Magnetic ethyl-based organosilica supported Schiff-base/indium: A very efficient and highly durable nanocatalyst

Article abstract of DOI:10.1016/j.jallcom.2019.03.203

In the present study a novel core-shell structured magnetic bifunctional organosilica was prepared through modification of Fe₃O₄ nanoparticles with a mixture of bis(triethoxysilyl) ethane (BTEE) and 3-aminopropyltrimethoxysilane (APTES) followed by treatment with 2-hydroxybenzaldehyde. This nanomaterial was applied as efficient support for immobilization of indium chloride. The prepared nanomaterial was denoted as Fe₃O₄@BOS@SB/In and characterized using Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and powder X-ray diffraction (PXRD). The Fe₃O₄@BOS@SB/In was successfully applied as a powerful catalyst for green reduction of nitrobenzenes in water at room temperature. This catalyst was recovered and reused several times without significant decrease in efficiency and stability.

Full text of DOI:10.1016/j.jallcom.2019.03.203

Accepted Manuscript
Magnetic ethyl-based organosilica supported Schiff-base/indium: A very efficient and
highly durable nanocatalyst
Reza Mirbagheri, Dawood Elhamifar
PII:
S0925-8388(19)31019-9
DOI:
https://doi.org/10.1016/j.jallcom.2019.03.203
JALCOM 49967
Reference:
To appear in: Journal of Alloys and Compounds
Received Date: 1 February 2019
Revised Date: 4 March 2019
Accepted Date: 13 March 2019
Please cite this article as: R. Mirbagheri, D. Elhamifar, Magnetic ethyl-based organosilica supported
Schiff-base/indium: A very efficient and highly durable nanocatalyst, Journal of Alloys and Compounds
(2019), doi: https://doi.org/10.1016/j.jallcom.2019.03.203.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT
Graphical abstract

ACCEPTED MANUSCRIPT
1
2
Magnetic ethyl-based organosilica supported Schiff-base/indium: A very
efficient and highly durable nanocatalyst
3
4
Reza Mirbagheri and Dawood Elhamifar
*
5
6
7
Department of Chemistry, Yasouj University Yasouj 75918-74831, Iran
E-mail: d.elhamifar@yu.ac.ir
Abstract
8
9
0
1
2
3
4
5
6
7
8
In the present study a novel core-shell structured magnetic bifunctional organosilica was
3 4
prepared through modification of Fe O nanoparticles with a mixture of bis(triethoxysilyl) ethane
1
1
1
1
1
1
1
1
1
(BTES) and 3-aminopropyltrimethoxysilane (APTES) followed by treatment with 2-
hydroxybenzaldehyde. This nanomaterial was applied as efficient support for immobilization of
indium chloride. The prepared nanomaterial was denoted as Fe O @BOS@SB/In and
3
4
characterized using Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric
analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, scanning electron microscopy
(SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and
powder X-ray diffraction (PXRD). The Fe O @BOS@SB/In was successfully applied as a
3
4
powerful catalyst for green reduction of nitobenzenes in water at room temperature. This catalyst
was recovered and reused several times without significant decrease in efficiency and stability.
19
2
0
1
Keywords: Magnetic nanoparticles, Core-shell, Schiff-base, Indium nanocatalyst, Reduction of
2
nitrobenzenes
1

ACCEPTED MANUSCRIPT
22
1. Introduction
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Magnetic iron oxides are one of the most important nanoparticles between chemists that have
been successfully used in different fields such as computer [1, 2],_electronics [3-5], health [6-9],
medicine [10-14] and even in our daily life [15, 16]. Also in chemistry, the use of magnetic
energy is very significant because its environmentally-friendly, low cast and so beneficial in
catalytic processes [17-21]. In the field of nanochemistry, also the aforementioned MNs are so
3 4
popular and there are many reports in this area [22-24]. Especially Fe O NPs are widely used in
many catalytic reactions due to their easy preparation, controllable particle size and also low
cast. Despite these advantages, the Fe O nanoparticles suffer from some restrictions such as
3
4
high surface energy and instability in the presence of air and acidic media [25, 26]. To overcome
these limitations, these MNs are modified with suitable stabilizers such as carbon [27, 28], silica
[29, 30] and polymer [31-33]. Among these, silica based ones is more interested due to high
stability, eco-friendly, non-toxicity as well as excellent capacity and surface area for
immobilization and stabilization of catalytic species [10, 34-37]. However, it is more desirable to
3 4 2
modify the Fe O @SiO surface with organic functional groups to increase the lipophilicity of
the silica shells for catalytic organic reactions. The modification of magnetic silicas with organic
moieties is achieved through both grafting and sol-gel approaches. To date some magnetic
organosilicas have been prepared and applied in catalysis and adsorption processes [38-40].
Some of recently developed systems are MNPs with 1,3-bis(4-triethoxysilyl-2,6-
diisopropylphenyl)-imiadzol-3-ium-trifluoro-methane (NHC) bridged groups supported
palladium used as catalyst for the Suzuki–Miyaura coupling [40], proline‐functionalized MNP
used as efficient and recyclable catalyst for aldol condensation [41], magnetically separable 2D-
hexagonally ordered thiol functionalized mesoporous silica material (Fe@TFMS) applied as
2

ACCEPTED MANUSCRIPT
45
46
47
48
49
3 4
catalyst in the biodiesel production [42], Fe O @mesoporous SBA-15 used as a robust and
magnetically recoverable catalyst for Biginelli reaction [43] and magnetic nanoparticles
supported Schiff-base/copper complex used as a nanocatalyst for preparation of 3,4-
dihydropyrimidinones [37]. Other interesting magnetic organosilicas were also prepared and
applied in a number of chemical processes [40, 44-46].
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
On the other hand, one of the most important transformations in chemistry is reduction of
organic compounds that has wide applications in chemical synthesis and industries such as pulp
and paper [47], pharmaceutical [48], metal recovery [49] and textiles [50]. Especially, reduction
of nitrobenzenes is more attracted due to the corresponding anilines are valuable intermediate in
different areas such as drug synthesis, rubber processing chemicals, dyes and pigments [51]. The
use of a metal as catalyst in the presence of reducing agents is a common method for reduction of
nitro-compounds [52]. Some of recently developed catalytic systems are Fe/ hydrazine [53],
Au/H [54], Ag/NaBH [55], Pd@NA@GO/NaBH [56], Pd–Fe O –Sm O –ZrO /NaBH [57]
2
4
4
3
4
2
3
2
4
and Pt-Ni catalyst/NaBH [58]. In addition, several indium-based catalysts have been reported in
4
this matter [59, 60]. However, most of these indium based catalysts have been applied under
homogeneous conditions in a toxic organic solvent and suffer from disadvantages such as
difficulty in and product separation, catalyst recovery and environmental pollution.
Consequently, there is a need to design and prepare suitable heterogeneous catalysts with high
efficiency and recoverability for reduction of nitrobenzenes. According to these notes and also
due to importance of magnetic-organosilica nanoparticles in catalysis chemistry, in the present
study we have designed novel magnetic bi-functional organosilica nanoparticles supported
Schiff-base/indium complex (Fe O @BOS@SB/In) with improved catalytic activity and
3
4
reusability in the green reduction of nitrobenzenes (Scheme 1). The Fe O @BOS@SB/In was
3
4
3

