. Q. Lan, and Z. M. Su, Chem. Sci. 2019, 10, 185-190. (h) W.
Sun, C. He, T. Liu, and C. Duan, Chem. Commun. 2019, 55,
3805-3808. (i) L. Chen, W. L. Chen, X. L. Wang, Y. G. Li, Z. M.
Su, and E. B. Wang, Chem. Soc. Rev. 2019, 48, 260-284.
11 (a) X. Xu, Y. H. Chen, Y. Zhang, Y. F. Liu, L. J. Chen and J. W.
Zhao, Inorg. Chem. 2019, 58, 11636-11648. (b) Z. J. Liang, H.
C. Wu, V. Singh, Y. Y. Qiao, M. M. Li, P. T. Ma, J. Y. Niu and J. P.
Wang, Inorg. Chem. 2019, 58, 13030-13036. (c) L. Li, Y. C. Zou,
Y. Hua, X. N. Li, Z. H. Wang and H. Zhang, Dalton Trans. 2020,
49, 89-94. (d) L. Chen, W. L. Chen, H. Q. Tan, J. S. Li, X. J. Sang
and E. B. Wang, J. Mater. Chem. A 2016, 4, 4125-4133. (e) H.
Liu, Y. Lv, S. Li, F. Yang, S. Liu, C. Wang, J. Q. Sun, H. Meng and
G. G. Gao, J. Mater. Chem. C 2017, 5, 9383-9388.
12 (a) X. Lu,W. Zhu, Y. Xie, X. Li, Y. Gao, F. Li and H. Tian, Chem.
Eur. J. 2010, 16, 8355–8364. (b) N. Sakai, R. Bhosale, D.
Emery, J. Mareda and S. Matile, J. Am. Chem. Soc. 2010, 132,
6923–6925. (c) Z. Chen, Y. Zheng, H. Yan and A. Facchetti, J.
Am. Chem. Soc. 2009, 131, 8–9.
13 (a) Y. Takashima, V. M. Mart&nez, S. Furukawa, M. Kondo, S.
Shimomura, H. Uehara, M. Nakahama, K. Sugimoto, S.
Kitagawa, Nat. Commun. 2011, 2, 168; (b) T. Ono, M.
Sugimoto, Y. Hisaeda, J. Am. Chem. Soc. 2015, 137, 9519–
9522. (c) S. V. Bhosale, C. H. Jani and S. J. Langford, Chem.
Soc. Rev. 2008, 37, 331-342.
14 X. Chen, C. Xu, T. Wang, C. Zhou, J. Du, Z. Wang, H. Xu, T. Xie,
G. Bi, J. Jiang, X. Zhang, J. N. Demas, C. O. Trindle, Y. Luo and
G. Zhang, Angew. Chem. Int. Ed. 2016, 55, 9872-9876.
15 (a) M. A. Kobaisi, R. S. Bhosale, M. E. El-Khouly, D. D. La, S. D.
Padghan, S. V. Bhosale, L. A. Jones, F. Antolasic, S. Fukuzumi,
S. V. Bhosale, Sci. Rep. 2017, 7, 16501; (b) S. R. Bobe, A.
Gupta, A. Rananaware, A. Bilic, S. V. Bhosale, S. V. Bhosale,
RSC Adv. 2015, 5, 4411–4415.
16 (a) J. Z. Liao, L. Meng, J. H. Jia, D. Liang, X. L. Chen, R. M. Yu,
X. F. Kuang and C. Z. Lu, Chem. Euro. J. 2018, 24, 10498-
10502. (b) H. L. Zhang, J. Z. Liao, W. Yang, X. Y. Wu and C. Z.
Lu, Dalton Trans. 2017, 46, 4898-4901. (c) J. Z. Liao, C. Wu,
X. Y. Wu, S. Q. Deng and C. Z. Lu, Chem. Commun. 2016, 52,
7394-7397. (d) J. Z. Liao, H. L. Zhang, S. S. Wang, J. P. Yong,
X. Y. Wu, R. Yu and C. Z. Lu, Inorg. Chem. 2015, 54, 4345-
4350. (e) J. Z. Liao, X. Y. Wu, J. P. Yong, H. L. Zhang, W. B.
