A new triazine-cored covalent organic polymer for catalytic applications

Article abstract of DOI:10.1016/j.apcata.2020.117411

A triazine based covalent organic polymer (CC-TAPT-COP) was designed and synthesized via nucleophilic substitution reaction between 1,3,5-tris-(p-aminophenyl) triazine and cyanuric chloride under refluxing conditions with bottom-up approach. The structura

Full text of DOI:10.1016/j.apcata.2020.117411

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A new triazine based covalent organic polymer for catalytic applications
Subodh, Kunal Prakash, Karan Chaudhary, Dhanraj T. Masram
PII:
S0926-860X(20)30004-1
DOI:
https://doi.org/10.1016/j.apcata.2020.117411
APCATA 117411
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Applied Catalysis A, General
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Please cite this article as: Subodh, Prakash K, Chaudhary K, Masram DT, A new triazine
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A new triazine based covalent organic polymer for catalytic applications
Subodh, Kunal Prakash, Karan Chaudhary, Dhanraj T. Masram*
dhanraj_masram27@rediffmail.com
* Department of Chemistry, University of Delhi, Delhi-7, India.
Graphical Abstract
Highlights
 A new triazine based COP has been synthesized and evaluated for catalytic applications.
 HR-TEM shows aggregation of particles with varying diameter.
1

 CC-TAPT-COP is metal-free, economic and sustainable heterogeneous catalyst.
CC-TAPT-COP acts as robust catalyst for quinazolines with enhanced response.
 Single Crystal-XRD confirmed the synthesis of quinazoline.

ABSTRACT
A triazine based covalent organic polymer (CC-TAPT-COP) was designed and synthesized via
nucleophilic substitution reaction between 1,3,5-tris-(p-aminophenyl) triazine and cyanuric
chloride under refluxing conditions with bottom-up approach. The structural and morphological
properties of CC-TAPT-COP were well characterized by various spectroscopic cum analytical
techniques. The CC-TAPT-COP appeared as irregular block morphology (SEM) and possesses
remarkable thermal stability. The physical properties like insolubility, chemical and thermal
stability of CC-TAPT-COP provide a sustainable alternative to classical metal and homogeneous
catalysts. In this report, we have explored CC-TAPT-COP as a heterogeneous catalyst for
expedient access to the substituted quinazoline, a family of N-containing biopharmaceutical
active heterocyclic compounds, at ambient conditions. Moreover, the present work not only
supports COPs for their synthesis, but also paves an opportunity for catalytic applications as
heterogeneous media.
Keywords: Covalent organic polymers; triazine; heterogeneous catalysis; quinazoline; MCRs
1. Introduction
Covalent organic polymers (COPs) are a well-known class of highly cross-linked porous
materials having amorphous to semi-crystalline nature, substantially formed by strong covalent
linkage [1, 2]. These materials are usually formed by organic building blocks consisting light
2

elements such as nitrogen and carbon, in-situ during the synthesis of 2/3D- ordered porous
materials [3]. In the recent research, COPs have been widely employed and categorized as
covalent triazine frameworks (CTFs) [4, 5], polymers of intrinsic micro porosity (PIMs) [6] and
conjugated micro/meso-porous polymers (CMPs) [7]. Unlike conventional porous materials such
as zeolites and porous carbon [8], COPs possess high surface area, integrated adsorptive sites,
flexibility, insolubility, low density, high thermal and chemical stability [9]. Subsequently, these
kind of functional materials have encouraging advantages such as catalysis [10], CO2 storage
[11, 12], oxygen reduction [13], gas sensors [14] and detection of nitro-aromatics [15].
In general, the conventional approaches for the synthesis of COPs include Schiff’s base
formation, nucleophilic substitution reaction and C-C coupling methodology [16-19]. Therefore,
for building up such rigid organic architectures, a task specific organic substrate is always of
paramount significance [20]. The architectures of COP depend upon the geometry of reactive
groups present in an altered fashion. Several research reports are available depending upon their
pore size and topology; they are categorized as triangular or hexagonal, which usually limit the
scope for the development of such networks [21]. Thus, we worked to find task specific and
functional sites bearing reactive groups in the core structure of COPs. Further, this approach
provides an alternative solution which results in broadening a bird’s view for monomers and also
encourage the development of COPs [22].
Recently, imine-linked covalent organic architectures have been thoroughly studied in
heterogeneous catalyst application because of promising advantages in comparison with other
supported materials such as Silica and graphene oxide [23-25]. COPs, in general, have low-
density, high thermal resistance and insolubility in organic solvents which make them alternative
catalytic materials for various organic transformations. COPs endowing triazine core with high
3

