Graphene oxide nanosheets supported manganese(III) porphyrin: a highly efficient and reusable biomimetic catalyst for epoxidation of alkenes with sodium periodate

Article abstract of DOI:10.1007/s13738-016-0867-1

Efficient epoxidation of alkenes catalyzed by tetrakis(p-aminophenyl)porphyrinatomanganese(III) chloride, [Mn(TNH₂PP)Cl], supported on graphene oxide nanosheets, is reported. The catalyst, [Mn(TNH₂PP)Cl]@GO, was prepared by covalent attachment of amino groups of porphyrin to carboxylic acid groups of GO. This new heterogenized catalyst was characterized by ICP, FT-IR and diffuse reflectance UV–vis spectroscopies, scanning electron microscopy and transmission electron microscopy. This catalyst was applied as an efficient and reusable catalyst in the epoxidation of alkenes with NaIO₄ at room temperature, in the presence of imidazole as axial ligand. The most noteworthy advantage of [Mn(TNH₂PP)Cl]@GO is its high reusability in the oxidation reactions, in which the catalyst was reused several times without significant loss of its catalytic activity.

Full text of DOI:10.1007/s13738-016-0867-1

J IRAN CHEM SOC
DOI 10.1007/s13738-016-0867-1
ORIGINAL PAPER
Graphene oxide nanosheets supported manganese(III) porphyrin:
a highly efficient and reusable biomimetic catalyst for epoxidation
of alkenes with sodium periodate
Alireza Zarrinjahan1 · Majid Moghadam1 · Valiollah Mirkhani1 ·
Shahram Tangestaninejad1 · Iraj Mohammadpoor‑Baltork1
Received: 6 March 2016 / Accepted: 16 April 2016
© Iranian Chemical Society 2016
Abstract Efficient epoxidation of alkenes catalyzed by
tetrakis(p-aminophenyl)porphyrinatomanganese(III)
chloride, [Mn(TNH2PP)Cl], supported on graphene oxide
nanosheets, is reported. The catalyst, [Mn(TNH2PP)Cl]@
GO, was prepared by covalent attachment of amino groups
of porphyrin to carboxylic acid groups of GO. This new
heterogenized catalyst was characterized by ICP, FT-IR
and diffuse reflectance UV–vis spectroscopies, scanning
electron microscopy and transmission electron microscopy.
This catalyst was applied as an efficient and reusable cata-
lyst in the epoxidation of alkenes with NaIO4 at room tem-
perature, in the presence of imidazole as axial ligand. The
most noteworthy advantage of [Mn(TNH2PP)Cl]@GO is
its high reusability in the oxidation reactions, in which the
catalyst was reused several times without significant loss of
its catalytic activity.
perfumes and epoxy resins [1]. Transition metal complexes
of porphyrin and Schiff base ligands have been extensively
used as models for the heme-containing cytochrome P-450
[2]. Cytochorome P-450 catalyzes a wide variety of reac-
tions including oxygen transfer to heteroatoms, epoxida-
tion of olefins, hydroxylation of aromatic hydrocarbons and
oxidative degradation of chemically inert xenobiotics such
as drugs and environmental contaminants [3]. To mimic
the action of cytochrome P-450 monooxygenation enzyme,
simple oxygen atom donors such as PhIO, ClO−, H2O2,
ROOH and IO4− have been used in the oxidation reactions
catalyzed by metalloporphyrins [4–9]. One of the most
important disadvantageous of homogeneous metallopor-
phyrin and Schiff base complexes is the catalyst deactiva-
tion by formation of µ-oxo dimer complex. Therefore, het-
erogenization of these catalysts is of great importance from
industrial point of view; this could combines the advan-
tages of homogeneous catalysts (high activity, selectivity,
etc.) with the benefits of heterogeneous catalysts (easy
catalyst separation, long catalytic life, thermal stability and
recyclability) [10]. Up to now, several homogeneous and
heterogenized metalloporphyrin catalysts have been devel-
oped for the oxidation of organic compounds [11–45].
Graphene, a two-dimensional material composed of sev-
eral planar sheets of sp2-bonded carbon atoms, has attracted
tremendous attention due to its unique thermal, chemi-
cal, physical, mechanical and electrical properties [46–50].
