Triazine-hyperbranched polymer-modified magnetic nanoparticles-supported nano-cobalt for C–C cross-coupling reactions

Article abstract of DOI:10.1007/s13738-021-02261-5

Design of hyperbranched polymers (HBPs) and crafting them in catalytic systems especially in organic chemistry are a relatively unexplored domain. This paper reports the utilization of triazine-hyperbranched polymer (THBP)-coated magnetic chitosan nanoparticles (MCs) as stabilizing matrix for cobalt nanoparticles. Cobalt nanoparticles were fabricated by coordination cobalt(II) ions with amine-terminated triazine polymer and then reduced into Co(0) using sodium borohydride in aqueous medium. The Co(0)-THBP@MCs were fully characterized by FT-IR, SEM–EDX, TEM, and TGA analyses. The presence of metallic cobalt was determined by ICP and XRD techniques. This novel hyperbranched polyaromatic polymer-encapsulated cobalt nanoparticles showed high catalytic activity in Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions. Heck and Suzuki reactions were carried out using 0.35 and 0.4?mol% of cobalt nanoparticles in which the turnover number (TON) values were calculated as 271 and 225, respectively. In addition, the produced heterogeneous catalyst could be recovered and reused without considerable loss of activity. Oxygen stability and high reusability over 7 runs with trace leaching of the cobalt into the reaction media as well as moisture stability of the immobilized cobalt nanoparticles are their considerable worthwhile advantages.

Full text of DOI:10.1007/s13738-021-02261-5

Journal of the Iranian Chemical Society
https://doi.org/10.1007/s13738-021-02261-5
ORIGINAL PAPER
Triazine‑hyperbranched polymer‑modifed magnetic
nanoparticles‑supported nano‑cobalt ꢀor C–C cross‑coupling reactions
Abdol R. Hajipour1,2 · Shaghayegh Sadeghi1
Received: 21 July 2020 / Accepted: 17 April 2021
©
Iranian Chemical Society 2021
Abstract
Design of hyperbranched polymers (HBPs) and crafting them in catalytic systems especially in organic chemistry are a
relatively unexplored domain. This paper reports the utilization of triazine-hyperbranched polymer (THBP)-coated mag-
netic chitosan nanoparticles (MCs) as stabilizing matrix for cobalt nanoparticles. Cobalt nanoparticles were fabricated by
coordination cobalt(II) ions with amine-terminated triazine polymer and then reduced into Co(0) using sodium borohydride
in aqueous medium. The Co(0)-THBP@MCs were fully characterized by FT-IR, SEM–EDX, TEM, and TGA analyses. The
presence of metallic cobalt was determined by ICP and XRD techniques. This novel hyperbranched polyaromatic polymer-
encapsulated cobalt nanoparticles showed high catalytic activity in Mizoroki–Heck and Suzuki–Miyaura cross-coupling
reactions. Heck and Suzuki reactions were carried out using 0.35 and 0.4 mol% of cobalt nanoparticles in which the turnover
number (TON) values were calculated as 271 and 225, respectively. In addition, the produced heterogeneous catalyst could
be recovered and reused without considerable loss of activity. Oxygen stability and high reusability over 7 runs with trace
leaching of the cobalt into the reaction media as well as moisture stability of the immobilized cobalt nanoparticles are their
considerable worthwhile advantages.
Keywords Hyperbranched polymer · Cobalt nanoparticles · Magnetic chitosan support · Heck and Suzuki cross-coupling
reactions
Introduction
known as an inexpensive, non-toxic, abundant, and highly
active catalyst [11], our research group has focused on using
cobalt as a green catalyst for cross-coupling reactions [12,
13]. In many reactions catalyzed by metal nanoparticles, the
metal surfaces should interact with the reacting substrates
directly to achieve eꢀcient catalytic reactions [14]. If the
metal nanoparticles were produced naked, the interaction
of metal–substrate would be more eꢀcient. However, the
electrostatic attraction and high surface energy between the
naked atoms of MNPs can induce aggregation, reduce the
accessible catalyst surface area, and result in decreased cata-
lytic activity [15, 16]. Therefore, the metal surfaces passiva-
tion has been developed by organic capping molecules [17]
Employing metal nanoparticles (MNPs)-catalyzed C–C
cross-coupling reactions is one of the most promising
approaches for the synthesis of organic materials [1].
Although the palladium nanoparticles have been exhibited
unique performance in cross-coupling reactions [2], the
toxicity and price of them lead to replacing it with more
sustainable and inexpensive metals [3]; therefore, the appli-
cation of various palladium-free catalytic systems including
nickel [4–6], copper [7], iron [8, 9], and cobalt [10] has
been developed. Since cobalt nanoparticles (CoNPs) are
(
ionic liquid [18], surfactants [19], polymers [20], etc.) or
*
Abdol R. Hajipour
haji@cc.iut.ac.ir
solid supports to prevent the aggregation of MNPs. How-
ever, this may be accompanied with decreased catalytic
activity because of the occupation of metal sites by organic
groups [21]. In comparison with other capping agents, poly-
mers are more advantageous and aꢁording better stabiliza-
tion [14]. Polymer architecture and functional groups allow
the control of the structure and morphology of MNPs [22].
1
Pharmaceutical Research Laboratory, Department
of Chemistry, Isfahan University of Technology,
8
415683111 Isfahan, Iran
2
Department of Neuroscience, Medical School, University
of Wisconsin, 1300 University Avenue, Madison,
WI 53706-1532, USA
Vol.:(0
1
123456789)
3