ACCEPTED MANUSCRIPT
68
69
70
71
prepared and completely characterized using various techniques such as Fourier transform
infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA), energy-dispersive X-ray
spectroscopy (EDS), scanning electron microscopy (SEM), vibrating sample magnetometer
(VSM), transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD).
7
2
3
7
2. Experimental section
74
75
76
77
78
79
80
81
82
83
84
85
All materials were used as received without further purification. FeCl .4H O and FeCl .6H O
2
2
3
2
(Merck,
99%),
1,2-bis(triethoxysilyl)ethane
(BTEE)
(Aldrich,
96%),
(3-
aminopropyl)triethoxysilane (APTES) (Aldrich, 98%), salicylaldehyde (Merck, 99%),
indium(III) chloride (Aldrich, 98%) were purchased and used in this study. Solvents were dried
and purified before use according to standard procedures. Scanning electron microscopy (SEM)
analysis was performed on a Philips, XL30 emission electron microscope. The thermal
gravimetric analysis (TGA) was measured from room temperature to 800 °C by NETZSCH STA
409 PC/PG. Fourier transform infrared (FT-IR) spectroscopy was recorded on a Brucker-Vector
22 spectrometer. Energy dispersive X-ray spectroscopy (EDX) was carried out by TESCAN
Vega Model. Powder X-ray diffraction (PXRD) was obtained using a Panalytical X-Pert
diffractometer. Transmission electron microscopy (TEM) images were taken on a FEI TECNAI
12 BioTWIN microscope.
86
3 4 3 4
2.1. Preparation of Fe O nanoparticles supported bifunctional organosilica (Fe O @BOS)
87
88
89
For this purpose, at first Fe
3 4
O nanoparticles were synthesized according to a well-known
procedure using 2 g of FeCl .4H O, 3 g of FeCl .6H O in H O (25 mL) and ammonia (40 mL, 25
2
2
3
2
2
%) [61]. Then, Fe O @BOS was prepared via a sol-gel method. For this, 0.5 g of Fe O
4
3
4
3
4

ACCEPTED MANUSCRIPT
90
91
92
93
94
95
nanoparticles were completely dispersed in solution of deionized water (6 mL) and ethanol (22.5
mL) under argon atmosphere. Then 3-aminopropyltrimethoxysilane (APTES, 0.5 mL), 1,2-
bis(triethoxysilyl)ethane (BTEE, 1 mL) and ammonia (2 mL, 25 %) were slowly added in
reaction vessel while stirring vigorously. After 16 hours, the resulting product was collected
using an external magnetic field and completely washed with a mixture of water and ethanol.
Finally, this material was dried at 60 °C for 12 h and denoted as Fe O @BOS.
3
4
96
2.2. Preparation of the Fe O @BOS@SB material with core-shell structure
3 4
9
9
9
7
8
9
For preparation of Fe
3
O
4
nanoparticles supported bifunctional organosilica with Schiff base
@BOS was firstly dispersed in toluene (10 mL) for 10
group (Fe @BOS@SB), 0.5 g of Fe O
3
O
4
3 4
min. Then, 2-hydroxybenzaldehyde (2 mL) was added and the obtained mixture was refluxed
under argon atmosphere for 24 h. The resulting material was collected using an external magnet,
washed completely with EtOH, dried at 60 °C for 12 h and denoted as Fe O @BOS@SB.
1
1
00
01
3
4
1
02
2.3.Preparation of the Fe O @BOS@SB supported indium (Fe O @BOS@SB/In)
3 4 3 4
1
1
1
1
1
1
03
04
05
06
07
08
For immobilization of indium, Fe O @BOS@SB (0.5 g) was firstly dispersed in acetonitrile for
3 4
10 min. Then, InCl (0.5 g) was added into reaction vessel and this mixture was stirred at room
3
temperature for 48 h under argon atmosphere. The resulting material was collected using an
external magnetic field, washed completely with acetonitrile, dried at 60 °C for 12 h and denoted
3 4
as Fe O @BOS@SB/In. According to EDS analysis the loading of indium amount on material
surface was obtained to be 0.5 mmol/g.
1
1
09
10
2.4.General procedure for the reduction of nitrobenzenes using Fe O @BOS@SB/In
3
4
catalyst
5

ACCEPTED MANUSCRIPT
1
1
1
1
1
11
12
13
14
15
In a typical procedure, 1 mmol of nitrobenzene, 2 mmol of sodium borohydride and 0.5 mol% of
the Fe O @BOS@SB/In catalyst were added in water. This mixture was stirred at room
3
4
temperature and progress of the reaction was monitored by TLC. After finishing of the reaction,
the catalyst was removed using a magnetic field and the aniline product was obtained by cooling
the residue mixture in an ice bath and then filtering.
1
16
2.5.General procedure for the recovery of Fe O @BOS@SB/In nanocatalyst
3
4
1
1
1
1
1
1
17
18
19
20
21
22
For this, 4-nitrobenzaldehyde (1 mmol), NaBH (2 mmol) and Fe O @BOS@SB/In (0.5 mol%)
4 3 4
were added in water. The resulted mixture was magnetically stirred at room temperature. After
completion of the reaction, the catalyst was separated using an external magnet and the product
was obtained as previous procedure. The recovered catalyst was dried and applied in the next run
under the same conditions as the first run. These steps were repeated several times and the yield
of each run was calculated.
1
23
2.6. General procedure for the leaching test on Fe O @BOS@SB/In nanocatalyst
3
4
1
1
1
1
24
25
26
27
For this, 4-nitrobenzaldehyde (1 mmol), NaBH (2 mmol) and Fe O @BOS@SB/In (0.5 mol%)
4 3 4
were added in water (5 mL). After 5 minutes mixing, the catalyst was separated by an external
magnetic field and the catalyst-free mixture was allowed to stir for 20 minutes under optimized
conditions. The progress of the reaction was monitored by TLC.
1
28
3. Results and discussion
1
1
1
29
30
31
For the preparation of the desired catalyst, firstly the magnetic bifunctional organosilica
(Fe O @BOS) was prepared via hydrolysis and co-condensation of 1,2-bis(triethoxysilyl)ethane
3
4
(BTEE) and 3-aminopropyltriethoxysilane (APTES) around Fe O nanoparticles. This was then
3
4
6