Since 2004, it has been as a promising candidate for gener-
ating novel hybrid materials with excellent properties for a
wide variety of potential applications in catalyst support [51,
52], electronic components [53, 54], chemical sensors [55,
56], and Li ion batteries [57–59]. However, the graphene is
chemically inert and has no surface functionalization and
therefore, it is difficult to support the catalytic active species
on its surface [60, 61]. The carbonyl, carboxyl and hydroxyl
Keywords Graphene oxide · Manganese porphyrin ·
Supported catalyst · Epoxidation · Sodium periodate
Introduction
Catalytic epoxidation of alkenes in the liquid phase is an
important area in synthetic organic chemistry because
epoxides are very useful and essential precursors in the
synthesis of various important substances like plasticizers,
* Majid Moghadam
moghadamm@sci.ui.ac.ir
* Valiollah Mirkhani
mirkhani@sci.ui.ac.ir
1
Catalysis Division, Department of Chemistry, University
of Isfahan, 81746-73441 Isfahan, Iran
1 3

J IRAN CHEM SOC
permanganate ions before copious washing with a dilute
acid solution (1 M HCl). After filtration, the GO product
was dried under air before further use.
Chlorination of GO‑COOH
Scheme 1 Epoxidation of alkenes with NaIO4 in the presence of
[Mn(TNH2PP)Cl]@GO]
In a 100-ml round-bottomed flask equipped with a con-
denser and a magnetic stirrer bar, GO-COOH (1 g), and
SOCl2 (50 ml) were mixed and refluxed for 12 h. After this,
the reaction mixture was cooled and the SOCl2 was evapo-
rated. The resulting precipitate was chlorinated graphene
oxide, GO-COCl.
functional groups can be introduced on the surface of gra-
phene nanosheets by its oxidation with strong oxidants [62,
63]. The produced GO is insoluble in most solvents and can
be used as catalyst support. In continuation of our interest
on the oxidation of organic compounds catalyzed by sup-
ported manganese(III) porphyrins, and by combining the
advantages of GO as catalyst support and high catalytic
activity of Mn(III) porphyrins in the alkene epoxidation,
here, we report highly efficient epoxidation of alkenes with
sodium periodate catalyzed by tetrakis(p-aminophenyl)
porphyrinatomanganese(III) chloride, Mn(TNH2PP)Cl, sup-
ported on functionalized grapheme oxide, GO (Scheme 1).
Supporting of [Mn(TNH2PP)Cl] on GO‑COCl
To a solution of Mn(TNH2PP)Cl (0.1 g) in DMF (100 ml),
GO-COCl (1 g) and triethylamine (5 ml) were added and
the reaction mixture was vigorously stirred at 100 °C for
72 h. After cooling the mixture, the black solids were col-
lected by filtration, washed thoroughly with dichlorometh-
ane, methanol and diethyl ether, successively, and dried in
vacuum for several hours.
Experimental
General procedure for alkene epoxidation with NaIO4
catalyzed by [Mn(TNH2PP)Cl]@GO
Materials and methods
The alkenes were obtained from Merck chemical company
and passed through a column containing active alumina to
remove peroxide impurities. Tetra(p-aminophenyl)porphyrin
was prepared and metallated according to the literature [64,
65]. FT-IR spectra were obtained with potassium bromide
pellets in the range 400–4000 cm−1 on a JASCO 6300 spec-
trophotometer. The diffuse reflectance UV–vis spectra, (DR
UV–vis), were recorded by a JASCO V-670 UV–vis spectro-
photometer. A field emission scanning electron micrograph
of [Mn(TNH2PP)Cl]@GO was taken on a Philips Sigma FE-
SEM instrument. Transmission electron micrograph of the cat-
alyst was recorded by a EM10C-100 kV instrument. The ICP
analyses were carried out by a Perkin-Elmer Optima 7300 DV
spectrometer. Gas chromatography experiments (GC) were
performed by a Shimadzu GC-16A instrument using a 2 m
column packed with silicon DC-200 or Carbowax 20 M. In the
GC experiments, n-decane was used as an internal standard.