surface area and N-rich architecture provide sustainable and environmentally friendly alternative
to their homogeneous analogues with respect to stability, selectivity, ease of separation and
recyclability. Moreover, the N-rich active sites are beneficial to hold the reactants and also
provide the solid supports to enhance the catalytic activity. Despite this, COPs not being only act
as support materials but they can be helpful in base-catalyzed reactions.
In trend, a diversified range of covalent organic polymers were already reported for
heterogeneous catalysis and a broad scope of various organic transformations has been
successfully implemented by COPs [2]. Among all, many of COPs were used as support
materials, which show significant advantages over traditional methods. Pitchumani et al reported
the metal immobilized COP as catalyst for Mizoroki-Heck cross-coupling reactions [26].
Recently, Yadav et al reported the first synthesis of unsymmetrical covalent organic polymer as
demonstrated its metal free action as sustainable catalyst for non-classical catalytic amide
synthesis [27]. Nonetheless, the COPs catalyzed transformations are less practiced and hunted in
the field of heterogeneous catalysis and MCRs. To the best of our knowledge, a range of COP
based catalysts have been developed but nowhere used for one pot multi-component reactions
(MCRs) for the synthesis of substituted quinazoline.
Quinazolines, an important class of N-heterocycles with ubiquitous structure have significant
utilization in bio- [28] and pharma industries [29]. The substituted derivatives of quinazoline are
varyingly found in numerous natural products and have several implications as pesticides and
drugs [30]. Modern methods for the synthesis of quinazoline are well established but these
methods have some limitations such as solubility of catalyst and formation of by-products.
Therefore, these routine challenges always promote material chemists to find a complementary
method by the development of schematic and smart approach for the synthesis of quinazoline.
4

So, there is always a step ahead to develop a generous synthetic method to deal with such
difficulties.
Herein, we have designed and synthesized a triazine based covalent organic polymer and
successfully employed, for the first time, as promising heterogeneous catalyst to demonstrate
efficient one pot synthesis of highly functionalized quinazoline derivatives. It was found that
CC-TAPT-COP acts as robust approach for an easy and quick access to functionalized
quinazoline.
2. Experimental Section
2.1 Materials p-amino benzonitrile was purchased from Alfa Aesar Pvt. Ltd. and cyanuric
chloride was purchased from SigmaAldrich Pvt. Ltd. Both tetrahydrofuran and methanol were of
A.R. grade obtained from SpectroChem. Pvt. Ltd. All the solvents and chemicals were used as
received. Double deionised water was obtained from USIC, University of Delhi, India. The
instrumentation, general procedure, optimization and recyclability are listed in sections (SI, Page
S3).
2.2 Synthesis of CC-TAPT-COP A solution of cyanuric chloride 1 (208 mg, 1.128 mmol) was
prepared in THF (10 mL). 2, 4, 6-tris-(p-aminophenyl)-1,3,5-triazine (TAPT) was synthesized as
per procedure with slight modification (Fig. S1) [12]. In an oven-dried R.B. flask, a solution of
TAPT 2 (400 mg, 1.128 mmol) in THF (10 mL) was taken followed by addition of DIPEA
(589µL, 3.38 mmol). Then, the solution (1) was added dropwise to the above reaction mixture
(2) over a period of 30min with constant stirring and kept on reflux for next 24h. The resulting
precipitate was filtered through G4 crucible, and washed successively with THF, methanol and
double deionised water, dried at 80°C in vacuo. Color: Orange-Yellow; Yield 430 mg.
5