ACCEPTED MANUSCRIPT
1
1
1
1
32
33
34
35
modified with 2-hydroxybenzaldehyde to deliver corresponding Schiff-base ligand
(Fe O @BOS@SB). Finally, the Fe O @BOS@SB/In nanocatalyst was obtained through
3
4
3
4
immobilization of InCl onto Fe O @BOS@SB (Scheme 1). This catalyst was characterized
3
3
4
using several techniques such as FT-IR, TGA, EDS, SEM, VSM, TEM and PXRD.
7

ACCEPTED MANUSCRIPT
1
36
1
1
37
38
Scheme 1. Preparation of Fe O @BOS@SB/In nanocatalyst
3 4
The magnetic property of the catalyst was investigated using vibrating sample magnetometer
(VSM) analysis (Figure 1). This showed a magnetic ability about 12.5 emu/g for the
1
1
1
39
40
41
3 4 3 4
Fe O @BOS@SB/In that is lower than magnetic Fe O NPs confirming successful modification
of iron oxide cores with organosilica shells.
8

ACCEPTED MANUSCRIPT
1
1
5
0
5
0
5
-
10000
-5000
0
5000
10000
-
-
-
10
15
Applied Field (Oe)
1
42
1
1
1
43
44
45
Figure 1. VSM pattern of Fe O @BOS@SB/In nanocatalyst
3 4
Thermal gravimetric (TG) analysis was performed to study the thermal stability of the material.
As shown in Figure,2 a weight loss of about 2.5 % below 120 °C is due to removal of physically
adsorbed water and organic solvents. Afterward, two weight losses were found, first one about 8
% at 200–400 °C and the second one about 18% at 401–800 °C corresponding to elimination of
supported propyl-Schiff-base and incorporated bridged-ethyl groups, respectively. These confirm
well-immobilization of ethyl and propyl-Schiff-base functional groups onto/into material
framework and also show high thermal stability of the catalyst.
1
1
1
1
1
1
46
47
48
49
50
51
9

ACCEPTED MANUSCRIPT
1
52
1
1
53
54
3 4
Figure 2. TG analysis of the Fe O @BOS@SB/In nanocatalyst
1
1
1
55
56
57
Energy-dispersive X-ray spectroscopy (EDS) demonstrated the presence of In, Fe, Si, C, N, O
and Cl elements in the material proving successful incorporation and/or immobilization of
organic groups and indium chloride into/onto material framework (Figure 3).
1
0

ACCEPTED MANUSCRIPT
1
58
1
1
59
60
3 4
Figure 3. EDS spectrum of the Fe O @BOS@SB/In nanocatalyst
1
1
1
1
1
1
1
1
1
1
1
61
62
63
64
65
66
67
68
69
70
71
Fourier transform infrared (FT-IR) spectra of Fe O , Fe O @BOS, Fe O @BOS@SB and
3 4 3 4 3 4
Fe O @BOS@SB/In are demonstrated in Figure 4. For all samples the signal of F-O bond is
3
4
-1
−1
observed about 573 cm . The absorption peaks at 700–800 cm are attributed to C–Si stretching
−
1
vibrations. The bands observed at 1095 and 930 cm are assigned to the symmetric and
asymmetric stretching vibrations of Si–O–Si bonds. C–H stretching vibrations of ethyl and
−
1
propyl functional groups are observed at 2927 cm . In addition, the broad signal around 3350
−
1
cm can be assigned to N–H and O–H bonds of material surface. Interestingly, for
-
1
Fe O @BOS@SB/In a new peak at 1645 cm corresponding to C=N bond is observed
3
4
confirming successful formation of Schiff-base ligand during catalyst preparation (Figure 4c,
4d). These are in good agreement with EDS and TGA results and successfully confirm the
presence of expected functional groups in the structure of the material.
1
1

ACCEPTED MANUSCRIPT
1
72
1
1
73
74
3 4 3 4 3 4
Figure 4. FT-IR spectra of the Fe O (a), Fe O @BOS (b), Fe O @BOS@SB (c) and
Fe O @BOS@SB/In (d)
3
4
1
75
1
1
1
76
77
78
The morphology and particle size of the catalyst was determined using SEM (Figure 5). This
showed well-distributed spherical particles with average size of 50 nm. Moreover, the uniformity
and well-ordering of the particles are also clear in this Figure.
1
2

ACCEPTED MANUSCRIPT
1
79
1
1
80
81
Figure 5. SEM image of the Fe O @BOS@SB/In nanocatalyst
3
4
1
1
82
83
According to TEM image (Figure 6) the designed nanocatalyst has a core-shell structure with
black core (Fe O ) and gray shell (organosilica).
3
4
1
1
84
85
Figure 6. TEM image of the Fe O @BOS@SB/In nanocatalyst
3
4
1
86
1
3

ACCEPTED MANUSCRIPT
1
1
1
1
1
1
1
1
1
87
88
89
90
91
92
93
94
95
The availability of Fe O NPs in Fe O @BOS, Fe O @BOS@SB and Fe O @BOS@SB/In
3
4
3
4
3
4
3
4
nanomaterials was determined by powder X-ray diffraction (PXRD) analysis (Figure 7).For all
samples the Miller indices values (hkl) of 220, 311, 400, 422, 511 and 440 are cleared,
respectively, at 2θ of 30, 36, 43, 54, 57 and 64 degrees. These prove good to high magnetic
properties of designed materials. In fact, the aforementioned peaks are corresponded to Fe O
3
4
NPs and confirm high stability of crystalline structure of these particles during catalyst
preparation. Moreover, the intensity of aforementioned peaks is decreased after each
modification step confirming the successful incorporation and/or immobilization of organic and
inorganic species onto magnetic iron oxide surface.
1
96
1
1
97
98
Figure 7. PXRD analysis of Fe O @BOS (black), Fe O @BOS@SB (red) and Fe O @BOS@SB/In
3
4
3
4
3
4
nanocatalyst (blue)
1
4

