Nanoarchitecturing of open metal site Cr-MOFs for oxodiperoxo molybdenum complexes [MoO(O2)2@En/MIL-100(Cr)] as promising and bifunctional catalyst for selective thioether oxidation

Article abstract of DOI:10.1016/j.mcat.2017.11.003

In this work, open metal site metal-organic framework of MIL-100(Cr) was selected as a support for the multi-step grafting of molybdenum complexes. The oxodiperoxo molybdenum complexes were coordinated onto the ethylene diamine-decorated MIL-100(Cr) pore

Full text of DOI:10.1016/j.mcat.2017.11.003

Molecular Catalysis 445 (2018) 12–20
Contents lists available at ScienceDirect
Molecular Catalysis
journal homepage: www.elsevier.com/locate/mcat
Research paper
Nanoarchitecturing of open metal site Cr-MOFs for oxodiperoxo
molybdenum complexes [MoO(O ) @En/MIL-100(Cr)] as promising
2
2
and bifunctional catalyst for selective thioether oxidation
∗
Sadegh Rostamnia , Farahnaz Mohsenzad
Organic and Nano Group (ONG), Department of Chemistry, Faculty of Science, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
In this work, open metal site metal-organic framework of MIL-100(Cr) was selected as a support
for the multi-step grafting of molybdenum complexes. The oxodiperoxo molybdenum complexes
were coordinated onto the ethylene diamine-decorated MIL-100(Cr) pore cage, that this bifunctional
MoO(O2)2@En/MIL-100(Cr) catalyst was successfully applied for H2O2 (30%) mediate green and selective
thioether oxidation process. Component activity and recyclability test for the MoO(O2)2@En/MIL-100(Cr)
catalyst showed a successful reusability for 8 runs.
Received 22 September 2017
Received in revised form 31 October 2017
Accepted 2 November 2017
Keywords:
Metal-organic framework
Open metal site MOF
©
2017 Elsevier B.V. All rights reserved.
Oxodiperoxo molybdenum complexes
MoO(O2)2@En/MIL-100(Cr)
Thioether oxidation
1
. Introduction
metal and also mass transferring are necessary. Corma and Garcia
n+
m+
et al., extensively synthesized various bifunctional M /M -MOFs
with variable catalytically active centers [12,14–17]. Recently, Lu
[18], Guan [19], Xu [20], Fischer [21] and others reported transi-
tion metal supported MOFs as efficient catalyst in some organic
transformations. On the other hand, new type of metal-organic
frameworks with open metal sites are promising candidates for
gas capture and catalysis [22–25]. Our group [8] and Corma [12]
have recently reported on the catalytic application of open metal
site metal-organic frameworks featuring directed ligand grafted to
metal center of MOFs to leading bifunctional MOFs with various
abilities. In the works, we have reported the use of the Cu-BDC
Nanoarchitectonics are expected to achieve an effective
guidance in fabricating functional nanoporous materials. Nano-
orientation of materials is a widely demanding tool in nanoarchi-
tecturing to reach out a new material with higher surface area [1–4].
Among them, creating an organic-inorganic hybrid nanoporous
metal-organic frameworks (MOFs) material is one of the important
and crucial parts of research areas [1,5–8].
Nanoporous organic-inorganic hybrid metal-organic frame-
works (MOFs) are self-assembled from organic linkers and
inorganic connectors of metal ions/clusters, that they have inter-
esting perspectives in the application of catalysis as they exhibit
chemical/mechanical/physical properties differing from the usual
inorganic metal oxides [9–11]. The possible organization of active
centers like metallic connectors, linkers, and their chemical syn-
thetic functionalization on the nanoscale shows potential to build
up MOFs particularly modified for catalytic challenges [11]. Among
them, metal-organic frameworks with open metal sites are promis-
ing candidates for gas capture, and recently, metal-grafting to
catalysis purposes [8,12,13]. However, for all practical applications,
the choice of the MOF and ligand prevent aggregation, leaching of
and Corma used Cu (BTC)2 as an bifunctional open metal site MOF
3
catalyst containing palladium and copper (II) for the Suzuki reac-
tion and annulation of acetylenic compounds, respectively. In other
interesting work Abbasi et al. also grafted the molybdenum ions
inside pore channels of Cu (BTC)2 to achieve Mo-Cu/MOF as good
3
catalyst in epoxidation of alkenes.