Results and Discussions
The synthesis route for triazine based CC-TAPT-COP was driven by poly-(N-arylation) of
cyanuric chloride with 2, 4, 6-tris-(p-amino phenyl) triazine under refluxing conditions in THF
for 24h (Scheme 1). The as-synthesized CC-TAPT-COP and starting precursors were
characterized by FT-IR to probe the bonding feature of polymers (Fig. 1a).
The N-H stretching of newly formed C-NH-C bond was observed as a broad band between 3450-
3050 cm-1 with disappearance of two characteristic peaks (3322 and 3213 cm-1) of –NH2 group of
TAPT and an intense C-Cl str. at 845 cm-1 confirmed the successful attempt for the synthesis of
CC-TAPT-COP [31, 32]. The peaks observed at 1285, 1358 and 1578 cm-1, respectively can be
assigned to triazine core unit present in COP and starting precursors (Fig. 1a) [33]. A
characteristic peak of aromatic C=C str. was observed at 1488 cm-1. The rise of a new peak at
1235 cm-1 may be attributed to C-N bond str. in as-synthesized polymer (Fig. 1a). The breathing
mode of imine (C=N) of triazine core was observed at approx. 810 cm-1 [34]. The possible
chemical transformation can be easily interpreted in the respective FT-IR of organic polymer.
6

CC-TAPT-COP
CC-TAPT-COP
Scheme 1. Synthesis route of CC-TAPT-COP.
The as synthesized CC-TAPT-COP exhibits amorphous nature as indicated by three broad
patterns observed in PXRD measurements (Fig. 1b) [35]. A broad diffraction pattern at
2Ɵ=26.1⁰ may be assigned to π-π stacking between the layered structure of CC-TAPT-COP (Fig.
1b). The angular strain between precursors prevent formation of symmetric framework of
polymer and consequently, we have observed broad peaks for amorphous CC-TAPT-COP [36].
The thermal stability is promising requirement for the development of materials, a TGA
experiment was performed which was further categorized into three major stages. The initial
degradation starts with removal of guest solvents loss (~5.72% around 100°C), successive weight
loss of ~15.8% between 150°-290°C was observed due to degradation of triazine core (Fig. 1c).
The last stage shows sharp degradation of ~77.8% between 460-630°C due to degradation of
organic polymers till complete carbonization (Fig. 1c) [37].
7

Fig.1. (a) FT-IR of precursors, CC-TAPT-COP and recovered CC-TAPT-COP, (b) PXRD of
CC-TAPT-COP and Reused CC-TAPT-COP. (c) TGA and (d) N2 sorption isotherm of CC-
TAPT-COP [Inset: Pore size distribution of CC-TAPT-COP].
The porosity and textural features of CC-TAPT-COP were evaluated by N2
adsorption/desorption experiment at 77 K. The significant uptake of relative pressure p/p0 of
0.995 indicated type III isotherm [38]. Thus, the BJH surface area, pore volume and average pore
diameter were found to be as 26.7 m2 g-1, 0.139 m3 g-1 and 28.6 Ǻ, respectively (Fig. 1d) [39].
The featured agglomeration of small and regular size particles directed towards the pore
distribution, which further tells us about the mesoporous nature of CC-TAPT-COP (Fig. 1d).
8

100 nm
(b)
(c)
500 nm
(a)
50 nm
Fig. 2. High Resolution-TEM images of CC-TAPT-COP (a) 500 nm, (b) 100 nm and (c) 50 nm.
The morphological behaviour of CC-TAPT-COP was examined by SEM and TEM spectroscopy.
From FESEM micrograph, the CC-TAPT-COP attained supramolecular self-assembling to form
agglomerated particles with average diameter range of ~50-100 nm which was found in
consistency with TEM results (Fig. S2) [40]. The HR-TEM images at different resolution
indicated that approx. ~50-100 nm of particle size upon agglomeration results in formation of as-
synthesized CC-TAPT-COP (Fig. 2). However, the irregular morphology was also observed in
similar COPs [36].
Further, to study the bonding correlation in CC-TAPT-COP, the sample was analysed by XPS.
XPS complete survey spectrum confirms C, N and O elements (Fig. 3a). The appearance of O
element was well expected due to presence of guest solvents in CC-TAPT-COP. In deconvoluted
C1s, the three peaks with binding energy at 284.6, 285.2 and 288.8 eV can be assigned to C=C,
C-N and C=N, respectively (Fig. 3b) [41, 42]. In N1s, the deconvoluted spectra reveals two
significant peaks with binding energy at 401.8 eV and 403.2 eV attributed to triazine N and
9