Yang, R. Yu and C. Z. Lu, Cryst. Growth Des. 2015, 15,
4952−4958.
Conflicts of interest
There are no conflicts to declare.
Acknowledgements
This work was supported by the Key Program of Frontier Science, CAS
(QYZDJ-SSW-SLH033), the Strategic Priority Research Program of the
Chinese Academy of Sciences (XDB20000000), the National Natural
Science Foundation of China (21521061, 21875252, 21773247,
51672271, 21701177, 21701169, 21701170, and 21701172) and the
Natural Science Foundation of Fujian Province (2006L2005).
Notes and references
1 (a) Q. Zhao, C. Huang and F. Li, Chem. Soc. Rev. 2011, 40, 2508–
2524. (b) S. M. A. Fateminia, Z. Mao, S. Xu, Z. Yang, Z. Chi and
B. Liu, Angew. Chem. Int. Ed. 2017, 56, 12160–12164. (c) K. Y.
Zhang, Q. Yu, H. Wei, S. Liu, Q. Zhao and W. Huang, Chem. Rev.
2018, 118, 1770-1839.
2
(a) X. Yang, G. Zhou and W. Y. Wong, Chem. Soc. Rev. 2015, 44,
8484–8575. (b) Z. He, W. Zhao, J. W. Y. Lam, Q. Peng, H. Ma,
G. Liang, Z. Shuai and B. Z. Tang, Nat. Commun. 2017, 8, 416.
(a) S. Xu, R. Chen, C. Zheng and W. Huang, Adv. Mater. 2016,
28, 9920–9940. (b) S. Cai, H. Shi, J. Li, L. Gu, Y. Ni, Z. Cheng, S.
Wang, W. Xiong, L. Li, Z. An and W. Huang, Adv. Mater. 2017,
29, 1701244.
3
4
Y. Han, Y. You, Y. -M. Lee and W. Nam, Adv. Mater. 2012, 24,
2748–2754.
5 (a) T. Itoh, Chem. Phys. Lett. 1988, 151, 166-168. (b) S. Scypinski
and L. J. C. Love, Anal. Chem. 1984, 56, 322-327. (c) Y. Tao, K.
Yuan, T. Chen, P. Xu, H. H. Li, R. F. Chen, C. Zheng, L. Zhang and
W. Huang, Adv. Mater. 2014, 26, 7931-7958. (d) Z. Y. Yang, Z.
Mao, Z. L. Xie, Y. Zhang, S. W. Liu, J. Zhao, J. R. Xu, Z. G. Chi and
M. P. Aldred, Chem. Soc. Rev. 2017, 46, 915-1016.
6
(a) P. Lehner, C. Staudinger, S. M. Borisov and I. Klimant, Nat.
Commun. 2014, 5, 4460. (b) C. Fan and C. Yang, Chem. Soc.
Rev. 2014, 43, 6439-6469. (c) J. Z. Zhao, K. J. Xu, W. B. Yang, Z.
J. Wang and F. F. Zhong, Chem. Soc. Rev. 2015, 44, 8904-8939.
(d) O. Bolton, K. Lee, H. J. Kim, K. Y. Lin and J. Kim, Nat. Chem.
2011, 3, 205-210.
(a) C.L. Hill, Chem. Rev. 1998, 98, 1–389. (b) A. Dolbecq, E.
Dumas, C. R. Mayer and P. Mialane, Chem. Rev. 2010, 110,
6009–6048. (c) A. Banerjee, B. S. Bassil, G. -V. Rçschenthaler
and U. Kortz, Chem. Soc. Rev. 2012, 41, 7590-7604. (d) A.
Proust, B. Matt, R. Villaneau, G. Guillemot, P. Gouzerh and G.
Izzet, Chem. Soc. Rev. 2012, 41, 7605-7622. (e) H. N. Miras, L.
Vilà-Nadal and L. Cronin, Chem. Soc. Rev. 2014, 43, 5679-
7
17 (a) X. Ma, Z. Zhang, W. Shi, L. Li, J. Zou and P. Cheng, Chem.
Commun. 2014, 50, 6340-6342. (b) Z. J. Michael and C. L.
Miranda, PCT Int. Appl. 2008073613, 2008.