To a mixture of alkene (1 mmol), [Mn(TNH2PP)Cl]@
GO (0.032 mmol) and imidazole (0.2 mmol) in CH3CN
(10 ml), a solution of NaIO4 (2 mmol) in H2O (10 ml) was
added and the reaction mixture was stirred magnetically at
room temperature. The progress of the reaction was moni-
tored by GC. At the end of the reaction, the reaction mix-
ture was diluted with Et2O (20 ml) and filtered. The catalyst
was thoroughly washed with Et2O and combined washings
and filtrates were purified on a silica gel plate or a silica gel
column to obtain the pure products.
Catalyst reuse and stability
The reusability of [Mn(TNH2PP)Cl]@GO was investigated
in the repeated epoxidation of cyclooctene, as described
above. At the end of each reaction, the catalyst was sepa-
rated from the reaction mixture by simple filtration, washed
with Et2O and dried carefully before using it in the next run.
Preparation of graphene oxide nanosheets supported
manganese porphyrin, [Mn(TNH2PP)Cl]@GO
Results and discussion
Preparation of graphene oxide nanosheets
Preparation and characterization of the catalyst,
[Mn(TNH2PP)Cl]@GO
GO was prepared via a modified Hummer’s method where
graphite powder was vigorously stirred with H2SO4 and
KMnO4 at 35 °C for 4 h to yield GO [66, 67]. The oxi-
dized product was treated with H2O2 to remove residual
Scheme 2 shows the preparation route for [Mn(TNH2PP)
Cl]@GO. First, the carboxylic acid groups were converted
1 3

J IRAN CHEM SOC
Scheme 2 Preparation of
[Mn(TNH2PP)Cl]@GO
to acyl chloride to increase the reactivity of GO-COOH. In
the next step, the Mn(TNH2PP)Cl was reacted with GO-
COCl to obtain the catalyst. The prepared catalyst was
characterized by ICP, FT-IR spectroscopy, DR UV–vis
spectrophotometry, FE-SEM and TEM analyses. The load-
ing of manganese porphyrin on the catalyst, determined
by measuring the Mn content by ICP, was obtained about
160 µmol per gram of the catalyst.
The most informative spectroscopic data, which con-
firmed the covalent anchoring of [Mn(TNH2PP)Cl] on the
functionalized GO, were obtained by comparison of the
FT-IR spectra of GO-COOH, GO-COCl and [Mn(TNH2PP)
Cl]@GO (Fig. 1). The C=O stretching band of the acidic
groups was appeared at 1729 cm−1. This vibration shifted
to 1711 cm−1 upon conversion to acid chloride. When the
porphyrin was attached to GO-COCl, an amide vibration
was observed at 1657 cm−1. These observations clearly
confirmed the attachment of the manganese porphyrin to
the GO.
The DR UV–vis of the [Mn(TNH2PP)Cl]@GO resem-
bles the homogeneous counterpart spectrum (Fig. 2) and
shows the Soret band at 466 nm which is a good indica-
tion for attachment of metalloporphyrin on the surface of
GO. Since the GO shows no absorption peak in its dif-
fuse reflectance spectrum, therefore, it is confirmed that
[Mn(TNH2PP)Cl] has been supported on GO.
1 3

J IRAN CHEM SOC
Fig. 1 The FT-IR spectrum of: a GO-COOH; b GO-COCl and c
[Mn(TNH2PP)Cl]@GO
Fig. 2 a UV–vis spectrum of homogeneous [Mn(TNH2PP)Cl], b dif-
fuse reflectance UV–vis spectrum of GO and c [Mn(TNH2PP)Cl]@GO
The scanning electron micrograph of catalyst (Fig. 3a)
shows the morphology of the GO used in this study. As can
be seen, the catalyst has a wrinkled layered structure with
thin thickness and smooth surface. Also, the EDX spec-
trum clearly shows the presence of Mn in the catalyst tex-
ture (Fig. 3b). The TEM image of [Mn(TNH2PP)Cl]@GO
(Fig. 4), clearly indicates that manganese porphyrin has
been supported on the GO. The light regions belong to GO
and the dark parts are the Mn porphyrins.