pyrrolic N respectively (Fig. 3c) [43, 44]. In deconvoluted O1s, two peaks with binding energy at
530.08 eV and 531.66 eV attributed to C-O-H and C-O-C bond, respectively (Fig. S3). The
elemental mapping of CC-TAPT-COP also confirmed C and N elements (Fig. 3d).
Fig. 3. (a) Complete XPS survey spectrum, deconvoluted (b) C1s and (c) N1s of CC-TAPT-
COP. (d) Elemental mapping of CC-TAPT-COP.
With an interest for catalytic application of COPs, we choose multi-component reaction (MCR)
to evaluate its catalytic efficiency. The idea of MCR always encouraged us to perform such
reaction because of their efficient advantages such as one pot analogy, minimum reaction time
and easy work-up methods [45]. Multi-component reaction involves the consecutive synthetic
approach of all the reactants, solvent and catalyst together in a vial through one pot approach,
10

which further attain a supramolecular assembly and results in crowding of reactants over the
surface of catalyst, the method is known as cascade synthesis [46, 47]. The purpose for this
approach is to obtain high efficacy under cleaner reaction conditions. Above all, only a few
literature reports are presented by organic chemists in respect to above considerations. With this
prediction, we believe that the present catalytic system could act as a smart heterogeneous
catalyst for one pot synthesis of highly congested substituted quinazoline.
Table 1. Optimization of reaction conditions.a
Solvent COP Temp/°C Time/h Yieldb
EtOH
SF*
CH2Cl2 10
THF 10
EtOAc 10
CH3CN 10
Toluene 10
H2O
H2O
EtOH
CFc
10
80
100
45
50
70
84
110
50
100
50
2
3
2
2
2
2
2
3
3
2
17
-
72
68
48
57
75
22
65
93
10
10
10
EtOH
EtOH
EtOH
10
10
10
RT
60
60
2
0.7
1
70
88
96
EtOH
EtOH
10
10
60
70
2
1
96
96
EtOH
15
60
1
95
aReaction conditions: 2-amino-5-chlorobenzophenone (1 mmol), p-
chlorobenzaldehyde (1 mmol), NH4OAc (2 mmol), CC-TAPT-COP
(10 mg), solvent (10 ml). bIsolated yields (%). cCatalyst Free. *Solvent
Free.
Therefore, the catalytic activity of CC-TAPT-COP as heterogeneous catalyst was evaluated for
the synthesis of substituted quinazoline, which are classical base-mediated MCRs [48].
Subsequently, the reaction conditions were optimized to support the evaluation under the essence
of typical loading, time, temperature and % yields (Table 1). Initially, we step up using
11

procedure of model reaction (Section 1.2, SI), the aforementioned MCRs proceeded efficiently to
yield the desired products with CC-TAPT-COP. Whereas, the blank experiment was forwarded
without catalyst resulted in negligible amount of product (Table 1). It was clearly observed that
the use of polar/non-polar organic solvents resulted in varied range of yields, but only ethanol
resulted in remarkable yield (Table 1). The further studies revealed that the reaction was not
efficient at room temperature and upon increasing the temperature to 60°C, resulted in better
yields, whereas prolonged heating for 2h was found insignificant. Therefore, the optimal
bestowed reaction conditions were used where a satisfactory conversion to quinazoline was
achieved.
After the careful evaluation for the optimization of reaction conditions with or without COP, we
alternatively drive down in order to extend the scope of present COP as a sustainable catalyst to
get an easy access to the library of highly congested quinazoline derivatives. Therefore, a range
of substituted aromatic aldehyde having electron rich/deficient functional groups was used to
investigate the scope of reaction which resulted in the formation of desired products with varied
yields (Table 2). Upon careful investigation, we found that with electron-withdrawing substrates,
the % yield was obtained in the range of 93-96%, comparatively higher than the electron
donating substrates where the % yield was observed in the range of 90-93% (Table 2). This trend
suggested that the reaction proceeded smoothly with electron withdrawing (EW) groups instead
of electron-donating (ED) substituents, which directed towards an idea that the –C=O (aldehyde)
group is more prone to the nucleophilic attack by –NH2 group. At last, the CC-TAPT-COP
catalyst comes up with an enhanced catalytic response, in support with above hypothesis.
12