Journal of the Iranian Chemical Society
Among polymers, hyperbranched polymers have received
considerable attention [23] due to their highly branched,
porosity, and three-dimensional structures. They exhibit
multiple internal and external functional groups such as
alkanamine, alkanthiol, or alkanhydroxy, which prevent the
formation of well-packed MNPs [24]. Hence, hyperbranched
polymers are well suited as host for metal catalysts due to
their strong capability of coordinating with metals, which
leads to better catalytic activity [25, 26]. Hyperbranched
polymer-based catalysts with branching structures allow the
reactants to reach the entrapped nanoparticles, while at the
same time inhibiting the nanoparticles from aggregation and
stabilizing them [27, 28]. The ꢂrst studies on hyperbranched
polymers stabilized CoNPs were carried out by Kutyreva′s
group [29]. Moreover, hyperbranched molecules-encap-
sulated nanoparticles demonstrate diꢁerent applications in
nanomedicine [30], photonic [31], and molecular electronics
activities were assayed in cross-coupling of aryl chlorides,
bromides, and iodides with methyl acrylates and phenylbo-
ronic acids under mild conditions. Since the prepared cata-
lyst could catalyze aryl chlorides which are less reactive in
cross-coupling reactions than aryl iodides and aryl bromides,
this catalyst can be a promising candidate for examining it
in other cross-coupling reactions. The accessibility of the
triazine-hyperbranched polymer and the presence of CoNPs
on the surface of MaNPs as well as the stability of the cobalt
nanoparticles cause an increased catalytic activity.
Experimental section
Materials and methods are described in the supporting
information.
[
32], and are also applied as nanocatalyst [33]. Among vari-
Catalyst preparation
ous hyperbranched polymers, triazine-based polymers have
been much reported [34] due to their chemoselective reactiv-
ity and low cost [35]. For instance, Landarani et al. recently
reported the synthesis and catalytic properties of triazine-
based polymer-stabilized PdNPs in cross-coupling reactions
Synthesis oꢀ magnetic chitosan (MCs)
Although different methods have been used to prepare
Fe O , co-precipitation which may be the simplest chemical
3
4
[
36]. In another example, the synthesis and application of
approach was employed in this work [53]. First, FeSO ·7H O
4
2
triazine-based hyperbranched polymer which stabilized Pd
nanoparticles as the catalyst in cross-coupling reactions
were studied by Moghadam et al. [37]. In another report,
cobalt-grafted triazine functionalized magnetic nanoparti-
cles were used as a catalyst in Heck cross-coupling reaction
(5.2 mmol, 1.46 g) was added to a round-bottom flask
containing a mixture of FeCl ·6H O (7.4 mmol, 2 g) and
3
2
100 mL of distilled deionized water (DDW). The mixture
obtained was then dispersed for about 30 min. Next, NH
3
solution (alkaline precipitation agent) was added dropwise
into the homogeneous mixture until the pH reached 10 and a
black precipitate formed. Afterward, the mixture was stirred
at 80 °C in nitrogen atmosphere for about 2 h to complete the
crystallization. The precipitate was separated by an exter-
nal magnetic bar from the reaction mixture, washed several
times with deionized water (DW) and ethanol, and dried in
an oven at 50 °C.
[
38]. Although polymers can serve as the catalyst support,
their stabilization on an inorganic solid support is believed
to improve the catalytic activities of metal nanoparticles.
On the other hand, hyperbranched polymers are nearly too
small, even those with high generations to be separated from
the reaction media and used again [39]. Thus, there are many
works which reported heterogenizing polymers on solid sup-
ports [40] such as carbon nanotubes [41], silica [42] gra-
Subsequently, the surface modification of magnetic
nanoparticles with chitosan was performed to address the
agglomeration of MaNPs and also generate amine groups
[54]. For this purpose, MaNPs (0.236 g) and 2 mL of acetic
acid solution were mixed with a mixture of deionized water
(11 mL) and chitosan (0.472 g), and the resultant mixture
was stirred for 15 min. Afterward, sodium sulfate solution
(20% W/V) was dispersed in the mixture of chitosan and
vigorously stirred for 1 h at room temperature. Finally, the
magnetic chitosan was separated from the reaction media by
an external permanent magnet, washed with ethanol several
times, and dried at 70 °C.
,
phene sheets [43], and TiO [44]. However, lack of eꢀcient
2
functional groups restricts the application of these solid
supports [45]. Magnetic nanoparticles (MaNPs) are attrac-
tive alternative for heterogenizing catalysts, because their
magnetic properties cause easy separation of the catalyst
by an external magnetic ꢂeld [46–48]. Moreover, MaNPs
attract signiꢂcant interest in the area of drug delivery [49],
magnetic storage media [50], biomedicine [51], and chemi-
cal reactions [52].
The preparation and the catalytic properties of the cobalt
nanoparticles immobilized on the hyperbranched polymer-
functionalized nano-magnetic chitosan were studied in
this work. Triazine-based hyperbranched polymer bearing
amine groups were attached to the cobalt nanoparticles
Preparation oꢀ MCs‑CC1
(
Co(0)-THBP@MCs) as a surface ligand. After preparation
The general procedure for the construction of THBP is
as follows: the magnetic chitosan (0.5 g) was added to a
and characterization of Co(0)-THBP@MCs, its catalytic
1
3

Journal of the Iranian Chemical Society
solution of cyanuric chloride (10 mmol, 1.85 g) and trieth-
ylamine (10 mmol, 1.7 mL) in 15 mL of THF. The resulting
mixture was allowed to stir overnight at 0 °C. The desired
product was collected by an external magnetic bar, separated
from white triethyl ammonium chloride salt and washed
with THF several times to remove redundant and then dried
in a vacuum oven at 50 °C [36].
remove the unreacted starting materials, and dried at room
temperature to aꢁord the (Co(II)-THBP@MCs) complex as
a brown solid. 0.5 g of the Co(II)-complex in distilled water
(10 mL) was then reduced by 10 mL of NaBH solution
4
(100 mM) under stirring. After 2 h, the catalyst was sepa-
rated from the mixture, washed several times with ethanol
and dried in vacuum to obtain a brown solid powder.
Preparation oꢀ triazine‑hyperbranched
General procedure for Heck reaction
polymer‑ꢀunctionalized magnetic chitosan (G1)
In a round-bottom ꢃask containing a mixture of DMF:H O
2
The amidation of triazine ring with diamino pyridine is as
follows: to a slurry of MCs-CC1 (0.34 g) in DMF (12 mL),
(1:2 V/V, 6 mL) as the solvent, a mixture of aryl halide
(1.0 mmol), methyl acrylate (1.2 mmol), K PO (2.0 mmol),
3
4
2
,6-diamino pyridine (16 mmol, 0.7 g) and triethylamine
and 0.35 mol% of the catalyst was added. For an appropriate
amount of time, the reaction mixture was agitated at 90 °C.
The completion of the reaction was monitored by TLC (Hex-
ane/EtOAc, 80:20) and gas chromatography (GC). The reac-
tion mixture was then cooled at room temperature and the
organic layer was extracted with ethyl acetate. Afterward,
(
16 mmol, 1.5 mL) were added. The reaction mixture was
stirred at 80 °C for 16 h. The solid product was obtained
with a magnetic ꢂeld, washed with hot ethanol to remove
the unreacted substrates and dried in a vacuum oven at 50 °C
[
36].
1
the products were characterized by comparison of their H-
1
3
Preparation oꢀ MCs‑CC2
NMR and C-NMR spectra with those previously reported.
For construction of the second generation of THBP on the
surface of magnetic chitosan, Michael addition and amida-
tion condensation were repeated one more time. Triazine-
hyperbranched polymer-supported magnetic chitosan,
General procedure for Suzuki reaction
In a round-bottom ꢃask, a mixture of aryl halide (1.0 mmol),
phenylboronic acid (1.2 mmol), K PO (2.0 mmol),
3
4
(
(
G1) (0.26 g) was added to a solution of cyanuric chloride
3 mmol, 0.7 g) and triethylamine (3 mmol, 1.56 mL) in
and 0.4 mol% of the catalyst was added to a mixture of
DMF:H O (1:2 V/V, 6 mL) solvent. For an appropriate
2
1
5 mL THF. The reaction mixture was agitated at 0 °C
period of time, the reaction mixture was stirred at 90 °C.
for 10 h, followed by separation and washing with THF to
remove the unreacted reactants. Finally, MCs-CC2 was dried
in a vacuum oven at 50 °C.
The reaction was carried out similarly to the Heck reaction.
1
Then, the corresponding products were characterized by H-
1
3
NMR and C-NMR analyses.
Preparation oꢀ triazine‑hyperbranched
polymer‑ꢀunctionalized magnetic chitosan (G2)
Results and discussion
To a slurry of MCs-CC2 (0.24 g) in 20 mL of DMF,
Fabrication and characterization of the synthesized
catalyst
2
,6-diaminopyridine (8.11 mmol, 0.3 g) and triethylamine
(
8.11 mmol, 1.4 mL) were added. The reaction mixture was
stirred at 80 °C for 16 h and then collected. The resulting
THBP@MCs (G2) were washed with hot ethanol to remove
the unreacted starting materials and dried in a vacuum oven
at 50 °C.
Hyperbranched polymers (HBPs) are a class of dendrimers
with branched conformation, which are comprised of a large
number of functional groups. In comparison with dendrim-
ers, HBPs have advantages including facile functionaliza-
tion process, self-assembly mechanism, and controllable
morphologies. HBPs, which are multifunctional polymers,
can be employed as stabilizing matrix for synthesizing cata-
lytic metal nanoparticles (MNPs) [30, 55]. These polymers-
encapsulated MNPs demonstrate some advantages such as
high and controlled activity and good air stability [56]. They
aꢁect signiꢂcantly the physiochemical properties of products
such as synthetic versatility and processability [57]. These
polymers have been found to be eꢁective homogeneous and
heterogeneous catalysts in cross-coupling reactions [40, 58,
Preparation oꢀ cobalt nanoparticles immobilized
on triazine‑hyperbranched polymer‑supported magnetic
chitosan (Co(II)‑THBP@MCs)
In order to coordinate triazine rings of THBP@MCs to
cobalt, G2 (0.5 g) was added to 4.2 mmol of CoCl 6H O
2
.
2
dissolved in ethanol (10 mL). The reaction mixture was
reꢃuxed under stirring for 18 h at 70 °C. The resulting com-
plex was separated, washed several times with ethanol to
1
3

