Controllable Synthesis of Lindqvist Alkoxopolyoxovanadate Clusters as Heterogeneous Catalysts for Sulfoxidation of Sulfides

Article abstract of DOI:10.1021/acs.inorgchem.7b00366

Six alkoxohexavanadate-based Cu- or Co-POVs [Cu(dpa)(acac)(H₂O)]₂[V₆O₁₃(OMe)₆] (1), [Cu(phen)(acac)(MeOH)]₂[V₆O₁₃(OMe)₆] (2), [Co(dpa)(acac)₂]₂[V₆O₁₃(OMe)₆]·2MeOH (3), [Co(phen)(acac)₂]₂[V₆O₁₃(OMe)₆] (4), [Cu(dpa)(acac)]₂[V^IV₂V^V₄O₁₂(OMe)₇] (5), and [Cu(dpa)(acac)(MeOH)]₂[V^IV₂V^V₄O₁₁(OMe)₈] (6) (POV = polyoxovanadate; dpa = 2,2′-dipyridine amine; phen = 1,10-phenanthroline; acac = acetylacetone anion) have been synthesized by controlling the reaction conditions and characterized by single-crystal X-ray diffraction and powder X-ray diffraction analyses, FT-IR spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In compounds 1-4 and 6, Cu or Co complexes and alkoxohexavanadate anions are assembled through electrostatic interactions. Differently, in compound 5, seven-methoxo-substituted Lindqvist-type [V₆O₁₂(OMe)₇]^2- are bridged to Cu complex via terminal O atoms by coordination bonds. All compounds 1-6 exhibit excellent heterogeneous catalytic performance in oxidative desulfurization and CEES ((2-chloroethyl) ethyl sulfide, a sulfur mustard simulant) abatement with H₂O₂ as oxidant. Among them, the catalytic activity of 6 [conv. of DBT (dibenzothiophene) up to 100% in 6 h; conv. of CEES reached 100% and selectivity of CEESO ((2-chloroethyl) ethyl sulfoxide) up to 85% after 4 h] outperforms others and can be reused without losing its activity.

Full text of DOI:10.1021/acs.inorgchem.7b00366

Article
pubs.acs.org/IC
Controllable Synthesis of Lindqvist Alkoxopolyoxovanadate Clusters
as Heterogeneous Catalysts for Sulfoxidation of Sulfides
§
,†,‡
§,†
‡
†
†
,†
Ji-Kun Li,
Jing Dong, Chuan-Ping Wei, Song Yang, Ying-Nan Chi, Yan-Qing Xu,*
,
†
and Chang-Wen Hu*
†Key Laboratory of Cluster Science Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic, School of
Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P.R. China
‡
College of Chemistry and Chemical Engineering, Taishan University, Tai’an 271021, Shandong, P.R. China
*
S Supporting Information
ABSTRACT: Six alkoxohexavanadate-based Cu- or Co-POVs [Cu(dpa)(acac)-
(
(
(
(
H O)] [V O (OMe) ] (1), [Cu(phen)(acac)(MeOH)] [V O (OMe) ] (2), [Co(dpa)-
2 2 6 13 6 2 6 13 6
acac) ] [V O (OMe) ]·2MeOH (3), [Co(phen)(acac) ] [V O (OMe) ] (4), [Cu-
2
2
6
13
6
2 2
6
13
6
I V
V
d p a ) ( a c a c ) ] [ V
V
O 1 2 ( O M e ) 7 ] ( 5 ) , a n d [ C u ( d p a ) ( a c a c ) -
2
2
4
IV
V
MeOH)] [V V O (OMe) ] (6) (POV = polyoxovanadate; dpa = 2,2′-dipyridine
2
2
4
11
8
amine; phen = 1,10-phenanthroline; acac = acetylacetone anion) have been synthesized by
controlling the reaction conditions and characterized by single-crystal X-ray diffraction and
powder X-ray diffraction analyses, FT-IR spectroscopy, element analyses, and X-ray
photoelectron spectroscopy. In compounds 1−4 and 6, Cu or Co complexes and
alkoxohexavanadate anions are assembled through electrostatic interactions. Differently, in
2−
compound 5, seven-methoxo-substituted Lindqvist-type [V O (OMe) ] are bridged to
6
12
7
Cu complex via terminal O atoms by coordination bonds. All compounds 1−6 exhibit
excellent heterogeneous catalytic performance in oxidative desulfurization and CEES ((2-
chloroethyl) ethyl sulfide, a sulfur mustard simulant) abatement with H O as oxidant. Among them, the catalytic activity of 6
2
2
[
conv. of DBT (dibenzothiophene) up to 100% in 6 h; conv. of CEES reached 100% and selectivity of CEESO ((2-chloroethyl)
ethyl sulfoxide) up to 85% after 4 h] outperforms others and can be reused without losing its activity.
2
,6
INTRODUCTION
amount of water. However, it is known that introducing
water is often inevitable in most liquid-phase oxidation
reactions. Therefore, it is essential to explore synthetic methods
for more stable and highly active catalysts based on
alkoxohexavanadates. We have succeeded in combining Pd-
complex cation and alkoxohexavanadates to stabilize the POVs
clusters and enable excellent catalytic activity for oxidation of
■
Polyoxovanadates (POVs) as a unique branch of polyoxome-
talates (POMs), have recently become an area of great interest
because of their enormous structural and chemical diversities
leading to potential applications in many fields, such as
catalysis, redox, molecular magnetism and drugs. Among the
POVs, alkoxopolyoxovanadate has attracted interest because of
its potential catalytic applications and fascinating electronic,
1
12d
benzyl-alkanes. However, the use of noble metal seems to
limit its practical application to some degree. Therefore, to
further obtain the more economical heterogeneous catalyst,
here we moved forward this work to replace the noble ion of Pd
with the transitional metal ions for the consideration of the
potential applications.
On the other hand, reducing the level of sulfur content in
fuel oils has become an attractive scientific field in recent years
for environmental reasons.
ing fuels is responsible for the formation of sulfur oxides (SOx),
which can cause acid rain and lead to the growth of the PM
(particulate matter), a serious environmental problem in
developing country. Moreover, these sulfur-containing com-
pounds can poison the catalysts used to remove hydrocarbons
and nitrogen oxides derived from combustion reactions. Thus,
it is an important work to remove sulfur from the original
2
,3
magnetic, or photochemical properties. The alkoxide ligands
serving to reduce the charge of polyanions are introduced into
this system to stabilize the POVs clusters. Following this
strategy, a series of multidentate trisalkoxo-ligand-substituted
alkoxohexavanadates were synthesized after the first case [(n-
C H ) N] [V O {O NC(CH O) } ] contributed by Zubieta
4
9 4
2
6
13
2
2
3 2
4
and co-workers. Additionally, a surge of methoxo and ethoxo
13−16
Combustion of sulfur-contain-
ligands substituted alkoxohexavanadates including
2
−
5
−
6
2−
7
9
[
[
[
[
V O (OMe) ] , [V O (OMe) ] , [V O (OMe) ] ,
6
13
6
6
12
7
6
11
8
8
+
8
V O (OMe) ], [V O (OMe) ] , [V O (OEt) ],
6
8
nV
11
6
8
11
6
7
12
IV
V
(4−n)
10
V
V
O (O Me) ]
O (OR) ] (R = −Me, n = 0, 1; R = −Et, n
0, 1, 2) have sprung up. In these compounds, however, very
(n = 3, 4, 5, 6),
and
6−n
7
12
IV
V
n+
(4−n)V
(2+n)
7
12
1
1
=
few alkoxohexavanadates examples with respect to their
catalytic properties have been reported, although they are
expected to have excellent performance as oxidation catalyst.
