Covalent attachment of 3-(aminomethyl)pyridine to graphene oxide: A new stabilizer for the synthesis of a palladium thin film at the oil-water interface as an effective catalyst for the Suzuki-Miyaura reaction

Article abstract of DOI:10.1039/c5ra07171b

This study describes the oxidation of graphite to graphene oxide (GO), followed by its covalent functionalization with 3-(aminomethyl)pyridine (3-ampy). A thin film was produced based on the reduction of the organopalladium(ii) complex, [PdCl₂(

Full text of DOI:10.1039/c5ra07171b

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Table of contents entry
Covalent attachment of 3-(aminomethyl)pyridine to graphene oxide: A new stabilizer for
the synthesis of palladium thin film at oil–water interface as an effective catalyst for
Suzuki–Miyaura reaction
S. Jafar Hoseini,* Hedieh Ghanavat Khozestan and Roghayeh Hashemi Fath
A toluene-water planar interface has been used as an ideal template for self-assembly of Pd/3-
(aminomethyl)pyridine-reduced graphene oxide nanohybrid.

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Covalent attachment of 3-(aminomethyl)pyridine to graphene oxide: A new stabilizer for
the synthesis of palladium thin film at oil–water interface as an effective catalyst for
Suzuki–Miyaura reaction
∗
S. Jafar Hoseini, Hedieh Ghanavat Khozestan and Roghayeh Hashemi Fath
Department of Chemistry, Faculty of Sciences, Yasouj University, Yasouj 7591874831, Iran.
Abstract
This work describes the graphite oxidation to graphene oxide (GO), followed by its
functionalization covalently with 3ꢀ(aminomethyl)pyridine (3ꢀampy). Thin film was produced
based on the reduction of organopalladium(II) complex [PdCl (cod)] (cod = 1,5ꢀcyclooctadiene),
2
at the toluene – water interface, that the N group of pyridine ring in the 3ꢀampy helps in the
uniform distribution of the Pd(0) nanoparticles (NPs) and also holds the particles strongly during
the catalytic runs. Pd/3ꢀampyꢀreducedꢀGO (rGO) nanohybrid was characterized by Fourier
transform infrared spectroscopy (FTꢀIR), Raman spectroscopy, energy dispersive analysis of Xꢀ
rays (EDAX), Xꢀ ray diffraction (XRD) and transmission electron microscopy (TEM). The
covalent functionalization reactions of GO include the formation of covalent bonds between NH2
functional group of 3ꢀampy and the epoxy group. Our studies show that Pd/3ꢀampyꢀrGO
nanohybrid was suitable for the Suzuki –Miyaura carbon–carbon coupling reaction. Compared to
the classical reactions, this method consistently has the advantages of wellꢀdispersed Pd(0) NPs
over the support, short reaction times, low catalyst loading, high yields and reusability of the
catalyst without considerable loss of the catalytic activity and a facile and lowꢀcost method for
preparing catalysts. Pd/3ꢀampyꢀrGO nanohybrid thin film showed highly improved catalytic
activity toward aryl chloride derivatives as compared with other catalysts reported.
Introduction
Carbon– carbon cross coupling is one of the most powerful tools in the synthesis of many drugs,
natural products, industrially important starting materials and for the construction of carbonꢀ
1
based molecules and materials. The Suzuki−Miyaura crossꢀcoupling reaction, in which organoꢀ
∗
Corresponding author: Eꢀmail: jhosseini@ yu.ac.ir , sjhoseini54@yahoo.com , Fax: +98 7433342172; Tel: +98
7
432223048.
1

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boron compounds (mainly organoboronic acids) couple with organic halides (or triflates) in the
presence of a Pd catalyst and a base, is one of the most efficient methods for the construction of
2
C− C bonds.
Graphene oxide (GO) and functionalized GO are widely used as excellent carbon supports
for catalysts to achieve the desired activity and stability. For example, it has been reported that
graphene/GOꢀsupported metal or metal oxide nanoparticles (NPs) could improve the
performance of catalysts in oxygen reduction reaction (ORR), hydrogen evolution reaction,
3
oxygen evolution reaction, and carbon–carbon coupling reaction. Theoretical calculations have
shown that the interaction between metal and graphene would change the Fermi level of both the
4
metal and graphene, which plays an important role in enhancing the catalytic activity. Thus, it is
of great interest to prepare graphene/GOꢀbased metal NPs with excellent catalytic activity.
Palladium is an important metal for catalyzing many organic reactions such as Suzuki, Heck, and
Stille coupling reactions. In recent years, there is a growing interest to prepare Pd nanostructures
5
with morphological control. The organic amine group containing N acts as a linker, thereby
binding Pd NPs covalently through a Pd−N bond. Depositing Pd NPs on such a functionalized
support containing nitrogen atoms seems a promising way for the formulation of a stable
6
catalyst. Currently, two approaches have been widely used to synthesize graphene/GOꢀ
7
supported metal NPs, i.e., an in situ growth method and an ex situ assembly method. The ex situ
assembly approach usually needs surface modification of the NPs and/or graphene/GO, so that
they can bind together through noncovalent interactions or chemical bonding.
Recently, the use of the liquid–liquid interface as a medium for preparing ultrathin films of
8
metals, chalcogenides and oxides was demonstrated. The most important advantages of this
assembly strategy are the significant simplicity and universality found in almost all of the related
low dimensional nanostructures. The quality of the films is generally better than that of films
9
fabricated by other methods. In recent years, application of organometallic complexes has
10
appeared as an important alternative route for the synthesis of nanomaterials. We have reported
the effect of different organoplatinum(II) and organopalladium(II) complexes on the morphology
9
,11
and size of Pt NPs and Pt–Pd NPs alloys at oil–water interface in the absence of stabilizer.
Recently, we synthesis Pd/reducedꢀGO (rGO) and Pd free stabilizer NPs and investigating the
application of thin films obtained from an oil–water interface in the Suzuki–Miyaura reaction for
2
b
the first time, that they exhibit a high catalytic activity. Also, the application of Fe O NPs,
3
4
2