Journal of the Iranian Chemical Society
5
9]. In this study, magnetic nanoparticles were selected as
other mono-layered compound such as 3‐(trimethoxysilyl)‐
propylamine, chitosan can provide more amine groups due
to its polymeric nature. Since the amino groups of chitosan
are more nucleophilic than hydroxyl groups to attack the
cyanuric chloride, OH groups remain free and intact. Then,
the achieved magnetic chitosan reacts with cyanuric chloride
at 0 °C for substitution of only one of the chlorine atoms to
yield MCs-CC1. In the following step, the reaction of MCs-
CC1 with 2,6-diamino pyridine was carried out at 90 °C to
remove both of the reside chlorine atoms in MCs-CC1 to
give G1. Next, G1 was converted to MCs-CC2 during reac-
tion with cyanuric chloride. Finally, MCs-CC2 reacts with
2,6-diamino pyridine which produced the THBP@MCs as
the support for CoNPs (Scheme 1). The loading amount of
Co onto the THBP@MCs determined by inductively cou-
proper support which cause convenient separation of the
synthesized catalyst in each step of the synthesis. Many
reports on the employment of triazine-based polymers as
support for diꢁerent metals in catalytic system have been
published [58, 60]. However, to the best our knowledge,
there are only a few reports on the application of these pol-
ymers in cross-coupling reactions. As we know, this is the
ꢂrst report on the application of magnetic THBP-supported
cobalt nanoparticles as catalyst in Heck and Suzuki cou-
pling reactions without any co-catalyst. The pathway for the
preparation of the catalyst is illustrated in Scheme 1. First, to
assist the immobilization of THBP, MaNPs were functional-
ized with chitosan to aꢁord magnetic chitosan with reactive
amine groups. On the other hand, chitosan is a biocompati-
ble, non-toxic, and abundant bio-polymer with free hydroxyl
and amine functional groups, and also in comparison with
−
1
pled plasma analysis (ICP) was 2.48 mmol g . The proce-
dure was also monitored by FT-IR and TGA techniques. The
Scheme 1 Synthesis route for the preparation of the catalyst
1
3

Journal of the Iranian Chemical Society
The oxidation state of cobalt in the synthesized catalyst
was indicated by high-resolution XPS spectrum (Fig. S1).
According to the previous report [62], the peak with binding
energy of 799.4 eV is assigned to Co 2p and the peak at
1
/2
7
79.5 eV is attributed to Co 2p which can be indexed to
3/2
Co(0). The XPS data conꢂrm the formation of cobalt nano-
particles on THBP.
The amount of organic moieties and thermal degradation
of MaNPs, MCs, MCs-CCl, G1, and G2 were studied by
thermal gravimetric analysis (TGA). The weight loss per-
centages of all cited compounds between 30 and 700 °C
were determined by TGA which is an irreversible process
(
Fig. 2). As shown in Fig. 2a, a 3 wt% weight loss observed
for Fe O in the range of 250–400 °C is related to the
3
4
removal of physically absorbed water. In the case of MCs,
two decomposition stages were observed. However, the 10%
weight loss in the 180–400 °C range is related to release of
moisture on the structure. In addition to water loss, above
4
00 °C, chitosan starts to degrade and is completely depo-
Fig. 1 FT-IR spectra: (a) MaNPs, (b) CS, (c) MCs, (d) MCs-CC1, (e)
lymerized at 700 °C. The observed weight loss (12 wt%) in
Fig. 2c demonstrates the successful immobilization of the
cyanuric chloride on the surface of MCs. The TGA plots
of G1 and the synthesized catalyst result from the removal
of absorbed water and elimination of organic matter on the
surface. Furthermore, the total weight loss of G2 (31%) was
larger than of G1 (24%), demonstrating the higher content
of the organic moieties bonded on the catalyst. These results
evidently prove the successful immobilization of the hyper-
branched polymer on the magnetic surface.
G1, and (f) the synthesized catalyst
catalyst was characterized by FE-SEM, EDX, TEM, XPS,
and XRD analyses.
In order to conꢂrm the synthesis of MaNPs, Cs, MCs,
MCs-CC1, G1, and the synthesized catalyst FT-IR spectra
were recorded (Fig. 1a–f). The presence of bands at 580 and
−
1
3
420 cm is characteristic of the Fe–O and O–H stretching
vibration, respectively [61] (Fig. 1a). In the case of chitosan,
−1
the absorption bands around 1081, 3365, and 1583 cm cor-
respond to the stretching vibration of C–O, O–H, and N–H
The presence of Fe O and cobalt nanoparticles in the
3
4
catalyst was conꢂrmed by the XRD patterns. XRD analysis
was applied to investigate the crystalline nature and pres-
ence of iron and cobalt in the synthesized catalyst. Figure 3
(
primary amine) of pristine chitosan, respectively (Fig. 1b).
The bands corresponding to the C–H (stretching vibration)
−
1
of the chitosan backbone appear at 2921 and 2881 cm
Fig. 1b). It is noteworthy to mention that the bands shift to
(
−
1
higher wavelengths (3369, 2926, 2887 cm ) in comparison
with pure chitosan upon the immobilization of chitosan on
MaNPs (Fig. 1c). The characteristic absorption bands in the
range of 1490–1620 attributed to C–N and C=N, and the
−1
C–Cl stretching vibration at 1091 cm (Fig. 1d) appear after
the addition of triazine units on the magnetic chitosan. As
observed in Fig. 5e, the stretching vibration of the primary
−
1
amine groups (N–H) at 3410–3450 cm , the stretching
vibration of the secondary amine groups overlapped with
the primary amine bands, and the stretching vibration of
−
1
C=N groups at 1626 cm verify the eꢁective immobiliza-
tion of 2,6-diaminopyridine on the functionalized magnetic
chitosan. Eventually, in the case of Co(0)-THBP@MCs
−
1
(
(
Fig. 5f), a slight shift of the band at 1626 cm is observed
−
1
−1
1626 cm → 1631 cm ), which is probably characteristic
of the primary amine groups after interaction with the cobalt
nanoparticles. Therefore, the functional groups have been
successfully grafted onto the MCs surface.
Fig. 2 TGA thermogram of (a) MaNPs, (b) MCs, (c) MCs-CC1, (d)
G1, and (e) G2
1
3

