Decoration of β-CD-ZrO on Fe3O4 magnetic nanoparticles as a magnetically, recoverable and reusable catalyst for the synthesis of 2,3-dihydro-1H-perimidines

Article abstract of DOI:10.1007/s11164-018-3574-y

Abstract: This study focuses on covalent grafting of ZrO to β-CD to prepare an organic–inorganic hybrid material. The synthesised product was successfully linked on the surface of Fe₃O₄ magnetic nanoparticles and characterized by TGA

Full text of DOI:10.1007/s11164-018-3574-y

Research on Chemical Intermediates
https://doi.org/10.1007/s11164-018-3574-y(0123456789(). -, vo Vl
)
0
1
2
3
4
5
6
7
8
9
(
)
.
-
v
o
l
V
)
Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles
as a magnetically, recoverable and reusable catalyst
for the synthesis of 2,3-dihydro-1H-perimidines
Mohammad Ali Amrollahi1 Fatemeh Vahidnia1
•
Received: 9 May 2018 / Accepted: 25 August 2018
Ó Springer Nature B.V. 2018
Abstract
This study focuses on covalent grafting of ZrO to b-CD to prepare an organic–
inorganic hybrid material. The synthesised product was successfully linked on the
surface of Fe3O4 magnetic nanoparticles and characterized by TGA, XRF, XRD,
FT-IR and TEM techniques. Also, magnetism of the organomethalic complex was
investigated by the VSM technique. The synthesized magnetic complex was found
to be a highly effective heterogeneous catalyst for improving the cyclocondensation
reaction of 1,8-diaminonaphthalene with aromatic aldehydes to obtain 2,3-dihydro-
1H-perimidine derivatives. Simple isolation of products, easy recovering of the
catalyst by external magnet, reusability of the catalyst, high yields of the products,
mild reaction conditions, and avoiding toxic solvents are the main benefits of this
method.
&
Mohammad Ali Amrollahi
mamrollahi@yazd.ac.ir
1
Chemistry Department, Yazd University, P.O. Box 89195-741, Yazd, Iran
123

M. A. Amrollahi, F. Vahidnia
Graphical abstract
Keywords b-CD Á b-CD-ZrO complex Á Inclusion complex Á Heterogeneous
magnetic catalyst Á Perimidines
Introduction
In a few recent decades researchers have made much effort regarding the
development of new catalysts using effective methods for the synthesis of organic
compounds [1]. In this respect, technical improvements of immobilized catalysts
that allows the simple work-up procedure and easy separation from reaction
products is challenging and important [2]. Zirconium salts as homogeneous Lewis
acid catalysts have already been cited in the literature in a number of biologically
and pharmaceutically significant organic transformations [3–8]. b-cyclodextrin (b-
CD), a naturally occurring cyclic oligosaccharide, has been used to prevent
magnetite nanoparticles from aggregating, and represents an attractive choice for
preparation of functional materials. Low cost, solubility in water, low toxicity and
its ability to form inclusion complexes (host–guest complexes) are the main
advantages of this cyclic oligosaccharide [9–15]. The first step of our present work
is directed to modify zirconium oxide on to the b-CD for the synthesis of an
organic–inorganic hybrid complex. Then, we have chosen Fe3O4 support due to its
high surface area, excellent stability both chemically and thermally, and good
accessibility to functionalize its surface groups by synthesized b-CD-ZrO Lewis
acid complex [16–20]. This organometallic nanoparticle, which can be recycled
from the medium of reaction by an external magnetic field, is easily prepared and
considered as an effective catalyst in the cyclocondensation reaction of 1,8-
diaminonaphthalene with aromatic aldehydes. Perimidines, resulting from reaction
of 1,8-diaminonaphthalene with aromatic aldehydes, are important substructures
and extensively shown worth synthetic properties for both medicinal and synthetic
123

Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles as…
organic chemists [21–33]. They have received much attention due to their potency
and wide spectrum of biological activities such as antifungal, antibacterial,
antimicrobial, antiulcer, antitumor agents, and optoelectronic properties. Although
there are many synthetic routes to obtain 2,3-dihydro-1H-perimidine derivatives,
they suffer from several limitations such as drastic reaction conditions, low product
yields, tedious work-up procedures, the use of toxic metal salts as catalysts, and
expensive reagents. The main disadvantage of most existing methods was that the
catalysts were destroyed in the work-up procedure and could not be recovered or
reused. Therefore, development of facile, efficient and green methods for the
synthesis of 2,3-dihydro-1H-perimidines are still favourable. This study reports on
the preparation and characterization of a Fe3O4 magnetic nanoparticle-supported b-
CD-ZrO organometallic material (Fe3O4@b-CD-ZrO) as a novel composite. In
addition, we describe its utility for the synthesis of 2,3-dihydro-1H-perimidine
derivatives by cyclocondensation of 1,8-diaminonaphthalene with aromatic
aldehydes.
Experimental
General
All the chemicals were of reagent degree and were used as received without further
purification. 1H- and 13C-NMR spectra were recorded at 25 °C on a Bruker Avance-
400 MHz spectrometer in the presence of tetramethylsilane as the internal standard.
The chemical shifts were defined in sections per million (ppm). The IR spectroscopy
of the samples was recorded by KBr pills on a Bruker Eqinox-55 FT-IR
spectrometer in the 400–4000 cm-1 region. The melting points were obtained on
a Bu¨chi melting point B-540 B.V.CHI apparatus and are uncorrected. The reactions
and the purity of the products were controlled by thin-layer chromatography (TLC)
on aluminum-backed plates covered with Merck Kiesel gel 60 F254 silica gel. The
x-ray diffraction (XRD) data were collected with a Philips X-pert diffractometer
˚
equipped with a Cu-Ka radiation (k = 1.54 A) in the 2h range from 5 to 80. X-ray
fluorescence (XRF) analysis was carried out with a Bruker S4 Explorer instrument.
Thermogravimetric analysis (TGA) was performed on a STA 504 analyzer. The
magnetic measurements were performed using a Vibrating Sample Magnetometer
(VSM) Model LBKFB. Transmission electron microscopy (TEM) was performed
using a Zeiss EM10C with accelerating voltage of 100 kV.
Preparation b-CD-ZrO
A solution of NaOH (0.50 M, 50 mL) and b-CD (1 mmol, 1.14 g) was stirred at
room temperature. After the appearance of a clear solution, ZrOCl2 (0.02 M,
75 mL) was added, and the mixture was continuously stirred at room temperature
for 6 h. The resulting reaction mixture was filtered, and the precipitated b-CD-ZrO
complex was washed with ethanol and dried at room temperature. The formation of
the b-CD-ZrO complex can be rationalized as outlined in Scheme 1.
123

M. A. Amrollahi, F. Vahidnia
Scheme 1 Synthesis of covalently anchored ZrO onto b-CD
Preparation of Fe3O4-supported b-CD-ZrO nanoparticles
Fe3O4-supported b-CD-ZrO nanoparticles were prepared by a prevalent chemical
co-precipitation method. b-CD-ZrO (1.50 g), FeCl3Á6H2O (2.40 g), and FeCl2Á4H2O
(0.90 g) were dissolved in distilled water (10 mL) with intensive stirring at 90 °C.
Subsequently, NH4OH 25% (5 mL) was added drop-wise to the reaction mixture
with continuous stirring. The formed composite was collected by an external
magnet, washed with distilled water frequently and dried at room temperature for
24 h. The morphology and structure of the prepared Fe3O4@b-CD-ZrO nanopar-
ticles (Scheme 2) were characterized by TGA, XRF, XRD, VSM, FT-IR and TEM
analyses, which confirmed the successful preparation of the supported Fe3O4
nanoparticles.
Scheme 2 Fe3O4 magnetic nanoparticle-supported b-CD-ZrO complex
123

Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles as…
General procedure for preparation of 2,3-dihydro-1H-perimidines
A mixture of Fe3O4@b-CD-ZrO (0.04 g) and aromatic aldehyde (1 mmol) in EtOH
(5 mL) was stirred for 15 min at room temperature. Then, 1,8-diaminonaphthalene
(1 mmol) was added, and the reaction mixture was stirred at room temperature for
10–20 min later. After completion of the reaction, which was monitored by TLC,
the magnetic nanoparticles were separated by an external magnet from the reaction
mixture. The solvent was evaporated under reduced pressure, and the residue was
recrystallized from ethanol. All products were characterized, and their spectral data
had good accordance with the assigned structures. As an example, the spectra data
of 2-phenyl-2,3-dihydro-1H-perimidine are: IR (KBr) 3360 (NH stretching), 3039
(=CH stretching), 1593, 1481(C=C), 1H NMR (400 MHz, CDCl3) 4.56 (s, 2H, NH),
5.48 (s, 1H, CH), 6.55 (dd, J1 = 5.2 Hz, J2 = 1.6 Hz, 2H, ArH), 7.30 (m, 4H, ArH),
7.49 (m, 3H, ArH), 7.67(m, 2H, ArH), and 13C NMR (100 MHz, CDCl3) 68.4,
105.1, 113.5, 117.1, 127.0, 128.1, 128.1, 129.7, 135.0, 140.2, 142.2.
Results and discussion
The morphology and structure of the prepared Fe3O4@b-CD-ZrO composite were
characterized through TGA, XRF, XRD, VSM, FT-IR, and TEM analysis, which
verified the successful preparation of the supported Fe3O4 nanoparticles.
The thermal stability of b-CD-ZrO and Fe3O4@b-CD-ZrO was studied by TGA,
and the results are illustrated in Fig. 1. According to TG analysis, b-CD-ZrO
exhibited two weight loss steps at 40–120 °C and 140–440 °C. The former was
associated with the evaporation of water that had been adsorbed by b-CD-ZrO; the
latter was due to the decomposition of b-CD-ZrO (Fig. 1a). Two weight loss steps
were also observed in the TGA curve of Fe3O4@b-CD-ZrO composite. The weight
loss below 180 °C was estimated to be 6.0 wt% due to the loss of the adsorbed water
Fig. 1 TGA curve of the b-CD-ZrO (a) and Fe3O4@b-CD-ZrO (b)
123

M. A. Amrollahi, F. Vahidnia
as well as dehydration of the surface OH groups (the first step) and the weight loss
over the range of 200–420 °C (* 17.0 wt%) was attributed to the thermal
decomposition of Fe3O4@b-CD-ZrO composite.
Successful supporting of b-CD-ZrO complex on the magnetic surface was proved
from the obtained results of XRF analysis (Table 1).
XRD patterns of Fe3O4 and Fe3O4@b-CD-ZrO are shown in Fig. 2. Fe3O4 shows
diffraction peaks at 2h = 30.2°, 35.6°, 43.1°, 53.8°, 57.2°, and 62.9° which are quite
matched with the cubic spinel structure of pure Fe3O4 described in the literature
(Fig. 2a). The same peaks were also observed in the Fe3O4@b-CD-ZrO XRD
pattern, indicating retention of the crystalline spinel ferrite core structure during the
coating process. Moreover, weak diffraction peaks around 2h = 5–30 in the
Fe3O4@b-CD-ZrO composite could be related to the amorphous b-CD coated on
the Fe3O4 and no characteristic peaks for ZrO particles were observed (Fig. 2b). The
crystalline size of the synthesized composite was obtained according to the Debye–
Scherrer equation D = 0.9k/bcosh. The parameters in the Scherrer equation are
˚
defined as follows: D is the average crystalline size in angstrom (A), k is the x-ray
˚
wavelength (1.54 A), b represents the full width in radian subtended by the half
maximum intensity width of the (2h = 35.6) powder peak, and h corresponds to
Bragg’s angle of the (2h = 35.6) peak in degree. Based on this formula, the average
size of Fe3O4 and Fe3O4@b-CD-ZrO nanoparticles were estimated to be 26 and
23 nm, respectively.
The magnetic properties of Fe3O4@b-CD-ZrO were investigated by VSM
studies. Figure 3 shows the magnetic hysteresis loops of Fe3O4 (a) and Fe3O4@b-
CD-ZrO (b) in an applied magnetic field of 10,000 Oe at room temperature. The
hysteresis loops of the Fe3O4@b-CD-ZrO nanoparticles show a magnetic behaviour
with their re-dispersion stability in solution, without any aggregation. The saturation
magnetization of Fe3O4@b-CD-ZrO nanoparticles shown in Fig. 3b is about 25.0
Table 1 Results of XRF
analysis of Fe3O4@b-CD-ZrO
composite
Elemental component
Wt%
MnO
TiO2
Al2O3
HfO2
V2O5
SO3
0.033
0.045
0.17
0.18
0.23
0.29
0.68
2.22
2.3
Er2O3
SiO2
Na2O
Cl
5.17
5.206
29
ZrO2
CO2
Fe2O3
Total
55.52
100
123

Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles as…
Fig. 2 XRD diffraction pattern of Fe3O4 (a) and Fe3O4@b-CD-ZrO (b)
Fig. 3 Magnetization curves for the prepared Fe3O4 (a) and Fe3O4@b-CD-ZrO (b)
emu g-1, which is relatively lower than unsupported Fe3O4 in Fig. 3a. This is due to
the non-magnetic properties of b-CD-ZrO in the prepared catalyst.
IR spectroscopy is a suitable tool for the characterization of Fe3O4–supported b-
CD-ZrO. The IR spectra of b-CD, b-CD-ZrO, Fe3O4 and Fe3O4@b-CD-ZrO
complex are shown in Fig. 4. It is known that the sharp peak at 580 cm-1
corresponds to Fe-O stretching frequency. For Fe3O4@b-CD-ZrO spectra, an
additional peak was observed at 1028 cm-1 which corresponds to the asymmetry
C–O–C vibrations indicating that the magnetic Fe3O4 nanoparticles are coated by b-
CD-ZrO.
Figure 5 presents the TEM of Fe3O4@b-CD-ZrO, which was applied to
investigate the particle size and morphology of the composite. The TEM image
of the Fe3O4@b-CD-ZrO shows nanoparticles with nearly spherical shape, and the
diameter of these nanoparticles was found to be between 17 and 25 nm which was
different than that obtained by XRD analysis. The main reason for this difference
can be the fact that crystallite sizes are considered as the sizes of ‘‘coherently
123

M. A. Amrollahi, F. Vahidnia
Fig. 4 FT-IR spectrum of prepared b-CD, Fe3O4, b-CD-ZrO, and Fe3O4@b-CD-ZrO composite
Fig. 5 TEM images of
Fe3O4@b-CD-ZrO
123

Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles as…
diffracting domains’’ of crystals in XRD measurements whereas grains may contain
several types of these domains [34].
Catalytic activity of Fe3O4@b-CD-ZrO
The catalytic activity of Fe3O4@b-CD-ZrO was investigated for the synthesis of
2-phenyl-2,3-dihydro-1H-perimidine via reactions of 1,8-diaminonaphthalene
(1 mmol) and benzaldehyde (1 mmol) as the model reaction. The model reaction
behaviour was studied by adjusting various parameters such as solvent, catalyst, and
the amount of the catalyst. The results are summarized in Table 2. To find the best
solvent, several solvents such as n-hexane, AcOEt, MeCN, H2O, H2O/EtOH and
EtOH were employed as media (Table 2, entries 1–5). These results suggest that the
highest yield is achieved with EtOH at room temperature. Then, we explored the
catalytic efficiency of b-CD and the other composites such as b-CD/Fe3O4, b-CD-
Cu, Fe3O4@b-CD-Cu, and b-CD-ZrO (Table 2, entries 6–10). These results
establish the fact that amongst the various catalysts used, Fe3O4@b-CD-ZrO as a
magnetic hybrid material is the most effective catalyst for the synthesis of 2-phenyl-
Table 2 Optimization of reaction conditions on the reaction of 1,8-diaminonaphthalene and benzalde-
hydea
Entry
Catalyst (g)
Solvent
Time (min)
Yield (%)b
1
Fe3O4@b-CD-ZrO (0.04)
Fe3O4@b-CD-ZrO (0.04)
Fe3O4@b-CD-ZrO (0.04)
Fe3O4@b-CD-ZrO (0.04)
Fe3O4@b-CD-ZrO (0.04)
b-CD (0.04)
n-Hexane
AcOEt
H2O
10
10
10
10
10
45
45
10
10
10
10
10
10
30
50
40
50
90
75
75
80
80
90
60
90
30
2
3
4
H2O/EtOH
EtOH
5
6
EtOH
7
b-CD/Fe3O4 (0.04)
b-CD-Cu (0.04)
EtOH
8
EtOH
9
Fe3O4@b-CD-Cu (0.04)
b-CD-ZrO (0.04)
EtOH
10
11
12
13
EtOH
Fe3O4@b-CD-ZrO (0.03)
Fe3O4@b-CD-ZrO (0.05)
–
EtOH
EtOH
EtOH
aReaction conditions: 1,8-diaminonaphthalene (1 mmol), benzaldehyde (1 mmol), and solvent (5 mL)
bIsolated yields
123