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Pd/aminoclay NPs and Pd/Fe O /rGO nanohybrid were investigated as efficient catalysts for C–
3
4
2
c,12
C bond formation.
In this study, functionalized GO by 3ꢀampy was used as a substrate to prepare Pd NPs. This
strategy is an easy and inexpensive method for fabrication of NP thin films and only a beaker
and syringe are required for a highꢀquality thin film that can easily produced in a short time.
Transmission electron microscopy confirmed that nanometerꢀsized Pd particles were distributed
well on 3ꢀampyꢀGO substrate. The Pd/3ꢀampyꢀrGO nanohybrid functioned as an efficient
catalyst for Suzuki –Miyaura reactions for the formation of carbonꢀcarbon bonds. High electron
density group on Pd nanocatalyst increases the rate of oxidative addition that is the rate
determining step of the catalytic cycle, and just as we expect, C–C coupling reaction with Pd/3ꢀ
ampyꢀrGO nanohybrid is faster and in less time than Pd/rGO nanocatalyst.
Experimental
All of the chemical compounds were purchased from Merck Company. The complex
1
3
[
PdCl (cod)] (cod = cis,cisꢀ1,5ꢀcyclooctadiene)was synthesized using a reported procedure.
2
The powder Xꢀray diffraction patterns (XRD) were obtained by a Bruker AXS (D8, Advance)
instrument employing the reflection Bragg–Brentano geometry with CuꢀKα radiation. The
qualitative and quantitative elemental composition of the treated samples were acquired by
means of energy dispersive Xꢀray (EDAX, model Seron AIS 2300, Korea). Transmission
electron microscopy (TEM) images were taken with a Philips CMꢀ10 microscope operated at
ꢀ1
ꢀ1
1
00 kV. Raman spectra were recorded from 4250 cm to 100 cm on a high resolution
dispersive Raman Thermonicolet (LabRAM HR UV/Vis/NIR, Electrooptics). The loading
amount of palladium was determined by an ICP analyzer (Varian, VistaꢀPro). FTꢀIR spectra
1
were taken with a Jasco FT/IRꢀ680 plus spectrometer. H NMR spectra were taken with a Bruker
4
00 MHz ultraꢀshield spectrometer using CDCl as the solvent and TMS as the internal standard.
3
Preparation of 3-ampy-GO
1
4
GO was synthesized from natural graphite flakes by a modified Hummers method. 0.01 g of
GO was dispersed in distilled water and placed in a sonic bath for 10 min. Finally, a mixture
contains 3ꢀampy (0.01 mmol) and 0.01 g NaOH in water was added. The reaction mixture was
3

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heated under a reflux condenser at 80 °C for 24 h after which the mixture was centrifuged and
the black crystalline separated, washed with ethanol and water and airꢀdried (Scheme 1).
<
<Scheme 1>>
Preparation of Pd/3-ampy-rGO nanohybrid thin film at the oil–water interface
mM [PdCl (cod)] complex in toluene (25 ml) was sonicated for 15 min to prepare a yellow
1
2
color solution. This solution was stood in contact with distilled water (25 ml) containing 3ꢀampyꢀ
GO (10 mg) in a beaker (100 ml). Once the two layers were stabilized, an appropriate volume of
aqueous NaBH (10 ml, 0.1 M) was injected into the aqueous layer using a syringe with minimal
4
disturbance to the toluene layer. The onset of reduction was marked by a coloration of the
liquid–liquid interface. With the passage of time, the color became more vivid, finally resulting
in a film at the liquid–liquid interface. The aqueous and organic layers below and above the film
were, however, transparent.
General procedure for Suzuki–Miyaura coupling reaction
Arylhalide (0.5 mmol) and phenylboronic acid (0.75 mmol) were added to a flask containing the
Pd/3ꢀampyꢀrGO catalyst (0.004 mol% of Pd) and K CO (1 mmol) in 6 mL of EtOH/H O (1:1).
2
3
2
Reaction was carried out at 80 °C. After completion of the reaction (monitored by TLC), the
reaction mixture was cooled down to room temperature and then, dichloromethane (5 × 10 mL)
was added to the reaction vessel and separated solid catalyst. The organic phase was separated
and dried over anhydrous MgSO . Evaporation of the solvent gave the pure desired product.
4
1
Characterization of these compounds was established by comparison of their FT–IR and H
NMR spectra with those of authentic sample and the details are given in the supporting
information. The turnover number (TON (= mol of product/mol of catalyst)) and turnover
frequency (TOF (= TON/time (h))) were calculated on the basis of the amount of biaryl product
formed.
Results and discussion
Physicochemical characterization of the catalyst
In this study, the synthesis of Pd/3ꢀampyꢀrGO nanohybrid thin film involving chemical reduction
of the [PdCl (cod)] complex at the oil –water interface with NaBH is demonstrated. FTꢀIR
2
4
4

