Microwave-Assisted Synthesis of Tris-Anderson Polyoxometalates for Facile CO2Cycloaddition

Article abstract of DOI:10.1021/acs.inorgchem.1c00019

Four new tris-Anderson polyoxometalates (POMs), (NH4)4[ZnMo6O18(C4H8NO3)(OH)3]·4H2O (1), (NH4)4[CuMo6O18(C4H8NO3)(OH)3]·4H2O (2), (TBA)3(NH4)[ZnMo6O17(C5H9O3)2(OH)]·10H2O (3) (TBA = n-C16H36N), and (NH4)4[CuMo6O18(C5H9O3)2]·16H2O (4), were synthesized by a microwave-assisted method. Single-crystal X-ray diffraction revealed that 1 and 2 contained a tris (trihydroxyl organic compounds) ligand grafted on one side, while two tris ligands were grafted on two sides to form χ/δand δ/δisomers in 3 and 4, respectively. 1H and 13C NMR spectra of the χ/δisomer 3 were obtained for the first time, with six methylenes showing six peaks in the 1H NMR spectrum and only four peaks in the 13C NMR spectrum. Mass spectrometry monitoring revealed that during the microwave-assistant process the tris ligand can graft onto POMs to form 1, while tris directly coordinates with metallic heteroatoms to form isopolymolybdates during the conventional reflux synthesis process. In addition, 1-4 can catalyze CO2 with epoxides into cyclic carbonates with high selectivity and yields at an atmospheric pressure of CO2, which is lower than the pressure of CO2 in other catalysis using POMs as catalysts. Furthermore, 1-4 showed good catalytic stability and cycling properties. Mechanism studies substantiated POMs cocatalyzed with Br- to improve the catalytic yields.

Full text of DOI:10.1021/acs.inorgchem.1c00019

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Microwave-Assisted Synthesis of Tris-Anderson Polyoxometalates
for Facile CO2 Cycloaddition
Wei-Dong Yu,* Yin Zhang, Yu-Yang Han, Bin Li, Sai Shao, Le-Ping Zhang, Hong-Ke Xie, and Jun Yan*
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ABSTRACT: Four new tris-Anderson polyoxometalates (POMs),
(NH4 )4 [ZnMo6 O1 8 (C4 H8 NO3 )(OH)3 ]·4H2 O (1),
(NH4 )4 [CuMo6 O1 8 (C4 H8 NO3 )(OH)3 ]·4H2 O (2),
(TBA)3(NH4)[ZnMo6O17(C5H9O3)2(OH)]·10H2O (3) (TBA =
n-C16H36N), and (NH4)4[CuMo6O18(C5H9O3)2]·16H2O (4),
were synthesized by a microwave-assisted method. Single-crystal
X-ray diffraction revealed that 1 and 2 contained a tris (trihydroxyl
organic compounds) ligand grafted on one side, while two tris
ligands were grafted on two sides to form χ/δ and δ/δ isomers in 3
1
and 4, respectively. H and 13C NMR spectra of the χ/δ isomer 3
were obtained for the first time, with six methylenes showing six
1
peaks in the H NMR spectrum and only four peaks in the 13C
NMR spectrum. Mass spectrometry monitoring revealed that during the microwave-assistant process the tris ligand can graft onto
POMs to form 1, while tris directly coordinates with metallic heteroatoms to form isopolymolybdates during the conventional reflux
synthesis process. In addition, 1−4 can catalyze CO2 with epoxides into cyclic carbonates with high selectivity and yields at an
atmospheric pressure of CO2, which is lower than the pressure of CO2 in other catalysis using POMs as catalysts. Furthermore, 1−4
showed good catalytic stability and cycling properties. Mechanism studies substantiated POMs cocatalyzed with Br− to improve the
catalytic yields.
metal salt, and {β-Mo8O26} as starting materials;14 (2)
predesigned Anderson POMs and tris heated to reflux in
INTRODUCTION
Polyoxometalate (POM) as a traditional inorganic material has
■
aqueous solution;15 (3) using a predesigned Anderson POM
step-by-step strategy under hydrothermal conditions.16
Although lots of work about their synthesis have been done,
especially by Wu’s group,17 some structures are still not
available by these three ways. For example, unilateral tris
substitutions with a central heteroatom, Zn2+ or Cu2+, have not
been reported, which limits the development of Anderson
POM derivatives. Therefore, the search for new synthetic
methods to enrich the development of POM organic
derivatization is of great significance for POM chemistry.
Microwave-assisted synthesis is different from conventional
heating synthesis, which was first carried out in the middle
1980s18 and widely used in the synthesis the inorganic
nanostructure materials in recent years.19 Compared with
traditional synthetic methods, microwave-assisted synthesis has
the advantages of short synthesis time, low energy con-
been widely studied1 and used in the fields of optic materials,2
adsorption materials,3 electrochemistry,4 catalysis,5 biological
activity,6 and so on. In recent years, in order to broaden the
application fields of POMs, the combination of POMs with
functional organic groups to form new POM-based organic−
inorganic hybrid materials becomes the main direction of
POM synthesis.7 One of the common methods of synthesizing
the hybrid is to link organic functional groups to POM anions
by covalent bonds.8 This method is beneficial to the design and
synthesis of accurate molecular structures9 and makes POM
derivatives diverse.10 Anderson-type POMs are a kind of classic
structure and can be grafted tris (trihydroxyl organic
compounds) to obtain functional derivatives,11 which allow
them to have good application prospects in many aspects. For
example, Wei’s group has done a lot of research on Anderson
structural oxidation-catalyzed organic small molecules,12 and
Rompel’s group has made a great contribution to the biological
applications of Anderson-type POMs.13 Nevertheless, the
application of Anderson POMs is still lacking in some aspects,
such as photocatalysis, CO2 fixation, etc. This is mainly
because the synthesis of an Anderson POM-based organic
derivative is limited.
Received: January 5, 2021
Published: February 24, 2021
So far, there are three ways to add tris to Anderson-type
POMs in previous literature: (1) a “one-pot” method using tris,
https://dx.doi.org/10.1021/acs.inorgchem.1c00019
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sumption, and environmental protection.20 However, micro-
wave-assisted synthesis has received little attention in the
synthesis of POMs.21 In 2016, our group obtained a heteropoly
blue, [(HPO3)6Mo21O60(H2O)4]8−, by using a microwave-
driven method.22 However, when traditional heating was used,
reduced Keggin-type POM [PMo12O40]4− was obtained
instead. In 2018, a new POM-based 2D framework was
synthesized by using a microwave and applied for lithium-ion
batteries.23 On the basis of the foundation, we continue to
attempt to synthesize new Anderson POM hybrids by
microwave-assisted synthesis. Here, we synthesized a series
of Anderson POM hybrids by using microwave-assisted
synthesis: (NH4)4[ZnMo6O18(C4H8NO3)(OH)3]·4H2O (1),
(NH4 )4 [CuMo6 O1 8 (C4 H8 NO3 )(OH)3 ]·4H2 O (2),
(TBA)3[ZnMo6O17(C5H9O3)2(OH)]·10H2O (3; TBA = n-
C16H36N), and (NH4)4[CuMo6O18(C5H9O3)2]·16H2O (4).
After comprehensive characterization of these four com-
pounds, it was found that 3 was a χ/δ isomer and showed
different NMR spectrs, which was the reported for the first
time. The difference of the reaction mechanism between
microwave-assisted and conventional heating syntheses was
detected by mass spectrometry (MS). Additionally, CO2
cycloaddition catalysis has been studied, which broadened
the application field of Anderson-type POM hybrids.
method, the desired unilateral substitution structures were
obtained as (NH4)4[ZnMo6O18(C4H8NO3)(OH)3]·4(H2O)
(1) and (NH4)4[CuMo6O18(C4H8NO3)(OH)3]·4(H2O) (2).