M. A. Amrollahi, F. Vahidnia
Table 3 Synthesis of 2,3-dihydro-1H-perimidine derivatives in the presence of Fe3O4@b-CD-ZrO under
optimized conditionsa
Entry
R
H
Product
Time (min)
10
Yield (%)
90
1
4-OH
3-OH
20
85
2
3
20
20
85
75
80
2-OH
4-OMe
4-Me
4
5
6
15
15
90
85
75
4-NO2
4-F
20
20
7
8
2-F
20
85
9
4-Cl
20
20
90
85
10
11
2,4-Cl2
aReaction conditions: 1,8-diaminonaphthalene (1 mmol), aromatic aldehyde (1 mmol),
Fe3O4@β-CD-ZrO (0.04 g).
123

Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles as…
Table 4 Comparison of the efficiency of Fe3O4@b-CD-ZrO with that of the reported catalysts for the
synthesis of 2,3-dihydro-1H-perimidine derivatives
Entry
Catalyst
Reaction conditions
Time
Yield (%)
Ref.
1
2
3
4
5
6
7
8
RuCl3Á3H2O
NaY zeolite
EtOH, 40 °C
EtOH, r.t
EtOH, r.t
EtOH, r.t
EtOH, r.t
EtOH, r.t
Ionic liquid
EtOH, r.t
24 h
91
91
80
87
83
81
90
90
[21]
45 h
[22]
FePO4
NSSAa
12 h
[25]
25 min
10 min
25 min
1 min
10 min
[29]
Cu(NO3)2Á6H2O
nano-CuY zeolite
[BTBA]Cl-FeCl3
Fe3O4@b-CD-ZrO
[31]
[32]
[33]
This work
aNano-silica sulfuric acid
2,3-dihydro-1H-perimidine. To optimize the required catalyst amount, the model
reaction was carried out in the presence of the various amounts of Fe3O4@b-CD-
ZrO (Table 2, entries 5 and 11–13). Based on the results, the use of 0.04 g catalyst
at room temperature in EtOH has the best activity. The reusability of the catalyst
was also investigated on the model reaction. The magnetic nature of the catalyst
allowed its facile separation by magnetic decantation, washing with chloroform and
drying at room temperature to provide an opportunity for recycling experiments.
The separated magnetic catalyst was reused in the mentioned reaction four times
without considerable loss of its catalytic activity.
Under optimized conditions, 2,3-dihydro-1H-perimidines were synthesized
(Table 3). In all cases, the reactions proceeded efficiently to afford the correspond-
ing products. It can be observed that the process tolerates both electron-donating
and withdrawing substituents in benzaldehyde. All the products were characterized
1
by m.p. IR, H- and 13C-NMR spectra.
Finally, in order to assess the efficiency and generality of this methodology, we
compared this method with some reported results in the literature. By comparing our
results with the results depicted in Table 4, it was found that Fe3O4@b-CD-ZrO is
the most efficient magnetic catalyst with respect to reaction time, reaction
temperature and yield of the product.
The proposed mechanism for the synthesis of 2-phenyl-2,3-dihydro-1H-perim-
idine in the presence of Fe3O4@b-CD-ZrO is shown in Scheme 3.
123

M. A. Amrollahi, F. Vahidnia
Scheme 3 Synthetic pathway for preparation of 2-phenyl-2,3-dihydro-1H-perimidine
Conclusions
In summary, we have demonstrated the preparation and characterization of
Fe3O4@b-CD-ZrO as highly efficient, magnetically recyclable, cheap and novel
heterogeneous catalysts. The catalytic activity of the prepared catalyst was
investigated in the synthesis of 2,3-dihydro-1H-perimidine derivatives through the
reaction of 1,8-diaminonaphthalene and aromatic aldehydes under mild reaction
conditions. The remarkable advantages of this method are new, simple experimental
procedure, short reaction times, reusable and an easily recoverable heterogeneous
magnetic catalyst and the ease of product isolation.
Acknowledgements The authors thank the Research Council of Yazd University for the financial support.
References
1. N. Mizuno, M. Misono, Chem. Rev. 98, 199 (1998)
2. P.T. Anastas, J.C. Warner, Green Chemistry: Theory and Practice (Oxford University Press, Oxford,
1998)
3. H. Firouzabadi, N. Iranpoor, M. Jafarpour, A. Ghaderi, J. Mol. Catal. A Chem. 253, 249 (2006)
4. B. Eftekhari-Sis, A. Abdollahifar, M.M. Hashemi, M. Zirak, Eur. J. Org. Chem. 22, 5152 (2006)
5. Y. Wu, L.-N. He, Y. Du, J.-Q. Wang, C.-X. Miao, W. Li, Tetrahedron 65, 6204 (2009)
6. A.K. Chakraborti, A. Kondaskar, Tetrahedron Lett. 44, 8315 (2003)
7. A.K. Chakraborti, R. Gulhane, Synlett 4, 627 (2004)
8. T. Jari, M.A. Amrollahi, Z. Kheilkordi, Heterocycl. Commun. 21, 89 (2015)
9. J. Zhang, P.X. Ma, Adv. Drug Deliv. Rev. 65, 1215 (2013)
10. Y. Wei, J. Zhang, Y. Zhou, W. Bei, Y. Li, Q. Yuan, H. Liang, Carbohyd. Polym. 159, 152 (2017)
123