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spectra of GO, 3ꢀampyꢀGO and Pd/3ꢀampyꢀrGO are shown in Fig. 1. The results from FTꢀIR
spectroscopy revealed that the characteristic band of the carboxyl group in GO appears at ca.
−
1
1
729 cm (C=O stretching) (Fig. 1a). The C–O vibrations of epoxy groups in GO appeared at
−
1 2c,15
−1
ca. 1226 cm .
As shown in Fig. 1b, the peaks at 2865 and 2927 cm corresponds to
symmetrics ν CH and asymmetric ν CH of the 3ꢀampy, respectively. As the GO sheet
s
2
as
2
contains reactive epoxy groups, its exposure to amine groups would lead to a ring opening
reaction of the reactive threeꢀmembered epoxide ring, creating new C–N bonds and –OH
ꢀ1
functional groups. The increase of the peak intensities at 1575 and 1199 cm corresponds to a
stretching of the new NH bending and C–N vibration, respectively. Amine groups did not reacted
with carboxylic acid groups of GO through the amidation process because the amide ν NH
−
1
−1
vibration expected at 3300 cm is not present and the 1650–1750 cm region does not show a
−
1
strong ν C=O band. The absorption band at around 1700 cm is attributed to the carboxyl
groups. However, the corresponding absorption (Fig. 1b) at this range is not observable, likely
2
c,16
due to the overlapping of absorption of graphene sheets in this region.
The FTꢀIR result in
Fig. 1c shows that Pd/3ꢀampyꢀrGO nanohybrid is formed via a chargeꢀtransfer interaction
between 3ꢀampy and palladium demonstrated that the donation of an electron lone pair on the N
group of pyridine ring in the 3ꢀampy into an unoccupied orbital of the palladium NP surface is
8
b,17
responsible for the electron transfer and interaction of the Pd(II) complex with 3ꢀampyꢀGO.
ꢀ1
ꢀ1
For 3ꢀampyꢀGO, absorption bands appeared at 2915 cm and 2852 cm , which was attributed to
ꢀ1
CH , a stronger absorption band appeared at 1571 cm , which was assigned to NH, and an
2
ꢀ1
absorption band appeared at 1220 cm , which was assigned to CN (Fig. 1c). Compared with
reference 3ꢀampyꢀGO, the absorption of 3ꢀampy in Pd/3ꢀampyꢀrGO nanohybrid is shifted.
<
<Fig. 1>>
Raman spectroscopy has been widely used to probe structural and electronic characteristics
of graphite materials, providing useful information on the defects (D band) and in plane vibration
2
of sp carbon atoms (G band). Fig. 2 shows the Raman spectra of GO and Pd/3ꢀampyꢀrGO. The
prominent D Peak is from the structural imperfections created by the attachment of hydroxyl and
1
8
epoxide groups on the carbon basal plane. The Raman spectra in Fig. 2 show the characteristic
ꢀ1
peaks located at 1350 and 1592 cm corresponding to the D and G bands of graphene sheets,
respectively. As shown in Fig. 2b, the Raman spectrum of amineꢀfunctionalized GO also
5