Journal of the Iranian Chemical Society
emission-scanning electron microscopy (FE-SEM) (Fig. 5).
As shown in Fig. 5a, the surface of Fe O particles is rough
3
4
and shows considerable protuberances, which can be caused
by the reduced surface energy of Fe O particles. In com-
3
4
parison with magnetic nanoparticles, the magnetic chitosan
surface shows more irregular pores and higher roughness,
caused by the tightly bound structure between the surface of
chitosan and MaNPs (Fig. 5b), and the diameter of magnetic
chitosan was larger than that of Fe O diameter. As observed
3
4
in Fig. 5c, MCs-CC1 particles are highly irregular and angu-
larly shaped with various size ranges. As clearly observed
in Fig. 5d, the surface morphology varies and there is more
agglomeration after binding of diamine groups with triazine
molecules. The reaction between THBP@MCs and cobalt
after reduction with sodium borohydride yields similar non-
continuous layers, with particles of diꢁerent sizes. These
observations reveal the successfully linkage of the organic
materials to the magnetite nanoparticles.
Fig. 3 XRD patterns of the (a) Fe O and (b) Co (0)-THBP@MCs
3
4
The morphology and particle size of the catalyst were
studied by transmission electron microscopy (TEM) analysis
(Fig. 6). The structure and particle size of the synthesized
catalyst were conꢂrmed by TEM technique and found to be
16 nm. As observed, the dark color MaNPs cores were sur-
rounded by light gray spherical shell which belongs to the
organic compounds. The smaller dimensions of the nano-
particles provide larger surface to volume ratio and conse-
quently more eꢀcient catalytic activity.
shows the XRD patterns of Fe O and Co(0)-THBP@MCs
3
4
catalyst. In the displayed diagram, six characteristic dif-
fraction peaks at 2ꢀ= 30.5°, 35.6°, 43.3°, 53.6°, 57.3°, and
6
2.9° are observed, relating to the (220), (331), (400), (422),
(
511), and (440) crystal planes of the cubic inverse spinel
structure of Fe O (Fig. 3a), respectively, which match well
3
4
with the standard magnetic nanoparticles sample (JCPDS
card no. 85–1436) [63, 64]. The diꢁraction peaks positioned
at 2ꢀ = 43.43° and 53.6° are attributed to the reꢃection of
The VSM diagrams of Fe O , MCs, G2, and the synthe-
3
4
(
111) and (220) crystalline planes of the cobalt species with
sized catalyst at room temperature are presented in Fig. 7.
cubic spinal structure. It is worthwhile to point out that the
crystallographic phase of nanoparticles was not aꢁected by
their surface modiꢂcation. Moreover, average crystallite
size of the nanoparticles which establishes a relationship
between position and broadening peak was estimated by the
Scherrer’s equation. In this study, the nanoparticle size was
calculated to be 16 nm by the highest intensity peak (331),
which matches with the range of the size estimated by TEM
analysis [65, 66].
The saturation magnetization (M ) of Fe O , which reꢃects
s
3
4
paramagnetic properties, is about 40 emu/g. As shown in
Fig. 7b, M decreased to 23 emu/g, corresponded to covering
s
of the surface of magnetic material (Fe O ) with a non-mag-
3
4
netic compound (chitosan). A considerable reduction in the
magnetic property of G2 and the synthesized catalyst was
observed. The magnetic moment of these compounds was
9 and 11 emu/g, respectively. It is clear that the synthesized
catalyst demonstrates more magnetic properties compared to
G2, due to the production of metallic cobalt in fcc crystalline
nanoparticles [67].
The energy-dispersive X-ray (EDX) analyses of MaNPs,
MCs, MCs-CC1, G1, and the catalyst are shown in Fig. 4.
The EDX spectra indicate the grafting of THBP on Fe O
3
4
as well as immobilization of cobalt on the THBP@MCs.
The peaks of Fe and O are ascribed to the magnetic nano-
particles and the N and C peaks observed in Fig. 4b are
related to the functionalization of Fe O by chitosan. The
Application of Co(0)‑THBP@MCs in C–C
cross‑coupling reaction
After synthesis and characterization of the catalyst, the
catalytic activity was evaluated in Heck and Suzuki cross-
coupling reactions.
3
4
presence of chlorine atoms in Fig. 4c conꢂrms the reaction
of chitosan with cyanuric chloride. The removal of chlorine
atom peak in Fig. 4d is associated with the substitution of
chlorine atoms with amine groups of 2,6 diamino pyridine.
The appearance of cobalt atom peak in Fig. 4e shows the
stabilization of Co on the THBP@MCs support.
Optimization of the reaction conditions for the Heck
cross‑coupling reaction
The outer topography of MaNPs, MCs, MCs-CC1,
G1, and the synthesized catalyst was visualized by ꢂeld
Eꢁect of critical parameters such as solvent, base, tempera-
ture, and catalyst loading on the outcome of cross-coupling
1
3

Journal of the Iranian Chemical Society
Fig. 4 SEM–EDX spectra of a MaNPs, b MCs, c MCs-CC1, d G1, and e synthesized catalyst
reactions was evaluated [68, 69]. To reach this aim, the
reaction of iodobenzene and methyl acrylate was selected
as a model reaction to determine the optimum reaction
conditions.
reaction conditions, the reaction did not proceed even after
a long time.
Eꢁect oꢀ diꢁerent bases
Eꢁect oꢀ metal loading
The bases employed in the coupling reactions play a criti-
cal role in neutralizing hydrogen halides and preventing
the formation of homocoupling product [70]. Hence, dif-
ferent bases including Na CO , NaHCO , K CO , and
The impact of diꢁerent amounts of Co metal in the cata-
lytic activity in Heck reaction was evaluated. As shown
in Table 1, increasing the amount of loaded cobalt causes
a rise of the product yield (Table 1, entries 11–15). As
observed, the reaction reached 94% conversion for the metal
loading of 0.35 mol%. Moreover, when the experiment was
performed in the absence of the catalyst under the same
2
3
3
2
3
K PO were examined in the reaction. Among these bases,
3
4
K PO showed the best performance. Furthermore, the
3
4
amount of the base used considerably aꢁected the results
(Table 1, entries 1–6) and it was found that 2 mmol of
K PO aꢁorded the suitable yield of the product [71, 72].
3
4
1
3