In addition, two new bilateral substituted structures were also
s y n t h e s i z e d
a s
a
χ / δ
i s o m e r
(TBA)3[ZnMo6O17(C5H9O3)2(OH)]·10(H2O) (3) and a δ/
δ isomer (NH4)4[CuMo6O18(C5H9O3)2]·16(H2O) (4) (TBA
= n-C16H36N). It is worth mentioning that 3 and 4 can be
generated by conventional reflux method as well, while 1 and 2
cannot be obtained by reflux method. The result indicates that
microwave assisted synthesis protocol can be used to synthesis
some compounds which cannot be obtained by conventional
reflux method.
Single-crystal X-ray diffraction (SCXRD) revealed that 1
crystallizes in the triclinic system with space group P1. The
̅
anions are arranged in a dimer and shown in Figure 1A,E. Six
RESULTS AND DISCUSSION
■
Synthesis and Structures. In order to obtain the
functionalized Anderson-type POMs-based organic−inorganic
materials, trihydroxy compounds tris (tris-R, RNH2, tris-
(hydroxymethyl)methyl aminomethane; RCH3, 1,1,1-tris-
(hydroxymethyl)ethane) was chosen as the organic model,24
and series of new functionalized tris-Anderson POMs were
synthesized by microwave-assisted predesigned protocol. First,
we tried to synthesize unilateral {MMo6(tris-NH2)} (MZn2+
or Cu2+) using traditional heating method as the synthesis
method of {NiMo6(tris-NH2)},25 but the products are indeed
a large amount of {Mo7O24} (Scheme 1). According to study
reported by Rompel and co-workers,25 unilateral tris-Anderson
{MMo6(tris-NH2)} cannot be synthesized by “one-pot”
protocol because of the coordination of tris-R and metal,
which prevents the self-assembly process of Anderson-type
POMs and the coordination of tris-NH2 with POMs.
Interestingly, when using the microwave-assisted synthesis
Figure 1. Anion structures of compounds 1 (A), 2 (B), 3 (C), and 4
(D) and the crystal packings of 1 (E) and 2 (F). Cations, solvent
molecules, and partial H atoms are removed for clarity.
edge-sharing {MoO6} octahedra are around one central
{ZnO6} unit. tris-NH2 caps on one side by occupying three
μ2-O atoms of the {ZnO6} unit. On the other side, μ2-OH
formed hydrogen bonds with μ3 -O of another
[ZnMo6O18(C4H8NO3)(OH)3]4− anion to form a dimer.
Different from the dimers of {NiMo6(tris-NH2)}2 and
{CrMo6(tris-CH2OH)}2 reported previously,25,26 only four
hydrogen bonds are formed between the dimer instead of six.
In addition, although the structure of a single anion of 2 is
similar to that of 1 (Figure 1B), except for the central structure
was changed to a {CuMo6} octahedron. Compound 2 does not
form a dimer structure but is connected by hydrogen bonds to
form a zigzag-shaped chain structure, as shown in Figure 1F,
which is discovered in the tris-Anderson derivative structures
for the first time. Two hydrogen bonds are formed between
two adjacent anions, and a 1D chain structure is formed. This
different arrangement also results in 2 crystallizing in the
monoclinic system with space group P21/c, which is different
from 1. For compounds 3 and 4, there is no hydrogen bond
between the anions because of the different anion structures.
One tris-CH3 molecule in 3 replaces three μ2-O atoms, and
another tris-CH3 molecule replaces two μ2-O atoms and one
μ3-O atom to form the χ/δ isomer 3 (Figure 1C). Otherwise,
two tris-CH3 molecules replace six μ2-O atoms and cap on
each side of {CuMo6} to form the δ/δ isomer 4 (Figure 1D).
Although much has been reported about the different
configurations of tris-Anderson derivatives with the 3+ valence
of intermediate heteroatomic metals (Cr3+, Mn3+, Fe3+, etc.),
the Anderson structure with the 2+ valence of the intermediate
Scheme 1. Illustration of the Different Synthetic Conditions
a
Affecting the Products
a
Color code: black, C; red, O; orange, N; blue, Mo; yellow, metal.
tris-R = trihydroxyl organic compound.
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heteroatomic metal has not been reported much. For
comparison, Figure S3 and Table S2 show several classic
structures reported in the previous literature and this paper.
Characteristic. NMR spectra are used to demonstrate the
existing states of 1 and 3 in solution. Because of the molecular
symmetry of 1, only two peaks at 4.76 and 4.61 ppm are found
(Figure S4), which can be assigned to one amino group and
three methylene groups, respectively. Different from 1, 3 shows
six peaks assigned to six methylene groups in the range of
4.07−4.63 ppm (Figure 2A), indicating that the six methylene
overlapped most parts (Figure S8), and two chemical shifts in
the 13C NMR spectrum (16.99 and 18.80 ppm). The 2D
SHQC NMR spectrum (Figure S10) also demonstrates the
attribution of different C atoms. To the best of our knowledge,
this is the first time to obtain the NMR spectrum of the χ/δ
isomer.
Powder X-ray diffraction (PXRD; Figures S12−S15) analysis
is used to characterize the purity of the solid samples.
Compared with the PXRD spectra simulated from SCXRD, the
peaks are matched undifferentiated, which can verify the purity
of the compounds. Fourier transform infrared (FT-IR; Figure
S16) spectra of compounds 1−4 are typical of Anderson-type
POMs, and the characteristic peaks observed are consistent
with those of previous reports.27 All compounds displayed
similar characteristic Mo−O−Mo and MoO vibrations
because of the presence of the Anderson-type anion. Taking
1 as an example, the vibrational bands of the terminal MoO
groups are at about 891 and 808 cm−1, and the vibrational
bands of bridging Mo−O−Mo groups are at about 658 cm−1.
These peaks are consistent with the typical parent Anderson-
type structures. In addition, the peaks of 1118 and 1402 cm−1
can be assigned to the C−O and C−H bonds, which belong to
the tris-NH2 part. The thermogravimetric analysis (TGA) and
differential scanning calorimetry (DSC) curves show the
thermal stability of 1−4, and the molecular formula can be
confirmed by the weight loss. In the first stage of the weight
loss, it can correspond to the loss of water. Therefore,
according to Figure S17, the water of crystallization is figured
out, and the molecular formulas of compounds 1−4 are
confirmed as (NH4)4[ZnMo6O18(C4H8NO3)(OH)3]·4H2O,
( N H 4 ) 4 [ C u M o 6 O 1 8 ( C 4 H 8 N O 3 ) ( O H ) 3 ] · 4 H 2 O ,
(C16H36N)3[ZnMo6O17(C5H9O3)2(OH)]·10H2O, and
(NH4)4[CuMo6O18(C5H9O3)2]·16H2O, respectively.