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ꢀ1
exhibited fundamental vibrations similar to graphene oxide at 1598 and 1356 cm . The Raman
spectrum of 3ꢀampyꢀGO exhibits a higher relative D/G intensity ratio (1.45) compared to GO
2
(
0.95), implying the decreased size of the sp domains upon localized chemical reduction of the
1
6,18,19
GO by 3ꢀampy.
Typically, Raman spectroscopy is used for the determination of exfoliation
2
0
ꢀ1
ꢀ1
yield. The G band of GO observed at 1592 cm shifted to 1598 cm after 3ꢀampy
1
9
functionalization, indicating a better exfoliation of graphene layers.
<Fig. 2>>
XRD pattern of graphite is displayed in Fig. 3. The intense peak centered at 26.3°
<
2
1
corresponds to the (002) plane of graphite. Fig. 4(a) shows a SEM image and Fig. 4(b) the
XRD pattern of the bulk GO in the dry state. In the XRD pattern (Fig. 4b), a clear diffraction
2
b
band centered at 2θ~10° corresponds to the (002) plane of the GO. The XRD pattern of 3ꢀ
ampyꢀGO is shown in Fig. 5a. The first peak located at 2θ in 12.44 (002) is attributable to GO
that shifted to higher 2θ values (about 2 degree) compared to the XRD of GO, and weak and
broad peak at the 2θ value of 25.55° (002) confirm the GO intercalation with 3ꢀampy after the
additional ringꢀopening reaction due to the amine group of 3ꢀampy and the oxidation of graphite
that this peak is attributed to rGO. These findings allow us to confirm the successful conjugation
of 3ꢀampy onto the GO surface. After chemical reduction by sodium borohydride to produce the
rGOꢀsupported catalyst, the sharp diffraction peak of GO at 10 disappeared in the XRD pattern,
implying partial removal of the oxygen functional groups. The other characteristic peaks exhibit
the faceꢀcenteredꢀcubic (fcc) lattice structure of Pd, corresponding to the [(111), (200), (220),
1
1b
(
311) and (222)] planes that indicate presence of Pd(0) (Fig. 5b). The composition of the Pd/3ꢀ
ampyꢀrGO nanohybrid was further examined by energy dispersive analysis of Xꢀray (EDAX)
where the Pd and C elements were observed (Fig. 6). The palladium loading of the catalyst was
obtained using induced coupled plasma (ICP) that was 2.1 µg.
<
<
<
<
<Fig. 3>>
<Fig. 4>>
<Fig. 5>>
<Fig. 6>>
6

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Fig. 7 shows TEM images of the palladium NPs adhered on 3ꢀampyꢀGO sheets. The
reductions of Pd particles were further studied by using TEM to obtain the distribution of the
metal NPs on the functionalized GO (Fig. 7a and 7b). Spherical Pd NPs of a size around 5−6 nm
are wellꢀdispersed on the support (Fig. 7c), which is quite consistent with the data obtained from
the XRD analysis. Usually, small size NPs have the tendency to aggregate, and exactly this
phenomenon happened in the case of Pd/3ꢀampyꢀrGO nanohybrid. It is believed that the presence
of the organic amine moiety on the GO surface facilitated dispersion of the Pd(0) NPs on the GO
2
2
surface through coordination and acts as a stabilizing agent.
<
<Fig. 7>>
Catalytic evaluation
Carbon– carbon bond formation is one of the most fundamental reactions for the construction of
molecular frameworks in organic chemistry. Therefore, in this work, we studied the role of the
prepared catalyst toward Suzuki −Miyaura coupling reaction in the presence of EtOH/H O (1:1)
2
solvent (Table 1).
<
<Table 1>>
Solvent plays an immense role in improving the reactivity of this type of coupling reaction.
Therefore, we carried out rigorous investigations to define the best solvent for the Suzuki
−
Miyaura coupling reaction. Low yields were achieved with H O solvent, while EtOH/H O
2 2
solvent gave excellent yields. We examined the effect of the Pd/3ꢀampyꢀrGO nanohybrid system
in EtOH/H O solvent and interestingly an excellent yield of the product. As shown in Table 1,
2
the Suzuki–Miyaura reaction of phenylboronic acid with selected aryl halides in the presence of
Pd/3ꢀampyꢀrGO nanohybrid as palladium catalyst and aryl chlorides affording very high yields.
Normally, catalytic cycle of the present reactions includes three steps: (1) oxidative addition, (2)
23
transmetalation, and (3) reductive elimination. K CO was used as base for optimizing the
2
3
conditions of reaction. Usually, the activity of aryl halides decreases in the order of I > Br > Cl
2
2b
and the electronꢀdeficient aryl halide is generally more active than the electronꢀrich one.
Bromobenzene is faster than 4ꢀbromotoluene in the crossꢀcoupling reaction because CH is
3
electron donor group and reduces oxidative addition step speed (Table 1, entries 2 and 3).
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Chlorobenzene is slower than 1ꢀchloroꢀ4ꢀnitrobenzene due to NO group that is electronꢀ
2
2
withdrawing and cause weaken C(sp )ꢀCl bond and increase the speed of oxidative addition
(Table 1, entries 5 and 6). Thus, the oxidative addition step is generally considered as the rateꢀ
determining step (RDS). In the oxidative addition step, Pd(0) acts as a nucleophile and will
preferentially attack the most electronꢀdeficient position. It should be noted that, Pd/3ꢀampyꢀrGO
nanohybrid behaved as a very good catalyst toward the Suzuki–Miyaura coupling reaction. Pd/3ꢀ
ampyꢀrGO catalyst compared to other catalysts with graphene substrate and due to presence of
amine, oxidative addition is faster. As mentioned, functionalized GO with 3ꢀampy donation of a
lone pair of electrons from the N group of pyridine ring in the 3ꢀampy to Pd NPs improves the
reactivity of the catalyst than Pd/rGO. Also, the N group of pyridine ring in the 3ꢀampy stabilizes
the Pd(0) NPs and helps in increasing the activity and stability. Notice, we have compared the
activity of Pd/3ꢀampyꢀrGO with Pd/rGO in SuzukiꢀMiyaura reaction of bromobenzene and
phenylboronic acid in the presence of EtOH/H O (1:1) solvent at 80 ºC. As shown in Table 2,
2
higher TOF and higher yield are seen for Pd/3ꢀampyꢀrGO catalyst and more activity is
established for Pd/3ꢀampyꢀrGO catalyst.
<
<Table 2>>
When the Suzuki–Miyaura reaction of phenylboronic acid with bromobenzene was
completed, the Pd/3ꢀampyꢀrGO nanohybrid could be easily separated from the reaction mixture.
Centrifugation was applied to separate the catalyst from the reaction mixture which was then
washed with water and diethylether. The recovered catalysts were dried and checked with XRD
analysis. As shown in Table 3, the catalyst showed excellent catalytic activity even after 8 times
of recycling and the activity remained almost unaltered.
<
<Table 3>>
The TON and TOF a measure of efficiency of catalyst totally depends on the Pd
concentration, which reflects the structural development of supported palladium. Fox et al.,
reported that Suzuki coupling reaction over PdꢀNPꢀcored Gꢀ3 dendrimer catalyst gives [TON =
ꢀ1 24
2
3300] and [TOF = 1942 h ]. Hou et al., reported that Suzuki coupling reaction over Pdꢀ
ꢀ1 25
Ni/RGO catalyst gave [TON = 9687.5] and [TOF = 38750 h ]. In the current study using Pd/3ꢀ
ꢀ1
ampyꢀrGO as catalyst, higher TON [23750] and TOF [71250 h ] were observed for the Suzuki–
Miyaura reaction of phenylboronic acid with bromobenzene. The TON and TOF was recorded in
8