Journal of the Iranian Chemical Society
Fig. 5 FE-SEM images of a MaNPs, b Cs, c MCs, d MCs-CC1, e G1, and f Co(0)-THBP@MCs
Fig. 6 a TEM image and b particle size distribution of the catalyst
1
3

Journal of the Iranian Chemical Society
Eꢁect oꢀ solvent
To explore the eꢁect of solvent, the model reaction was
conducted using diꢁerent common solvents. A mixture of
DMF and H O in 1:2 ratio showed a signiꢂcant progress in
2
the reaction, resulting in a yield of 94%. Thus, this solvent
mixture was chosen as the most eꢁective solvent.
Eꢁect oꢀ temperature
The eꢁect of temperature on the Heck cross-coupling reac-
tion was also studied. Therefore, the model reaction was
carried out at diꢁerent temperatures (Table 1 entries 16–18).
According to the result obtained, the desired product with
the highest yield was obtained at 90 °C.
Evaluation of the catalytic activity of synthesized
catalyst
Finally, the applicability of this new catalytic system for
a set of substituted aryl halides (chlorides, bromides, and
iodides) with electron-donating or withdrawing groups in
Heck reaction was investigated under the optimum condi-
tions (Table 2). As summarized in Table 3, aryl halides
Fig. 7 Room temperature magnetization curves of the (a) Fe O , and
3
4
(
b) MCs, (c) G2, and (d) synthesized catalyst
Table 1 Optimization of
reaction conditions on Heck
reaction of iodobenzene with
methyl acrylate in the presence
of catalyst
a
Entry
Catalyst (mol%)
Base (mmol)
K CO (1.5)
Solvent
T (°C)
Yield (%)
Base efect
1
2
3
4
5
6
0.35
0.35
0.35
0.35
0.35
0.35
DMF:H O (1:2/V:V)
DMF:H O (1:2/V:V)
DMF:H O (1:2/V:V)
DMF:H O (1:2/V:V)
DMF:H O (1:2/V:V)
DMF:H O (1:2/V:V)
90
90
90
90
90
90
86
71
78
92
88
94
2
3
2
Na CO (1.5)
2
3
2
NaHCO (1.5)
3
2
K PO (1.5)
3
4
2
K PO (1)
3
4
2
K PO (2)
3
4
2
Solvent efect
7
8
9
1
0.35
K PO (2)
DMF:H O (1:1/V:V)
90
90
90
90
90
84
93
95
3
4
2
0.35
0.35
0.35
K PO (2)
H O
3
4
2
K PO (2)
DMF
DMSO
3
4
0
K PO (2)
3
4
Catalyst efect
1
1
1
1
1
1
2
3
4
5
-
K PO (2)
DMF:H O (1:2/V:V)
90
90
90
90
90
Trace
73
86
94
95
3
4
2
0.2
0.3
0.35
0.4
K PO (2)
DMF:H O (1:2/V:V)
3
4
2
K PO (2)
DMF:H O (1:2/V:V)
3
4
2
K PO (2)
DMF:H O (1:2/V:V)
3
4
2
K PO (2)
DMF:H O (1:2/V:V)
3
4
2
Temp. efect
16
17
18
0.4
0.4
0.4
K PO (2)
DMF:H O(1:2/V:V)
100
90
80
96
94
87
3
4
2
K PO (2)
DMF:H O(1:2/V:V)
3
4
2
K PO (2)
DMF:H O(1:2/V:V)
3
4
2
The optimum condition is exhibited in bold
a
GC yield
1
3

Journal of the Iranian Chemical Society
Table 2 Heck cross-coupling of various aryl halides in the presence of catalyst
b
b
b
b
X=I 3a: 2 h, 94%
TON: 268
X=I 3b: 2 h, 91%
TON: 260
X=I 3d: 2 h, 93%
TON: 265
b
b
X=I 3e: 2 h, 90%
TON: 257
X=I 3f: 2 h, 95%
TON: 271
X=Br 3 g: 3 h, 87%
TON: 248
X=Br 3 h: 3 h, 83%b
TON: 237
X=Br 3i: 3.5 h, 85%
TON: 242
b
b
X=Br 3j: 3 h, 90%
TON: 257
X=Br 3 k: 3 h, 89%b
TON: 254
X=Br 3 l: 3 h, 90%
b
X=Cl 3 m: 5 h, 80%
b
TON: 257
TON: 228
X=Cl 3n: 5 h, 78%b
TON: 222
X=Cl 3o: 5 h, 79%
b
X=Cl 3p: 5 h, 75%
b
TON: 225
TON: 214
X=Cl 3q: 5 h, 82%b
TON: 234
b
b
X=Cl 3r: 5 h, 81%
X=Cl 3 s: 5 h, 79%
TON: 231
TON: 225
a
The reaction was carried out with aryl halide (1.0 mmol), alkene (1.2 mmol), K PO (2 mmol), and catalyst (0.35 mol% of Co) in 6 mL DMF/
3
4
H O (1:2) at 90 °C
2
b
Isolated yield
Turn over number, yield of product/per mol of Co
c
bearing electron-withdrawing groups underwent coupling
with methyl acrylate in shorter times than those with elec-
tron-donating groups. The diꢁerent product yields observed
correspond to electronic eꢁect of the functional groups. In
addition, it was found that aryl iodides and bromides with
the same functional groups reacted with methyl acrylate in
1
3