Self-Assembly Study. The electrospray ionization mass
spectrometry (ESI-MS) spectra were used to obtain
information about the structures. The anion peaks can be
observed to prove the structures (Figures S18−S21) of the
compounds and infer the process of self-assembly.28 As shown
in Figure S22 and Table S3, a series ESI-MS spectra were
obtained at different microwave-assisted reaction times. With
an increase of the reaction time, a series of small ion fragment
peaks disappeared gradually, indicating that the small POM
fragments gradually self-assembled into larger ones. Thus, a
possible self-assembly process was proposed based on variation
of the ion peaks over time and shown in Figure 3. First,
{ZnMo6O24} decomposed into small structures ({Mo4O13},
{Mo3O16}, {ZnMo3O11}, and {ZnMo2O11}) and finally formed
the smallest {Mo2O7} unit. Second, {Mo2O7} and tris
reassembled to form the {(tris)Mo3O6}, {(tris)Mo4O9}, and
{(tris)Mo4O11} structures and then Zn2+ was added to obtain
{(tris)ZnMo4O12}. Finally, compound 1 was formed as the
final main product. On the other hand, different MS spectra
were also obtained under different conventional heating
reaction times and are shown in Figure S23. Different from
the microwave reactions, a series of isopolymolybdates were
found, while the ions containing Zn2+ were not observed.
Besides, [Zn(tris)(H2O)]+ was found at the positive mode,
which verified that Zn2+ and tris would combine and thus
prevent the combination of tris and POMs. With an increase of
the reaction time, the gradual disappearance of the small ion
fragment peaks indicated that the ions self-assembled into
large-structure isopolymolybdates and finally into the stable
{Mo7O24}. Therefore, two different synthetic methods affect
1
Figure 2. H (A) and 13C (B) NMR spectra of 3 in DMSO-d6.
groups of the χ/δ isomer are in different chemical environ-
ments. This is a big difference from the χ/χ isomer, which only
shows three methylene peaks.11a Besides, a singlet of μ3-OH
can be found at 5.03 ppm (provided in Figure S6), and the
peaks of TBA+ are also shown in the spectrum. The integral
ratio of TBA+ and methylene is 1:12, which verifies that the
ratio of anion [ZnMo6O17(C5H9O3)2(OH)]3− and cation
TBA+ is 1:3, is consistent with the SCXRD results. Moreover,
1
compared with the H NMR spectra of ligands tris-NH2 and
tris-CH3 (Figures S5 and S7), the chemical peaks of the
methylene groups in 1 and 2 shift toward low fields because of
the shield effects of metals. In order to figure out where the six
methylene peaks in 3 belong, 2D NOESY is carried out (Figure
S8). The results show that two double peaks and one single
peak can be assigned to one tris-CH3 ligand. Different from the
1H NMR spectrum, six methylene groups show only four peaks
in the 13C NMR spectrum in the range of 75−90 ppm (Figure
2B). In addition, two methyl groups show two singlets, which
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CO2 pressure and high temperature have also been verified to
be essential in the reaction. It is worth mentioning that the
pressure of CO2 used in the catalytic process is 1 atm, which is
much lower than that of the reported catalytic process by other
POMs.31 When the catalytic effects of 1−4 were compared, it
was found that the catalytic effects of 1 and 3 were better than
those of 2 and 4, indicating that the different heteroatoms in
Anderson-type POMs have different effects on the catalytic
reaction. In order to explore the stability of 1−4, PXRD and
FT-IR analyses were carried out on the catalyst before and
after reaction. As shown in Figures S23 and S24, the catalyst
did not change before and after catalytic reaction, indicating
the stability of 1−4. Moreover, when the catalysts were
repeated five times in the reaction, the catalytic yield did not
decrease significantly, suggesting that the Anderson-type
POMs had a good catalytic performance in the CO2
cycloaddition reaction. To further explore the cycloaddition
catalysis of CO2 at 1 atm, a series of different substrates were
explored, and the results are shown in Table S4. As can be
seen, the catalytic performance has a great relationship with the
structures of the catalysts. For the same catalyst, different types
of catalytic substrates also show different catalytic properties.
As shown in Table 1, entry 2, the reaction can also be carried
out with TBABr as the cocatalyst in the solution without
catalysts, suggesting that TBABr played an important role in
the reaction. According to the literature,30a this reaction
pathway is the epoxides catalyzed by TBABr. On this basis, the
possible mechanism in Figure 4 was proposed. The mechanism
Figure 3. Putative self-assembly mechanism of microwave-assisted
and reflux syntheses based on the ESI-MS spectra.
the connection of tris and metals, resulting in different
products.
CO2 Cycloaddition. CO2 transformation has been a
hotspot for a long time.29 As one of the products, cyclic
carbonates have received extensive attention because they can
be used as intermediates in fine chemicals, batteries, plastics,
etc.30 However, POMs as conventional catalysts are not widely
used in such catalytic reactions, and the catalytic conditions are
still harsh.31 In this work, compounds 1−4 were used as
catalysts to catalyze the cycloaddition of CO2 into a cyclic
carbonate, and an attempt was made to simplify the catalytic
conditions to expand application.
In order to explore the optimal reaction conditions,
epichlorohydrin, 1, and tetrabutylammonium bromide
(TBABr) were chosen as the substrate, catalyst, and cocatalyst,
respectively. As shown in Table 1, the cocatalyst itself could
convert the epoxide and CO2 into cyclic carbonate in low yield
(entry 2). However, the catalyst itself could not convert the
epoxide without the cocatalyst (entry 3). In addition, a certain
Table 1. Epichlorohydrin Cycloaddition with CO2 over
a
Different Conditions
cocatalyst
(mmol)
pressure
(atm)
t
T
yield
b
entry catalyst
(h) (°C)
(%)
Figure 4. Proposed reaction mechanism for the cycloaddition of CO2.
1
1
1
1
1
1
1
air
1
1
1
1
1
1
1
3
3
3
3
3
3
2
1
3
3
3
70
70
70
70
30
60
70
70
70
70
70
99.9
10.3
2
none
can be divided into two pathways, in which Path a is the
catalyst by Anderson-type POMs and Path b is the reaction
directly catalyzed by TBABr. In Path a, POM was first
interacted with epoxide to activate C−O bonds in the
substrates (the interaction between POMs and epoxide is
shown in Figure S28). The Br− belonging to TBABr attacks
the C−O bond, thus achieving the open-loop reaction of the
substrate. Then the C atom at the center of CO2 attacks the O
atom after the open ring and inserts into it. Finally, Br− leaves
after the C−Br bond breaks, and the C and O atoms connect
to form the final product, while the POM leaves the substrate
and participates in the next catalytic reaction. In Path b,
TBABr directly attacks the epoxide substrate without POM
3
4
5
6
7
8
9
10
11
1
1
1
1
1
1
2
3
4
none
1
1
1
1
1
1
1
1
19.8
90.3
94.7
81.7
91.3
99.9
95.2
a
Reaction conditions: epichlorohydrin, 20 mmol; catalyst, 0.03 mmol
b
(0.15 mol %); cocatalyst, TBABr. Determined by 1H NMR
spectroscopy; selectivities were over 99% in all cases.
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activation, and the subsequent reaction is similar to that in
Path a.
( N H 4 ) 4 [ C u M o 6 O 1 8 ( C 4 H 8 N O 3 ) ( O H ) 3 ] · 4 H 2 O ( 2 ) .
(NH4)4[CuMo6O24H6] (1.2 g, 1 mmol) and (CH2OH)3CNH2
(0.12 g, 1 mmol) were placed in a sealed glass tube containing 20
mL of deionized water and dissolved ultrasonically, and the resulting
solution was then placed in a microwave reactor. The reaction mixture
was heated to 140 °C for 10 min and maintained at 140 °C with a
microwave power of 30 W for 30 min. After cooling to room
temperature, the mixture was filtered and a blue block-shaped crystal
was obtained in a few days (45% yield, based on Mo). IR (KBr,
cm−1): 1635 (s), 1402 (vs), 889 (s), 804 (w), 648 (s), 577 (w), 474
(w). ESI-MS [(TBA)2[CuMo6O24H3((CH2)3CNH2)](H2O)2−].