1
2
One important reason is that they are commonly highly
reactive and extremely susceptible to hydrolysis by even a trace
Received: February 9, 2017
©
XXXX American Chemical Society
A
DOI: 10.1021/acs.inorgchem.7b00366
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Inorganic Chemistry
Article
a
Scheme 1. Simplified Representation of the Controlling Synthesis of 1−6
a
Color code: Co, pink; Cu, light blue; V, green; N, blue; O, red; C, gray.
IV
V
materials efficiently and in an environmentally friendly way.
However, the traditional approach to removing sulfur-
containing compounds, hydrodesulfurization (HDS), requires
innovation not only for the rigorous operating conditions (such
as high temperature and high pressure) but also for its
ineffectiveness at removing the refractory sulfur-containing
(acac)(MeOH)] [V V O (OMe) ] (6) by controlling the
2 2 4 11 8
synthetic or crystallization conditions carefully. The new
alkoxohexavanadate clusters were further used as highly
efficient heterogeneous catalysts in sulfoxidation of sulfides
with the environmentally benign H O as the terminal oxidant,
which has potential applications in oxidative desulfurization of
fuel oil and sulfur mustard abatement.
2
2
17,18
compounds, in particular, DBT, and its derivatives.
Thus, it
is necessary to develop non-HDS methods, which have been
1
9
long desired. Oxidative desulfurization (ODS) is regarded as a
promising strategy to obtain clean fuels because the refractory
sulfur-containing compounds can be oxidized into the
corresponding sulfoxides and sulfones under mild conditions
RESULTS AND DISCUSSION
Synthesis. All compounds were synthesized by the reaction
■
of VO(acac) , Cu(OAc) , or Co(OAc) and N-donor ligands in
2
2
2
the presence of Et N and methanol. As shown in Scheme 1,
3
20
12b,21
using an ionic liquid or a heteropolyacid
as catalyst,
compounds 1−6 all contain a so-called Lindqvist type
alkoxohexavanadate anion. As an organic base, Et N might
which can be further removed by extraction. Therefore, we
anticipated the alkoxohexavanadates species would also be a
good candidate because of its good oxidation catalytic ability
according to our previous work. Another case of bis(2-
chloroethyl)sulfide, as typical sulfur-containing compound, is
3
facilitate the deprotonation of methanol, and thus, six-methoxo-
2
−
substituted [V O (OMe) ] cluster (in 1, 2, 3, and 4), seven-
6
13
6
2
−
methoxo-substituted [V O (OMe) ] (in 5) and eight-
6
12
7
2
−
methoxo-substituted [V O (OMe) ] cluster (in 6) can be
6
11
8
22
the main component of sulfur mustard (mustard gas or HD).
obtained by carefully controlling the adding amounts of Et N.
3
The decontamination of sulfur mustard to nontoxic products
has also attracted significant attention. The common abatement
methodologies are oxidation, dehydrohalogenation, and hydrol-
During the synthetic process, by changing the kinds of
transition-metal ions (Cu2+ in 1 and 2, Co in 3 and 4) and
the N-donor ligands (dpa in 1 and 3, phen in 2 and 4) only
2+
2
3
ysis. Among such methods, partial oxidation of sulfur mustard
under the equal amounts of Et N, we obtained compounds 1−
3
24
2−
to the corresponding sulfoxide is the most promising route.
With all the above in mind, as well as to advance our research
4 all including a six-methoxo-substituted [V O (OMe) ]
6
13
6
cluster. From the above result, we can conclude that the
countercation part has little effect on the structure of
hexavanadate anion. Interestingly, due to the variability of the
valence, Co2+ was oxidized to Co under the synthetic
conditions of 3 and 4, which result in the different coordination
1
2d,25
in the field of oxidative catalytic activity of POVs
and
pursue more economical catalysts for the potential application,
we synthesized six Cu- or Co-complexes instead of noble Pd-
3+
complex combined Lindqvist alkoxohexavanadates [Cu(dpa)-
V
2+
(
(
(
(
[
acac)(H O)] [V O (OMe) ] (1), [Cu(phen)(acac)-
environment with Cu in 1 and 2. To synthesize compounds 5
2
2
6
13
6
V
M e O H ) ] [ V O 1 3 ( O M e ) 6 ] ( 2 ) , [ C o ( d p a ) -
and 6, we gradually increased the amounts of Et N under the
2
6
3
V
acac) ] [V O (OMe) ]·2MeOH (3), [Co(phen)-
same synthetic conditions of 1. When the reaction completed,
large amounts of precipitate were formed in the reactor of 5, yet
the solution of 6 remained clear. The precipitates were
2
2
6
13
6
V
a c a c ) 2 ] 2 [ V
Cu(dpa)(acac)] [V V O (OMe) ] (5), and [Cu(dpa)-
O 1 3 ( O M e ) 6
]
( 4 ) ,
6
IV
V
2
2
4
12
7
B
DOI: 10.1021/acs.inorgchem.7b00366
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Inorganic Chemistry
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2
−
2−
Figure 1. Methoxo-substituted hexavanadate anion in 1−6. (a) [V O (OMe) ] in 1, 2, 3, and 4; (b) [V O (OMe) ] in 5; and (c)
6
13
6
6
12
7
2
−
[
V O (OMe) ] in 6.
6 11 8
redissolved with DMSO and crystals of compound 5 were
obtained after about 2 weeks. In addition, compounds 1−4 and
of 1 was formed (Figure S2a). As a result of the replacement of
dpa by phen ligand, only one type of hydrogen bond exists in
6
were all directly crystallized from the mother liquor.
compound 2. The distance of the μ -oxo (O6) and O3 (derived
2
FT-IR Spectra. IR spectroscopy can provide helpful
from coordinated MeOH) is 2.918(6) Å (Figure S2b). There is
also only one type of hydrogen bonding interaction in
information for the analysis of alkoxopolyoxovanadium clusters.
−1
2−
Particularly, the 400−1200 cm region is of interest and
contains absorption bands due to metal−oxygen stretching
vibrations, which are characteristic of POMs spectra in general.
As can be seen from the IR spectra of compounds 1−6 (see
Figure S1), the apparent absorption bands in the range of
compound 3 between the μ -oxo of [V O (OMe) ] and
2
6
13
6
the amino group (derived from dpa ligand) with the O···N
distance of 2.805(3) Å (Figure S2c). No strong hydrogen bond
exists in 4 because of the absence of dpa ligand and other
coordinated solvent molecules. From the above result, we can
see that the different N-donor ligands and coordination mode
of the transition-metal center has a great impact on the
supramolecular structures of compounds 1−4.
−
1
−1
1
000−1100 cm and 950−1000 cm region are correspond8-
ing to the O−CH and VO stretching modes, respectively.
3
−1
The 540−650 cm region are ascribed to the V−O−V
7
−1
bending. Further absorption located in the 935−950 cm
region are attributed to VO vibration, whereas the 750−785
Crystal Structure of 5. By increasing the amount of base
Et N), compound 5 instead of 1 was obtained under the same
3
(
−1
cm region is assigned to V−O−V bridging fragments and the
reaction conditions. Interestingly, the SXRD analysis shows that
the number of the methoxo in 5 is found to be seven to form
−1
7,26
6
50−695 cm region to V-OCH fragments, respectively.