Table 2. CC-TAPT-COP catalysed synthesis of quinazoline derivatives.a
Productc
4a
4b
4c
4d
4e
X
R
Yieldb
95
92
93
94
95
92
93
93
94
96
94
93
94
93
90
90
91
91
-Cl -H
-Cl m-CH3
-Cl p-CH3
-Cl p-OH
-Cl p-OMe
-Cl p-NMe2
-Cl p-F
-Cl o-Cl
-Cl m-Cl
-Cl p-Cl
-Cl m-Br
4f
4g
4h
4i
4j
4k
4l
4m
4n
4o
4p
4q
4r
-Cl p-Br
-Cl p-CN
-Cl p-NO2
-Cl m,p-OMe
-Cl o,p-Cl
-Cl m-F, p-Cl
-Cl o-F, m-NO2
-Cl 2-Napthaldehyde 91
4s
-Cl Cuminaldehyde
92
94
94
92
90
4t
-H
-H
-H
-H
-H
m-Cl
p-Cl
p-F
o-F, m-NO2
4u
4v
4w
4x
4y
2-Napthaldehyde 90
aReaction conditions: 2-amino aryl ketone (1 mmol), substituted
aromatic aldehyde (1 mmol), NH4OAc (2 mmol), CC-TAPT-COP (10
mg), Ethanol (10 mL). Temperature 60°C. bIsolated yield (%). cProducts
were characterized by 1H/13C- NMR and ESI-HRMS.
Further, the synthesis of substituted quinazoline is also supported by single crystal X-ray
structure of 4s (Fig. 4). The crystal packing diagram of 4s at 50% probability level is presented
13

in Fig. S4. The associated details of other crystallographic parameters, bond length, bond angle
and hydrogen atom coordinates are listed in Table S1-S6.
Fig.4 ORTEP diagram of 4s at 50% probability level.
In order to determine the active catalytic sites of CC-TAPT-COP, control experiments were
performed using CC-TAPT-COP and TAPT (precursor). Precisely, the 75.3% conversion of
benzaldehyde was observed with CC-TAPT-COP (Table S7). It was observed that TAPT act as
homogeneous catalyst, showing conversion of benzaldehyde along with the formation of by-
products, whereas CC-TAPT-COP exhibited good catalytic efficiency with selective
transformation to quinazoline. In addition, it was inferred that the presence of -NH-
(primary/secondary) group may encourage the reaction to get proceed. By considering the fact
that the secondary amine groups are widely present in core structure of COPs, TAPT consists of
-NH2 groups, which further suggested that secondary amine of COPs could be identified as the
active sites for this specific transformation.
Then after, the dimension and molecular sizes of precursor and product were calculated using
Gauss view 5.0 [49] and compared with CC-TAPT-COP in order to ensure the influence of
14

porosity on its catalytic efficiency. Unfortunately, the results showed that the porosity is nowhere
relevant for being the main factor to the catalytic activity. Above all, the skeleton of COP, the
effects of pore size, surface area and other plausible factors may contribute to encourage the
catalytic activity, so the future research on this issue will be critically evaluated later [50].
.
In order to understand the plausible mechanism, we have envisioned roughly by probing the
theoretical aspects into it. Initially, the N-rich catalytic active sites of as-synthesized COP act as
soft center which increase the electrophilic character for –C=O group of substituted
benzaldehyde. Initially, the nucleophillic attack of –NH2 group (2-aminoaryl ketone) to the
activated –C=O (benzaldehyde) encourages the formation of aldimine intermediate. Then, the
aldimine intermediate reacts with NH4OAc to form ketimine intermediate which upon ring-
transformation and subsequent dehydration yield desired product upon tautomerization under air.
It is always in interest to discuss about the recyclability and stability of any material because of
some parameters such as being green and sustainable which is in synthetic interest for industrial
applications. After completion of reaction, the CC-TAPT-COP could be easily separated from
the reaction mixture without any expected difficulty due to its awakening insoluble behaviour
and could be subsequently used for next catalytic runs. Then, the recovered CC-TAPT-COP was
washed with ethanol, ethyl acetate and dried. Above all, it was clearly seen that CC-TAPT-COP
could be recycled after six runs without prominent loss in its catalytic activity, which was
identified by the yield of the desired product (Table S8).
15