Catalytic experiments
After preparation and characterization of the catalyst, its cat-
alytic activity was investigated in the epoxidation of olefins
with sodium periodate at room temperature. In this manner,
epoxidation of cyclooctene was chosen as model reaction,
and the catalyst amount, kind of solvent and oxidant were
1 3

J IRAN CHEM SOC
because this oxidant, which is inert in the absence of cata-
lyst, can give good oxidation conversion in CH3CN/H2O. For
choosing the reaction media, different solvents were checked
in the model reaction. Among the different mixtures of ace-
tonitrile, acetone, ethanol, dichloromethane with water, the
1:1 mixture of acetonitrile: water was chosen as the reaction
medium (Table 3). The high catalytic activity of the catalyst
in this in the acetonitrile/water mixture is attributed to the
polarity of the solvent and the high solubility of NaIO4 in it.
Natural metalloenzymes such as peroxidase and cytochrome
P-450 enzymes have axially coordinating histidine and thi-
olate residue, respectively. To completely mimic the action
of these enzymes and also to improve the catalytic activity of
these metalloporphyrin catalysts, addition of a donor ligand
is necessary. In this manner, in the [Mn(TNH2PP)Cl]@GO/
NaIO4 catalytic system, the effect of different axial ligands
was investigated in the epoxidation of cyclooctene (Table 4).
Pyridine and 4-methylpyridines, with weak π donating abil-
ity and pKb values, generally show low co-catalytic activity.
Among the nitrogen bases which are used as axial ligands,
imidazole exhibited the highest activity in the model reac-
tion. Strong π-donors such as imidazole and its derivatives
are the best co-catalysts among the nitrogen donors listed
in Table 4. The lower co-catalytic activity of 2-MeImH and
2-PhImH are due to the steric effects of the 2-substituent.
Bulky and flat BzImH displays a higher co-catalytic activity
in comparison with substituted imidazoles. Strong coordina-
tion of imidazole increases the electron density on the metal
and promotes facile cleavage of the O–IO3 bond in NaIO4.
In the absence of any axial ligand, only 17 % of cyclooctene
oxide was observed.
Fig. 3 a SEM images of [Mn(TNH2PP)Cl]@GO and b EDX spec-
trum of [Mn(TNH2PP)Cl]@GO
optimized in this reaction. To optimize the catalyst amount,
different amounts of catalyst were used in the epoxidation of
cyclooctene with NaIO4. The best results were obtained with
200 mg (0.032 mmol) of the catalyst (Table 1). The ability
of different single oxygen donors such as NaIO4, KHSO5
(Oxone) and H2O2 was investigated in the model reaction.
In the investigation of the effect of different oxidants on the
epoxidation of cyclooctene, we added the suitable co-catalyst
to the reaction mixture. The results, which are summarized
in Table 2, showed that NaIO4 is the best oxygen source
Epoxidation of alkenes with NaIO4 catalyzed
by [Mn(TNH2PP)Cl]@GO
After optimization of the reaction conditions, the
[Mn(TNH2PP)Cl]@GO catalyst was used for epoxida-
tion of olefins with NaIO4. The optimum conditions,
which obtained in the epoxidation of cyclooctene, were
catalyst, oxidant, imidazole and substrate in a molar
Fig. 4 TEM image of
[Mn(TNH2PP)Cl]@GO
1 3

J IRAN CHEM SOC
Table 1 Optimization of the catalyst amounts in the epoxidation of
Table 4 The effect of different axial ligands on the epoxidation of
cyclooctene
cyclooctene with sodium periodate catalyzed by [Mn(TNH2PP)Cl]@
GO
Entry
Catalyst amount (mmol)
Epoxide yield (%)a
Entry
Axial ligand
Time (min)
Yield (%)a
1
2
3
4
5
0
6
43
70
95
95
1
2
3
4
5
6
7
None
3
3
3
3
3
3
3
17
45
39
95
72
57
61
100 (0.016)
150 (0.024)
200 (0.032)
300 (0.048)
Pyridine
4-Methylpyridine
Imidazole
Benzimidazole
2-Methylimidazole
2-Phenylimidazole
Reaction conditions: cyclooctene (1 mmol), catalyst, oxidant
(2 mmol), imidazole (0.2 mmol) and CH3CN/H2O (10 ml /10 ml)
after 3 h
a
GC yield
Cyclooctene (1 mmol), NaIO4 (2 mmol), axial ligand (0.2 mmol) and
catalyst (0.032 mmol), imidazole (0.2 mmol) in CH3CN (10 ml)/H2O
(10 ml)
a
GC yield based on the starting cyclooctene
Table 2 The effect of oxidant on the epoxidation of cyclooctene cat-
alyzed by [Mn(TNH2PP)Cl]@GO at room temperature
catalytic system showed a high catalytic activity in the
alkene epoxidation in the presence of imidazole as the
axial base. Cyclohexene was oxidized in 91 % yield,
in which 83 % cyclohexene oxide was produced as the
major product and 2-cyclohexen-1-one was obtained in
8 % yield. In the epoxidation of styrene, 79 % styrene
oxide and 9 % benzaldehyde were produced. Oxida-
tion of α-methylstyrene produced 80 % α-methylstyrene
oxide and 11 % acetophenone. In the case of linear alk-
enes such as 1-octene and 1-decene, the correspond-
ing epoxides were obtained in 68 and 52 % yields with
100 % selectivity, respectively.