3
Crystal Structures of 1−4. Single-crystal X-ray diffraction
2−
[
[
V O (OMe) ] polyanion, as scarcely reported except for
6
12
7
(
SXRD) shows that compounds 1−4 all consist of one
−
6
2+
V O (OMe) ] . The five-coordinated Cu center is ligated
2
−
6
12
7
Lindqvist type [V O (OMe) ] polyanion (Figure 1a),
−
6
13
6
12d
by two N atoms from one dpa, two O atoms from acac anion,
and the third O atom derived from the vanadate cluster. In this
compound, the value of structural index τ is 0.023 for Cu1,
indicating that it is in slightly distorted square pyramid
which is comparable to [Pd(dpa)(acac)] [V O (OMe) ]
2
6
13
6
and [{VO(bmimpm)(acac) }{V O (OMe) }] (bmimpm =
2
6
13
6
5
a
bis(1-methylimidazol-2-yl)-4-methoxyphen-1-ylmethanol).2
+
The countercation parts in 1−4 are two five-coordinated Cu
2−
1 and 2) or six-coordinated Co3+ (3 and 4) complexes,
geometry. As part of the [V
O12(OMe)
6
]
7
ion, one terminal
(
2
+
oxygen atom O3 bridges the outer-shell Cu atom (Figure 2).
Remarkably, the observed distance between V1 and O3 is
respectively. The five-coordinated Cu center is ligated by two
N atoms from one dpa (in 1) or phen (in 2), two O atoms
−
from acac anion and one O atom from a water or methanol
molecule. The structural index τ, [β−α]/60 with α and β being
two largest angles, is zero for an ideal square pyramid and
27
becomes unity for an ideal trigonal bipyramid. In compounds
and 2, the value of structural index τ are 0.097 for 1 and 0.017
for 2, respectively, indicating that they are in slightly distorted
1
3
+
square pyramid geometry. The Co center in 3 and 4 has a
distorted-octahedral coordination environment, which bounds
−
to four O atoms from two acac anions and two N atoms from
one dpa (in 3) or phen (in 4). The BVS calculations show that
the oxidation states of all the vanadium atoms in compounds
1
−4 are +V, which are in good agreement with the charge
balance of the compounds (Table S1).
Besides electrostatic interactions, there exist strong hydro-
gen-bonding interactions between Cu- or Co-complex and
polyanions in compounds 1−3. Because of the diverse
coordination environment, the hydrogen bonds in 1−3 are
different from each other accordingly. In 1, two μ -oxo atoms of
2
2−
[
+
V O (OMe) ] (O8 and O9A, symmetry code: A, −x+1, −y
6
13
6
2, −z+1) connect with O3 (derived from coordinated H O)
2
and N3 (derived from dpa ligand) through hydrogen bonds
with the O···O and O···N distances of 2.767(8) Å and 2.760(7)
Å, respectively, and thus, a 1D chain supramolecular structure
Figure 2. Crystal structure of 5. All H atoms were omitted for clarity.
C
DOI: 10.1021/acs.inorgchem.7b00366
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Inorganic Chemistry
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Figure 3. 2D planar supramolecular structure of 5. The following symmetry transformation was used to generate equivalent atoms: B, −x+1/2, y−1/
, −z+1/2.
2
1
2d
1
.599(6) Å, which is expected for vanadyl bonds (VO),
ences in bond lengths and bond angles.
The BVS
whereas the Cu1−O3 bond is long (2.416(6) Å) because of the
calculations (Table S1) and XPS analysis (Figure S3)
investigations reveal that compound 6 also contains the
} to balance the charge of the cation.
There also exist two kinds of hydrogen bonds in compound
2
+
Jahn−Teller effect of the Cu cation. The two copper
complexes are attached to the hexavanadate core by O3
bridges as shown in Figure 2. To balance the charge of the
cation in 5, a mixed-valence state of vanadate anion containing
IV
V
mixed-valent {V 2
V
4
2−
6. Two μ
-oxo atoms of [V
O
6
11(OMe)
]
polyanion (O2C
2
8
IV
V
two V and four V are needed, which is further identified by
both BVS calculations (Table S1) and XPS analysis (Figure
S3).
and O4D, symmetry code: C, x+1, y, z; D, −x, −y+2, −z+1)
connect with O13 (derived from coordinated MeOH) and N2
(derived from dpa ligand) through hydrogen bonds with the
O···O and O···N distances of 2.753(1) Å and 2.684(1) Å,
respectively, forming a 1D chain supramolecular structure
(Figure S2d).
Catalytic Activities of Cu or Co-POVs. The oxidation of
DBT was selected as a model reaction to evaluate the catalytic
activities of Cu- or Co-POVs (Scheme 2). The reaction was
In addition, the coordination bonds between Cu center and
2−
μ -oxo atoms of [V O (OMe) ] , along with hydrogen bonds
2
6
12
7
formed by μ -oxo atoms and −NH groups with the O10B···N3
2
(
2
symmetry code: B, −x+1/2, y−1/2, −z+1/2) distance of
.799(8) Å), leads to the resultant 2D planar supramolecular
structure (Figure 3).
Crystal Structure of 6. Compared with the synthetic
procedure of compound 5, we further increased the adding
Scheme 2. Oxidation of DBT Using POVs as Catalysts under
Mild Conditions
amounts of Et N but keeping the other conditions unchanged.
3
+
Compound 6, consisting of two [Cu(dpa)(acac)H O] and one
V O (OMe) ] polyanion (Figure 1c), was obtained from
6 11 8
2
2−
[
the mother liquor. Herein, the interaction between Cu-complex
and alkoxohexavanadate clusters is different from the
coordination interaction of 5 but similar to 1−4 to be
cationic−anionic electrostatic interaction, which is caused by
one of the coordination sites of Cu in 6 is water oxygen atom
investigated first in acetonitrile with Cu-POVs catalyst
[Cu(dpa)(acac)(MeOH)] [V O (OMe) ] (6) using H O as
2−
instead of terminal oxygen derived from [V O (OMe) ] in
6
12
7
2
6
11
8
2
2
5. The geometry of five coordinated Cu1 is also a slightly
oxidant. The gas chromatography (GC) analyses showed that
DBT could be completely transformed to the corresponding
sulfoxides and sulfones at 40 °C in 1.5 h. Thus, acetonitrile was
selected as the appropriate solvent for the ODS process, in
which the sulfur content was set by fixing the dosage of DBT (S
content: 1000 ppm). A typical ODS process was performed as
following: the model oil (decalin containing DBT) and
acetonitrile mixture was stirred at 40 °C for 10 min, and
subsequently, catalyst and 30% aqueous H O were added to
distorted square pyramid indicated by the value of structural
index τ being 0.018. Concerning with the polyanion moiety, it
2−
belongs to the eight-methoxo-substituted α-[V O (OMe) ] .