ACCEPTED MANUSCRIPT
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
3 4
After successful characterization, the catalytic efficiency of the designed Fe O @BOS@SB/In
nanocatalyst was studied in the reduction of nitrobenzenes. Although there are some reports
about reduction ability of InCl under homogeneous conditions [62, 63], however, all of these
3
studies suffer from the restrictions of product separation, catalyst recoverability and additional
boring steps in extraction process. Therefore, the use of supported IN-catalyst is important
subject in this matter. To test the activity of our indium-based catalyst, the reduction of 4-
nitrobenzaldehyde was selected as a reaction model (Table 1). To obtain the optimum conditions,
the effect of solvent and catalyst loading was investigated in the reaction progress. Various
solvents such as ethanol, water, methanol and THF were tested (Table 1, entries 1-4). It is
important to note that the use of a protic polar solvent will increase the reaction rate due to
release H in the presence of NaBH [64]. As seen in Table 1, the catalyst efficiency is increased
2
4
by changing solvent from ethanol and methanol to water. In THF a low yield is observed. This is
due to formation of a borane/tetrahydrofuran complex (THF-BH ) during applied conditions
3
[60]. Then the amount of catalyst was optimized and the best result was obtained in the presence
3 4
of 0.5 mol% of Fe O @BOS@SB/In nanocatalyst (Table 1, entries 4-6). To show the neat effect
of indium centers in the catalytic process, the model reaction was performed without catalyst as
well as in the presence of indium-free Fe O @BOS@SB and Fe O @BOS materials under
3
4
3
4
conditions as above. Interestingly, for all of these no conversion was observed indicating that the
reduction process is actually catalyzed by supported indium species (Table 1, entries 7-9).
2
2
18
19
1
5

ACCEPTED MANUSCRIPT
Table 1 Optimization of the reaction conditions in reduction of 4-nitrobenzaldehyde
NO2
NH2
Fe O @BOS@SB/In
3
4
NaBH , solvent, r.t.
4
O
H
HO
b
Catalyst
Entry
Solvent
Time (min)
Yield (%)
(
mol %)
0.25
0.25
0.25
0.25
0.5
1
2
3
4
5
6
7
8
9
EtOH
MeOH
Water
THF
12
12
12
12
12
12
12
12
12
20
32
53
35
90
90
Water
Water
Water
Water
Water
0.7
c
-
-
d
c
Fe O @BOS@SB
-
3
4
e
c
Fe O @BOS
-
3
4
a
b
Reaction conditions: 4-nitrobenzaldehyde (1 mmol), NaBH
4
(2 mmol), room temperature.
c
d
Isolated yield.
No conversion was observed during reaction time.
0.01 g of
e
Fe O @BOS@SB was used. 0.01 g of Fe O @BOS was used.
3
4
3
4
2
20
2
2
2
21
22
23
After optimization of the reaction conditions, various derivatives of nitrobenzene were used as
substrate to investigate the activity of the catalyst (Table 2). Interestingly, both electron-
withdrawing and electron-donating substituents containing nitrobenzens were successfully
1
6

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
24
25
26
27
28
29
converted to their corresponding aniline derivatives at room temperature and very short times. It
is also important to note that the carbonyl functional moieties of substrates were also reduced to
their corresponding alcohol adducts under applied conditions (Table 2, entry 3). These results
strongly confirm high efficiency of designed nanocatalyst for green and fast reduction of
different nitrobenzene derivatives at room temperature that is an excellent advantage in the green
chemistry world.
3 4
Table 2. Reduction of nitrobenzenes using Fe O @BOS@SB/In nanocatalyst
Time
min)
M. P. (°C)
M. P. (°C)
b
Entry
1
X
Product
Yield (%)
94
(
Found
Reported [65]
4-Cl
7
7
70-72
67-70
2
3
4-NH2
92
90
143-145
61-63
138-143
4-CHO
12
60-65
1
7

ACCEPTED MANUSCRIPT
Table 2, continued
4
5
4-CH
2
OH
7
93
61-63
60-65
2-OH
12
10
87
91
171-173
79-81
170-175
6
2-CH
2
OH
81-83
a
Reaction conditions: Nitrobenzene derivative (1 mmol), NaBH
4
(2 mmol), catalyst (0.5
b
mol%), H O (3 mL) at room temperature. Isolated yield
2
2
30
2
2
2
2
2
31
32
33
34
35
In the next, the recoverability and reusability of desired indium-based catalyst were studied
(Figure 8). For this, after the reaction was completed, the catalyst was collected and separated
using an external magnetic field and it was reused in the next run under applied conditions as the
first run. These experiments were repeated and it was found that the catalyst could be recovered
and reused at least 6 times with keeping its productivity (Figure 8).
1
8

ACCEPTED MANUSCRIPT
2
36
2
2
37
38
Figure 8.The reusability of Fe O @BOS@SB/In nanocatalyst
3 4
2
2
2
2
2
2
2
2
39
40
41
42
43
44
45
46
To show the nature of actual catalyst in the reaction process, in another study a leaching test was
performed. To do this, after about 50% of the reduction process was completed, it was stopped
and the catalyst was removed using an external magnet. The catalyst-free filtrate was then
allowed to continue for 20 minutes. Pleasingly, in this case no further conversion was observed
indicating that the catalyst operates in a heterogeneous manner. Also to verify chemical stability
of the catalyst, the XRD analysis of the recovered nanocatalyst was performed. As shown in
Figure 9, the pattern of Miller indices values (hkl) is the same as its parent confirming the high
chemical stability of Fe O @BOS@SB/In nanocatalyst during applied conditions.
3
4
1
9