Journal of the Iranian Chemical Society
Table 3 Optimization of
reaction conditions on Suzuki
reaction of iodobenzene with
phenylboronic acid in the
presence of catalyst
a
Entry
Catalyst
mol%)
Base (mmol)
K PO (1.5)
Solvent
T (°C)
Yield (%)
(
Base efect
1
2
3
4
5
6
0.4
0.4
0.4
0.4
0.4
0.4
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
90
90
90
90
90
90
88
86
90
63
81
75
3
4
K PO (1)
3 4
K PO (2)
3 4
Na2CO3 (1.5)
K2CO3 (1.5)
NaHCO3 (1.5)
Solvent efect
7
8
9
0.4
0.4
0.4
0.4
K PO (2)
H2O
90
90
90
90
69
84
92
90
3
4
K PO (2)
DMF:H2O(1:1/V:V)
DMSO
DMF
3
4
K PO (2)
3
4
1
0
K PO (2)
3
4
Catalyst efect
1
1
1
1
1
1
2
3
4
5
0.1
0.2
0.3
0.4
0.5
K PO (2)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
90
90
90
90
90
61
72
83
90
92
3
4
K PO (2)
3
4
K PO (2)
3
4
K PO (2)
3
4
K PO (2)
3
4
Temp. efect
1
1
1
6
7
8
0.4
0.4
0.4
K PO (2)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
DMF:H2O(1:2/V:V)
100
90
80
92
90
85
3
4
K PO (2)
3
4
K PO (2)
3
4
The optimum condition is exhibited in bold
a
GC yield
shorter times in comparison with aryl chloride. This trend
can be explained by the increase in the bond energy in the
following order (C–Cl>C–Br>C–I). Since the formation
of C–Co–X catalyst species is suggested for the oxidative
addition of Co, the C–C coupling reactions by aryl chlo-
rides take longer compared with aryl iodides and bromides
because the C–Cl bond has a high dissociation energy [70].
Therefore, the coupling reactions with aryl chlorides do not
process similarly to aryl iodides and bromides. On the other
hand, aryl chlorides are favorable substrates for such reac-
tions because they are widely available and inexpensive. For
most studies, harsh conditions are required.
With the optimized conditions in hand, the versatility
of the Co(0)-THBP@MCs in Suzuki reactions of aryl hal-
ides (I, Br, Cl) containing various functional groups with
phenylboronic acid was investigated. It can draw conclu-
sion from Table 4, aryl iodides and bromides undergo more
successful coupling reactions with phenylboronic acid in
comparison with aryl chloride, although aryl iodides aꢁord
the suitable products in eꢀcient yields and high TONs. As
expected, chlorides generally show weak reactivity unless
they contain electron-withdrawing substituents on the ring.
Thus, the promotion of the reaction is aꢁected by the posi-
tion and electronic behavior of the reactants. Therefore, aryl
According to the results achieved in Heck cross-coupling
reaction, we were encouraged to explore the potential of our
catalyst in the Suzuki reaction. The reaction of phenylbo-
ronic acid with iodobenzene in the presence of our catalyst
was considered as a model reaction to ꢂnd the optimum
conditions. The eꢁect of parameters such as the type of sol-
vent, temperature, base, and catalyst amount was assessed
and the results are presented in Table 3. As is observed, the
highest yield was achieved by iodobenzene (1 mmol), phe-
nylboronic acid (1.2 mmol), K PO (2 mmol), and the cata-
halides containing –CN, and –NO groups are substantially
2
more reactive than those with –CH , –OCH , and –NH
3
3
2
groups.
To further examine the eꢀciency of the present catalytic
system, Co(0)-THBP@MCs were compared with some
reported catalysts in Heck and Suzuki cross-coupling reac-
tions (Table 5). It is obvious that our method is superior
to some reported catalyst due to lower temperature, shorter
reaction time, greener media (safe metal), and better yield.
Moreover, the low percentage of the catalyst used and mag-
netic recyclability are the advantages of this new protocol.
The high activity of our catalyst is probably due to the
3
4
lyst (0.4 mol% Co) in DMF:H O solvent mixture at 90 °C
2
(
Table 3, entry 3).
1
3

Journal of the Iranian Chemical Society
Table 4 Suzuki cross-coupling of various aryl halides in the presence of synthesized catalyst
X=I 5c: 3 h, 89%
TON: 222
X=I 5a: 3 h, 90%
TON: 225
X=I 5b: 3 h, 87%
TON: 217
X=Br 5f: 4 h, 83%
TON: 207
X=Br 5 h: 4 h, 82%,
TON: 205
X=Br 5 g: 4 h, 80%
TON: 200
X=Br 5i: 4 h, 85%
TON: 212
X=Br 5j: 4 h, 85%
TON: 212
X=Br 5 k: 4 h, 87%
TON: 217
X=Cl 5 l: 6 h: 78%
TON: 195
X=Cl 5n: 6 h, 76%
TON: 190
X=Cl 5 m: 6 h, 72%
TON: 180
X=Cl 5o: 6 h, 71%
TON: 177
X=Cl 5p: 6 h, 80%
TON: 200
X=Cl 5q: 6 h, 79%
TON: 197
X=Cl 5r: 6 h, 80%
TON: 200
a
The reaction was carried out with aryl halide (1.0 mmol), phenylboronic acid (1.2 mmol), K PO (2 mmol), and catalyst (0.4 mol% of Co) in
3
4
6
ml DMF/H O (1:2) at 90 °C
2
b
Isolated yield
Turnover number, yield of product/per mol of Co
c
Table 5 Comparison of
Entry Catalyst
Reaction condition
Time (h) Yield (%)
catalytic activities of our
catalyst with literature examples
for Heck and Suzuki reactions
1
2
4
5
6
7
9
1
1
1
1
Nano-Co [73]
Co/Al O [74]
Co-B [75]
Co (2 mol %) in NMP at 130 °C
Co (10 mol %) in NMP at 150 °C
Co (5 mol %) in NMP at 130 °C
Co (3.5 mol %) in PEG at 80 °C
Co (5 mol %) in toluene at 100 °C
Co (1.1 mol %) in PEG at 80 °C
14
24
12
5
78
56
98
85
87
88
90
88
73
81
94
2
3
Co-NHC@MWCNTs [76]
Co-IL@MWCNTs [18]
Co-Ms@MNPs/Cs [54]
Cobalt Schiꢁ base Complexes [77] Co (1 mol %) in toluene at 110 °C
Cobalt Schiꢁ base Complexes [78] Co (2 mol %) in dioxane at 110 °C
3
1
8
8
0
1
2
3
Cobalt hollow nanospheres [79]
Co@Fe O /L-dopa [80]
Co (1 mol %) in NMP at 130 °C
Co (1.84 mol%)in H O at 100 °C
Co (0.35 mol%) in DMF:H O at 90 °C
16
4
2
3
4
2
Present catalyst
2
1
3

Journal of the Iranian Chemical Society
separated by an external magnet, washed several times with
deionized water and ethanol, dried, and applied in the sub-
sequent runs. The results indicate that the catalyst could be
recovered seven times without any signiꢂcant loss of cata-
lytic activity.
In order to verify that the properties of the recycled
catalyst are identical to those of the fresh catalyst, ICP,
EDX, FE-SEM, and XRD analyses were performed. The
amount of leached cobalt was measured by ICP-OES and
the results showed that less than 1% of cobalt metal was
removed. The chemical composition, morphology, and
presence of cobalt nanoparticles after seven runs were
also analyzed by EDX, FE-SEM, and XRD techniques.
As shown in Fig. 8, it was found that the structure of the
catalyst did not change and no signiꢂcant changes were
observed in the morphology. The presence of cobalt in
the recovered catalyst was conꢂrmed by EDX analysis
(
Fig. 9).
According to Figure S2, the XRD pattern of reused
Fig. 8 Recyclability of the catalyst in the Suzuki reaction
catalyst also demonstrates a proꢂle similar to the fresh
catalyst.
To demonstrate the heterogeneous nature of the catalyst
and the amount of leached metal nanoparticles, hot ꢂltra-
tion test was carried out for the Suzuki reaction as a model
reaction under the optimized conditions. In this case, the
reaction between iodobenzene and phenylboronic acid
was done, after 30 min the reaction was stopped and the
catalyst was separated. Therefore, the reaction continued
for other 2 h in the absence of catalyst. The progress of
the reaction was monitored by TLC and GC. The results
achieved clearly revealed no further progress in product
good dispersion of cobalt nanoparticles and good synergis-
tic eꢁects of cobalt nanoparticles with ligands grafted on
MaNPs.
From the environmental and economic points of view,
the reusability and recycling of heterogeneous catalysts are
important. Therefore, the reusability of the Co(0)-THBP@
MCs catalyst under the optimized conditions was tested in
Suzuki reaction of iodobenzene with phenylboronic acid as
model reaction (Fig. 8). After each cycle, the catalyst was
Fig. 9 FE-SEM and EDX analyses of reused catalyst
1
3