Found: m/z 799.92. Theoretical: m/z 799.96. ICP-OES: Mo, 0.461
(calcd, 0.464); Cu, 0.049 (calcd, 0.051). Elem anal. Found (calcd): C,
0.034 (0.039); H, 0.030 (0.028); N, 0.054 (0.056).
CONCLUSION
■
Herein, we synthesized a series of tris-grafted Anderson POMs,
1−4, by using a microwave-assisted strategy. Although 3 and 4
can also be synthesized by conventional “one-pot” methods,
only 1 and 2 can be obtained by microwave protocol. MS
monitoring showed the self-assembly process of the microwave
synthesis, while a metal heteroatom would combine with tris
during the traditional synthesis, resulting in molybdenum self-
assembling into the {Mo7O24} structure. 3 as a χ/δ isomer
showed an NMR spectrum different from those of other
isomers, in which the six methylene groups showed six peaks in
1
the H NMR spectrum and only four peaks in the 13C NMR
M i c r o w a v e - A s s i s t e d
S y n t h e s i s
o f
spectrum. In addition, 1−4 can catalyze CO2 and epoxides into
cyclic carbonates with high selectivity and yield under an
atmospheric pressure of CO2, and two possible mechanism
pathways were proposed. This work not only explored new
microwave-assisted synthesis methods but also provided a
catalytic reaction of CO2 fixation under facile conditions.
( C1 6 H3 6 N)3 [ ZnMo6 O1 7 (C5 H9 O3 )2 ( OH)]·1 0H2 O (3 ).
(NH4)4[ZnMo6O24H6]·5H2O (1.1 g, 0.92 mmol) and
(CH2OH)3CCH3 (0.24 g, 2 mmol) were placed in a sealed glass
tube containing 25 mL of deionized water and dissolved ultrasoni-
cally, and the resulting solution was then placed in a microwave
reactor. The reaction mixture was heated to 140 °C for 10 min and
maintained at 140 °C with a microwave power of 30 W for 30 min.
After cooling to room temperature, TBABr (0.5 g, 1.5 mmol) was
added. The mixture was filtered, and a white block-shaped crystal was
obtained in a few days (65% yield, based on Mo). 1H NMR (DMSO-
d6, 400 MHz): δ 4.63 (s, 2H), 4.48−4.40 (m, 4H), 4.32 (s, 2H), 4.20
(d, 2H), 4.08 (d, 2H), 3.17 (t, 3H), 1.57 (m, 2H), 1.32 (m, 2H), 0.94
(t, 3H). IR (KBr, cm−1): 2964 (s), 2867 (s), 1653 (s), 1471 (s), 1396
(w), 1114 (w), 1030 (s), 923 (s), 665 (s), 595 (s), 543 (w). ESI-MS
[(TBA)2H[ZnMo6O24(C3H6CCH3)2H]−]. Found: m/z 1649.98.
EXPERIMENTAL SECTION
■
Materials and Physical Measurement. All reagents were
purchased from commercial sources and used without further
purification except those specifically noted. The NMR spectra were
performed on a Bruker Avance 400 MHz spectrometer in Deuterium
generation reagent with tetramethylsilane as the inner standard. FT-
IR spectra were obtained on an Alpha Centauri FT-IR spectrometer
in the 400−4000 cm−1 region with a KBr pellet. TGA−DSC was
performed on a PerkinElmer TGA7 instrument under flowing Ar, and
the temperature was set from 40 to 800 °C under a heating rate of 10
°C/min with an Ar flow of 25 mL/min. ESI-MS spectra were
recorded with a Bruker Compact quadrupole time-of-flight (QTOF)
mass spectrometer with an electrospray ionizer, and data analysis was
performed on a Bruker IsotopePattern. PXRD was employed using
Cu Kα in the range of 10−50° with a scanning rate of 10°/min. The
crystallographic data and structural refinements are given in Table S1.
SCXRD analysis was performed on a Bruker APEX-II diffractometer
with graphite-monochromated Mo Kα radiation at 296 K (λ =
0.71073 Å). A multiscan technique was used for absorption
correction. Using Olex2, the structure was solved with the ShelXT
structure solution program using intrinsic phasing and refined with
the ShelXL refinement package using least-squares minimization.32
CCDC 2053657, 2053743, 2053744, and 2053745 contain the
supplementary crystallographic data for this paper.
(NH4)4[ZnMo6O24H6]·5H2O ({ZnMo6}) and (NH4)4[CuMo6O24
H6]·5H2O ({CuMo6}) were synthesized according to a previous
report.33 The solubility tests in different solvents and stability tests in
water with pH values of 1−4 are shown in the Supporting
Information.
T h e o r e t i c a l :
m / z
1 6 4 9 . 9 6 .
E S I - M S
[(TBA)3[ZnMo6O24(C3H6CCH3)2H]−]. Found: m/z 1891.26. The-
oretical: m/z 1891.25. ICP-OES: Mo, 0.281 (calcd, 0.275); Zn, 0.029
(calcd, 0.031). Elem anal. Found (calcd): C, 0.302 (0.333); H, 0.078
(0.072); N, 0.026 (0.027).
M i c r o w a v e - A s s i s t e d
S y n t h e s i s
o f
(NH4)4[CuMo6O18(C5H9O3)2]·16H2O (4). (NH4)4[CuMo6O24H6]
(0.35 g, 0.29 mmol) and (CH2OH)3CCH3 (0.06 g, 0.5 mmol)
were placed in a sealed glass tube containing 10 mL of deionized
water and dissolved ultrasonically, and the resulting solution was then
placed in a microwave reactor. The reaction mixture was heated to
140 °C for 10 min and maintained at 140 °C with a microwave power
of 30 W for 30 min. After the solvent cooled to room temperature,
TBABr (0.24 g, 0.75 mmol) was added. The mixture was filtered, and
a blue block-shaped crystal was obtained in a few days (63% yield,
based on Mo). IR (KBr, cm−1): 2967 (w), 2859 (w), 1647 (s), 1465
(s), 1403 (s), 1113 (w), 1033 (s), 925 (s), 650 (s), 563 (w). ESI-MS
[(TBA)H2[CuMo6O24(C16H36CCH3)2]−]. Found: m/z 1406.48.
T h e o r e t i c a l : m / z 1 4 0 6 . 4 8 . E S I - M S [ ( T B A ) 2 H -
[CuMo6O24(C16H36CCH3)2]−]. Found: m/z 1647.96. Theoretical:
m/z 1647.96. ESI-MS [(TBA)3[CuMo6O24(C16H36CCH3)2]−].
Found: m/z 1889.24. Theoretical: m/z 1889.24. ICP-OES: Mo,
0.390 (calcd, 0.387); Cu, 0.040 (calcd, 0.042). Elem anal. Found
(calcd): C, 0.077 (0.079); H, 0.045 (0.043); N, 0.034 (0.037).
Traditional Heating Method. (NH4)4[MMo6O24H6]·5H2O
(MZn or Cu, 0.92 mmol) and (CH2OH)3CNH2 (1 mmol) were
placed in a round flask containing 20 mL of deionized water and
dissolved ultrasonically. The reaction mixture was heated to reflux for
12 h. After cooling to room temperature, the mixture was filtered and
a white block-shaped crystal was obtained in a few days (70% yield,
based on Mo). The crystal was analyzed as (NH4)[Mo7O24] by a
SCXRD test. In particular, although 3 and 4 can be obtained by
conventional heating, the compounds used in this paper were
synthesized by a microwave-assisted synthesis.