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2
4,25
the presence of different Pdꢀbased catalysts,
but unfortunately none of them reported about
Pd/3ꢀampyꢀrGO can react with aryl chlorides in
2
4ꢀ31
the reaction in the presence of aryl chlorides.
a high yield.
We compared our results with those of the noble metal based catalysts reported in the past
few years for Suzuki−Miyaura coupling reaction, taking the reactions of clorobenzeneand 1ꢀ
chloroꢀ4ꢀnitrobenzene with phenylboronic acid for Suzuki−Miyaura coupling as two examples
2
6ꢀ31
(Table 4).
Although some of them can also obtain high yields, the following factors make our
catalyst superior to the others for these reactions. (i) wellꢀdispersed Pd(0) NPs over the support
are strongly bound with the N moiety of pyridine ring in the 3ꢀampy which offers excellent
repeatability without loss of catalytic activity, (ii) the catalyst was prepared by a facile and lowꢀ
cost method, (iii) good results were obtained in short reaction times using low catalyst loading,
and (iv) large TON for catalyst indicates catalyst is stable and very longꢀlived.
<
<Table 4>>
Conclusion
In summary, we demonstrated a simple approach for the synthesis of Pd/3ꢀampyꢀrGO
nanohybrid by a simple threeꢀstep method. This nanometal has wellꢀdispersed 5−6 nm sized
Pd(0) NPs on its surface, which acted as the active site for the Suzuki − Miyaura C −C coupling
reactions. The N group of pyridine ring in the 3ꢀampy showed high affinity for the Pd(0) NPs,
making it durable for eight times repetitive use with consistent catalytic activity. Furthermore,
Pd/3ꢀampyꢀrGO nanohybrid behaved as a very good catalyst toward aryl chloride derivatives.
Acknowledgements
We thank the Yasouj University Research Council and Iranian Nanotechnology Initiative
Council for their support.
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References
1
(a) J. P. Corbet, G. Mignani, Chem. Rev., 2006, 106, 2651. (b) A. de Meijere and F.
Diederich, Eds.; Metal-Catalyzed Cross-Coupling Reactions, WileyꢀVCH, Weinheim,
2
004.
2
(a) L. Dong, J. Wen, S. Qin, N. Yang, H. Yang, Z. Su, X. Yu and C. Hu, ACS Catal.,
2012, 2, 1829. (b) S. J. Hoseini, M. Dehghani and H. Nasrabadi, Catal. Sci. Technol.,
2014, 4, 1078. (c) S. J. Hoseini, V. Heidari and H. Nasrabadi, J. Mol. Catal. A: Chem.,
2015, 396, 90. (d) S. J. Hoseini, A. Zarei and H. Rafatbakhsh Iran, Ligandless CꢀC bond
formation via SuzukiꢀMiyaura reaction in micelle or waterꢀethanol solution by PdPtZn
and PdZn nanoparticles thin film, Appl. Organometal. Chem., Manuscript number: AOCꢀ
1
5ꢀ0029.R1.
3
4
5
(a) V. Georgakilas, M. Otyepka, A. B. Bourlinos, V. Chandra, N. Kim, K. C. Kemp, P.
Hobza, R. Zboril and K. S. Kim, Chem. Rev., 2012, 112, 6156. (b)Y. X. Huang, J. F. Xie,
X. Zhang, L. Xiong, and H. Q. Yu, ACS Appl. Mater. Interfaces., 2014, 6, 15795.
(a) Q. J. Wang and J. G. Che, Phys. Rev. Lett., 2009, 103, 066802. (b) G. Giovannetti, P.