It is also of much interest to design stable bifunctional open
metal site MOF catalysts with commercially available and cheap
ligands and metal. This is not only of interest from the point of view
of catalysis, but also decrease investment costs because of process
intensification. We have recently reported on the catalytic appli-
cation of metal-organic frameworks featuring Al+3, Cu and Zn O
+2
4
ions/clusters coordinated to carboxylates acids [26–29]. However,
in spite of the extensive advantages, the use of these MOFs as cata-
lysts is relatively limited with regard to applications for direct metal
∗ Corresponding author.
E-mail addresses: srostamnia@gmail.com, rostamnia@maragheh.ac.ir
S. Rostamnia).
(
http://dx.doi.org/10.1016/j.mcat.2017.11.003
468-8231/© 2017 Elsevier B.V. All rights reserved.
2

S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
13
Fig. 1. Bifunctional MoO(O2)2@En/MIL-100(Cr) for green and selective oxidation of thioether. (For interpretation of the references to color in this figure legend, the reader
is referred to the web version of this article.)
complex grafting. Herein, we have demonstrated chromium ben-
zene tricarboxylate of MIL-100(Cr) as an efficient open metal site
Cr-MOFs towards the direct grafting of ethylene diamine (En) and
then complexation of that with oxodiperoxo molybdenum com-
plexes (MoO(O ) ·DMF) to achieve MoO(O ) @En/MIL-100(Cr).
clearly demonstrating the grafting of ethylene diamine ligands
onto Cr-CUSs octahedral cluster in the cages of the Cr-MIL-100 and
oxodiperoxo molybdenum complexes.
The peaks in the powder diffraction scans were compared
against the predicted peaks from the Refs. [35,36]. The XRD patterns
of synthesized MIL-100(Cr) in DMF without any activation demon-
strate that all the main diffraction peaks (none activated MOF with
broad peaks) are in agreement with the predicted pattern (Fig. 3b).
Comparison of the predicted XRD patterns of MIL-100(Cr) and the
modified sample with the MoO(O ) ·En complex revealed shift for
2
2
2 2
The synthesized bifunctional Mo/Cr-MOF was then applied as
heterogeneous catalyst for H O2 mediated selective thioether oxi-
2
dation (Fig. 1.).
2
2
2
. Results and discussion
main peak to bigger 2Â angles apart from some slight variations
in the Bragg intensities. This behavior represents the expansion
of the framework depending on the guest molecules (also higher
w% of Mo related to grafted En ligands show that free complex of
MoO(O ) ·DMF encapsulated into the MOF pores) inside the pores
For aiming a heterogeneous system, oxodiperoxo complexes
of Mo have mainly been immobilized on Cr-MOFs (Mo/Cr-MIL-
00). Abbasi et al., synthesized a polyoxotungstate into ionic
1
2
2
liquid modified MIL-100(Fe) W/Fe-MOF, which was successfully
applied to oxidation of alcohols [30]. Roch-Marchal and Horcajada’s
group prepared a benzene tricarboxylate-based iron MOF molyb-
and clearly confirms the successful grafting (Fig. 3).
To discern the surface morphology of synthesized MIL-100(Cr)
and MoO(O ) @En/MIL-100(Cr), SEM was carried out. The SEM
2
2
denum pre-catalyst of “H PMo12@MIL-100(Fe)” with Mo/Fe ratio
3
micrograph of the MIL-100(Cr) revealed the presence of stick
sphere MOFs (Fig. 4a). SEM image of MoO(O ) @En/MIL-100(Cr)
around 0.95 [31]. As an ongoing research in nanoporous materi-
als [32–34], we herein, synthesized open metal site Cr-MIL-100
using chromium (VI) oxide and 1,3,5-benzene tricarboxylic acid
2
2
shows its morphology after production (Fig. 4b). In fact, this mor-
phology is similar to morphology of MIL-100(Cr) which indicates
that after post-modification and Mo-complexation, the morphol-
ogy is still intact. Then image profile of the selected area of SEM
were measured (Fig. 3c and d). Line profile of the stamper surface
(
H BTC) as organic linker in hydrothermal conditions for synthe-
3
sis of MIL-100(Cr). Then, the activated MOF reacted with ethylene
diamine (En) moiety to produce free amine grafted MOF (En/MIL-
1
00(Cr)). Afterwards, oxodiperoxo MoO(O ) ·DMF was added to
2
2
of MIL-100(Cr) and MoO(O ) @En/MIL-100(Cr) are given in Fig. 4c
2
2
En/MIL-100(Cr) to produce MoO(O ) @En/MIL-100(Cr) MOF as a
2
2
and d, respectively.
catalyst for further studies (Scheme 1).