Solvent
Oxidant
Epoxide yield (%)a
Acetonitrile:H2O No oxidant
5
Acetonitrile:H2O NaIO4 (1 mmol)/imidazole 56
Acetonitrile:H2O NaIO4 (2 mmol)/imidazole 95
Acetonitrile:H2O KHSO5 (2 mmol)/pyridine 82
Acetonitrile
Acetonitrile
H2O2 (2 mmol)/imidazole
H2O2 (2 mmol)/NH4Ac
21
17
Reaction conditions: cyclooctene (1 mmol), oxidant, catalyst
(0.032 mmol), imidazole (0.2 mmol) and CH3CN/H2O (10 ml/10 ml)
after 3 h
a
GC yield based on starting alkene
Catalyst reuse and stability
Table 3 The effect of solvent on the epoxidation of cyclooctene with
NaIO4 catalyzed by [Mn(TNH2PP)Cl]@GO at room temperature
The reusability of a heterogeneous catalyst is an impor-
tant issue for industrial applications. While, homogeneous
[Mn(TNH2PP)Cl] cannot be recovered even once, the GO
supported catalyst can be filtered and reused several times
without significant loss of its activity. The reusability of
[Mn(TNH2PP)Cl]@GO was investigated in the multiple
sequential epoxidation of cyclooctene with NaIO4. The
catalyst was separated from the reaction mixture after each
experiment by simple filtration, washed with methanol
and dried carefully before using it in the subsequent run.
After using the catalyst five consecutive times, the epox-
ide yield was 86 % (Table 6). The filtrates were collected
for determination of Mn leaching. The results showed that
after the five runs, no manganese was detected in the fil-
trates by atomic absorption spectrometry. The nature of
the recovered catalyst has been followed by IR. The results
indicated that the catalyst, after reusing it several times,
showed no change in its IR spectrum. These observations
Entry
Solvent
Time (h)
Yield (%)a
1
2
3
4
5
6
Acetonitrile:H2O (1:2)
Acetonitrile:H2O (1:1)
Acetonitrile:H2O (2:1)
Acetone: H2O
3
3
3
3
3
3
39
95
61
27
43
20
Ethanol:H2O
Dichloromethane:H2O
Reaction conditions: cyclooctene (1 mmol), NaIO4 (2 mmol), catalyst
(0.032 mmol), imidazole (0.2 mmol)
a
GC yield based on starting alkene
ratio of 1:60:6:30. Under the optimized reaction condi-
tions, different cyclic, linear and phenyl substituted ole-
fins were subjected to epoxidation with NaIO4. As can
be seen in Table 5, the [Mn(TNH2PP)Cl]@GO/NaIO4
1 3

J IRAN CHEM SOC
Table 5 Epoxidation of alkenes
with NaIO4 catalyzed by
[Mn(TNH2PP)Cl]@GO
Entry
1
Olefin
Conversion (%)a
95
Epoxide yield (%)a
95
Time (h)
3
TOF (h−1
)
9.89
2
91
83b
2.5
11.37
3
4
88
91
79c
80d
3
3
9.16
9.47
5
75
75
3
7.81
6
7
68
52
68
52
3.5
3.5
6.07
4.64
Reaction conditions: Alkene (1 mmol), NaIO4 (2 mmol), catalyst (0.032 mmol), CH3CN/H2O
(10 ml/10 ml)
a
GC yield based on the starting alkene
b
The by-product is allylic ketone
c
The by-product is benzaldehyde
d
The by-product is acetophenone
Acknowledgments We acknowledge the support of this work by the
Research Council of the University of Isfahan.