Khomyakov, G. Brocks, V. Karpan, J. van den Brink and P. Kelly, Phys. Rev. Lett., 2008,
1
01, 026803.
(a) A. Molnar, Chem. Rev., 2011, 111, 2251. (b) Y. H. Chen, H. H. Hung and M. H.
Huang, J. Am. Chem. Soc., 2009, 131, 9114.
6
7
8
G. B. B. Varadwaj, S. Rana and K. Parida, J. Phys. Chem. C., 2014, 118, 1640.
X. Huang, X. Qi, F. Boey and H. Zhang, Chem. Soc. Rev., 2012, 41, 666.
(a) C. N. R. Rao, G. U. Kulkarni, V. V. Agrawal, U. K. Gautam, M. Ghosh and U.
Tumkurkar, J. Colloid Interface Sci., 2005, 289, 305. (b) S. J. Hoseini, M. Rashidi and
M. Bahrami, J. Mater. Chem., 2011, 21, 16170.
9
1
S. J. Hoseini, N. Mousavi, M. Roushani, L. Mosadeghi, M. Bahrami and M. Rashidi,
Dalton Trans., 2013, 42, 12364.
0 (a) M. Green, Chem. Commun., 2005, 3002. (b) B. Chaudret and K. Philippot, Oil Gas
Sci. Technol. Rev. IFP., 2007, 62, 799.
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1
1 (a) S. J. Hoseini, M. Bahrami and M. Dehghani, RSC Adv., 2014, 4, 13796. (b) S. J.
Hoseini, M. Bahramin and M. Roushani, RSC Adv., 2014, 4, 46992. (c) S. J. Hoseini, Z.
Barzegar, M. Bahrami, M. Roushani and M. Rashidi, J. Organomet. Chem., 2014, 769, 1.
2 (a) H. Firouzabadi, N. Iranpoor, M. Gholinejad and J. Hoseini, Adv. Synth. Catal., 2011,
1
3
53, 125. (b) H. Firouzabadi, N. Iranpoor, A. Ghaderi, M. Ghavami and S. J. Hoseini,
Bull. Chem. Soc. Jpn., 2011, 84, 100.
1
1
3 H. S. Booth, L. F. Audrieth and J. C. Bailar, Inorganic synthesis, McGrawꢀHill, New
York and London, 1939.
4 (a) W. S. Hummers and R. E. O ffeman, J. Am. Chem. Soc., 1958, 80, 1339. (b) S. Li, D.
Wu, Ch. Cheng, J. Wang, F. Zhang, Y. Su and X. Feng, Angew. Chem., 2013, 125,
1
2327.
5 H. A. Becerril, J. Mao, Z. Liu, R. M. Stoltenberg, Z. Bao and Y. Chen, ACS Nano., 2008,
, 463.
1
1
2
6 Y, Xue, Y. Liu, F. Lu, J. Qu, H. Chen and L. Dai, J. Phys. Chem. Lett. 2012, 3, 1607. (b)
F. Perreault, M. E. Tousley and M. Elimelech, Environ. Sci. Technol. Lett., 2014, 1, 71.
(c) J. R. Lomeda, C. D. Doyle, D. V. Kosynkin, W. F. Hwang, and J. M. Tour, J. Am.
Chem. Soc. 2008, 130, 16201. (d) F, Zhang, H. Jiang, X. Li, X. Wu and H. Li, ACS
Catal., 2014, 4, 394.
1
7 K. A. Flanagan, J. A. Sullivan and H. MuellerꢀBunz, Langmuir, 2007, 23, 12508.
8 K. N. Kudin, B. Ozbas, H. C. Schniepp, R. K. Prud’homme, I. A. Aksay and R. Car,
Nano Lett., 2008, 8, 36.
1
1
9 E. Y. Choi, T. H. Han, J. Hong, J. E. Kim, S. H. Lee, H. W. Kim and S. O. Kim, J.
Mater. Chem., 2010, 20, 1907. (b) F. Tuinstra and J. L. Koenig, J. Chem. Phys., 1970, 53,
1
126.
2
2
0 A. Ciesielski and P. Samorı, Chem. Soc. Rev., 2014, 43, 381.
1 S. Khodabakhshi, B. Karami, Kh. Eskandari, S. J. Hoseini and A. Rashidi, RSC Adv.,
2
014, 4, 17891.
2
2 (a) G. B. Varadwaj, S. Rana and K. Parida, J. Phys. Chem. C., 2014, 118, 1640. (b) G.
Wei, W. Zhang, F. Wen, Y. Wang and M. Zhang, J. Phys. Chem. C., 2008 ,112, 10827.
3 L. Dong, J. Wen, S. Qin, N. Yang, H. Yang, Z. Su, X. Yu and C. Hu, ACS Catal., 2012,
2
2
, 1829.
11