6
11
8
All the eight methoxo groups are distributed in a symmetrical
mode by taking the central O of Lindqvist cluster as the center,
which is similar to the polyanion structure in our reported
examples [Pd(dpa)(acac)] [V O (OMe) ] and [Pd-
2
6
11
8
(
DMAP) (acac)] [V O (OMe) ]·H O with only slight differ-
2 2 6 11 8 2
2
2
D
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Inorganic Chemistry
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initiate the reaction. At various time intervals, the mixture was
quantitatively analyzed by GC. The different conversion of
DBT catalyzed by 1−6 showed that the best result was
achieved when using 6 as catalyst (Table 1, entries 1−6). From
Figure 4 we can see that above 96% DBT was oxidized to the
corresponding sulfoxide and sulfone after 4 h. Another 2 h later,
the conversion of DBT reached 100% under the relatively mild
conditions. The catalytic result of compounds 1−6 were almost
the same as shown in Table 1 (entries 1−6), which indicated
Table 1. Catalytic Oxidative Desulfurization of DBT by
that the active center of the catalysts was the {V } core and the
6
a
Different Catalysts
slight difference in the types of the counter cations and the
number of substituted methoxo had no obvious effect on the
terminal catalytic performance of all the catalysts.
Compound 6 with the best catalytic activity was selected as a
representative to further investigate the ODS process. The test
without catalyst (blank test) showing a negligible DBT
removing (Figure 4), which demonstrated that the catalysts
played a vital role in the ODS system. To further probe the role
of the Cu-complex cation and hexavanadate anion in the
entry
catalyst
conv. (%)
reaction system
1
2
3
4
5
6
7
8
9
1
98.5
98
heterogeneous
heterogeneous
heterogeneous
heterogeneous
heterogeneous
heterogeneous
homogeneous
homogeneous
_
2
3
97
4
97
5
96.5
100
100
5
6
[NHEt ] [V O (OMe)]
6
3
2
6
13
catalytic reaction, control experiments were conducted. When
Cu(OAc) +dpa
2
12d
[
NHEt ] [V O (OMe) ]
was used as homogeneous
3
2
6
13
6
blank
<5
catalyst (Table 1, entry 7), the conversion of DBT reached
00% within 6 h, proving the present catalysis of 6 originated
a
Reaction conditions: model oil (2 mL), catalyst (1.5 mol %),
acetonitrile (2 mL), and 30% H O (0.5 mmol) at 40 °C for 6 h.
1
2
2
from the alkoxohexavanadate anion. When the mixture of
Cu(OAc) and dpa with the molar ration of 1:1 was involved
2
(
Table 1, entry 8), the conversion (5%) was comparable to that
of blank experiment. The above results indicated that the Cu-
complex nearly had no contribution to accelerate the ODS
reaction rate. The combination of Cu-complex and alkoxohex-
avanadate cluster through electrostatic interaction or coordina-
tion bonds led to the formation of heterogeneous catalysts.
Fortunately, the activity of alkoxohexavanadate was not reduced
by the complexation.
To further elucidate the heterogeneity of 6 in the oxidative
system, a hot leaching test was carried out. The solid catalyst 6
was filtrated off from the mixture after 1 h of reaction, and the
filtrate was subsequently stirred at 40 °C for another 5 h. GC
analysis of the resulting reaction mixture showed a negligible
conversion after filtration (Figure S4). Atomic absorption
analysis shows that there were no copper and vanadium ions in
the filtrate of the reaction system (S5 in the Supporting
Information). These results collectively confirmed that the
catalytic system is heterogeneous in nature. Furthermore, 6 can
be easily separated by centrifugation after the reaction and can
be recycled at least 4 times without considerable decrease in
activity (DBT conversion of the forth run remained above 98%,
Figure 4. Time profile for the ODS using 6 as catalyst. Reaction
conditions: model oil (2 mL), 6 (1.5 mol %), acetonitrile (2 mL), and
3
0% H O (0.5 mmol) at 40 °C for 6 h. Black: with catalyst; red:
2 2
blank.
Figure 5. Recycling of 6 for oxidative desulfurization of DBT.
E
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Figure 5). The PXRD patterns (Figure S6) together with IR
spectrum (Figure S7) before and after catalysis demonstrated
that the structure and the crystallinity of 6 was maintained
during the reaction process.
Scheme 3. Proposed Mechanism of the ODS Process in the
Biphasic System
From the point of practical applications, the broad-spectrum
removing of refractory sulfur-containing compounds in fuel oils
is desired. Benzothiophene (BT) and 4,6-dimethyldibenzothio-
phene (4, 6-DMDBT) were also used to assess the general
applicability of 6. As shown in Table 2, BT and 4, 6-DMDBT
Table 2. Results of Oxidative Desulfurization of DBT and Its
a
Derivatives Catalyzed by 6 using H O Oxidant
2
2
of 6 in the selective oxidation system (Scheme 4). To obtain
higher sulfoxide selectivity, diluted H O (3% in water) was
2
2
Scheme 4. Oxidative Abatement of CEES to CEESO and
CEESO Catalyzed by Compound 6
2
a
Reaction conditions: model oil (2 mL), catalyst (1.5 mol %),
acetonitrile (2 mL) and 30% H O (0.5 mmol) at 40 °C.
2
2
used, which could also be used as a disinfectant for cuts and
abrasion. As shown in Figure 6, CEES was converted
were converted completely after 8 and 6.5 h, respectively. The
above results show that the nature of the substrates is a critical
factor influencing the desulfurization process. BT shows the
lowest oxidative activity due to the lowest electron density on
the S atom. Yet, compared with 4,6-DMDBT, DBT with lower
electron density on the S atom shows a higher conversion to
the corresponding suloxide and sulfone. The result indicates
that the reactivity of the substrates not only ascribe to the
electron density of sulfur atom but also to the steric hindrance
(
methyl group) on the sulfur atom, which is in line with the
28,29
previous researches.
The proposed mechanism of the ODS process in the
presence of 6 has also been preliminary studied. Comparative
experiment using H O and 6 in only decalin showed a
2
2
negligible conversion because of the poor solubility of H O in
2
2
decalin. In acetonitrile, however, DBT was transformed
completely within 1.5 h under the same conditions as the
early experiment showed. An additional experiment showed
that the distribution coefficient of DBT in equivalent
acetonitrile and decalin was about 0.82, and it remained almost
unchanged when the concentration of DBT reduced to half
Figure 6. Catalytic abatement of CEES with 6. Black: CEES; green:
CEESO; red: CEESO
0.034 mmol), 1,3-dichlorobenzene (0.25 mmol), 3% H O (0.525
. Reaction conditions: CEES (0.5 mmol), 6
2
(
2
2
mmol), and acetonitrile (4 mL) at room temperature for 4 h.
(Table S3). These results further supported our speculation
that acetonitrile was an efficient solvent in the biphasic system,
which is appropriate for liquid−liquid extraction as well as
suitable for oxidative transformation. As shown in Scheme 3,
the ODS process consists of two steps: DBT was extracted by
acetonitrile from the decalin phase, and then, in the presence of
completely within 4 h. During the first hour, CEESO was the
only product as long as CEES was still present. After reaction
for 1 h, a small amount of CEESO was further oxidized to the
CEESO , which is as toxic as the pristine sulfur mustard.
2
6
, it was oxidized to the sulfoxide or sulfone, which were
Fortunately, the selectivity of CEESO was still above 85% when
CEES was completely consumed, and no dangerous poly-
merized sulfur-containing compounds were detected. As a
heterogeneous catalyst, 6 can be reused at least three times
without any appreciable loss of its high catalytic performance in
the CEES oxidative abatement process (Figure S8).
maintained in the acetonitrile phase and separated from the
model oil.