ACCEPTED MANUSCRIPT
2
47
2
2
48
49
Figure 9. The XRD analysis of the recovered nanocatalyst after nitrobenzene reduction
2
2
2
2
2
2
2
50
51
52
53
54
55
56
In the final study, the performance of our catalyst was compared with some of reported catalytic
systems in the reduction of nitrobenzenes (Table 3). The results showed that although the
previously reported catalytic systems have good activity for reduction of nitrobenzenes;
however, in most cases the reaction is performed in organic solvents at temperatures higher than
that employed for the present catalyst. Also we used lower amount of catalyst (0.5 mol%) than
previous reports. Moreover, the recycling times of the present Fe O @BOS@SB/In nanocatalyst
3
4
were shown to be more or less superior than the most of previous catalysts.
2
2
2
57
58
59
2
0

ACCEPTED MANUSCRIPT
Table 3. Comparative study of the efficiency of the Fe O @BOS@SB/In nanocatalyst with
3
4
previously reported catalytic systems in the reduction of nitrobenzenes
Recovery
Catalyst
Conditions
Time (min)
Ref.
[66]
times
1
.48 mol% catalyst,
[NAP-Mg-Pd (0)]
120
5
THF, r.t., H2
1
0 mol% catalyst,
Cu NPs
THF/H O, 50 °C,
120
3
[67]
2
NaBH4
2
5 mg catalyst,
AgNPs@CeO2
dodecane, 110 °C,
360
7-120
360
2
8
[68]
[69]
[70]
[71]
H
2
0
.2 mg catalyst,
water, r.t., NaBH4
mol% catalyst,
THF/H O, 110 °C,
3 4
Fe O @PDA–Au
1
Co-L1/C
Pd/PEG
10
10
2
H
2
1
00 mg catalyst,
EtOH, r.t., H2
180
5
mol% catalyst,
In (OH) (BDC)
1.5
40 °C (autoclave),
H2
220
12
4
6
[72]
2
3
0
.5 mol% catalyst,
Fe O @BOS@SB/In
This work
3
4
water, r.t., NaBH4
Abbreviations: [NAP-Mg-Pd (0)]: Nanocrystalline magnesium oxide-stabilized palladium
0). AgNPs@CeO : Silver–Cerium dioxide core–shell nanocomposite. Fe @PDA–Au:
gold nanoparticles on the surface of polydopamine (PDA)-encapsulated Fe O nanoparticles.
(
2
3 4
O
3
4
Co-L1/C: cobalt oxide-phenanthrolinev/carbon. Pd/PEG: palladium nanoparticles in
polyethylene glycol (PEG). BDC: 1,4-benzendicarboxylate
2
1

ACCEPTED MANUSCRIPT
2
2
2
2
60
61
62
63
It is also important to note that using hydrogen gas in reduction is so dangerous, because of
explosion potential, but in this report we used sodium borohydride that is safe, affordable and
has a mild reaction condition. These findings significantly confirm the high efficiency of the
present catalyst in the reduction of different derivatives of nitrobenzenes.
2
2
64
65
4. Conclusion
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
In conclusion, for the first time a novel magnetic bifunctional organosilica supported
3 4
indium/Schiff-base catalyst (Fe O @BOS@SB/In) was prepared. The magnetic properties of this
were investigated using VSM showing good magnetic ability of the material. TG analysis
confirmed well immobilization of ethyl and propyl-Schiff-base functional groups on magnetic
iron oxide cores and also showed high thermal stability of the catalyst. Energy-dispersive X-ray
spectroscopy (EDS) demonstrated the presence of expected In, Fe, Si, C, N, O and Cl elements
in the material. Also the FT-IR analysis confirmed the EDS and TGA results and successfully
proved the presence of expected functional groups in the structure of the material. The
morphology and particle size of the catalyst was determined using SEM and TEM analyses.
These demonstrated a core-shell structure with spherical morphology for the catalyst. The PXRD
pattern confirmed the high stability of Fe O NPs during catalyst preparation. The catalytic
3
4
efficiency of the designed Fe O @BOS@SB/In nanocatalyst was studied in the reduction of
3
4
nitrobenzene in which some parameters such as temperature, catalyst loading and solvent were
optimized. A set of different nitrobenzene derivatives were converted to their corresponding
anilines in the presence of low loading of catalyst. The designed Fe O @BOS@SB/In was also
3
4
recovered and reused at least 6 times with keeping its performance. The leaching test and PXRD
analysis of the recovered catalyst showed high stability and durability of this material during
2
2

ACCEPTED MANUSCRIPT
2
2
2
83
84
85
applied conditions. Other advantages of the present study are the use of water as solvent, easy
product and catalyst separation and high reaction rate at green conditions. Some applications of
this catalyst in other organic transformations are underway in our laboratories.
2
86
2
3