Table 6 The results of [Mn(TNH2PP)Cl]@GO catalyst recovery and
the amounts of manganese leached in the epoxidation of cyclooctene
with sodium periodate
Entry
Time (h)
Epoxide yield (%)a
Mn leached (%)b
References
1
2
3
4
5
3
3
3
3
3
92
90
88
88
86
0
0
0
0
0
1. M. Beller, C. Bolm, Transition Metals for Fine Chemicals and
Organic Synthesis, vol. 2 (Wiley, Weinheim, 1998), pp. 261–267
2. T. Katsuki, J. Mol. Catal. A Chem. 113, 87–107 (1996)
3. P.R. Ortiz de Montellano, Cytochrome P‑450, Structure, Mecha‑
nism and Biochemistry, 2nd edn. (Plenum Press, NewYork, 1995)
4. B.A. Arndtsen, R.G. Bergman, T.A. Mobley, T.H. Peterson, Acc.
Chem. Res. 28, 154–162 (1995)
5. M.J. Coon, R.E. White, in Dioxygen Binding and Activation by
Metal Centers, ed. by T.G. Spiro (Wiley, New York, 1980)
6. J.T. Groves, T.E. Nemo, J. Am. Chem. Soc. 105, 5786–5791
(1983)
Reaction conditions: alkene (1 mmol), NaIO4 (2 mmol), catalyst
(0.032 mmol), CH3CN/H2O (10 ml/10 ml)
a
GC yield
b
Determined by atomic absorption spectroscopy
7. O. Bortolini, B. Meunier, J. Chem. Soc. Perkin Trans. 2, 1967–
1970 (1984)
8. B. Meunier, E. Guilmet, M.E. De Carvalho, R. Poilblanc, J. Am.
show that [Mn(TNH2PP)Cl]@GO is a robust catalyst dur-
ing the catalytic cycles.
Chem. Soc. 106, 6668–6676 (1984)
9. D. Mohajer, S. Tangestaninejad, J. Chem. Soc., Chem. Commun.
240–241 (1993)
10. P.J. Collman, L. Zeng, I.J. Brauman, Inorg. Chem. 43, 2672–
2679 (2004)
11. F.S. Vinhado, P.R. Martins, A.P. Masson, D.G. Abreu, E.A. Vid-
oto, O.R. Nascimento, Y. Iamamoto, J. Mol. Catal. A Chem. 188,
141–151 (2002)
12. F. Zadehahmadi, S. Tangestaninejad, M. Moghadam, V.
Mirkhani, I. Mohammadpoor-Baltork, A.R. Khosropour, R.
Kardanpour, J. Solid State Chem. 218, 56–63 (2014)
13. H.C. Sacco, Y. Iamamoto, J.R. Lindsay, Smith. J. Chem. Soc.
Perkin Trans. 2, 181–190 (2001)
Conclusion
In conclusion, [Mn(TNH2PP)Cl]@GO/NaIO4 catalytic sys-
tem was used as a highly efficient system for biomimetic
epoxidation of alkenes with sodium periodate under agita-
tion with magnetic stirring. The corresponding epoxides
were obtained in good to excellent yield (52–95 %) and
high selectivity was highly reusable and recycled five times
without appreciable decrease in its initial activity.
14. F.S. Vinhado, C.M.C. Prado-Manso, H.C. Sacco, Y. Iamamoto, J.
Mol. Catal. A Chem. 174, 279–288 (2001)
1 3

J IRAN CHEM SOC
43. M. Moghadam, V. Mirkhani, S. Tangestaninejad, I. Mohammad-
poor-Baltork, A.A. Abbasi-Larki, Appl. Catal. A Gen. 349, 177–
181 (2008)
44. M. Moghadam, V. Mirkhani, S. Tangestaninejad, I. Mohammad-
poor-Baltork, H. Kargar, J. Mol. Catal. A Chem. 288, 116–124
(2008)
45. V. Mirkhani, M. Moghadam, S. Tangestaninejad, I. Mohammad-
poor-Baltork, H. Kargar, M. Araghi, Appl. Catal. A Gen. 353,
61–67 (2009)
46. S. Park, K.S. Lee, G. Bozoklu, W. Cai, S.T. Nguyen, R.S. Ruoff,
ACS Nano 3, 572–578 (2008)
15. Z. Li, C.-G. Xia, X.-M. Zhang, J. Mol. Catal. A Chem. 185,
47–56 (2002)