M i c r o w a v e - A s s i s t e d
S y n t h e s i s
o f
( N H 4 ) 4 [ Z n M o 6 O 1 8 ( C 4 H 8 N O 3 ) ( O H ) 3 ] · 4 H 2 O ( 1 ) .
(NH4)4[ZnMo6O24H6]·5H2O (1.1 g, 0.92 mmol) and
(CH2OH)3CNH2 (0.12 g, 1 mmol) were placed in a sealed glass
tube containing 15 mL of deionized water and dissolved ultrasoni-
cally, and the resulting solution was then placed in a microwave
reactor. The reaction mixture was heated to 140 °C for 10 min and
maintained at 140 °C with a microwave power of 30 W for 30 min.
After cooling to room temperature, the mixture was filtered and a
white block-shaped crystal was obtained in a few days (52% yield,
based on Mo). 1H NMR (DMSO-d6, 400 MHz): δ 6.81 (s, 6H), 3.17
(t, 3H), 1.57 (m, 2H), 1.32 (m, 2H), 0.94 (t, 3H). IR (KBr, cm−1):
1631 (s), 1402 (vs), 891 (vs), 808 (w), 657 (s), 571 (w), 479 (w).
ESI-MS [{(TBA)2[ZnMo6O24H3((CH2)3CNH2)](H2O)}2−]. Found:
m/z 800.47. Theoretical: m/z 800.46. ICP-OES: Mo, 0.466 (calcd,
(NH4)4[ZnMo6O24H6]·5H2O (0.92 mmol) and (CH2OH)3CCH3
(2 mmol) were placed in a round flask containing 25 mL of deionized
water and dissolved ultrasonically. The reaction mixture was heated to
3984
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Inorg. Chem. 2021, 60, 3980−3987

Inorganic Chemistry
pubs.acs.org/IC
Article
reflux for 12 h. After cooling to room temperature, TBABr (1.5
mmol) was added. The mixture was filtered, and a white block-shaped
crystal was obtained in a few days (71% yield, based on Mo). The
crystal was analyzed as (TBA)3(NH4)[ZnMo6O17(C5H9O3)2(OH)]·
10(H2O) (3) by a SCXRD test.
Le-Ping Zhang − Hunan Institute of Nuclear Agricultural
Science and Space Breeding, Hunan Academy of Agricultural
Science, Changsha 410000, P. R. China
Hong-Ke Xie − Hunan Institute of Nuclear Agricultural
Science and Space Breeding, Hunan Academy of Agricultural
Science, Changsha 410000, P. R. China
(NH4)4[CuMo6O24H6] (0.29 mmol) and (CH2OH)3CCH3 (0.5
mmol) were placed in a round flask containing 25 mL of deionized
water and dissolved ultrasonically, and the reaction mixture was
heated to reflux for 12 h. After the solvent cooled to room
temperature, TBABr (0.75 mmol) was added. The mixture was
filtered, and a blue block-shaped crystal was obtained in a few days
(60% yield, based on Mo). The crystal was analyzed as
(NH4)4[CuMo6O18(C5H9O3)2]·16(H2O) (4) by a SCXRD test.
CO2 Cycloaddition. The corresponding epoxide (20 mmol),
catalyst (0.03 mmol, 0.15 mol %), and TBABr (0.32 g, 1 mmol) were
added to an Erlenmeyer flask. After the bottle was full of CO2, which
was achieved by using balloons and a three-way valve, the solution
was stirred at 70 °C for 3 h. The productivity was calculated by using
1H NMR. After the reaction, CH2Cl2 was added to the solution to
precipitate the catalyst. Then the precipitate was filtered, and the
impurities were washed away with a large amount of CH2Cl2. After
drying, the catalyst was recovered and used for the next cycles.
Complete contact information is available at:
https://pubs.acs.org/10.1021/acs.inorgchem.1c00019
Funding
This work was supported by the Natural Science Foundation
of Hunan Province (Grant 2020JJ4684).
Notes
The authors declare no competing financial interest.
REFERENCES
(1) (a) Pope, M. T.; Mu
■
̈
ller, A. Polyoxometalate chemistry: an old
field with new dimensions in several disciplines. Angew. Chem., Int. Ed.
Engl. 1991, 30, 34−38. (b) Long, D. L.; Burkholder, E.; Cronin, L.
Polyoxometalate clusters, nanostructures and materials: from self
assembly to designer materials and devices. Chem. Soc. Rev. 2007, 36,
105−121.
ASSOCIATED CONTENT
■
(2) Chen, L.; Chen, W. L.; Wang, X. L.; Li, Y. G.; Su, Z. M.; Wang,
E. B. Polyoxometalates in dye-sensitized solar cells. Chem. Soc. Rev.
2019, 48, 260−284.
sı
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/acs.inorgchem.1c00019.
(3) Li, J. H.; Wang, X. L.; Song, G.; Lin, H. Y.; Wang, X.; Liu, G. C.
Various Anderson-type polyoxometalate-based metal-organic com-
plexes induced by diverse solvents: assembly, structures and selective
adsorption for organic dyes. Dalton Trans. 2020, 49, 1265−1275.
(4) (a) Jia, X.; Wang, J.; Hu, H.; Song, Y. F. Three-dimensional
carbon framework anchored polyoxometalate as a high-performance
anode for lithium-ion batteries. Chem. - Eur. J. 2020, 26, 5257−5263.
(b) Du, J.; Lang, Z. L.; Ma, Y. Y.; Tan, H. Q.; Liu, B. L.; Wang, Y. H.;
Kang, Z. H.; Li, Y. G. Polyoxometalate-base electron transfer
modulation for efficient electrocatalytic carbon dioxide reduction.
Chem. Sci. 2020, 11, 3007−3015.
Details of SCXRD, NMR spectra, PXRD, FT-IR, TGA
and DSC, ESI-MS, and CO2 cycloaddition, and
solubility tests in different solvents and stability tests
in H2O with pH values, including Figures S1−S54 and
Tables S1−S7 (PDF)
Accession Codes
CCDC 2053657 and 2053743−2053745 contain the supple-
mentary crystallographic data for this paper. These data can be
obtained free of charge via www.ccdc.cam.ac.uk/data_request/
cif, or by emailing data_request@ccdc.cam.ac.uk, or by
contacting The Cambridge Crystallographic Data Centre, 12
Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
(5) (a) Samaniyan, M.; Mirzaei, M.; Khajavian, R.; Eshtiagh-
Hosseini, H.; Streb, C. Heterogeneous catalysis by polyoxometalates
in metal-organic frameworks. ACS Catal. 2019, 9, 10174−10191.
(b) Wang, S. S.; Yang, G. Y. Recent advances in polyoxometalate-
catalyzed reactions. Chem. Rev. 2015, 115, 4893−4962.
(6) (a) Bijelic, A.; Aureliano, M.; Rompel, A. Polyoxometalates as
potential next-generation metallodrugs in the combat against cancer.
Angew. Chem., Int. Ed. 2019, 58, 2980−2999. (b) Blazevic, A.; Al-
Sayed, E.; Roller, A.; Giester, G.; Rompel, A. Tris-functionalized
hybrid Anderson polyoxometalates: synthesis, characterization, hydro-
lytic stability and inversion of protein surface charge. Chem. - Eur. J.
2015, 21, 4762−4771.