For the sulfur mustard abatement, taken into account the
high toxicity of real agent, a sulfur mustard simulant, CEES, was
selected as the substrate to further study the catalytic activities
F
DOI: 10.1021/acs.inorgchem.7b00366
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Table 3. Crystallographic Data for Compounds 1−6
1
2
3
4
5
6
formula
Mr
C H N O Cu V
C H N O Cu V
C H N O Co V
C H N O Co V
C H N O Cu V
C H N O Cu V
40 64 6 25 2 6
3
6
54
6
25
2
6
42 56
4
25
2
6
48 72
6
29
2
6
50 62
4
27
2
6
37 53
6
23
2
6
1403.57
triclinic
P-1
1449.62
1620.62
1574.53
1382.57
1461.69
cryst syst
space group
T (K)
triclinic
monoclinic
P2(1)/c
monoclinic
P2(1)/c
monoclinic
C2/c
triclinic
P-1
P-1
296(2) K
9.831(3)
12.003(4)
13.179(4)
74.939(6)
70.669(6)
68.287(6)
1346.6(7)
1
296(2) K
296(2) K
10.6093(3)
12.9751(4)
23.5982(7)
90
296(2) K
11.0869(4)
11.1026(4)
24.7041(9)
90
296(2) K
22.1519(6)
14.6490(6)
18.5252(6)
90
296(2) K
10.097(9)
11.715(11)
12.835(12)
78.426(16)
73.825(17)
72.759(16)
1381(2)
1
a (Å)
10.8434(18)
11.3914(18)
12.250(2)
82.018(6)
81.561(6)
64.109(5)
1341.8(4)
1
b (Å)
c (Å)
α (deg)
β (deg)
γ (deg)
V (Å3)
92.4320(10)
90
90.3780(10)
90
121.271(2)
90
3245.52(17)
2
3040.85(19)
2
5138.1(3)
4
Z
Dcalc (g cm−3)
F(000)
R1 [I > 2σ(I)]
1.731
1.794
1.658
1.720
1.787
1.757
708
732
1652
1596
2788
742
0.0707
0.0570
0.0397
0.1081
0.0476
0.1177
1.076
0.0462
0.1191
0.0560
0.1285
1.099
0.0540
0.1688
0.0635
0.1773
1.117
0.0950
wR [I > 2σ(I)]
2
0.1458
0.1343
0.2604
R1(all data)
0.1100
0.1064
0.1546
wR (all data)
2
0.1739
0.1581
0.3163
GOF
1.043
0.993
1.012
CCDC no.
1523620
1464434
1460874
1469333
1523621
940415
CONCLUSIONS
suitable for X-ray diffraction grew upon after leaving the solution to
■
stand for a week. Yield: 65.5%. Anal. Calcd for C H N O V Cu : C,
36
54
6
25
6
2
In summary, by controlling the reaction conditions, we have
synthesized six methoxohexavanadate compounds. The hexa-,
hepta-, and octa-substituted methoxohexavanadate clusters
3
4
0.81 ; H, 3.88 ; N, 5.99 ; V, 21.78 ; Cu, 9.05. Found: C, 31.02; H,
.11; N, 5.86; V, 22.04; Cu, 9.25. IR spectrum, ν (cm ): 3430 (O−H,
−1
s), 3190 (N−H, m), 3076 (Ar−H, w), 1645 (s), 1582 (CN, s), 1525
(s), 1481 (CC, s), 1430 (s), 1235 (s), 1166 (s), 1034 (s), 958 (s),
769 (s), 655400 (s), 450 (Cu−N, m).
could be obtained through varying amounts of Et N. The
3
introduction of Cu- or Co-complexes make compounds 1−6
more stable, and they can be used as heterogeneous catalyst in
the selective oxidation of sulfides using hydrogen peroxide with
high catalytic activities. Specifically, compound 6 exhibits
extraordinary efficiency in oxidative desulfurization (conv. of
DBT up to 100% in 6 h) and CEES abatement (conv. of CEES
reached 100% and selectivity of CEESO up to 85% after 4 h)
and can be reused by filtration. Investigations on the use of
these methoxohexavanadate catalysts for other potential
catalytic reactions are in progress.
Synthesis of [Cu(phen)(acac)(MeOH)] [V O13(OMe) ] (2). The
2 6 6
synthetic procedure was the same as for compound 1, except that
1
,10-phenanthroline (36.1 mg, 0.2 mmol) was used instead of 2,2′-
dipyridine amine. The reaction mixture was stirred for 12 h. From the
resulting solution, green crystals suitable for X-ray diffraction grew
upon after leaving the solution to stand for a week. Yield: 64.2%. Anal.
Calcd for C H N O V Cu : C, 34.8; H, 3.89; N, 3.86; V, 21.11; Cu,
42
56
4
25
6
2
8
.77. Found: C, 34.92; H, 3.91; N, 4.05; V, 22.38; Cu, 9.71. IR
−1
spectrum, ν (cm ): 3439 (O−H, s), 2914 (Ar−H, w), 1626 (s), 1581
CN, s), 1512 (s), 1428 (CC, s), 1384 (s), 1143 (w), 1106 (w),
035 (s), 954 (s), 846 (s), 757 (s), 719 (w), 668 (s), 445 (Cu−N, w).
Synthesis of [Co(dpa)(acac) [V 13(OMe) ]·2MeOH (3). The
(
1
EXPERIMENTAL SECTION
General Methods and Materials. All reagents and solvents for
synthesis were purchased from commercial suppliers and used as
received unless otherwise noted. The metal content of the compounds
−6 was measured by inductively coupled plasma (ICP) on a JY-
ULTIMA2 analyzer. The FT-IR spectra were recorded from KBr
pellets in the range of 4000−400 cm on a Nicolet 170 SXFT/IR
spectrometer. The powder X-ray diffraction pattern was collected by
using a Rigaku D/max-2550 diffractometer with Cu Kα radiation and
the XPS spectra were recorded on an ESAY ESCA spectrometer with
an Mg Kα achromatic X-ray source. The resulting mixture was
analyzed by GC-MS and GC using naphthalene as internal standard
substrate after the catalytic reaction was completed. The GC analyses
were performed on Shimadzu GC-2014C with a FID detector
equipped with an Rtx-1701 Sil capillary column. The GC-MS spectra
were recorded on Agilent 7890A-5975C at an ionization voltage of
]
2
2
O
6
6
■
synthetic procedure was similar to for compound 1, only replacing
Cu(OAc) ·H O with Co(OAc) ·4H O (49.8 mg, 0.2 mmol). The
2
2
2
2
reaction mixture was stirred for 12 h. From the resulting solution,
brown crystals suitable for X-ray diffraction grew upon after leaving the
solution to stand for a week. Yield: 60.4%. Anal. Calcd for
C H N O V Co : C, 35.57; H, 4.48; N, 5.19; V, 18.86; Co, 7.27.
1
−
1
48
72
6
29
6
2
Found: C, 35.52; H, 4.15; N, 5.35; V, 17.38; Co, 6.92. IR spectrum, ν
−1
(
cm ): 3443 (O−H, s), 3182 (N−H, w), 3064 (Ar−H, w), 1642 (s),
564 (CN, s), 1526 (s), 1473 (CC, s), 1375 (s), 1290 (s), 1166
s), 1030 (s), 951 (s), 755 (s), 657 (s), 448 (Co−N, m).