Further, we have studied the direct monitoring of reaction using UV-Vis spectroscopy, we have
opted for an on-site sampling during the course of reaction after every 3 min interval over 1h
(Fig. S5). In addition, it was observed that CC-TAPT-COP was insoluble in a variety of solvents.
The collected samples were subjected to UV-Vis study which indicated that the conversion was
efficient with respect to time (Fig. S6).
In connection to find the novelty of our present work, we have compared the present material
CC-TAPT-COP with other reported catalytic materials used for the synthesis of substituted
quinazoline varied in accordance with reaction conditions and yields (Table S9). Further, this can
be explained on fact that n-channels allow the precursors to stay and clubbed together in order to
orient a feasible geometry and desired product formation via pre-organisation concept through
nano-channels. However, the present material CC-TAPT-COP acts as a robust heterogeneous
material which could proceed organic transformation in its ability to cope with high temperature,
which may increase the flux between the reactants. In addition, supramolecular host-guest
interaction thorough π-channels may assist the reaction and could make the material more
promising and valuable. Therefore, CC-TAPT-COP is presented as a smart catalyst for MCRs in
the synthesis of substituted quinazoline.
3. Conclusions
In summary, we have successfully synthesized a new triazine based CC-TAPT-COP by poly-(N-
arylation) between TAPT and cyanuric chloride using bottom-up approach. CC-TAPT-COP
shows irregular block morphology and good thermal stability along with average pore diameter
of 2.86 nm. Further, we found that CC-TAPT-COP acts as propitious heterogeneous catalyst for
synthesis of substituted quinazoline which was confirmed by single crystal X-ray
crystallography. CC-TAPT-COP shows robust recovery and efficacy with intriguing catalytic
16

activity. Moreover, this study opens up a new horizon for catalytic application of COPs in MCRs
other than novel applications viz. biomedical applications which will be discussed in our future
research work.
Conflict of Interest
The authors declare no conflict of interest.
Acknowledgements
Authors are grateful to the Department of Chemistry, University of Delhi for providing the
necessary infrastructure and facilities. Subodh acknowledge the UGC, India for providing Senior
Research Fellowship. Authors gratefully acknowledge the USIC-DU and SAIF-AIIMS TEM
facility for characterization.
17

References
[1] Y. Zhang, S.N. Riduan, Functional porous organic polymers for heterogeneous catalysis,
Chem. Soc. Rev., 41 (2012) 2083-2094.
[2] P. Puthiaraj, Y.-R. Lee, S. Zhang, W.-S. Ahn, Triazine-based covalent organic polymers:
design, synthesis and applications in heterogeneous catalysis, J. Mater. Chem. A, 4 (2016)
16288-16311.
[3] D.M. Fischbach, G. Rhoades, C. Espy, F. Goldberg, B.J. Smith, Controlling the crystalline
structure of imine-linked 3D covalent organic frameworks, Chem. Commun., 55 (2019) 3594-
3597.
[4] P. Kuhn, M. Antonietti, A. Thomas, Porous, covalent triazine‐ based frameworks prepared
by ionothermal synthesis, Angew. Chem. Int. Ed., 47 (2008) 3450-3453.
[5] J. Roeser, K. Kailasam, A. Thomas, Covalent triazine frameworks as heterogeneous catalysts
for the synthesis of cyclic and linear carbonates from carbon dioxide and epoxides,
ChemSusChem, 5 (2012) 1793-1799.
[6] N.B. McKeown, P.M. Budd, Polymers of intrinsic microporosity (PIMs): organic materials
for membrane separations, heterogeneous catalysis and hydrogen storage, Chem. Soc. Rev., 35
(2006) 675-683.
[7] H.-L. Cao, H.-B. Huang, Z. Chen, B. Karadeniz, J. Lꢀ, R. Cao, Ultrafine silver nanoparticles
supported on a conjugated microporous polymer as high-performance nanocatalysts for
nitrophenol reduction, ACS Appl. Mater. Interfaces, 9 (2017) 5231-5236.
18