FT-IR analyses were obtained
MoO(O ) @En/MIL-100(Cr). Fig. shows the spectra of the
SEM-EDS analysis were performed for the synthesized MOF
materials. Based on this analysis, Cr, C, O and N atoms exist in the
structure of En/MIL-100(Cr) and Mo, Cr, C, O and N atoms exist in
the structure of MoO(O ) @En/MIL-100(Cr) which exhibit the suc-
for
synthesized
2
2
2
starting MIL-100(Cr) compound compared with the samples after
oxodiperoxo molybdenum complexes grafting. As for MIL-100(Cr),
2
2
cessful grafting of Mo to MOF (Fig. 5). To the best of our knowledge,
existence of chloride in EDX of MoO(O ) @En/MIL-100(Cr) come
−1
the band at 2921 cm is assigned to aromatic C H asymmetric
stretching vibrations of terephthalic ligands, and the characteristic
2
2
from the used HCl in preparation of MoO(O ) ·DMF from NaMoO .
−
1
2
2
4
peak at 1577 and 1453 cm are due to C C vibrations of aromatic
ring moiety. The strong peaks at 1644 and 1392 are corresponds
to asymmetric and symmetric vibrations of carboxylate anions
present in the MOF material[8]. Furthermore, the frequencies of
Fig.
6 shows the N -adsorption/desorption isotherms of
2
MoO(O ) @En/MIL-100(Cr). The MOF isotherm exhibits IV curves
2
2
with H2-type hysteresis loop and indicates the presence of meso-
pores. The BET surface area and total pore volume for the prepared
the Cr O of octahedral CrO of the metal cluster appears at 523
6
2
−1
3
−1
MoO(O ) @En/MIL-100(Cr) is 219 m g and 0.4 cm g , respec-
−1
2 2
and 668 cm . The FTIR of MoO(O ) @En/MIL-100(Cr) shows that
2
2
tively. The modified sample still possesses a large surface area to
provide sufficient space for the introduction of oxodiperoxo molyb-
denum species.
the structure didn’t change considerably after attachment of the
Mo onto the surface of the MOF. The appearance of characteristic
−1
bands at 937 cm , relating to the Mo O, proves the formation of
Mo complexes in the Cr-MOF. Additionally, the existence double
After sufficient characterization of MoO(O ) @En/MIL-100(Cr)
2
2
and according to industrially interests of oxidation of aromatic
thioether [37], it was studied in selective oxidative reaction of
−1
bands at 3412 and 3238 cm , relating to the NH , proves the
2
ethylene diamine in the MOF structure. It is worth noting that
the observed C N vibration of coordinated ethylene diamine
thioether using H O2 30%. One of the problems encountered with
2

1
4
S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
Scheme 1. Step-wise synthesis of MoO(O2)2@En/MIL-100(Cr).
Fig. 2. FT-IR analysis of MIL-100(Cr) and MoO(O2)2@En/MIL-100(Cr).

S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
15
Fig. 3. XRD pattern of (a) predicted, (b) non-activated MIL-100(Cr), and (c) MoO(O2)2@En/MIL-100(Cr).
Fig. 4. a) SEM image of a) MIL-100(Cr) and b) MoO(O2)2@En/MIL-100(Cr). (c, d) Image profile and selected area highlighted of MIL-100(Cr) and MoO(O2)2@En/MIL-100(Cr).
◦
this method is tramping overoxidation of made thioether oxides
to thioether dioxides (sulfones), lacking selectivity and then lead
to undesired compounds. In this work, the catalytic ability of the
model reaction under, including 25 C, reaction time (30 min),
sulfide:H O (1:4) and H O (1 mL) that reaction scale was 0.5 mmol.
2
2
2
Several amounts of catalyst were added to reaction mixtures and
among them 0.04 g (18.3 mol% Mo) of supported oxodiperoxo
molybdenum complexes was found to be more efficient from the
point view of methyl phenyl sulfoxide yield in each reaction (Fig. 7).
Several protic, non-polar and polar solvents were investigated
on the selectivity and yield towards sulfoxide product through
MoO(O ) @En/MIL-100(Cr) in the oxidation reaction of thioether
2
2
without using any salts or stabilization was explored. Oxidation of
methyl phenyl sulfide (MPS) as model benchmark reaction was first
examined with MoO(O ) @En/MIL-100(Cr) using H O (Scheme 2).