16. J. Poltowicz, E.M. Serwicka, E. Bastardo-Gonzalez, W. Jones, R.
Mokaya, Appl. Catal. A Gen. 218, 211–217 (2001)
17. G. Karimipour, S. Kowkabi, J. Iran. Chem. Soc. 13, 171–179 (2016)
18. S. Zakavi, L. Ebrahimi, Polyhedron 30, 1732–1738 (2011)
19. F.G. Doro, J.R. Lindsay Smith, A.G. Ferreira, M.D. Assis, J.
Mol. Catal. A Chem. 164, 97–108 (2000)
20. M.S. Saeedi, S. Tangestaninejad, M. Moghadam, V. Mirkhani,
I. Mohammadpoor-Baltork, A.R. Khosropour, Polyhedron 49,
158–166 (2013)
47. J. Wu, W. Pisula, K. Müllen, Chem. Rev. 107, 718–747 (2007)
48. M.J. Allen, V.C. Tung, R.B. Kaner, Chem. Rev. 110, 132–145
(2010)
49. C.G. Navarro, M. Burghard, K. Kern, Nano Lett. 8, 2045–2049
(2008)
50. C.G. Navarro, R.T. Weitz, A.M. Bittner, M. Scolari, A. Mews, M.
Burghard, K. Kern, Nano Lett. 7, 3499–3503 (2007)
51. R. Kou, Y. Shao, D. Wang, M.H. Engelhard, J.H. Kwak, J. Wang,
V.V. Viswanathan, C. Wang, Y. Lin, Y. Wang, I.A. Aksay, J. Liu,
Electrochem. Commun. 11, 954–957 (2009)
21. F. Zadehahmadi, S. Tangestaninejad, M. Moghadam, V.
Mirkhani, I. Mohammadpoor-Baltork, A.R. Khosropour, R.
Kardanpour, Appl. Catal. A Gen. 477, 34–41 (2014)
22. M.S. Saeedi, S. Tangestaninejad, M. Moghadam, V. Mirkhani, I.
Mohammadpoor-Baltork, A.R. Khosropour, Mater. Chem. Phys.
146, 113–120 (2014)
23. S. Rayati, F. Nejabat, Polyhedron 104, 52–57 (2016)
24. I.L.V. Rosa, C.M.C.P. Manso, O.A. Serra, Y. Iamamoto, J. Mol.
Catal. A Chem. 160, 199–208 (2000)
25. M. Araghi, F. Bokaei, Polyhedron 53, 15–19 (2013)
26. R. Zhang, W.-Y. Yu, H.-Z. Sun, W.-S. Liu, C.-M. Che, Chem.
Eur. J. 8, 2495–2507 (2002)
52. Y. Li, X. Fan, J. Qi, J. Ji, S. Wang, G. Zhang, F. Zhang, Nano
Res. 3, 429–437 (2010)
53. X. Wang, L. Zhi, K. Müllen, Nano Lett. 8, 323–327 (2008)
54. V.Y. Aristov, G. Urbanik, K. Kummber, D.V. Vyalikh, O.V.
Molodtsova, A.B. Preobrajenski, A.A. Zakharov, C. Hess, T.
Hänke, B. Büchner, I. Vobornik, J. Fujii, G. Panaccione, Y.A.
Ossipyan, M. Knupfer, Nano Lett. 10, 992–995 (2010)
55. J.D. Fowler, M.J. Allen, W.C. Tung, Y. Yang, R.B. Kaner, B.H.
Weiller, ACS Nano 3, 301–306 (2009)
27. S. Zakavi, M, Fathi. J. Iran. Chem. Soc. 11, 1667–1674 (2014)
28. J.-L. Zhang, C.-M. Che, Org. Lett. 4, 1911–1914 (2002)
29. M. Zakeri, M. Moghadam, I. Mohammadpoor-Baltork, S. Tang-
estaninejad, V. Mirkhani, A.R. Khosropour, J. Coord. Chem. 65,
1144–1157 (2012)