Journal of the Iranian Chemical Society
yield and proved that metal leaching into reaction media
was negligible.
7. G. Evano, N. Blanchard, Copper-Mediated Cross-Coupling Reac-
tions (Wiley, 2013)
8
9
.
.
H. Yamamoto, W. Muramatsu, Synfacts 16, 0113 (2020)
A. Piontek, E. Bisz, M. Szostak, Angew. Chem. Int. Ed. 57,
1
1116–11128 (2018)
Conclusion
10. M. Hapke, G. Hilt, Cobalt Catalysis in Organic Synthesis: Meth-
ods and Reactions (2020), pp. 1–23
1
1. M. Kazemnejadi, Z. Rezazadeh, M.A. Nasseri, A. Allahresani, M.
In this work, magnetic hyperbranched polymer-encapsulated
cobalt nanoparticles were successfully designed and syn-
thesized through the complexation of Co(II) cations with
amines-terminated triazine polymer along with the reduc-
Esmaeilpour, Green Chem. 21, 1718–1734 (2019)
12. C.S. Guo, C.M. Weng, F.E. Hong, Eur. J. Inorg. Chem. 2010,
3220–3228 (2010)
1
3. J.M. Hammann, D. Haas, P. Knochel, Angew. Chem. Int. Ed. 54,
4
478–4481 (2015)
tion of cobalt cations by NaBH . The Co(0)-THBP@MCs
4
14. A.V. Biradar, A.A. Biradar, T. Asefa, Langmuir 27, 14408–14418
(2011)
catalyst demonstrated eꢀcient performances in Heck and
Suzuki cross-coupling reactions. The high catalytic activ-
ity of Co(0)-THBP@MCs in comparison with other catalyst
is believed to be related to the cross-linked hyperbranched
triazine polymer structure with multiple amine groups,
which provide excellent stabilization of the cobalt nanopar-
ticles species and providing an available space for reacting
molecules. The deposition of the cobalt nanoparticles on a
substrate with many functional groups was recognized as
a highly active, oxygen-insensitive, moisture-stable, and
recyclable heterogeneous catalyst separated by an exter-
nal magnet. The hyperbranched triazine polymer is able to
entrap cobalt without remarkable metal leaching to the reac-
tion media. Moreover, environmentally friendly procedure
15. J.A. Moulijn, A. Van Diepen, F. Kapteijn, Appl. Catal. A Gen.
2
12, 3–16 (2001)
1
1
6. Y. Xing, Z. Liu, S.L. Suib, Chem. Mater. 19, 4820–4826 (2007)
7. G. Jayamurugan, C. Umesh, N. Jayaraman, J. Mol. Catal. A Chem.
307, 142–148 (2009)
18. A.R. Hajipour, Z. Khorsandi, H. Karimi, Appl. Organomet. Chem.
2
9, 805–808 (2015)
1
9. H. Heinz, C. Pramanik, O. Heinz, Y. Ding, R.K. Mishra, D. Mar-
chon, R.J. Flatt, I. Estrela-Lopis, J. Llop, S. Moya, Surf. Sci. Rep.
72, 1–58 (2017)
20. M.Z. Burkeev, T. Khamitova, D. Havlicek, A. Bakibaev, E. Tazh-
baev, S.Z. Davrenbekov, G. Kozhabekova, Catal. Ind. 10, 270–278
(
2018)
2
1. Y.-S. Shon, H. Choo, C. R. Chim. 6, 1009–1018 (2003)
22. I. Venditti, J. King Saud Univ. Sci. 31, 398–411 (2019)
23. W. Dai, H. Shi, X. Zhao, S. Cao, Org. Lett. 18, 4284–4287 (2016)
2
4. B. Asadi, I. Mohammadpoor-Baltork, S. Tangestaninejad, M.
Moghadam, V. Mirkhani, A. Landarani-Isfahani, New J. Chem.
(
palladium-free, DMF:H O as solvent, 90 °C), short reac-
2
tion times, considerable yield, and low metal contamina-
tion make Co(0)-THBP@MCs as a usable catalyst for C–C
coupling reactions. Moreover, the catalyst was reused seven
times with no signiꢂcant decrease in catalytic activity, due
to the strong covalent bond between cobalt nanoparticles and
triazine-hyperbranched polymer.
4
0, 6171–6184 (2016)
25. S.I. Bhat, Y. Ahmadi, S. Ahmad, Ind. Eng. Chem. Res. 57, 10754–
10785 (2018)
2
6. A. Daneshvar, M. Moghadam, S. Tangestaninejad, V. Mirkhani, I.
Mohammadpoor-Baltork, A. Khalili, Organometallics 35, 1747–
1
755 (2016)
27. A. Eskandari, M. Jafarpour, A. Rezaeifard, M. Salimi, New J.
Chem. 42, 6449–6456 (2018)
Supplementary Inꢀormation The online version contains supplemen-
28. R.J. Kalbasi, F. Zamani, RSC Adv. 4, 7444–7453 (2014)
29. O. Medvedeva, S. Kambulova, O. Bondar, A. Gataulina, N. Ulak-
hovich, A. Gerasimov, V. Evtugyn, I. Gilmutdinov, M. Kutyreva,
J. Nanotechnol. 2017 (2017)
tary material available at https://doi.org/10.1007/s13738-021-02261-5.
Declarations
3
0. I.N. Kurniasih, J. Keilitz, R. Haag, Chem. Soc. Rev. 44, 4145–
4
164 (2015)
Conꢀlict oꢀ interest There are no conꢃicts to declare.
31. J. Zhang, H. Yong, Q. Xu, Y. Miao, J. Lyu, Y. Gao, M. Zeng, D.
Zhou, Z. Yu, H. Tai, Chem. Mater. 30, 6091–6098 (2018)
3
3
2. Y. Zheng, S. Li, Z. Weng, C. Gao, Chem. Soc. Rev. 44, 4091–4130
(
2015)
3. T. Verheyen, N. Santillo, D. Marinelli, E. Petricci, W.M. De
References
Borggraeve, L. Vaccaro, M. Smet, ACS Appl. Polym. Mater. 1,
1
496–1504 (2019)
1
2
3
.
.
.
M. Pittelkow, K. Moth-Poulsen, U. Boas, J.B. Christensen, Lang-
muir 19, 7682–7684 (2003)
34. P. Puthiaraj, Y.-R. Lee, S. Zhang, W.-S. Ahn, J. Mater. Chem. A
4, 16288–16311 (2016)
A. Bej, K. Ghosh, A. Sarkar, D.W. Knight, RSC Adv. 6, 11446–
35. M.B. Steꢁensen, E. Hollink, F. Kuschel, M. Bauer, E.E. Simanek,
J. Polym. Sci., Part A Polym. Chem. 44, 3411–3433 (2006)
36. A. Landarani Isfahani, I. Mohammadpoor-Baltork, V. Mirkhani,
A.R. Khosropour, M. Moghadam, S. Tangestaninejad, Eur. J. Org.
Chem. 2014, 5603–5609 (2014)
1
1453 (2016)
K.S. Egorova, V.P. Ananikov, Angew. Chem. Int. Ed. 55, 12150–
1
2162 (2016)
4
5
.
.
E. Richmond, J. Moran, Synthesis 50, 499–513 (2018)
H. Shi, W. Dai, B. Wang, S. Cao, Organometallics 37, 459–463
37. M. Amini, M. Hajjari, A. Landarani-Isfahani, V. Mirkhani, M.
Moghadam, S. Tangestaninejad, I. Mohammadpoor-Baltork, M.
Ahmadi, Nanochem. Res. 1, 237–248 (2016)
(
2018)
6
.
Y.A. Al-Hamadani, M.S. Yusoꢁ, M. Umar, M.J. Bashir, M.N.
Adlan, J. Hazard. Mater. 190, 582–587 (2011)
38. M. Arghan, N. Koukabi, E. Kolvari, Appl. Organomet. Chem. 33,
e4823 (2019)
1
3