ACCEPTED MANUSCRIPT
2
87
References
2
2
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
88
89
90
91
92
93
94
95
96
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
[1] J. Belleson, E. Grochowski, The era of giant magnetoresistive heads, Hitachi Global Storage
Technologies, (1998).
[2] M. Kanellos, A Divide Over the Future of Hard Drives, Cnet News, published Aug, 23
(2006).
[3] H.V. Thakur, S.M. Nalawade, S. Gupta, R. Kitture, S. Kale, Photonic crystal fiber injected
with Fe3O4 nanofluid for magnetic field detection, ApPhL, 99 (2011) 161101.
[4] C. Ban, Z. Wu, D.T. Gillaspie, L. Chen, Y. Yan, J.L. Blackburn, A.C. Dillon, Nanostructured
Fe3O4/swnt electrode: binder
‐
free and high
‐ rate li‐ ion anode, Adv. Mater., 22 (2010).
[5] S. Abanades, I. Villafan
‐
Vidales, CO2 valorisation based on Fe3O4/FeO thermochemical
redox reactions using concentrated solar energy, Int. J. Energy Res., 37 (2013) 598-608.
[6] S.-W. Cao, Y.-J. Zhu, M.-Y. Ma, L. Li, L. Zhang, Hierarchically nanostructured magnetic
hollow spheres of Fe3O4 and γ-Fe2O3: preparation and potential application in drug delivery, J.
Phys. Chem. C, 112 (2008) 1851-1856.
[7] Y. Zhu, T. Ikoma, N. Hanagata, S. Kaskel, Rattle‐ type Fe3O4@ SiO2 hollow mesoporous
spheres as carriers for drug delivery, Small, 6 (2010) 471-478.
[8] X. Li, X. Huang, D. Liu, X. Wang, S. Song, L. Zhou, H. Zhang, Synthesis of 3D hierarchical
Fe3O4/graphene composites with high lithium storage capacity and for controlled drug delivery,
J. Phys. Chem. C, 115 (2011) 21567-21573.
[9] F. Chen, Q. Gao, J. Ni, The grafting and release behavior of doxorubincin from Fe3O4@
SiO2 core–shell structure nanoparticles via an acid cleaving amide bond: the potential for
magnetic targeting drug delivery, Nanotechnology, 19 (2008) 165103.
[10] Y. Zhu, Y. Fang, S. Kaskel, Folate-conjugated Fe3O4@ SiO2 hollow mesoporous spheres
for targeted anticancer drug delivery, J. Phys. Chem. C, 114 (2010) 16382-16388.
[11] Z. Yuanbi, Q. Zumin, J. Huang, Preparation and Analysis of Fe3O4 Magnetic Nanoparticles
Used as Targeted-drug Carriers Supported by the Technology Project of Jiangxi Provincial
Education Department and Jiangxi Provincial Science Department, Chin. J. Chem. Eng., 16
(2008) 451-455.
[12] X. Wang, R. Zhang, C. Wu, Y. Dai, M. Song, S. Gutmann, F. Gao, G. Lv, J. Li, X. Li, The
application of Fe3O4 nanoparticles in cancer research: a new strategy to inhibit drug resistance, J
Biomed Mater Res A, 80 (2007) 852-860.
[13] B.-L. Lin, X.-D. Shen, S. Cui, Application of nanosized Fe3O4 in anticancer drug carriers
with target-orientation and sustained-release properties, Biomed. Mater., 2 (2007) 132.
[14] D. Pan, H. Zhang, T. Fan, J. Chen, X. Duan, Nearly monodispersed core–shell structural
Fe3O4@ DFUR–LDH submicro particles for magnetically controlled drug delivery and release,
Chem. Commun., 47 (2011) 908-910.
[15] X. Lou, J. Huang, T. Li, H. Hu, B. Hu, Y. Zhang, Hydrothermal synthesis of Fe3O4 and α-
Fe2O3 nanocrystals as anode electrode materials for rechargeable Li-ion batteries, J. Mater. Sci.:
Mater. Electron., 25 (2014) 1193-1196.
[16] T.A. Gad-Allah, S. Kato, S. Satokawa, T. Kojima, Treatment of synthetic dyes wastewater
utilizing a magnetically separable photocatalyst (TiO2/SiO2/Fe3O4): Parametric and kinetic
studies, Desalination, 244 (2009) 1-11.
[17] Y. Jiao, D. Han, L. Liu, L. Ji, G. Guo, J. Hu, D. Yang, A. Dong, Highly Ordered
Mesoporous Few
‐ Layer Graphene Frameworks Enabled by Fe3O4 Nanocrystal Superlattices,
Angew. Chem., 127 (2015) 5819-5823.
2
4

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
[18] W. Gu, X. Deng, X. Gu, X. Jia, B. Lou, X. Zhang, J. Li, E. Wang, Stabilized,
superparamagnetic functionalized graphene/Fe3O4@ Au nanocomposites for a magnetically-
controlled solid-state electrochemiluminescence biosensing application, AnaCh, 87 (2015) 1876-
1881.
[19] H. Veisi, A. Sedrpoushan, B. Maleki, M. Hekmati, M. Heidari, S. Hemmati, Palladium
immobilized on amidoxime‐ functionalized magnetic Fe3O4 nanoparticles: a highly stable and
efficient magnetically recoverable nanocatalyst for sonogashira coupling reaction, Appl
Organomet Chem, 29 (2015) 834-839.
[20] N. Zohreh, S.H. Hosseini, A. Pourjavadi, C. Bennett, Immobilized copper (II) on nitrogen
rich polymer entrapped Fe3O4 nanoparticles: a highly loaded and magnetically recoverable
catalyst for aqueous click chemistry, Appl Organomet Chem, 30 (2016) 73-80.
‐
‐
[21] S. Wang, Z. Zhang, B. Liu, Catalytic Conversion of Fructose and 5-Hydroxymethylfurfural
into 2, 5-Furandicarboxylic Acid over a Recyclable Fe3O4–CoO x Magnetite Nanocatalyst, ACS
SUSTAIN. CHEM. ENG, 3 (2015) 406-412.
[22] L. Z Fekri, M. Nikpassand, K. H Pour, Green aqueous synthesis of mono, bis and
trisdihydropyridines using nano Fe3O4 under ultrasound irradiation, Curr. Org. Synth., 12 (2015)
76-79.
[23] M.A. Tamilmagan, G.A. PriyaBijesh, Biodiesel production from waste cooking oil using
green synthesized nanoFe2O3 and CuO impregnated nano Fe3O4, Int J Chemtech Res, 8 (2015)
90-96.
[24] K. Osouli-Bostanabad, H. Aghajani, E. Hosseinzade, H. Maleki-Ghaleh, M. Shakeri, High
microwave absorption of nano-Fe3O4 deposited electrophoretically on carbon fiber, MMP, 31
(2016) 1351-1356.
[25] B. Amirheidari, M. Seifi, M. Abaszadeh, Evaluation of magnetically recyclable nano-Fe3O4
as a green catalyst for the synthesis of mono-and bis-tetrahydro-4H-chromene and mono and bis
1, 4-dihydropyridine derivatives, Res. Chem. Intermed., 42 (2016) 3413-3423.
[26] A.R. Kiasat, M. Daei, S.J. Saghanezhad, Synthesis and characterization of a novel nano-
Fe3O4-copoly [(styrene/acrylic acid)/grafted ethylene oxide and its application as a magnetic
and recyclable phase-transfer catalyst in the preparation of
Res. Chem. Intermed., 42 (2016) 581-594.
β-azido alcohols and β-nitro alcohols,
[27] T. Wu, Y. Liu, X. Zeng, T. Cui, Y. Zhao, Y. Li, G. Tong, Facile hydrothermal synthesis of
Fe3O4/C core–shell nanorings for efficient low-frequency microwave absorption, ACS Appl.
Mater. Interfaces, 8 (2016) 7370-7380.
[28] A. Samadi, M. Amjadi, Magnetic Fe3O4@ C nanoparticles modified with 1-(2-
thiazolylazo)-2-naphthol as a novel solid-phase extraction sorbent for preconcentration of copper
(II), Microchim. Acta, 182 (2015) 257-264.
[29] X. Wang, B. Song, M. Huo, Y. Song, Z. Lv, Y. Zhang, Y. Wang, Y. Song, J. Wen, Y. Sui,
Fast and sensitive lateral photovoltaic effects in Fe3O4/Si Schottky junction, RSC Adv., 5 (2015)
65048-65051.
[30] K. Faghihi, A. Raeisi, M. Amini, M. Shabanian, A.R. Karimi, Sulfonic acid-functionalized
Fe3O4 reinforced soluble polyimide: synthesis and properties, Polym.-Plast. Technol. Eng., 55
(2016) 259-267.
[31] T. Wang, L. Zhang, C. Li, W. Yang, T. Song, C. Tang, Y. Meng, S. Dai, H. Wang, L. Chai,
Synthesis of core–shell magnetic Fe3O4@ poly (m-phenylenediamine) particles for chromium
reduction and adsorption, Environ Sci Technol, 49 (2015) 5654-5662.
2
5