Page 13 of 21
RSC Advances
View Article Online
DOI: 10.1039/C5RA07171B
2
2
2
2
2
2
4 K. R. Gopidas, J. K. Whitesell and M. A. Fox, Nano Lett., 2003, 3, 1757.
5 R. Nie, J. Shi, W. Du and Z. Hou, Appl. Catal., A: Gen., 2014, 473, 1.
6 J. Han, Y. Liu and R. Guo, J. Am. Chem. Soc., 2009, 131, 2060.
7 S. Li, Y. Lin, J. Cao and S. Zhang, J. Org. Chem., 2007, 72, 4067.
8 N. E. Leadbeater and M. Marco, Org. Lett., 2002, 4, 2973.
9 M. L. Kantam, S. Roy, M. Roy, B. Sreedhar and B. M .Choudary, Adv. Synth. Catal.,
005, 347, 2002.
2
3
0 M. Navidi, N. Rezaei and B. Movassagh, J. Organomet. Chem., 2013, 743, 63.
1 an der M. Heiden and H. Plenio, Chem. Eur. J., 2004, 10, 1789.
3
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Figure Captions:
Scheme 1 Schematic illustration of the preparation of 3ꢀampyꢀGO.
Fig. 1 (a) FTꢀIR spectra of GO, (b) 3ꢀampyꢀGO, and (c) Pd/3ꢀampyꢀrGO.
Fig. 2 (a) Raman spectra of GO and (b) 3ꢀampyꢀGO.
Fig. 3 XRD pattern of the Graphite.
Fig. 4 (a) SEM image of GO and (b) XRD pattern of GO.
Fig. 5 (a) XRD pattern of the 3ꢀampyꢀGO. (b) XRD pattern of the Pd/3ꢀampyꢀrGO nanohybrid
thin film deposited on a glass.
Fig. 6 EDAX spectrum of Pd/3ꢀampyꢀrGO nanohybrid.
Fig. 7 (a and b) TEM image of Pd/3ꢀampyꢀrGO nanohybrid and (c) histogram of particle size
distribution.
Table Captions:
Table 1 SuzukiꢀMiyaura crossꢀcoupling of aryl halides with phenylboronic acid catalyzed by
Pd/3ꢀampyꢀrGO nanohybrid
Table 2 Suzuki–Miyaura reaction between bromobenzene and phenylboronic acid in the
presence of Pd/rGO NPs and Pd/3ꢀampyꢀrGO nanohybrid in the presence of EtOH/H O (1:1)
2
solvent at 80 ºC
Table 3 Recycling result of the coupling reaction of phenylboronic acid with bromobenzene
Table 4 Study of the efficacy of the present system compared with previous reports
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DOI: 10.1039/C5RA07171B
Figures:
Scheme 1 Schematic illustration of the preparation of 3ꢀampyꢀG
1
00
(a)
95
90
1
00
8
5
C=O
C=C
8
0
9
5
75
(b)
c)
C-O
C-N
(
70
9
0
C-H
C-H
6
5
60
N-H
85
C-N
80
N-H
4
000 3500 3000 2500 2000 1500 1000 500
-
1
wavenumber (cm )
Fig. 1 (a) FTꢀIR spectra of GO, (b) 3ꢀampyꢀGO, and (c) Pd/3ꢀampyꢀrGO.
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Fig. 2 (a) Raman spectra of GO and (b) 3ꢀampyꢀGO.
Fig. 3 XRD pattern of the graphite.
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Fig. 4 (a) SEM image of GO and (b) XRD pattern of GO.
Fig. 5 (a) XRD pattern of the 3ꢀampyꢀGO. (b) XRD pattern of the Pd/3ꢀampyꢀrGO nanohybrid
thin film deposited on a glass.
16