Synthesis of [Co(phen)(acac) ] [V O (OMe) ] (4). The synthetic
1
(
2 2
6
13
6
procedure was similar to for compound 2, only replacing Cu(OAc)2·
H O with Co(OAc) ·4H O (49.8 mg, 0.2 mmol). The reaction
2
2
2
mixture was stirred for 12 h. From the resulting solution, brown
crystals suitable for X-ray diffraction grew upon after leaving the
solution to stand for a week. Yield: 61.2%. Anal. Calcd for
1
200 V. The C, H, and N elemental analyses were conducted on
PerkinElmer 240C elemental analyzer.
Synthesis of [Cu(dpa)(acac)(H O)] [V O (OMe) ] (1). VO(acac)
0.6 mmol, 159.1 mg) and triethylamine (0.6 mmol) were added to 8
C
H
62
N
O
27
V
6
Co
: C, 38.14; H, 3.97; N, 3.56; V, 19.41; Co, 7.49.
50
4
2
Found: C, 37.41; H, 3.40; N, 3.73; V, 18.57; Co, 7.52. IR spectrum, ν
2
2
6
13
6
2
−1
(
(cm ): 3052 (Ar−H, w), 1642 (w), 1570 (CN, s), 1519 (s), 1428
(CC, s), 1369 (s), 1284 (s), 1030 (s), 953 (s), 945 (s), 847 (s), 768
(s), 716 (m), 664 (s), 454 (Co−N, m).
mL of methanol. The resulting solution was stirred at 40 °C for 20
min, and then 2, 2′-dipyridine amine (34.3 mg, 0.2 mmol), Cu(OAc) ·
2
H O (39.9 mg, 0.2 mmol) were successively added. The reaction
Synthesis of [Cu(dpa)(acac)] [V O (OMe) ] (5). VO(acac) (0.6
2
2
6
12
7
2
mixture was stirred for 12 h. From the resulting solution, green crystals
mmol, 159.1 mg) and triethylamine (0.7 mmol) were added to 8 mL
G
DOI: 10.1021/acs.inorgchem.7b00366
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
of methanol. The resulting solution was stirred at 40 °C for 20 min,
and then 2,2′-dipyridine amine (34.3 mg, 0.2 mmol), Cu(OAc) ·H O
AUTHOR INFORMATION
■
2
2
Corresponding Authors
E-mail: cwhu@bit.edu.cn. Tel: +86-10-68912631. Fax: +86-
0-68912631.
*E-mail: xyq@bit.edu.cn.
ORCID
Chang-Wen Hu: 0000-0002-1344-161X
Author Contributions
J.K.L. and J.D. contributed equally
(
39.9 mg, 0.2 mmol) were successively added. The reaction mixture
*
was stirred for 12 h, and the precipitate was filtrated and redissolved in
DMSO. After about 2 weeks, brown crystals suitable for X-ray
diffraction were obtained. Yield: 63.5%. Anal. Calcd for
C H N O V Cu : C, 32.14; H, 3.86; N, 6.08; V, 22.11; Cu, 9.19.
1
3
7
53
6
23
6
2
Found: C, 31.65; H, 3.91; N, 6.12; V, 21.06; Cu, 9.25. IR spectrum, ν
−1
(
cm ): 3128 (N−H, w), 3076 (Ar−H, w), 1636 (s), 1585 (CN, s),
1
520 (s), 1474 (CC, s), 1390 (s), 1273 (s), 1163 (s), 1027 (s), 955
§
(
s), 787 (s), 728 (w), 650 (s), 585 (s), 448 (Cu−N, m).
Synthesis of [Cu(dpa)(acac)(MeOH)] [V O (OMe) ] (6). VO-
2
6
11
8
Notes
(
acac) (0.6 mmol, 159.1 mg) and triethylamine (0.8 mmol) were
2
The authors declare no competing financial interest.
added to 8 mL of methanol. The resulting solution was stirred at 40
C for 20 min, and then 2,2′-dipyridine amine (34.3 mg, 0.2 mmol),
Cu(OAc) ·H O (39.9 mg, 0.2 mmol) were successively added. The
°
ACKNOWLEDGMENTS
2
2
■
(
reaction mixture was stirred for 12h. From the resulting solution, green
crystals suitable for X-ray diffraction grew upon after leaving the
solution to stand for a week. Yield: 62.2%. Anal. Calcd (found) for
C H N O V Cu : C, 32.87; H, 4.41; N, 5.75; V, 20.91; Cu, 8.69.
This work was financially supported by the NNSFC
21231002, 21671019), the 111 Project (B07012), 973
Program (2014CB932103), the Natural Science Foundation
of Shandong Province (ZR2013BL012), Taian Municipal
Science and Technology project (2015GX2057), the Talent
Introduction Project of Taishan University (Y2015-1-009), and
the Research Foundation of Beijing Institute of Technology
(No. 20151942007).
4
0
64
6
25
6
2
Found: C, 32.65; H, 4.58; N, 5.56; V, 20.82; Cu, 8.52. IR spectrum, ν
−
1
(
1
(
cm ): 3325 (O−H, w), 3182 (N−H, m), 3068 (Ar−H, w), 1629 (s),
572 (CN, s), 1544 (s), 1459 (CC, s), 1255 (s), 1168 (s), 1035
s), 953 (s), 942 (s), 916 (s), 785 (s), 675 (s), 445 (Cu−N, m).
X-ray Crystallography. Single-crystal X-ray diffraction data for
compounds 1−6 were conducted on a Bruker-AXS CCD diffrac-
tometer equipped with a graphite-monochromated Mo Kα radiation
REFERENCES
■
(λ = 0.71073 Å) at 296 K. All absorption corrections were applied
(
1) (a) Crans, D. C.; Smee, J.; Gaidamauskas, E.; Yang, L. The
chemistry and biochemistry of vanadium and the biological activities
exerted by vanadium compounds. Chem. Rev. 2004, 104, 849−890.
(b) Aureliano, M.; Crans, D. C. Decavanadate (V O ) and
oxovanadates: Oxometalates with many biological activities. J. Inorg.
Biochem. 2009, 103, 536−546. (c) Seliverstov, A.; Streb, C. A new class
of homogeneous visible-light photocatalysts: Molecular cerium
vanadium oxide clusters. Chem. - Eur. J. 2014, 20, 9733−9738.
d) Monakhov, K. Y.; Bensch, W.; Ko
functionalised polyoxovanadates. Chem. Soc. Rev. 2015, 44, 8443−
483. (e) Zhang, Y.; Wang, X.; Li, S.; Song, B.; Shao, K.; Su, Z. Ligand-
using the multiscan technique. The structures were solved by the
direct method and refined through full-matrix least-squares techniques
2
method on F using the SHELXTL 97 crystallographic software
6
‑
30,31
10 28
package.
The hydrogen atoms of the organic ligands were refined
as rigid groups. Crystallographic data for compounds 1−6 are
summarized in Table 3. The crystallographic data have been deposited
with the Cambridge Crystallographic Data Centre (CCDC) as entries
1
9
523620 (1), 1464434 (2), 1460874 (3), 1469333 (4), 1523621 (5),
40415 (6). The selected bond lengths and bond angles of
(
̈
gerler, P. Semimetal-
compounds 1−6, please see Table S2.
8
Catalytic Oxidative Desulfurization Process (ODS). DBT was
dissolved in decalin to produce the model oil (S content: 1000 ppm).