Journal of the Iranian Chemical Society
3
9. T. Iwasawa, M. Tokunaga, Y. Obora, Y. Tsuji, J. Am. Chem. Soc.
60. C. Hajji, R. Haag, in Dendrimer Catalysis (Springer, 2006), pp.
149–176
1
26, 6554–6555 (2004)
4
4
0. J. Anjali, K. Sreekumar, Catal. Lett. 149, 1952–1964 (2019)
61. I. Dindarloo Inaloo, S. Majnooni, H. Eslahi, M. Esmaeilpour, ACS
Omega 5, 7406–7417 (2020)
1. C.-Y. Hong, Y.-Z. You, D. Wu, Y. Liu, C.-Y. Pan, Macromolecules
3
8, 2606–2611 (2005)
62. Y. Yao, C. Xu, J. Qin, F. Wei, M. Rao, S. Wang, Ind. Eng. Chem.
Res. 52, 17341–17350 (2013)
4
4
2. M. Khan, W.T. Huck, Macromolecules 36, 5088–5093 (2003)
3. C. Wu, X. Huang, G. Wang, X. Wu, K. Yang, S. Li, P. Jiang, J.
Mater. Chem. 22, 7010–7019 (2012)
63. J. Shen, Y. Zhu, X. Yang, J. Zong, C. Li, Langmuir 29, 690–695
(2013)
4
4
4
4
4
4. A. Di Gianni, S. Trabelsi, G. Rizza, M. Sangermano, H. Althues,
S. Kaskel, B. Voit, Macromol. Chem. Phys. 208, 76–86 (2007)
5. G.I. Dar, M. Saeed, A. Wu, TiO2 Nanopart. Appl. Nanobiotech-
nol. Nanomed. 67–103 (2020)
64. K. Manna, S.K. Srivastava, Langmuir (2020)
65. C. Liao, X. Li, K. Yao, Z. Yuan, Q. Chi, Z. Zhang, ACS Sustain.
Chem. Eng. 7, 13646–13654 (2019)
66. X. Zheng, H. Cheng, J. Yang, D. Chen, R. Jian, L. Lin, ACS Appl.
Nano Mater. 1, 2754–2762 (2018)
6. M.B. Gawande, P.S. Branco, R.S. Varma, Chem. Soc. Rev. 42,
3
371–3393 (2013)
67. S. Hatamie, M.M. Ahadian, A. Rashidi, A. Karimi, O. Akhavan,
Appl. Phys. A 123, 341 (2017)
7. K.N. Koo, A.F. Ismail, M.H.D. Othman, N. Bidin, M.A. Rahman,
Malays. J. Fundam. Appl. Sci. 15, 23–31 (2019)
68. S. Jana, S. Haldar, S. Koner, Tetrahedron Lett. 50, 4820–4823
(2009)
8. J. Shan, L. Wang, H. Yu, J. Ji, W. Amer, Y. Chen, G. Jing, H.
Khalid, M. Akram, N. Abbasi, Mater. Sci. Technol. 32, 602–614
69. S. Bhunia, R. Sen, S. Koner, Inorg. Chim. Acta 363, 3993–3999
(2010)
(
2016)
4
5
5
5
5
5
5
5
5
9. P.M. Price, W.E. Mahmoud, A.A. Al-Ghamdi, L.M. Bronstein,
Front. Chem. 6, 619 (2018)
70. M. Arghan, N. Koukabi, E. Kolvari, Appl. Organomet. Chem. 33,
e5075 (2019)
0. Z. Duriagina, R. Holyaka, T. Tepla, V. Kulyk, P. Arras, E. Eyn-
gorn, Biomater. Regen. Med. 379 (2018)
71. P. Ncube, T. Hlabathe, R. Meijboom, J. Cluster Sci. 26, 1873–
1888 (2015)
1. M.R. Ghazanfari, M. Kasheꢂ, S.F. Shams, M.R. Jaafari, Biochem.
Res. Int. 2016 (2016)
72. B.W. Glasspoole, J.D. Webb, C.M. Crudden, J. Catal. 265, 148–
154 (2009)
2. R.K. Sharma, S. Dutta, S. Sharma, R. Zboril, R.S. Varma, M.B.
Gawande, Green Chem. 18, 3184–3209 (2016)
73. H. Qi, W. Zhang, X. Wang, H. Li, J. Chen, K. Peng, M. Shao,
Catal. Commun. 10, 1178–1183 (2009)
3. A.R. Hajipour, M. Check, Z. Khorsandi, Appl. Organomet. Chem.
74. S. Iyer, V.V. Thakur, J. Mol. Catal. A Chem. 157, 275–278 (2000)
75. Z. Zhu, J. Ma, L. Xu, L. Xu, H. Li, H. Li, ACS Catal. 2, 2119–
2125 (2012)
3
1, e3769 (2017)
4. A.R. Hajipour, F. Rezaei, Z. Khorsandi, Green Chem. 19, 1353–
361 (2017)
5. A.-M. Caminade, D. Yan, D.K. Smith, Chem. Soc. Rev. 44, 3870–
1
76. A.R. Hajipour, Z. Khorsandi, Catal. Commun. 77, 1–4 (2016)
77. R.M. Ansari, L.K. Mahesh, B.R. Bhat, Chin. J. Chem. Eng. 27,
556–563 (2019)
3
873 (2015)
6. S. Basaveni, N. Kuchkina, Z. Shifrina, M. Pal, M. Rajadurai, J.
Nanopart. Res. 21, 91 (2019)
78. R.M. Ansari, L. Kumar, B.R. Bhat, Russ. J. Coord. Chem. 44, 1–8
(2018)
7. N. Karak, B. Roy, B. Voit, J. Polym. Sci. Part A Polym. Chem. 48,
79. P. Zhou, Y. Li, P. Sun, J. Zhou, J. Bao, Chem. Commun. 1418–
1420 (2007)
3
994–4004 (2010)
5
5
8. Z. Dong, Z. Ye, Appl. Catal. A Gen. 489, 61–71 (2015)
9. S.J. Tabatabaei Rezaei, A. Shamseddin, A. Ramazani, A. Mash-
hadi Malekzadeh, P. Azimzadeh Asiabi, Appl. Organomet. Chem.
80. H. Sharma, S. Sharma, C. Sharma, S. Paul, J.H. Clark, Mol. Catal.
469, 27–39 (2019)
3
1, e3707 (2017)
1
3