2
2
2
2
Various conditions were tested by
a model reaction of
phenyl methylthioether and under an optimized conditions,
MoO(O ) @En/MIL-100(Cr) was found to be efficient in the cataly-
the model reaction. Among them, H O and methanol had better
results for selective sulfoxide synthesis. However, due to the fact
that water is a nontoxic, available and therefore a greener solvent
2
2
2
sis of green oxidation of phenyl methylthioether. First, the effect
of MoO(O ) @En/MIL-100(Cr) amount were examined on the
2
2

1
6
S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
Fig. 5. a) SEM-EDX of a) MIL-100(Cr) and b) MoO(O2)2@En/MIL-100(Cr).
Table 1
a
Optimization conditions for the oxidation of model reaction.
◦
Entry
Temp. ( C)
H2O2 (eq.)
Yield (%)
Sulfoxide
Sulfone
1
2
3
4
5
6
7
25
40
70
100
25
25
25
4
4
4
4
2
6
8
75
50
40
30
93
45
31
25
50
60
70
7
55
69
a
Reaction conditions: reaction conditions: 0.5 mmol of MPS, 0.04 g catalyst, H2O
1 mL) during 30 min.
(
less than 25% of sulfone (Table 1). Amount of H O oxidant was also
2
2
optimized for the model oxidation reaction. Based on this study, the
best amount of H O for the selectivity of model reaction to gener-
2
2
ate sulfoxide was 2 mmol for each mmol of sulfide. Table 1, entry
and 5–7 represents the results for four different amount of H O2
1
2
which was performed in the similar conditions.
In the next step, various aryl thioethers were incorporated
to find out their reactivity and selectivity under the catalysis of
MoO(O ) @En/MIL-100(Cr). Certainly, aryl alkyl thioethers have
2
2
a higher activity rather to their corresponding biaryl thioethers.
This fact was also observed in this work. Accordingly, no signifi-
cant difference were observed in the yields of various synthesized
thioethers which were synthesized from an electron donor substi-
tute (Table 2, entry 1–4). Upon optimization of reaction conditions,
the scope of the reaction was subsequently extended to the utiliza-
tion of heterocyclic thioethers (Table 2, entry 6 and 7).
Fig. 6. Nitrogen sorption isotherms of MoO(O2)2@En/MIL-100(Cr).
and also a bit higher product yield, it was selected as an optimized
solvent towards selective synthesis of sulfoxide (Fig. 8).
The temperature effect was also examined in the product yields.
In this regard, temperatures including 25, 40, 70, 60, and 100 C of
◦
model reaction were tested. One considerable point in this com-
Due to the fact that the nature of the bimetallic
◦
parison was that the reaction at 25 C with 4 eq. of H O had lower
MoO(O ) @En/MIL-100(Cr) as Mo/Cr-MOF may play an important
2
2
2 2
reaction completion time for selective synthesis of sulfoxide with
role in the thioethers oxidation reaction, in comparison with same

S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
17
Scheme 2. Benchmark model reaction over of MoO(O2)2@En/MIL-100(Cr).
◦
Fig. 7. Reaction conditions: reaction conditions: 0.5 mmol of MPS, 2 mmol of H2O2, in water (1 mL) at 25 C during 30 min.
Fig. 8. Reaction conditions: reaction conditions: 0.5 mmol of MPS, 2 mmol of H2O2,
◦
.04 g catalyst, solvent (1 mL) at 25 C during 30 min.
0
Scheme 3. Plausible mechanisms of oxodiperoxo Mo-mediated thioether oxidation.
sulfoxide obtained 90% yield during 30 min, instead for Cr-MOF/En
and MOF/En the yield of sulfoxide was 85 and 80, respectively
(
Fig. 9).
A possible explanation mechanism for the thioether oxida-
tion using H O2 over the MoO(O ) @En/MIL-100(Cr) catalyst was
2
2 2
proposed in Scheme 3. Based on literature experimental and the-
oretical reports on oxidation process by oxodiperoxo mechanism
[
38,39], we propose that MoO(O ) @En/MIL-100(Cr) easily reacts
Fig. 9. Comparison reactivity of various MOFs.