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
[32] Y. Chen, J. Nan, Y. Lu, C. Wang, F. Chu, Z. Gu, Hybrid Fe3O4-poly (acrylic acid)
Nanogels for theranostic cancer treatment, J. Biomed. Nanotechnol., 11 (2015) 771-779.
[33] X. Liu, X. Zhao, M. Lu, Pd Nanoparticles Immobilized on Fe3O4@ Poly (ethylene glycol)
Bridged Amine Functionalized Imidazolium Ionic Liquid: A Magnetically Separable Catalyst for
Heck in Water, CatL, 145 (2015) 1549-1556.
[34] Y. Jiang, J. Jiang, Q. Gao, M. Ruan, H. Yu, L. Qi, A novel nanoscale catalyst system
composed of nanosized Pd catalysts immobilized on Fe3O4@ SiO2–PAMAM, Nanotechnology,
19 (2008) 075714.
[35] L. Zhou, C. Gao, W. Xu, Robust Fe3O4/SiO2-Pt/Au/Pd magnetic nanocatalysts with
multifunctional hyperbranched polyglycerol amplifiers, Langmuir, 26 (2010) 11217-11225.
[36] M. Shao, F. Ning, J. Zhao, M. Wei, D.G. Evans, X. Duan, Preparation of Fe3O4@ SiO2@
layered double hydroxide core–shell microspheres for magnetic separation of proteins, J. Am.
Chem. Soc., 134 (2012) 1071-1077.
[37] D. Elhamifar, P. Mofatehnia, M. Faal, Magnetic Nanoparticles Supported Schiff-
base/Copper Complex: An Efficient Nanocatalyst for Preparation of Biologically Active 3, 4-
Dihydropyrimidinones, J. Colloid Interface Sci., (2017).
[38] M. Ma, F. Yan, M. Yao, Z. Wei, D. Zhou, H. Yao, H. Zheng, H. Chen, J. Shi, Template-
Free Synthesis of Hollow/Porous Organosilica–Fe3O4 Hybrid Nanocapsules toward Magnetic
Resonance Imaging-Guided High-Intensity Focused Ultrasound Therapy, ACS Appl. Mater.
Interfaces, 8 (2016) 29986-29996.
[39] J. Li, Y. Wei, W. Li, Y. Deng, D. Zhao, Magnetic spherical cores partly coated with
periodic mesoporous organosilica single crystals, Nanoscale, 4 (2012) 1647-1651.
[40] H. Yang, G. Li, Z. Ma, Magnetic core–shell-structured nanoporous organosilica
microspheres for the Suzuki–Miyaura coupling of aryl chlorides: improved catalytic activity and
facile catalyst recovery, J. Mater. Chem., 22 (2012) 6639-6648.
[41] Z. Yacob, A. Nan, J. Liebscher, Proline‐ Functionalized Magnetic Core‐ Shell
Nanoparticles as Efficient and Recyclable Organocatalysts for Aldol Reactions, Adv. Synth.
Catal., 354 (2012) 3259-3264.
[42] P. Bhanja, T. Sen, A.J.J.o.M.C.A.C. Bhaumik, A magnetically recoverable nanocatalyst
based on functionalized mesoporous silica, J. Mol. Catal. A: Chem., 415 (2016) 17-26.
[43] J. Mondal, T. Sen, A.J.D.T. Bhaumik, Fe3O4@ mesoporous SBA-15: a robust and
magnetically recoverable catalyst for one-pot synthesis of 3, 4-dihydropyrimidin-2 (1 H)-ones
via the Biginelli reaction, Dalton Trans., 41 (2012) 6173-6181.
[44] M. Hasanzadeh, F. Farajbakhsh, N. Shadjou, A. Jouyban, Mesoporous (organo) silica
decorated with magnetic nanoparticles as a reusable nanoadsorbent for arsenic removal from
water samples, Environ Technol, 36 (2015) 36-44.
[45] J. Kim, H.S. Kim, N. Lee, T. Kim, H. Kim, T. Yu, I.C. Song, W.K. Moon, T. Hyeon,
Multifunctional uniform nanoparticles composed of a magnetite nanocrystal core and a
mesoporous silica shell for magnetic resonance and fluorescence imaging and for drug delivery,
Angew. Chem. Int. Ed., 47 (2008) 8438-8441.
[46] A.K. Gupta, M. Gupta, Cytotoxicity suppression and cellular uptake enhancement of surface
modified magnetic nanoparticles, Biomaterials, 26 (2005) 1565-1573.
[47] T. Mahmood, A. Elliott, A review of secondary sludge reduction technologies for the pulp
and paper industry, Water Res, 40 (2006) 2093-2112.
2
6