AUTHOR INFORMATION
■
Corresponding Authors
Wei-Dong Yu − Hunan Institute of Nuclear Agricultural
Science and Space Breeding, Hunan Academy of Agricultural
Science, Changsha 410000, P. R. China; orcid.org/0000-
0001-6937-6944; Email: fenly18@sina.com
Jun Yan − School of Chemistry and Chemical Engineering,
Central South University, Changsha 410000, P. R. China;
orcid.org/0000-0002-6158-0614; Email: yanjun@
csu.edu.cn
(7) (a) Dolbecq, A.; Dumas, E.; Mayer, C. R.; Mialane, P. Hybrid
organic-inorganic polyoxometalate compounds: from structural
diversity to applications. Chem. Rev. 2010, 110, 6009−6048. (b) Li,
C. F.; Mizuno, N.; Yamaguchi, K.; Suzuki, K. Self-assembly of anionic
polyoxometalate-organic architectures based on lacunary phospho-
molybdates and pyridyl ligands. J. Am. Chem. Soc. 2019, 141, 7687−
7692. (c) Yang, X. X.; Yu, W. D.; Yi, X. Y.; Liu, C. Accurate regulating
of visible-light absorption in polyoxotitanate-calix[8]arene systems by
ligand modification. Inorg. Chem. 2020, 59, 7512−7519. (d) Yang, X.
X.; Yu, W. D.; Yi, X. Y.; Li, L. J.; Liu, C. Monocarboxylate-driven
structural growth in calix[n]arene-polyoxotitanate hybrid systems:
utility in hydrogen production from water. Chem. Commun. 2020, 56,
14035−14038. (e) Yu, W.; Li, B.; Zhang, Y.; Yan, Q.; Yan, J.
Discovery of a fullerene-polyoxometalate hybrid exhibiting enhanced
photocurrent response. Inorg. Chem. 2020, 59, 5266−5270.
(8) (a) Xu, Q. H.; Yuan, S. S.; Zhu, L.; Hao, J.; Wei, Y. G. Synthesis
of novel bis(Triol)-functionalized Anderson clusters serving as
potential synthons for forming organic-inorganic hybrid chains.
Chem. Commun. 2017, 53, 5283−5286. (b) Diab, M.; Mateo, A.; Al
Authors
Yin Zhang − Junior Education Department, Changsha Normal
University, Changsha 410100, P. R. China
Yu-Yang Han − School of Chemistry and Chemical
Engineering, Central South University, Changsha 410000, P.
R. China
Bin Li − School of Chemistry and Chemical Engineering,
Central South University, Changsha 410000, P. R. China
Sai Shao − Hunan Institute of Nuclear Agricultural Science
and Space Breeding, Hunan Academy of Agricultural Science,
Changsha 410000, P. R. China
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pubs.acs.org/IC
Article
Cheikh, J.; Haouas, M.; Ranjbari, A.; Bourdreux, F.; Naoufal, D.;
Cadot, E.; Bo, C.; Floquet, S. Unprecedented coupling reaction
between two anionic species of a closo-decahydrodecaborate cluster
and an Anderson-type polyoxometalate. Dalton Trans. 2020, 49,
4685−4689.
(9) (a) Luo, Y.; Maloul, S.; Wächtler, M.; Winter, A.; Schubert, U.
S.; Streb, C.; Dietzek, B. Is electron ping-pong limiting the catalytic
hydrogen evolution activity in covalent photosensitizer-polyoxometa-
late dyads. Chem. Commun. 2020, 56, 10485−10488. (b) Li, X. H.;
Liu, Y. W.; Lu, Y.; Zhang, Z.; Tian, H. R.; Liu, S. M.; Liu, S. X. A
universal strategy for fabrication and morphology control of
polyoxometalate-based metal-organic frameworks. Chem. Commun.
2020, 56, 1641−1644.
T.; Rau, S.; Streb, C. Experimental and theoretical investigation of the
light-driven hydrogen evolution by polyoxometalate-photosensitizer
dyads. Chem. - Eur. J. 2017, 23, 15370−15376.
(14) (a) Macdonell, A.; Johnson, N. A. B.; Surman, A. J.; Cronin, L.
Configurable nanosized metal oxide oligomers via precise “Click”
coupling control of hybrid polyoxometalates. J. Am. Chem. Soc. 2015,
137, 5662−5665. (b) Musumeci, C.; Rosnes, M. H.; Giannazzo, F.;
Symes, M. D.; Cronin, L.; Pignataro, B. Smart high-κ nanodielectrics
using solid supported polyoxometalate-rich nanostructures. ACS Nano
2011, 5, 9992−9999. (c) Yin, P. C.; Zhang, J.; Li, T.; Zuo, X. B.; Hao,
J.; Warner, A. M.; Chattopadhyay, S.; Shibata, T.; Wei, Y. G.; Liu, T.
B. Self-recognition of structurally identical, rod-shaped macroions
with different central metal atoms during their assembly process. J.
Am. Chem. Soc. 2013, 135, 4529−4536. (d) Santoni, M. P.; Pal, A. K.;
Hanan, G. S.; Proust, A.; Hasenknopf, B. Discrete covalent organic-
inorganic hybrids: terpyridine functionalized polyoxometalates
obtained by a modular strategy and their metal complexation. Inorg.
Chem. 2011, 50, 6737−6745.
(10) (a) Zhang, J. W.; Huang, Y. C.; Li, G.; Wei, Y. G. Recent
advances in alkoxylation chemistry of polyoxometalates: from
synthetic strategies, structural overviews to functional applications.
Coord. Chem. Rev. 2019, 378, 395−414. (b) Anyushin, A. V.;
Kondinski, A.; Parac-Vogt, T. V. Hybrid polyoxometalates as post-
functionalization platforms: from fundamentals to emerging applica-
tions. Chem. Soc. Rev. 2020, 49, 382−432. (c) Li, X. X.; Zhao, D.;
Zheng, S. T. Recent advances in POM-organic frameworks and POM-
organic polyhedral. Coord. Chem. Rev. 2019, 397, 220−240.
(11) (a) Hasenknopf, B.; Delmont, R.; Herson, P.; Gouzerh, P.
Aderson-type heteropolymolybdates containing tris(alkoxo) ligands:
synthesis and structural characterization. Eur. J. Inorg. Chem. 2002, 12,
1081−1087. (b) Marcoux, P. R.; Hasenknopf, B.; Vaissermann, J.;
Gouzerh, P. Developing remote metal binding sites in hetero-
polymolybdates. Eur. J. Inorg. Chem. 2003, 13, 2406−2412.
(c) Debela, A. M.; Ortiz, M.; Beni, V.; Thorimbert, S.; Lesage, D.;
Cole, R. B.; O’Sullivan, C. K.; Hasenknopf, B. Biofunctionalization of
polyoxometalates with DNA primers, their use in the polymerase
chain reaction (PCR) and electrochemical detection of PCR products.
Chem. - Eur. J. 2015, 21, 17721−17727. (d) Li, X. X.; Ma, X.; Zheng,
W. X.; Qi, Y. J.; Zheng, S. T.; Yang, G. Y. Composite hybrid cluster
built from the integration of polyoxometalate and a metal halide
cluster: synthetic strategy, structure, and properties. Inorg. Chem.
2016, 55, 8257−8259. (e) Song, Y. F.; Long, D. L.; Cronin, L.
Noncovalently connected frameworks with nanoscale channels
assembled from a tethered polyoxometalate-pyrene hybrid. Angew.
Chem., Int. Ed. 2007, 46, 3900−3904. (f) Gao, N.; Du, Z.; Guan, Y. J.;
Dong, K.; Ren, J. S.; Qu, X. G. Chirality-selected chemical modulation
of amyloid aggregation. J. Am. Chem. Soc. 2019, 141, 6915−6921.
(g) Mukhacheva, A. A.; Volchek, V. V.; Yanshole, V. V.; Kompankov,
N. B.; Gushchin, A. L.; Benassi, E.; Abramov, P. A.; Sokolov, M. N. Is
it possible to prepare a heterometal Anderson-Evans type anion?