30. K.K. Wai, T.H. Chen, W. Luo, H. Jeddi, R. Zhang, Inorg. Chim.
Acta 430, 176–183 (2015)
56. X. Kang, J. Wang, H. Wu, I.A. Aksay, J. Liu, Y. Lin, Biosens.
31. S. Zakavi, S. Talebzadeha, S. Rayati, Polyhedron 31, 368–372
(2012)
Bioelectron. 25, 901–905 (2009)
57. G. Wang, X. Shen, J. Yao, J. Park, Carbon 47, 2049–2053 (2009)
58. J.K. Lee, K.B. Smith, C.M. Hayner, H.H. Kung, Chem. Com-
mun. 46, 2025–2027 (2010)
59. D. Choi, D. Wang, V.V. Viswanathan, I.T. Bae, W. Wang, Z. Nie,
J.G. Zhang, G.L. Graff, J. Liu, Z. Yang, T. Duong, Electrochem.
Commun. 12, 378–381 (2010)
32. Z. Kainan, O.K. Farha, J.T. Hupp, S.T. Nguyen, Acs. Catal. 5,
4859–4866 (2015)
33. R. Hajian, S. Tangestaninejad, M. Moghadam, V. Mirkhani,
I. Mohammadpoor-Baltork, J. Iran. Chem. Soc. (2016).
doi:10.1007/s13738-016-0820-3
34. M. Moghadam, S. Tangestaninejad, M.H. Habibi, V. Mirkhani, J.
60. J.P. Zhong, Y.J. Fan, H. Wang, R.X. Wang, L.L. Fan, X.C. Shen,
Z.J. Shi, Electrochim. Acta 113, 653–660 (2013)
61. L. Li, J. Zhang, Y. Liu, W. Zhang, H. Yang, J. Chen, Q. Xu, ACS
Sustain. Chem. Eng. 1, 527–533 (2013)
62. C.C. Huang, C. Li, G.Q. Shi, Energy Environ. Sci. 5, 8848–8868
(2012)
Mol. Catal. A Chem. 217, 9–12 (2004)
35. S. Tangestaninejad, M. Moghadam, V. Mirkhani, H. Kargar,
Ultrason. Sonochem. 10, 32–36 (2006)
36. M. Moghadam, S. Tangestaninejad, V. Mirkhani, I. Mohammad-
poor-Baltork, H. Kragar, Bioorg. Med. Chem. 13, 2901–2905
(2005)
63. L. Yan, Y.B. Zheng, F. Zhao, S.J. Li, X.F. Gao, B.Q. Xu, P.S.
Weiss, Y.L. Zhao, Chem. Soc. Rev. 41, 97–114 (2012)
64. A. Bettleheim, B.A. White, S.A. Raybuck, R.W. Murray, Inorg.
Chem. 26, 1009–1017 (1987)
37. M. Moghadam, M. Nasr-Esfahani, S. Tangestaninejad, V.
Mirkhani, M.A. Zolfigol, Can. J. Chem. 84, 1–4 (2006)
38. M. Moghadam, S. Tangestaninejad, V. Mirkhani, H. Kargar, H.
Komeili-Isfahani, Catal. Commun. 6, 688–693 (2005)
39. S. Tangestaninejad, M.H. Habibi, V. Mirkhani, M. Moghadam,
Molecules 7, 264–270 (2002)
65. A.D. Adler, F.R. Long, F. Kampas, J. Kim, J. Inorg. Nucl. Chem.
32, 2443–2445 (1970)
66. W.S. Hummers, R.E. Offeman, J. Am. Chem. Soc. 80, 1339
(1958)
67. S. Stankovich, A.D. Dmitriy, O.C. Compton, G.H.B. Dommett,
R.S. Ruoff, S.T. Nguyen, Chem. Mater. 22, 4153–4157 (2010)
40. M. Zakeri, M. Moghadam, I. Mohammadpoor-Baltork, S. Tang-
estaninejad, V. Mirkhani, A.R. Khosropour, M. Alizadeh, Transi-
tion Met. Chem. 37, 45–53 (2012)
41. Y. Murakami, K. Konishi, New J. Chem. 32, 2134–2139 (2008)
42. M. Nasr-Esfahani, M. Moghadam, S. Tangestaninejad, V.
Mirkhani, Bioorg. Med. Chem. Lett. 15, 3276–3278 (2005)
1 3