ACCEPTED MANUSCRIPT
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
[48] D.J. Constable, P.J. Dunn, J.D. Hayler, G.R. Humphrey, J.L. Leazer Jr, R.J. Linderman, K.
Lorenz, J. Manley, B.A. Pearlman, A. Wells, Key green chemistry research areas—a perspective
from pharmaceutical manufacturers, Green Chem., 9 (2007) 411-420.
[49] Z. Szcygiel, C. Lara, S. Escobedo, O. Mendoza, The direct reduction of sulfide minerals for
the recovery of precious metals, JOM, 50 (1998) 55.
[50] A. Pielesz, The process of the reduction of azo dyes used in dyeing textiles on the basis of
infrared spectroscopy analysis, J. Mol. Struct., 511 (1999) 337-344.
[51] D. Hartter, The Use and Importance, Toxicity of nitroaromatic compounds, 1 (1985).
[52] L.-X. Cheng, J.-J. Tang, H. Luo, X.-L. Jin, F. Dai, J. Yang, Y.-P. Qian, X.-Z. Li, B. Zhou,
Antioxidant and antiproliferative activities of hydroxyl-substituted Schiff bases, Bioorg. Med.
Chem. Lett., 20 (2010) 2417-2420.
[53] U. Sharma, P.K. Verma, N. Kumar, V. Kumar, M. Bala, B. Singh, Phosphane
‐
Free Green
Protocol for Selective Nitro Reduction with an Iron‐ Based Catalyst, Chem. Eur. J., 17 (2011)
5903-5907.
[54] A. Corma, P. Serna, Chemoselective hydrogenation of nitro compounds with supported gold
catalysts, Sci, 313 (2006) 332-334.
[55] N. Pradhan, A. Pal, T. Pal, Silver nanoparticle catalyzed reduction of aromatic nitro
compounds, Colloids Surf. Physicochem. Eng. Aspects, 196 (2002) 247-257.
[56] E. Yilmaz, M.J.J.o.t.I.C.S. Soylak, Facile and green solvothermal synthesis of palladium
nanoparticle-nanodiamond-graphene oxide material with improved bifunctional catalytic
properties, 14 (2017) 2503-2512.
[57] E. Yilmaz, Y. Tut, O. Turkoglu, M.J.J.o.t.I.C.S. Soylak, Synthesis and characterization of
Pd nanoparticle-modified magnetic Sm 2 O 3–ZrO 2 as effective multifunctional catalyst for
reduction of 2-nitrophenol and degradation of organic dyes, 15 (2018) 1721-1731.
[58] S.K. Ghosh, M. Mandal, S. Kundu, S. Nath, T. Pal, Bimetallic Pt–Ni nanoparticles can
catalyze reduction of aromatic nitro compounds by sodium borohydride in aqueous solution,
Appl. Catal., A, 268 (2004) 61-66.
[59] C.J. Moody, M.R. Pitts, Indium as a reducing agent: reduction of aromatic nitro groups,
Synlett, 1998 (1998) 1028-1028.
[60] J.Z. Saavedra, A. Resendez, A. Rovira, S. Eagon, D. Haddenham, B. Singaram, Reaction of
InCl3 with various reducing agents: InCl3–NaBH4-mediated reduction of aromatic and aliphatic
nitriles to primary amines, J. Org. Chem., 77 (2011) 221-228.
[61] Y.S. Kang, S. Risbud, J.F. Rabolt, P. Stroeve, Synthesis and characterization of nanometer-
size Fe3O4 and γ-Fe2O3 particles, Chem. Mater., 8 (1996) 2209-2211.
[62] D.C. Barman, A.J. Thakur, D. Prajapati, J.S. Sandhu, InCl3-Zn. A Novel Reduction System
for the Deoxygenative Coupling of Carbonyl Compounds to Olefins, Synlett, 2001 (2001) 0515-
0516.
[63] P. Li, L. Wang, Y. Yang, X. Sun, M. Wang, J. Yan, A novel reduction of sodium alkyl
thiosulfates with InCl3 (cat.)/Sm (0) system in aqueous media: Facile synthesis of disulfides,
Heteroat. Chem, 15 (2004) 376-379.
[64] A. E Johnson, V. Tamara Perchyonok, On the Scope of Radical Reactions Utilizing
InCl3/coreductant as an Efficient Reagent for Synthetically Useful Transformations in Aqueous
and Organic Solvents, Curr. Org. Chem., 14 (2010) 2007-2011.
[65] Aldrich Catalog Handbook of Fine Chemicals, in: A.C. Company (Ed.), 2012–2014.
2
7

ACCEPTED MANUSCRIPT
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
[66] M.L. Kantam, R. Chakravarti, U. Pal, B. Sreedhar, S. Bhargava, Nanocrystalline
Magnesium Oxide‐ Stabilized Palladium (0): An Efficient and Reusable Catalyst for Selective
Reduction of Nitro Compounds, Adv. Synth. Catal., 350 (2008) 822-827.
[67] Z. Duan, G. Ma, W. Zhang, Preparation of copper nanoparticles and catalytic properties for
the reduction of aromatic nitro compounds, Bull. Korean Chem. Soc., 33 (2012) 4003-4006.
[68] T. Mitsudome, Y. Mikami, M. Matoba, T. Mizugaki, K. Jitsukawa, K. Kaneda, Design of a
silver–cerium dioxide core–shell nanocomposite catalyst for chemoselective reduction reactions,
Angew. Chem. Int. Ed., 51 (2012) 136-139.
[69] T. Zeng, H.-y. Niu, Y.-r. Ma, W.-h. Li, Y.-q. Cai, In situ growth of gold nanoparticles onto
polydopamine-encapsulated magnetic microspheres for catalytic reduction of nitrobenzene,
Appl. Catal., B, 134 (2013) 26-33.
[70] F.A. Westerhaus, R.V. Jagadeesh, G. Wienhöfer, M.-M. Pohl, J. Radnik, A.-E. Surkus, J.
Rabeah, K. Junge, H. Junge, M. Nielsen, Heterogenized cobalt oxide catalysts for nitroarene
reduction by pyrolysis of molecularly defined complexes, Nat. Chem., 5 (2013) 537-543.
[71] F. Harraz, S. El-Hout, H. Killa, I. Ibrahim, Palladium nanoparticles stabilized by
polyethylene glycol: Efficient, recyclable catalyst for hydrogenation of styrene and nitrobenzene,
J. Catal., 286 (2012) 184-192.
[72] B. Gomez-Lor, E. Gutierrez-Puebla, M. Iglesias, M. Monge, C. Ruiz-Valero, N. Snejko, In2
(oh) 3 (bdc) 1.5 (bdc= 1, 4-benzendicarboxylate): an In (iii) supramolecular 3d framework with
catalytic activity, Inorg. Chem., 41 (2002) 2429-2432.
4
4
4
4
4
4
4
4
4
4
85
86
87
88
89
90
91
92
93
94
2
8