Inorg. Chem. 2020, 59, 2116−2120.
(12) (a) Yu, H.; Wang, J. J.; Zhai, Y. Y.; Zhang, M. Q.; Ru, S.; Han,
S.; Wei, Y. G. Visible-light-driven photocatalytic oxidation of organic
chlorides using air and an inorganic-ligand supported nickel-catalyst
without photosensitizers. ChemCatChem 2018, 10, 4274−4279.
(b) Yu, H.; Zhai, Y. Y.; Dai, G. Y.; Ru, S.; Han, S.; Wei, Y. G.
Transition-metal-controlled inorganic ligand-supported non-precious
metal catalysts for the aerobic oxidation of amines to lmines. Chem. -
Eur. J. 2017, 23, 13883−13887. (c) Zhang, M. Q.; Zhai, Y. Y.; Ru, S.;
Zang, D. J.; Han, S.; Yu, H.; Wei, Y. G. Highly practical and efficient
preparation of aldehydes and ketones from aerobic oxidation of
alcohols with an inorganic-ligand supported iodine catalyst. Chem.
Commun. 2018, 54, 10164−10167. (d) Yu, H.; Ru, S.; Dai, G. Y.;
Zhai, Y. Y.; Lin, H. L.; Han, S.; Wei, Y. Y. An efficient iron(III)-
catalyzed aerobic oxidation of aldehydes in water for the green
preparation of carboxylic acids. Angew. Chem., Int. Ed. 2017, 56,
3867−3871. (e) Wei, Z. Y.; Ru, S.; Zhao, Q. X.; Yu, H.; Zhang, G.;
Wei, Y. G. Highly efficient and practical aerobic oxidation of alcohols
by inorganic-ligand supported copper catalysis. Green Chem. 2019, 21,
4069−4075.
(15) (a) Ai, H.; Wang, Y.; Li, B.; Wu, L. X. Synthesis and
characterization of single-side organically grafted Anderson-type
polyoxometalates. Eur. J. Inorg. Chem. 2014, 17, 2766−2772.
(b) Blazevic, A.; Al-Sayed, E.; Roller, A.; Giester, G.; Rompel, A.
Tris-functionalized hybrid Anderson polyoxometalates: synthesis,
characterization, hydrolytic stability and inversion of protein surface
charge. Chem. - Eur. J. 2015, 21, 4762−4771. (c) Zhang, J. W.; Liu, Z.
H.; Huang, Y. C.; Zhang, J.; Hao, J.; Wei, Y. G. Unprecedented χ
isomers of single-side triol-functionalized Anderson polyoxometalates
and their proton-controlled isomer transformation. Chem. Commun.
2015, 51, 9097−9100.
(16) (a) Lin, C. G.; Chen, W.; Long, D. L.; Cronin, L.; Song, Y. F.
Step-by-step covalent modification of Cr-templated Anderson-type
polyoxometalates. Dalton Trans. 2014, 43, 8587−8590. (b) Zhang, J.
W.; Luo, J. H.; Wang, P. M.; Ding, B.; Huang, Y. C.; Zhao, Z. L.;
Zhang, J.; Wei, Y. G. Step-by-step strategy from achiral precursors to
polyoxometalates-based chiral organic-inorganic hybrids. Inorg. Chem.
2015, 54, 2551−2559.
(17) (a) Wang, Y.; Li, B.; Qian, H. J.; Wu, L. X. Controlled triol-
derivative bonding and decoration transformation on Cu-centered
Anderson-Evans polyoxometalates. Inorg. Chem. 2016, 55, 4271−
4277. (b) Wang, Y.; Liu, X. T.; Xu, W.; Yue, Y.; Li, B.; Wu, L. X.
Triol-ligand modification and structural transformation of Anderson-
Evans oxomolybdates via modulating oxidation state of Co-
heteroatom. Inorg. Chem. 2017, 56, 7019−7028. (c) Wang, Y.;
Kong, X. P.; Xu, W.; Jiang, F. R.; Li, B.; Wu, L. X. Ratio-controlled
precursors of Anderson-Evans polyoxometalates: synthesis, structural
transformation, and magnetic and catalytic properties of a series of
triol ligand-decorated {M2Mo6} clusters (MCu2+, Co2+, Ni2+,
Zn2+). Inorg. Chem. 2018, 57, 3731−3741. (d) Zhang, B.; Yue, L.;
Wang, Y.; Yang, Y.; Wu, L. X. A novel single-side azobenzene-grafted
Anderson-type polyoxometalate for recognition-induced chiral migra-
tion. Chem. Commun. 2014, 50, 10823−10826.
(18) (a) Komarneni, S.; Roy, R. Titania gel spheres by a new sol-gel
process. Mater. Lett. 1985, 3, 165−167. (b) Gedye, R.; Smith, F.;
Westaway, K.; Ali, H.; Baldisera, L.; Laberge, L.; Rousell, J. The use of
microwave ovens for rapid organic synthesis. Tetrahedron Lett. 1986,
27, 279−282.
(19) (a) Zhu, Y. J.; Chen, F. Microwave-assisted preparation of
inorganic nanostructures in liquid phase. Chem. Rev. 2014, 114,
6462−6555. (b) Laybourn, A.; Katrib, J.; Ferrari-John, R. S.; Morris,
C. G.; Yang, S.; Udoudo, O.; Easun, T. L.; Dodds, C.; Champness, N.
R.; Kingman, S. M.; Schröder, M. Metal-organic frameworks in
seconds via selective microwave heating. J. Mater. Chem. A 2017, 5,
7333−7338. (c) Wingen, L. M.; Scholz, M. S. B-Cyanodicarba-closo-
dodecaboranes: facile synthesis and spectroscopic features. Inorg.
Chem. 2016, 55, 8274−8276.
(13) (a) Blazevic, A.; Rompel, A. The Anderson-Evans polyox-
ometalate: from inorganic building blocks via hybrid organic-
inorganic structures to tomorrows “Bio-POM”. Coord. Chem. Rev.
2016, 307, 42−64. (b) Schönweiz, S.; Heiland, M.; Anjass, M.; Jacob,
(20) (a) Patete, J. M.; Peng, X. H.; Koenigsmann, C.; Xu, Y.; Karn,
B.; Wong, S. S. Visible methodologies for the synthesis of high-quality
nanostructures. Green Chem. 2011, 13, 482−519. (b) Dahl, J. A.;
3986
https://dx.doi.org/10.1021/acs.inorgchem.1c00019
Inorg. Chem. 2021, 60, 3980−3987

Inorganic Chemistry
pubs.acs.org/IC
Article
Maddux, B. L. S.; Hutchison, J. E. Toward greener nanosynthesis.
Chem. Rev. 2007, 107, 2228−2269.
carbon with ultrahigh concentrations of single Zn atoms for efficient
carbon dioxide conversion. Angew. Chem., Int. Ed. 2019, 58, 3511−
3515. (c) Liu, Y. X.; Wang, H. H.; Zhao, T. J.; Zhang, B.; Su, H.; Xue,
Z. H.; Li, X. H.; Chen, J. S. Schottky barrier induced coupled interface
of electron-rich N-doped carbon and electron-deficient Cu: In-built
lewis acid-base pairs for highly efficient CO2 fixation. J. Am. Chem.
Soc. 2019, 141, 38−41. (d) He, L.; Nath, J. K.; Lin, Q. P. Robust
multivariate metal-porphyrin frameworks for efficient ambient fixation
of CO2 to cyclic carbonates. Chem. Commun. 2019, 55, 412−415.