2 2
with thioether to form a dioxoperoxo Mo adduct 1. Then, with H O2
2
attach to 1, the thioether oxide (sulfoxide) will remove the reaction
cycle and a Mo-pendant OOH (Mo-OOH, 2) adduct may undergo
a cleavage of its O OH bond to generate catalyst for next runs,
in which MPS can be oxidized to the corresponding sulfoxide (or
sulfone in repeat steps).
structure, the initial reaction was carried out using MIL-100(Cr)
and En/MIL-100(Cr) catalyst. The MoO(O ) @En/MIL-100(Cr) as
bimetallic Mo/Cr-MOF was assessed for its catalytic activity in
the model reaction to produce of methyl phenyl sulfoxide as
the principal product. When the model reaction was run using
bimetallic Mo/Cr-MOF, the conversion product was 100% and
2
2
In this study, MoO(O ) @En/MIL-100(Cr) could be recycled for
2
2
8 runs (Fig. 10). After completion of the reaction, the catalyst was

1
8
S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
Table 2
a
Optimized reaction conditions for the oxidation of aromatic thioether.
a
Reaction conditions: reaction scale (0.5 mmol).
recovered by centrifuge and washed with dichloromethane, dis-
3.2. Preparation of MIL-100(Cr)
◦
persed and heated in 3 mL of fresh DMF at 100 C for 2 h, activated
◦
under vacuum at 60 C for 5 h, which was subsequently reused.
MOF of MIL-100(Cr) and ethylene diamine grafted MIL-100(Cr)
were synthesized according to Chang and Férey et al. [40] reported
method. 1.2 g (12 mmol) of chromium trioxide, 2.52 g (11.99 mmol)
No Mo was detected in reaction solution until 6th run (analyzing
by atomic absorption spectroscopy), confirming the good stability
of the systems under the investigated reaction conditions. How-
ever, after 6th runs, a significant drop in the yield can be observed.
Fig. 10b shows SEM image of MoO(O ) @En/MIL-100(Cr) in 8th run.
of trimesic acid (H BTC), 12 mmol of hydrofluoric acid (HF, 40%)
3
and 58 mL of deionized water were mixed in a Teflon-lined stain-
less steel autoclave and stirre at 298 K during 2 h and then kept at
2
2
4
93 K for 4 days. The resulting green solid was washed with water
and dried at room temperature under air. The Cr- MOF was then
characterized using a variety of different techniques.
3
. Experimental section
3.1. Material and apparatus
3
.3. Post-synthesis modification of MIL-100(Cr) with ethylene
All reagents were purchased from Merck (Germany), Fluka
Switzerland) and Sigma-Aldrich and used without further
diamine (En)
(
purification. The crystalline phases of the nanoparticles were
recognized by XRD measurements (Philips-PW1800 diffractome-
ter). Homogeneous stirring was done by ultrasonic (Ultrasonic
Homogenizer-model APU500 Advanced Equipment Engineering
Company-Adeeco, Iran). Scanning electron microscopy (SEM) and
SEM-EDS were recorded on VEGA3 TESCAN. Powder X-ray diffrac-
tion spectra was recorded on Philips PW1800.
The open metal site MOF of MIL-100(Cr) was activated in hot
DMF (110 C, 4 h) and then 16 h at room temperature at 393 K under
◦
vacuum for 12 h. The same activated method were done using
◦
◦
ethanol and water in the solvent at 60 C and 90 C, respectively.
Then, 0.1 g of MIL-100(Cr), activated at 473 K for 2 h, was suspended
in 10 mL of anhydrous toluene and 1 mL of ethylene diamine was
added to this suspension, and the mixture was stirred under Ar for

S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
19
tional Mo/Cr-MOF material was found to be an efficient nanoporous
coordination polymer with hydrophobic nature which had high
capacity for the catalysis of the green thioether oxidation reaction
at room temperature in short reaction time. In this method, the
reaction progress led to products, thioethers (sulfoxide), in high
yields without side-products.
Appendix A. Supplementary data
Supplementary data associated with this article can be found,
in the online version, at http://dx.doi.org/10.1016/j.mcat.2017.11.
0
03.
References
[
[
1] K. Ariga, A. Vinu, Y. Yamauchi, Q. Ji, J.P. Hill, Nanoarchitectonics for
mesoporous materials, Bull. Chem. Soc. Jpn. 85 (1) (2011) 1–32.
2] K. Ariga, Y. Yamauchi, G. Rydzek, Q. Ji, Y. Yonamine, K.C.-W. Wu, J.P. Hill,
Layer-by-layer nanoarchitectonics: invention, innovation, and evolution,
Chem. Lett. 43 (1) (2013) 36–68.