Decoration of b-CD-ZrO on Fe3O4 magnetic nanoparticles as…
´
11. L. Szente, J. Szeman, T. Sohajda, J. Pharm. Biomed. Anal. 130, 347 (2016)
12. Y. Ren, Y. Liu, R. Niu, X. Liao, J. Zhang, B. Yang, J. Mol. Struct. 1117, 1 (2016)
13. S. Mahpishanian, H. Sereshti, J. Chromatogr. A 1485, 32 (2017)
´
14. V. Perez-Fernandez, M.J. Gonzalez, M.A. Garcıa, M.L. Marina, Anal. Chim. Acta 782, 67 (2013)
´
´
´
15. L. Lin, C. Zou, J. Chem. Eng. Data 62, 762 (2017)
´
16. H.A. Elazab, S. Moussa, A.R. Siamaki, B.F. Gupton, M.S. El-Shall, Catal. Lett. 147, 1510 (2017)
17. B. Eftekhari-Sis, M. Akbari, A. Akbari, M. Amini, Catal. Lett. 147, 2106 (2017)
18. X. Chen, J. Rao, J. Wang, J.J. Gooding, G. Zou, Q. Zhang, Chem. Commun. 47, 10317 (2011)
19. Q. Chang, K. Deng, L. Zhu, G. Jiang, C. Yu, H. Tang, Microchim. Acta 165, 299 (2009)
20. S. Azad, B.F. Mirjalili, RSC Adv. 6, 96928 (2016)
21. J. Zhang, S.L. Zhang, J.M. Zhang, Chin. Chem. Lett. 18, 1057 (2007)
22. A. Mobinikhaledi, N. Forughifar, N. Bassaki, Turk. J. Chem. 33, 555 (2009)
23. A.F. Pozharskii, V. Dal’Nikovskaya, Russ. Chem. Rev. 50, 816 (1981)
24. Y. Tokimizu, Y. Ohta, H. Chiba, S. Oishi, N. Fujii, H. Ohno, Tetrahedron 67, 5168 (2011)
25. F. Behbahani, F.M. Golchin, J. Taibah Univ. Sci. 11, 85 (2017)
26. H. Alinezhad, M. Zare, J. Chil. Chem. Soc. 58, 1840 (2013)
27. M.A. Bodaghifard, N. Ahadi, Iran. J. Catal. 6, 377 (2016)
28. M. Hari Krishna, P. Thriveni, J. Chem. Pharm. Res. 8, 809 (2016)
29. A. Mobinikhaledi, H. Moghanian, F. Sasani, Int. J. Green Nanotechnol. Phys. Chem. 2, 47 (2010)
30. A. Mobinikhaledi, M.A. Bodaghi Fard, F. Sasani, M.A. Amrollahi, Bulg. Chem. Commun. 45, 353
(2013)
31. A. Mobinikhaledi, P.J. Steel, Synth. React. Inorg. Met. Org. Nano Met. Chem. 30, 133 (2009)
32. M. Kalhor, N. Khodaparast, Res. Chem. Intermed. 41, 3235 (2015)
33. K. Bahrami, S. Saleh, Synth. React. Inorg. Met. Org. Nano Met. Chem. 46, 852 (2016)
34. A. Mobinikhaledi, H. Moghanian, S.M.B. Hosseini Ghazvini, A. Dalvand, J. Porous Mater. 25, 1123
(2018)
123