(31) (a) Lu, J. K.; Ma, X. Y.; Singh, V.; Zhang, Y. J.; Wang, P.; Feng,
J. W.; Ma, P. T.; Niu, J. Y.; Wang, J. P. Facile CO2 cycloaddition to
epoxides by using a tetracarbonyl metal selenotungstate derivate
[{Mn(CO)3}4(Se2W11O43)]8‑. Inorg. Chem. 2018, 57, 14632−14643.
(b) Cheng, W. W.; Xue, Y. S.; Luo, X. M.; Xu, Y. A rare three-
dimensional POM-based inorganic metal polymer bonded by CO2
with high catalytic performance for CO2 cycloaddition. Chem.
Commun. 2018, 54, 12808−12811. (c) Jia, J. M.; Niu, Y. J.; Zhang,
P. P.; Zhang, D. D.; Ma, P. T.; Zhang, C.; Niu, J. Y.; Wang, J. P. A
monomeric tricobalt(II)-substituted Dawson-type polyoxometalate
(21) (a) Bagno, A.; Bonchio, M.; Sartorel, A.; Scorrano, G.
Microwave-assisted rapid incorporation of ruthenium into lacunary
Keggin-type polyoxotungstates: one-step synthesis, 99Ru, 183W NMR
characterization and catalytic activity of [PW11O39RuII(DMSO)]5‑.
Eur. J. Inorg. Chem. 2000, 2000, 17−20. (b) Besson, C.; Chen, S. W.;
Villanneau, R.; Izzet, G.; Proust, A. A new synthetic route towards
Ru(III) substituted heteropolytungstate anion. Inorg. Chem. Commun.
2009, 12, 1042−1044. (c) Farhadi, S.; Mahmoudi, F.; Simpson, J. A
new nano-scale manganese(II) coordination polymer constructed
from semicarbzaone Schiff base and dicyanamide ligands: synthesis,
crystal structure and DFT calculations. J. Mol. Struct. 2016, 1108,
583−589. (d) Farhadi, S.; Mahmoudi, F.; Dusek, M.; Eigner, V.;
Kucerakova, M. A new inorganic-organic nanohybrid based on a
3‑
copper(II) semicarbazone complex and the PMo12O40 polyanion:
synthesis, characterization, crystal structure and photocatalytic activity
for degradation of cationic dyes. Polyhedron 2017, 122, 247−256.
(e) Ritchie, C.; Bryant, G. Microwave assisted synthesis of a mono
organoimido functionalized Anderson polyoxometalate. Dalton Trans.
2015, 44, 20826−20829.
(22) Jin, X. X.; Yu, W. D.; Nie, Y. M.; Liu, M. S.; Yan, J.
[(HPO3)6Mo21O60(H2O)4]8‑: a new redox active heteropoly blue
cluster with layered shape containing a phosphite template that self-
assembles under controlled microwave irradiation. Dalton Trans.
2016, 45, 3268−3271.
(23) Nie, Y. M.; Liang, S.; Yu, W. D.; Yuan, H.; Yan, J. Microwave-
assisted preparation and characterization of a polyoxometalate-based
inorganic 2D framework anode for enhancing lithium-ion battery
performance. Chem. - Asian J. 2018, 13, 1199−1205.
d e c o r a t e d b y
a
m e t a l c a r b o n y l g r o u p :
[P2W15O56Co3(H2O)3(OH)3Mn(CO)3]8‑. Inorg. Chem. 2017, 56,
10131−10134. (d) Ge, W. L.; Wang, X. C.; Zhang, L. Y.; Du, L.;
Zhou, Y.; Wang, J. Fully-occupied Keggin type polyoxometalate as
solid base for catalyzing CO2 cycloaddition and Knoevenagel
condensation. Catal. Sci. Technol. 2016, 6, 460−467.
(32) Sheldrick, G. M. Crystal structure refinement with SHELXL.
Acta Crystallogr., Sect. C: Struct. Chem. 2015, C71, 3−8.
(33) Nomiya, K.; Takahashi, T.; Shirai, T.; Miwa, M. Anderson-type
heteropolyanions of molybdenum (VI) and tungsten (VI). Polyhedron
1987, 6, 213−218.
(24) Santoni, M.; Hanan, G. S.; Hasenknopf, B. Covalent multi-
component systems of polyoxometalates and metal complexes:
towards multi-functional organic- inorganic hybrids in molecular
and material sciences. Coord. Chem. Rev. 2014, 281, 64−85.
(25) Gumerova, N. I.; Roller, A.; Rompel, A. Synthesis and
characterization of the first nickel(II)-centered single-side tris
functionalized Aderson-type polyoxomolybdate. Eur. J. Inorg. Chem.
2016, 36, 5507−5511.
(26) Wu, P. F.; Yin, P. C.; Zhang, J.; Hao, J.; Xiao, Z. C.; Wei, Y. G.
Single-side organically functionalized Anderson-type polyoxometa-
lates. Chem. - Eur. J. 2011, 17, 12002−12005.
(27) (a) Zhu, M. C.; Huang, Y. Y.; Ma, J. P.; Hu, S. M.; Wang, Y.;
Guo, J.; Zhao, Y. X.; Wang, L. S. Coordination polymers based on
organic-inorganic hybrid rigid rod comprising a backbone of
Anderson-Evans POMs. Cryst. Growth Des. 2019, 19, 925−931.
(b) Gao, N.; Du, Z.; Guan, Y. J.; Dong, K.; Ren, J. S.; Qu, X. G.
Chirality-selected chemical modulation of amyloid aggregation. J. Am.
Chem. Soc. 2019, 141, 6915−6921. (c) Vanhaecht, S.; Quanten, T.;
Parac-Vogt, T. N. A simple nucleophilic substitution as a versatile
postfunctionalization method for the coupling of nucleaophiles to an
Anderson-type polyoxometalate. Inorg. Chem. 2017, 56, 3095−3101.
(28) (a) Wilson, E. F.; Miras, H. N.; Rosnes, M. H.; Cronin, L. Real-
time observation of self-assembly of hybrid polyoxometalates using
mass spectrometry. Angew. Chem., Int. Ed. 2011, 50, 3720−3724.
(b) Surman, A. J.; Robbins, P. J.; Ujma, J.; Zheng, Q.; Barran, P. E.;
Cronin, L. Sizing and discovery of nanosized polyoxometalate clusters
by mass spectrometry. J. Am. Chem. Soc. 2016, 138, 3824−3830.
(c) Thiel, J.; Yang, D. M.; Rosnes, M. H.; Liu, X. L.; Yvon, C.; Kelly,
S. E.; Song, Y. F.; Long, D. L.; Cronin, L. Observing the hierarchical
self- assembly and architectrural bistability of hybrid molecular metal
oxides using ion-mobility mass spectraometry. Angew. Chem., Int. Ed.
2011, 50, 8871−8875.
(29) Yu, B.; Zou, B.; Hu, C. W. Recent applications of
polyoxometalates in CO2 capture and transformation. J. CO2 Util.
2018, 26, 314−322.
(30) (a) Huang, K.; Zhang, J. Y.; Liu, F. J.; Dai, S. Synthesis of
porous polymeric catalysts for the conversion of carbon dioxide. ACS
Catal. 2018, 8, 9079−9102. (b) Yang, Q.; Yang, C. C.; Lin, C. H.;
Jiang, H. L. Metal-organic-frmework-derived hollow N-doped porous
3987
https://dx.doi.org/10.1021/acs.inorgchem.1c00019
Inorg. Chem. 2021, 60, 3980−3987