[
[
3] K. Ariga, Q. Ji, M.J. McShane, Y.M. Lvov, A. Vinu, J.P. Hill, Inorganic
nanoarchitectonics for biological applications, Chem. Mater. 24 (5) (2011)
728–737.
4] M. Ramanathan, L.K. Shrestha, T. Mori, Q. Ji, J.P. Hill, K. Ariga, Amphiphile
nanoarchitectonics: from basic physical chemistry to advanced applications,
Phys. Chem. Chem. Phys. 15 (26) (2013) 10580–10611.
[
[
5] J. Tang, Y. Yamauchi, Carbon materials: MOF morphologies in control, Nat.
Chem. 8 (2016) 638–639.
6] S. Rostamnia, H. Xin, N. Nouruzi, Metal–organic frameworks as a very suitable
reaction inductor for selective solvent-free multicomponent reaction:
IRMOF-3 as a heterogeneous nanocatalyst for Kabachnik–Fields
three-component reaction, Microporous Mesoporous Mater. 179 (2013)
Fig. 10. a) Recyclability study of MoO(O2)2@En/MIL-100(Cr) (scale: 10 mmol) and
b) its SEM image after 9th run.
99–103.
[
7] S. Rostamnia, A. Morsali, Basic isoreticular nanoporous metal–organic
framework for Biginelli and Hantzsch coupling: IRMOF-3 as a green and
recoverable heterogeneous catalyst in solvent-free conditions, RSC Adv. 4 (21)
(2014) 10514–10518.
1
6 h to facilitate amine grafting. The resulting En/MIL-100(Cr) solid
was collected by filtration and repeatedly washed with acetone to
remove the unreacted En, and then dried at 100 C during 18 h.
◦
[8] S. Rostamnia, H. Alamgholiloo, X. Liu, Pd-grafted open metal site
copper-benzene-1, 4-dicarboxylate metal organic frameworks (Cu-BDC
MOF’s) as promising interfacial catalysts for sustainable Suzuki coupling, J.
Colloid Interface Sci. 469 (2016) 310–317.
3.4. En/MIL-100(Cr)-coordinately immobilized oxodiperoxo
[
9] J. Lee, O.K. Farha, J. Roberts, K.A. Scheidt, S.T. Nguyen, J.T. Hupp, Metal–organic
framework materials as catalysts, Chem. Soc. Rev. 38 (5) (2009) 1450–1459.
molybdenum complexes [MoO(O ) @En/MIL-100(Cr)]
2
2
[
[
10] H. Bux, F. Liang, Y. Li, J. Cravillon, M. Wiebcke, J.R. Caro, Zeolitic imidazolate
framework membrane with molecular sieving properties by
The obtained En/MIL-100(Cr) [40] was then incorporated with
oxodiperoxo molybdenum complexes. 2 mmol of the oxodiperoxo
molybdenum of MoO(O ) ·DMF was dissolved in 15 mL CHCl fol-
microwave-assisted solvothermal synthesis, J. Am. Chem. Soc. 131 (44) (2009)
16000–16001.
2
2
3
11] K.K. Tanabe, S.M. Cohen, Engineering a metal–organic framework catalyst by
using postsynthetic modification, Angew. Chem. 121 (40) (2009) 7560–7563.
lowed by addition of 1 g of En/MIL-100(Cr) under vigorous stirring
the suspension for 24 h. Finally, the solid was collected by filter-
[12] A. Arnanz, M. Pintado-Sierra, A. Corma, M. Iglesias, F. Sánchez, Bifunctional
metal organic framework catalysts for multistep reactions: MOF-Cu
ing and Soxhlet with EtOH for 2 h and then after sonicate around
(
BTC)-[Pd] catalyst for one-pot heteroannulation of acetylenic compounds,
◦
2
min in chloroform, it was dried at 60 C at vacuum. According to
Adv. Synth. Catal. 354 (7) (2012) 1347–1355.
atomic absorption analysis (AAS) of the composite, the Wt% of Mo
in MoO(O ) @En/MIL-100(Cr) was 20 per 100 mg of composite.
[13] P. Puthiaraj, P. Suresh, K. Pitchumani, Aerobic homocoupling of arylboronic
acids catalysed by copper terephthalate metal–organic frameworks, Green
Chem. 16 (5) (2014) 2865–2875.
2
2
[
[
[
14] A. Dhakshinamoorthy, H. Garcia, Catalysis by metal nanoparticles embedded
on metal–organic frameworks, Chem. Soc. Rev. 41 (15) (2012) 5262–5284.