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Fig. 6 EDAX spectrum of Pd/3ꢀampyꢀrGO nanohybrid.
Fig. 7 (a and b) TEM images of Pd/3ꢀampyꢀrGO nanohybrid and (c) histogram of particle size
distribution.
17

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DOI: 10.1039/C5RA07171B
Tables:
Table 1 SuzukiꢀMiyaura crossꢀcoupling of aryl halides with phenylboronic acid catalyzed by
Pd/3ꢀampyꢀrGO nanohybrid
G
+
B(OH)2
Pd/3-ampy-GO
K CO , EtOH/H O, reflux
G
X
Y
2
3
2
Y
1
1
a; Y = C, G = H
b; Y = C, G = Me
Y = C, N
G = H, Me, OMe, CN, NO2
X = Cl, Br, I
1c; Y = C, G = OMe
1d; Y = C, G = NO2
1e, Y = C, G = CN
1f; Y = N, G= H
a
b
ꢀ1 b
#
1
2
3
4
5
6
7
Substrate
C H I
Product Time (min) Yield (%) TON TOF (h )
1a
1a
1b
10
20
60
˃99
95
87
80
85
72
76
86
24750 148500
23750 71250
21750 21750
20000 8000
21250 42500
18000 72000
19000 76000
21500 5375
6
5
C H Br
6
5
4ꢀMeC H Br
6
4
4ꢀMeOC H Br 1c
150
30
6
4
C H Cl
1a
6
5
4ꢀNO C H Cl 1d
15
2
6
4
4ꢀCNC H Cl
1e
1f
15
240
6
4
8
C H NCl
5
4
a
Isolated yields.
b
See experimental section for calculation of TONs and TOFs.
Table 2 Suzuki–Miyaura reaction between bromobenzene and phenylboronic acid in the
presence of Pd/rGO NPs and Pd/3ꢀampyꢀrGO nanohybrid in the presence of EtOH/H O (1:1)
2
solvent at 80 ºC
ꢀ1
#
1
2
Catalyst
Time (min) Yield (%)
TON
111
TOF (h )
222
Ref
Pd/rGO
30
20
87
95
2b
Pd/3ꢀampyꢀrGO
23750
71250
This work
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Table 3 Recycling result of the coupling reaction of phenylboronic acid with bromobenzene
B(OH)2
Pd/3-ampy-GO
+
Br
K CO , EtOH/H O, reflux, 20 min
2 3 2
Run
1st 2nd 3rd 4th 5th 6th 7th 8th
Yield (%) 89 88 90 86 88 88 86 87
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Table 4 Study of the efficacy of the present system compared with previous reports
#
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
G
Catalyst
Solvent
Base
Temp (ºC) Time (h) Yield (%) Ref
a
H
Au
H O
2
NaOH
K CO
80
4
87
33
73
45
65
53
85
75
80
85
67
90
90
78
70
74
72
26
b
H
Pd(OAc) .(1f)
H O:EtOH=3:2
2
80
48
27
2
2
2
3
c
H
Pd(OAc) .(1g)
H O:EtOH=3:2
2
K CO
2
80
10
27
2
2
3
d
H
Pd(OAc)2
H O
2
Na CO
150ꢀ170
130
65
5 min
2ꢀ 6
7
28
2
3
e
H
NAPꢀMgꢀPd(0)
DMA
K PO
3
29
4
f
H
Pd(II)ꢀMWCNTs
H2O:DMF=1:1
K CO
2
30
3
3
3
3
3
3
g
H
Pd/Fe O /rGO
H O
2
K CO
2
80
2.5
4
2c
3
4
h
H
PdFS
Pd/rGO
H O
2
K CO
2
80
2b
i
H
H O
2
K CO
2
80
3
2b
0
1
2
3
4
5
6
7
H
Pd/3ꢀampyꢀrGO
EtOH:H O=1:1
K CO
2
80
30 min
10
This work
2
b
NO2
NO2
NO2
NO2
NO2
NO2
NO2
Pd(OAc) .(1f)
H O:EtOH=3:2
2
K CO
2
R.T
80
27
2
2
j
Na [PdCl ]
H Oꢀ DMSO
2
KF, K PO
18
31
2
4
3
4
e
NAPꢀMgꢀPd(0)
DMA
K PO
3
130
80
2ꢀ 6
1.5
2.5
1.5
15 min
29
4
Pd/Fe O /rGO
H O
2
K CO
2
2c
3
4
3
3
3
3
h
PdFS
Pd/rGO
Pd/3ꢀampyꢀrGO
H O
2
K CO
2
80
2b
i
H O
2
K CO
2
80
2b
1
EtOH:H O=1:1
K CO
2
80
This work
2
a
b
poly(2ꢀaminothiophenol) supported gold NPs (0.05 mol). Pd(OAc) .(1f) , (1f):1,1,3,3ꢀTetramethylꢀ2ꢀnꢀbutylguanidine) (2mol%).
2
2
c
e
d
Pd(OAc) .(1g) , (1g): 1,1,3,3ꢀtetramethylꢀ2ꢀsecꢀbutylguanidine) (2mol%), TBAB (0.1 equiv) as the additive. Pd(OAc) (0.4 mol%).
NAPꢀMgꢀPd(0) (3 mol%). PdꢀSchiff base@MWCNTs (0.2 mol%). Pd/Fe O /rGO nanohybrid (0.36 mol%). PdFS NP thin film
2
2
2
f
g
h
3
4
i
j
(0.48 mol%). Pd/rGO NP thin film (0.48 mol%). Na [PdCl ] (0.5 mol%).
2 4
2
0