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 6
Dalton Transactions
Please do not adjust margins
Journal Name
COMMUNICATION
18 (a) R. M. Duke, E. B. Veale, F. M. Pfeffer, P. E. Kruger and T.
Gunnlargsson, Chem. Soc. Rev. 2010, 39, 3936-3953. (b) C. Y.
Sun, S. X. Liu, D. D. Liang, K. Z. Shao, Y. H. Ren and Z. M. Su,
J. Am. Chem. Soc. 2009, 131, 1883–1888. (c) F. J. Ma, S. X.
Liu, C. Y. Sun, D. D. Liang, G. J. Ren, F. Wei, Y. G. Chen and Z.
M. Su, J. Am. Chem. Soc. 2011, 133, 4178–4181. (d) C. Zou,
Z. Zhang, X. Xu, Q. Gong, J. Li and C. Wu, J. Am. Chem. Soc.
2012, 134, 87–90. (f) W. H. Zhu, M. Zeng, J. Wang, C. Y. Li, L.
H. Tian, J. C. Yin and Y. K. Liu, Dalton Trans. 2016, 45, 10141–
10145.
View Article Online
DOI: 10.1039/D0DT00159G
19 (a) T. Ono, M. Sugimoto and Y. Hisaeda, J. Am. Chem. Soc.
2015, 137, 9519-9522. (b) S. Kumar, J. Shukla, K. Mandal, Y.
Kumar, R. Prakash, P. Ram, P. Mukhopadhyay, Chem. Sci.
2019, 10, 6482-6493. (c) L. Li, Y. Hua, X. N. Li, Y. Guo and H.
Zhang, Dalton trans. 2019, 48, 10683-10688.
20 (a) S. Wang, W. Fan, Z. Liu, A. Yu and X. Jiang, J. Mater. Chem.
C., 2018, 6, 191-212. (b) C. M. Wu, S. Naseem, M. H. Chou, J.
H. Wang and Y. Q. Jian, Front. Mater. 2019, 6, 49. (c) X.
Lopez, J. M. Maestre, C. Bo and J. M. Poblet, J. Am. Chem.
Soc. 2001, 123, 9571-9576. (d) C. Zhang, W. Bu, D. Ni, C. Zuo,
Z. Cheng, Q. Li, L. Zhang, Z. Wang and J. Shi, J. Am. Chem. Soc.
2016, 138, 8156-8164
21 (a) E. Coronado and C. J. Gomez-Garcia, Chem. Rev. 1998, 98,
273-296. (b) T. Yamase, Chem. Rev., 1998, 98, 307-325. (c) Y.
Wang, H. Li, C. Wu, Y. Yang, L. Shi and L. Wu, Angew. Chem.
Int. Ed. 2013, 52, 4577-4581. (d) D. F. Shen, S. Li, H. Liu, W.
Jiang, Q. Zhang and G. G. Gao, J. Mater. Chem. C. 2015, 3,
12090-12097.
22 H. M. Asif, Y. S. Zhou, L. J. Zhang, N. Shaheen, D. Yang, J. Q.
Li, Y. Long, A. Iqbal and Y. Q. Li, Inorg. Chem. 2017, 56, 9436-
9447.
23 X. Wang, Y. Liu, M. Jin, Y. Wu, L. Chen and J. W. Zhao, Cryst.
Growth Des. 2017, 17, 5295-5308.
24 (a) L. Wang, R. Yan, Z. Huo, L. Wang, J. Zeng, J. Bao, X. Wang,
Q. Peng and Y. Li, Angew. Chem. Int. Ed. 2005, 44, 6054-
6057. (b) J. Peng, W. Xu, C. L. Teoh, S. Y. Han, B. Kim, A.
Samanta, J. C. Er, L. Wang, L. Yuan, X. G. Liu and Y. T. Chang,
J. Am. Chem. Soc. 2015, 137, 2336-2342.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Dalton Transactions
Page 6 of 6
View Article Online
DOI: 10.1039/D0DT00159G
A series of polyoxometalate-based host-guest materials emit strong red room-temperature
phosphorescence attributed to intermolecular charge-transfer states which was caused by the
unorthodox anion-π interactions.