15] A. Dhakshinamoorthy, A.M. Asiri, H. Garcia, Catalysis by metal–organic
frameworks in water, Chem. Commun. 50 (85) (2014) 12800–12814.
16] M. Pintado-Sierra, A.M. Rasero-Almansa, A. Corma, M. Iglesias, F. Sánchez,
Bifunctional iridium-(2-aminoterephthalate)–Zr-MOF chemoselective
catalyst for the synthesis of secondary amines by one-pot three-step cascade
reaction, J. Catal. 299 (2013) 137–145.
17] F. Cirujano, F.L. Xamena, A. Corma, MOFs as multifunctional catalysts: one-pot
synthesis of menthol from citronellal over a bifunctional MIL-101 catalyst,
Dalton Trans. 41 (14) (2012) 4249–4254.
18] X.-Y. Wu, Q.-K. Zhang, X.-F. Kuang, W.-B. Yang, R.-M. Yu, C.-Z. Lu, Two hybrid
polyoxometalate-pillared metal–organic frameworks, Dalton Trans. 41 (38)
(2012) 11783–11787.
19] D. Zhang, Y. Guan, E.J. Hensen, L. Chen, Y. Wang, Porous MOFs supported
palladium catalysts for phenol hydrogenation: a comparative study on
MIL-101 and MIL-53, Catal. Commun. 41 (2013) 47–51.
20] H.-L. Jiang, B. Liu, T. Akita, M. Haruta, H. Sakurai, Q. Xu, Z.I.F.-8 Au@, CO
oxidation over gold nanoparticles deposited to metal- organic framework, J.
Am. Chem. Soc. 131 (32) (2009) 11302–11303.
21] M. Meilikhov, K. Yusenko, D. Esken, S. Turner, G. Van Tendeloo, R.A. Fischer,
Metals@ MOFs–loading MOFs with metal nanoparticles for hybrid functions,
Eur. J. Inorg. Chem. 2010 (24) (2010) 3701–3714.
3
.5. General procedure for the oxidation of thioethers
In a round-bottomed flask (25 mL) equipped with a magnetic
stirrer, sulfide (0.5 mmol) was added to reaction flask in the pres-
ence of 1 mmol H O (30% w/w) and MoO(O ) @En/MIL-100(Cr)
2
2
2 2
◦
(
0.04 g) in 1 mL water and stirred at 25 C for an appropriate
[
[
[
[
[
time (Table 2). After completion of the reaction, the product was
extracted from reaction mixture with chloroform and then final
product was obtained by evaporating chloroform from thioether
oxide (sulfoxide).
4
. Conclusion
In summary, oxodiperoxo complex of molybdenum coordi-
nated ethylene diamine [MoO(O ) /En] was successfully achieved
on the cage of open metal site MOF of MIL-100(Cr). Under the
optimized conditions, MoO(O ) @En/MIL-100(Cr) as a new bifunc-
2
2
2
2

2
0
S. Rostamnia, F. Mohsenzad / Molecular Catalysis 445 (2018) 12–20
[
[
[
[
22] B. Chen, N.W. Ockwig, A.R. Millward, D.S. Contreras, O.M. Yaghi, High H2
adsorption in a microporous metal–organic framework with open metal sites,
Angew. Chem. 117 (30) (2005) 4823–4827.
23] D. Britt, H. Furukawa, B. Wang, T.G. Glover, O.M. Yaghi, Highly efficient
separation of carbon dioxide by a metal-organic framework replete with open
metal sites, Proc. Natl. Acad. Sci. 106 (49) (2009) 20637–20640.
24] H. Wu, W. Zhou, T. Yildirim, High-capacity methane storage in metal- organic
frameworks M2 (dhtp): the important role of open metal sites, J. Am. Chem.
Soc. 131 (13) (2009) 4995–5000.
25] A.O. Yazaydın, A.I. Benin, S.A. Faheem, P. Jakubczak, J.J. Low, R.R. Willis, R.Q.
Snurr, Enhanced CO2 adsorption in metal-organic frameworks via occupation
of open-metal sites by coordinated water molecules, Chem. Mater. 21 (8)
[32] S. Rostamnia, A. Hassankhani, H.G. Hossieni, B. Gholipour, H. Xin, Brønsted
acidic hydrogensulfate ionic liquid immobilized SBA-15:[MPIm][HSO 4]@
SBA-15 as an environmentally friendly, metal-and halogen-free recyclable
catalyst for Knoevenagel–Michael-cyclization processes, J. Mol. Catal. A:
Chem. 395 (2014) 463–469.