The mixture of model oil (2 mL) and acetonitrile (2 mL) was stirred
at 40 °C for 10 min. After that, catalyst (1.5 mmol %) and 30%
aqueous H O (0.5 mmol) were added. The reaction was monitored
directed assembly of polyoxovanadate-based metal-organic polyhedra.
Inorg. Chem. 2016, 55, 8770−8775. (f) Zhang, H. M.; Yang, J.; Kan, W.
Q.; Liu, Y. Y.; Ma, J. F. Photocatalytic properties and luminescent
sensing for Cr3 cations of polyoxovanadates-based inorganic-organic
hybrid compounds with multiple lewis basic sites. Cryst. Growth Des.
+
2
2
by GC at various time intervals. Catalytic abatement of CEES: CEES
2
(
016, 16, 265−276.
2) Hayashi, Y. Hetero and lacunary polyoxovanadate chemistry:
Synthesis, reactivity and structural aspects. Coord. Chem. Rev. 2011,
55, 2270−2280.
3) (a) Zueva, E. M.; Borshch, S. A.; Petrova, M. M.; Chermette, H.;
Kuznetsov, A. M. Ferromagnetic coupling in a mixed-valence
hexavanadate core: Quantum-chemical forecast. Eur. J. Inorg. Chem.
2007, 2007, 4317−4325. (b) Kodama, S.; Taya, N.; Inoue, Y.; Ishii, Y.
Synthesis and interconversion of V , V , and V oxide clusters:
(
0.5 mmol) and 1, 3-dichlorobenzene (internal standard, 0.25 mmol)
was dissolved in acetonitrile (4 mL), followed by addition of
compound 6 (0.034 mmol). After stirring the mixture for 2 min at
room temperature, 3% aqueous H O (0.525 mmol) was added
2
(
2
2
dropwise. The reaction was monitored by GC at various time intervals.
ASSOCIATED CONTENT
■
4
7
8
*
S
Supporting Information
unexpected formation of neutral heptanuclear oxido(alkoxido)-
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.7b00366.
t
vanadium(V) clusters [V O (OR)(4,4′- Bubpy) ] (R = Et,
7
17
3
MeOC H ). Inorg. Chem. 2016, 55, 6712−6718. (c) Zhang, Y. T.;
2
4
Wang, X. L.; Li, S. B.; Gong, Y. R.; Song, Q. S.; Shao, K. Z.; Su, Z. M.
Anderson-like alkoxopolyoxovanadate clusters serving as unprece-
dented second building units to construct metal-organic polyhedra.
Chem. Commun. 2016, 52, 9632−9635.
Some structural figures, X-ray powder diffraction
patterns, IR spectra, XPS spectra and ICP analysis
(
4) Chen, Q.; Zubieta, J. Synthesis and structural characterization of a
polyoxovanadate coordination complex with a hexametalate core: [(n-
(
PDF)
X-ray crystallographic data (CIF)
X-ray crystallographic data (CIF)
X-ray crystallographic data (CIF)
X-ray crystallographic data (CIF)
X-ray crystallographic data (CIF)
X-ray crystallographic data (CIF)
C H ) N] [V O {O NC(CH O) } ]. Inorg. Chem. 1990, 29, 1456−
4
9
4
2
6
13
2
2
3 2
1458.
(
5) (a) Piepenbrink, M.; Triller, M. U.; Gorman, N. H. J.; Krebs, B.
Bridging the gap between polyoxometalates and classic coordination
compounds: A novel type of hexavanadate complex. Angew. Chem., Int.
Ed. 2002, 41, 2523−2525. (b) Domae, K.; Uchimura, D.; Koyama, Y.;
Inami, S.; Hayashi, Y.; Isobe, K.; Kameda, H.; Shimoda, T. Synthesis of
a bowl-type dodecavanadate by the coupling reaction of alkoxohex-
H
DOI: 10.1021/acs.inorgchem.7b00366
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
avanadate and discovery of a chiral octadecavanadate. Pure Appl. Chem.
(20) Zhang, B. Y.; Jiang, Z. X.; Li, J.; Zhang, Y. N.; Lin, F.; Liu, Y.; Li,
C. Catalytic oxidation of thiophene and its derivatives via dual
activation for ultra-deep desulfurization of fuels. J. Catal. 2012, 287, 5−
12.
2
(
009, 81, 1323−1330.
6) Hou, D.; Kim, G. S.; Hagen, K. S.; Hill, C. L. Synthesis and
characterization of a polyvanadate polyester involving a monodentate
alcohol, [(n-C H ) N][V O (OCH ) ]. Inorg. Chim. Acta 1993, 211,
(21) (a) Zhang, J.; Wang, A. J.; Li, X.; Ma, X. H. Oxidative
desulfurization of dibenzothiophene and diesel over
4
9
4
6
12
3 7
1
(
27−130.
7) Adach, A.; Daszkiewicz, M.; Ciesl
́
ak-Golonka, M. Cobalt(II)
[Bmim]
Zhao, S.; Chen, W.; Wang, M.; Song, Y. F. Highly efficient extraction
and oxidative desulfurization system using Na H LaW O ·32H O in
PMo12O40. J. Catal. 2011, 279, 269−275. (b) Xu, J. H.;
3
scorpionate-like complexes obtained from in situ synthesized ligand
created in [Co(0)-1-hydroxymethyl-3,5-dimethylpyrazole-VOSO4-
7
2
10 36
2
[
bmim]BF at room temperature. Chem. - Eur. J. 2012, 18, 4775−
NH SCN] system. Polyhedron 2012, 47, 104−111.
4
4
IV
V
4781.
(
8) Daniel, C.; Hartl, H. A mixed-valence V /V alkoxopolyox-
n±
(22) (a) Liu, Y. Y.; Moon, S. Y.; Hupp, J. T.; Farha, O. K. Dual-
function metal-organic framework as a versatile catalyst for detoxifying
chemical warfare agent simulants. ACS Nano 2015, 9, 12358−12364.
ovanadium cluster series [V O (OCH ) ] : Exploring the influence
6
8
3 11
of a μ-oxo ligand in a spin frustrated structure. J. Am. Chem. Soc. 2009,
31, 5101−5114.
9) Kessler, V. G.; Seisenbaeva, G. A. The mystery of VO(OEt)3
1
(
(b) Guo, W. W.; Lv, H. J.; Sullivan, K. P.; Gordon, W. O.; Balboa, A.;
Wagner, G. W.; Musaev, D. G.; Bacsa, J.; Hill, C. L. Broad-spectrum
liquid-and gas-phase decontamination of chemical warfare agents by
one-dimensional heteropolyniobates. Angew. Chem., Int. Ed. 2016, 55,
conversion on microhydrolysis disclosed: the X-ray single crystal study
of V O (OEt) . Inorg. Chem. Commun. 2000, 3, 203−204.
6
7
12
(
̈
10) Spandl, J.; Daniel, C.; Brudgam, I.; Hartl, H. Synthesis and
7
(
403−7407.
structural characterization of redox-active dodecamethoxoheptaoxo-
23) (a) Bae, S. Y.; Winemiller, M. D. Mechanistic insights into the
hexavanadium clusters. Angew. Chem., Int. Ed. 2003, 42, 1163−1166.