[33] S. Rostamnia, H. Xin, X. Liu, K. Lamei, Simultaneously application of SBA-15
sulfonic acid nanoreactor and ultrasonic irradiation as a very useful novel
combined catalytic system: an ultra-fast selective, reusable and waste-free
green approach, J. Mol. Catal. A: Chem. 374 (2013) 85–93.
[34] S. Rostamnia, H. Xin, Pd (OAc) 2@ SBA-15/PrEn nanoreactor: a highly active,
reusable and selective phosphine-free catalyst for Suzuki–Miyaura
cross-coupling reaction in aqueous media, Appl. Organomet. Chem. 27 (6)
(2013) 348–352.
(
2009) 1425–1430.
[
[
26] S. Rostamnia, Z. Karimi, Preparation and catalytically study of metal–organic
frameworks of amine/MIL-53 (Al) as a powerful option in the rapid
[35] P. Miao, G. Li, G. Zhang, H. Lu, Co (II)-salen complex encapsulated into
MIL-100 (Cr) for electrocatalytic reduction of oxygen, J. Energy Chem. 23 (4)
(2014) 507–512.
[36] J. Juan-Alca n˜ iz, M.G. Goesten, E.V. Ramos-Fernandez, J. Gascon, F. Kapteijn,
Towards efficient polyoxometalate encapsulation in MIL-100 (Cr): influence
of synthesis conditions, N. J. Chem. 36 (4) (2012) 977–987.
[37] K. Kaczorowska, Z. Kolarska, K. Mitka, P. Kowalski, Oxidation of sulfides to
sulfoxides. Part 2: Oxidation by hydrogen peroxide, Tetrahedron 61 (35)
(2005) 8315–8327.
[38] M. Jia, W.R. Thiel, Oxodiperoxo molybdenum modified mesoporous MCM-41
materials for the catalytic epoxidation of cyclooctene, Chem. Commun. 20
(2002) 2392–2393.
[39] C.J. Carrasco, F. Montilla, E. Álvarez, C. Mealli, G. Manca, A. Galindo,
Experimental and theoretical insights into the
N-formylation condensation in neat conditions, Inorg. Chim. Acta 428 (2015)
1
33–137.
27] S. Rostamnia, H. Alamgholiloo, M. Jafari, R. Rookhosh, A.R. Abbasi, Synthesis
and catalytic study of open metal site metal–organic frameworks of Cu3 (BTC)
2
1
microbelts in selective organic sulfide oxidation, Appl. Organomet. Chem.
1 (30) (2016) 954–958.
[
[
28] S. Rostamnia, M. Jafari, Metal–organic framework of amine-MIL-53 (Al) as
active and reusable liquid-phase reaction inductor for multicomponent
condensation of Ugi-type reactions, Appl. Organomet. Chem. 31 (4) (2017).
29] S. Rostamnia, H. Xin, Basic isoreticular metal–organic framework (IRMOF-3)
porous nanomaterial as a suitable and green catalyst for selective
unsymmetrical Hantzsch coupling reaction, Appl. Organomet. Chem. 28 (5)
(
2014) 359–363.
oxodiperoxomolybdenum-catalysed sulphide oxidation using hydrogen
peroxide in ionic liquids, Dalton Trans. 43 (36) (2014) 13711–13730.
[40] Y.K. Hwang, D.Y. Hong, J.S. Chang, S.H. Jhung, Y.K. Seo, J. Kim, A. Vimont, M.
Daturi, C. Serre, G. Férey, Amine grafting on coordinatively unsaturated metal
centers of MOFs: consequences for catalysis and metal encapsulation, Angew.
Chem. Int. Ed. 47 (22) (2008) 4144–4148.
[
30] S. Abednatanzi, A. Abbasi, M. Masteri-Farahani, Immobilization of
catalytically active polyoxotungstate into ionic liquid-modified MIL-100 (Fe):
A recyclable catalyst for selective oxidation of benzyl alcohol, Catal. Commun.
9
6 (2017) 6–10.
[
31] R. Canioni, C. Roch-Marchal, F. Sécheresse, P. Horcajada, C. Serre, M.
Hardi-Dan, G. Férey, J.-M. Greneche, F. Lefebvre, J.-S. Chang, Stable
polyoxometalate insertion within the mesoporous metal organic framework
MIL-100 (Fe), J. Mater. Chem. 21 (4) (2011) 1226–1233.