IV
V
hydrolysis of 2-chloroethyl ethyl sulfide: The expanded roles of
sulfonium salts. J. Org. Chem. 2013, 78, 6457−6470. (b) Singh, B.;
Mahato, T. H.; Srivastava, A. K.; Prasad, G. K.; Ganesan, K.;
Vijayaraghavan, R.; Jain, R. Significance of porous structure on
degradatin of 2 2′ dichloro diethyl sulphide and 2 chloroethyl ethyl
sulphide on the surface of vanadium oxide nanostructure. J. Hazard.
Mater. 2011, 190, 1053−1057.
(
11) Daniel, C.; Hartl, H. Neutral and cationic V /V mixed-valence
n+
alkoxopolyoxovanadium clusters [V O (OR) ] (R = − CH , −
6
7
12
3
C H ): Structural, cyclovoltammetric and IR-spectroscopic inves-
2
5
tigations on mixed valency in a hexanuclear core. J. Am. Chem. Soc.
005, 127, 13978−13987.
12) (a) Han, J. W.; Hill, C. L. A coordination network that catalyzes
O -based oxidations. J. Am. Chem. Soc. 2007, 129, 15094−15095.
2
(
2
(24) Carniato, F.; Bisio, C.; Psaro, R.; Marchese, L.; Guidotti, M.
(
b) Yin, P.; Wang, J.; Xiao, Z.; Wu, P.; Wei, Y.; Liu, T.
Niobium(V) saponite clay for the catalytic oxidative abatement of
Polyoxometalate-organic hybrid molecules as amphiphilic emulsion
chemical warfare agents. Angew. Chem., Int. Ed. 2014, 53, 10095−
catalysts for deep desulfurization. Chem. - Eur. J. 2012, 18, 9174−9178.
1
0098.
(
c) Yin, P.; Bayaguud, A.; Cheng, P.; Haso, F.; Hu, L.; Wang, J.;
(25) (a) Chen, B.; Huang, X.; Wang, B.; Lin, Z.; Hu, J.; Chi, Y.; Hu,
Vezenov, D.; Winans, R. E.; Hao, J.; Li, T.; Wei, Y.; Liu, T.
Spontaneous stepwise self-assembly of a polyoxometalate-organic
hybrid into catalytically active one-dimensional anisotropic structures.
Chem. - Eur. J. 2014, 20, 9589−9595. (d) Li, J. K.; Huang, X. Q.; Yang,
S.; Ma, H. W.; Chi, Y. N.; Hu, C. W. Four alkoxohexavanadate-based
Pd-polyoxovanadates as robust heterogeneous catalysts for oxidation
of benzyl-alkanes. Inorg. Chem. 2015, 54, 1454−1461.
C. Three new imidazole-functionalized hexanuclear oxidovanadium
clusters with exceptional catalytic oxidation properties for alcohols.
Chem. - Eur. J. 2013, 19, 4408−4413. (b) Li, J. K.; Xu, Y. Q.; Hu, C. W.
In situ synthesis of a novel dioxidovanadium-based nickel complex as
catalyst for deep oxidative desulfurization with molecular oxygen.
Inorg. Chem. Commun. 2015, 60, 12−14.
(26) Kurup, M. R. P.; Seena, E. B.; Kuriakose, M. Synthesis, spectral
and structural studies of oxovanadium(IV/V) complexes derived from
2-hydroxyacetophenone-3-hydroxy-2-naphthoylhydrazone: poly-
(
13) Kasp
converters: Current status and some perspectives. Catal. Today 2003,
7, 419−449.
14) Cape, J. N.; Fowler, D.; Davison, A. Ecological effects of sulfur
̌
ar, J.; Fornasiero, P.; Hickey, N. Automotive catalytic
7
(
morphs of oxovanadium(V) complex [VOL(OCH )]. Struct. Chem.
3
2010, 21, 599−605.
dioxide, fluorides, and minor air pollutants: Recent trends and research
(27) Addison, A. W.; Rao, T. N.; Reedijk, J.; van Rijn, J.; Verschoor,
G. C. Synthesis, structure, and spectroscopic properties of copper(II)
compounds containing nitrogen-sulphur donor ligands; the crystal and
molecular structure of aqua[1,7-bis(N-methylbenzimidazol-2′-yl)-2,6-
dithiaheptane]copper(II) perchlorate. J. Chem. Soc., Dalton Trans.
1984, 1349−1356.
needs. Environ. Int. 2003, 29, 201−211.
(
15) Geurts, J. J.; Sarneel, J. M.; Willers, B. J.; Roelofs, J. G.;
Verhoeven, J. T.; Lamers, L. P. Interacting effects of sulphate pollution,
sulphide toxicity and eutrophication on vegetation development in
fens: A mesocosm experiment. Environ. Pollut. 2009, 157, 2072−2081.
(
16) Komintarachat, C.; Trakarnpruk, W. Oxidative desulfurization
(28) (a) Zhang, J.; Wang, A.; Wang, Y.; Wang, H.; Gui, J.
Heterogeneous oxidative desulfurization of diesel oil by hydrogen
peroxide: Catalysis of an amphipathic hybrid material supported on
using polyoxometalates. Ind. Eng. Chem. Res. 2006, 45, 1853−1856.
17) Rothlisberger, A.; Prins, R. Intermediates in the hydro-
desulfurization of 4,6-dimethyl-dibenzothiophene over Pd/γ-Al O . J.
(
̈
SiO . Chem. Eng. J. 2014, 245, 65−70. (b) Zhang, M.; Zhu, W.; Xun,
2
2
3
S.; Li, H.; Gu, Q.; Zhao, Z.; Wang, Q. Deep oxidative desulfurization
of dibenzothiophene with POM-based hybrid materials in ionic
liquids. Chem. Eng. J. 2013, 220, 328−336.
Catal. 2005, 235, 229−240.
(
18) Choudhary, T. V.; Malandra, J.; Green, J.; Parrott, S.; Johnson,
B. Towards clean fuels: Molecular-level sulfur reactivity in heavy oils.
Angew. Chem., Int. Ed. 2006, 45, 3299−3303.
(29) Wang, X.; Huang, Y.; Lin, Z.; Cao, R. Phosphotungstic acid
encapsulated in the mesocages of amine-functionalized metal-organic
frameworks for catalytic oxidative desulfurization. Dalton Trans. 2014,
(
́
19) (a) Yang, R. T.; Hernandez-Maldonado, A. J.; Yang, F. H.
Desulfurization of transportation fuels with zeolites under ambient
conditions. Science 2003, 301, 79−81. (b) Hernandez-Maldonado, A.
4
3, 11950−11958.
30) Sheldrick, G. M. SHELXS-97, Program for Crystal Structure
Solution; Gottingen University: Germany, 1997.
31) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; Gottingen University: Germany, 1997.
́
(
J.; Yang, R. T. Desulfurization of diesel fuels by adsorption via π-
complexation with vapor-phase exchanged Cu(I)-Y zeolites. J. Am.
Chem. Soc. 2004, 126, 992−993. (c) Cychosz, K. A.; Wong-Foy, A. G.;
Matzger, A. J. Liquid phase adsorption by microporous coordination
polymers: Removal of organosulfur compounds. J. Am. Chem. Soc.
̈
(
̈
2
008, 130, 6938−6939. (d) Cychosz, K. A.; Wong-Foy, A. G.;
Matzger, A. J. J. Enabling cleaner fuels: Desulfurization by adsorption
to microporous coordination polymers. J. Am. Chem. Soc. 2009, 131,
1
4538−14543.
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DOI: 10.1021/acs.inorgchem.7b00366
Inorg. Chem. XXXX, XXX, XXX−XXX