[8] K. Chaudhary, Subodh, K. Prakash, N.K. Mogha, D.T. Masram, Fruit waste (Pulp) decorated
CuO NFs as promising platform for enhanced catalytic response and its peroxidase mimics
evaluation, Arab. J. Chem., (2019) DOI: 10.1016/j.arabjc.2019.1009.1007.
[9] P. Puthiaraj, S.-M. Cho, Y.-R. Lee, W.-S. Ahn, Microporous covalent triazine polymers:
efficient Friedel–Crafts synthesis and adsorption/storage of CO 2 and CH 4, J. Mater. Chem. A,
3 (2015) 6792-6797.
[10] D. Yadav, S.K. Awasthi, Pd NPs confined novel covalent organic polymer for catalytic
application, New J. Chem., (2020) DOI: 10.1039/C1039NJ05827C.
[11] Z. Xiang, X. Zhou, C. Zhou, S. Zhong, X. He, C. Qin, D. Cao, Covalent-organic polymers
for carbon dioxide capture, J. Mater. Chem. A, 22 (2012) 22663-22669.
[12] R. Gomes, P. Bhanja, A. Bhaumik, A triazine-based covalent organic polymer for efficient
CO 2 adsorption, Chem. Commun., 51 (2015) 10050-10053.
[13] Z. Xiang, D. Cao, L. Huang, J. Shui, M. Wang, L. Dai, Nitrogen‐ Doped Holey Graphitic
Carbon from 2D Covalent Organic Polymers for Oxygen Reduction, Adv. Mater., 26 (2014)
3315-3320.
[14] Subodh, K. Prakash, D. Masram, Reversible chromogenic covalent organic polymer for gas
sensing applications, Dalton Trans., (2020) DOI: 10.1039/C1039DT04788C.
[15] Z. Xiang, D. Cao, Synthesis of luminescent covalent–organic polymers for detecting
nitroaromatic explosives and small organic molecules, Macromol. Rapid Commun., 33 (2012)
1184-1190.
[16] S. Delpierre, B. Willocq, G. Manini, V. Lemaur, J. Goole, P. Gerbaux, J. Cornil, P. Dubois,
J.-M. Raquez, A Simple Approach for Self-Healable and Stiff Polymer Network from
Iminoboronate-Based Boroxine Chemistry, Chem. Mater., 31 (2019) 3736-3744.
19

[17] D. Rodríguez-San-Miguel, F. Zamora, Processing of covalent organic frameworks: an
ingredient for a material to succeed, Chem. Soc. Rev., 48 (2019) 4375-4386.
[18] L.-M. Wang, J.-Y. Yue, X. Cao, D. Wang, Insight into the Transimination Process in the
Fabrication of Surface Schiff-Based Covalent Organic Frameworks, Langmuir, 35 (2019) 6333-
6339.
[19] J.L. Segura, M.J. Mancheno, F. Zamora, Covalent organic frameworks based on Schiff-base
chemistry: synthesis, properties and potential applications, Chem. Soc. Rev., 45 (2016) 5635-
5671.
[20] H. Wang, Z. Zeng, P. Xu, L. Li, G. Zeng, R. Xiao, Z. Tang, D. Huang, L. Tang, C. Lai,
Recent progress in covalent organic framework thin films: fabrications, applications and
perspectives, Chem. Soc. Rev., 48 (2019) 488-516.
[21] C.J. Heard, J. Čejka, M. Opanasenko, P. Nachtigall, G. Centi, S. Perathoner, 2D oxide
nanomaterials to address the energy transition and catalysis, Adv. Mater., 31 (2019) 1801712.
[22] H. Wang, Z. Zeng, P. Xu, L. Li, G. Zeng, R. Xiao, Z. Tang, D. Huang, L. Tang, C. Lai,
Recent progress in covalent organic framework thin films: fabrications, applications and
perspectives, Chem. Soc. Rev., 48 (2019) 488-516.
[23] V.R. Bakuru, D. Davis, S.B. Kalidindi, Cooperative catalysis at the metal–MOF interface:
hydrodeoxygenation of vanillin over Pd nanoparticles covered with a UiO-66(Hf) MOF, Dalton
Trans., 48 (2019) 8573-8577.
[24] A.B. Kulal, M.M. Kasabe, P.V. Jadhav, M.K. Dongare, S.B. Umbarkar, Hydrophobic
WO3/SiO2 catalyst for the nitration of aromatics in liquid phase, Applied Catalysis A: General,
574 (2019) 105-113.
20

[25] Subodh, K. Chaudhary, K. Prakash, D.T. Masram, TiO2 nanoparticles immobilized organo-
reduced graphene oxide hybrid nanoreactor for catalytic applications, Appl. Surf. Sci., (2019)
144902.
[26] P. Puthiaraj, K. Pitchumani, Palladium nanoparticles supported on triazine functionalised
mesoporous covalent organic polymers as efficient catalysts for Mizoroki–Heck cross coupling
reaction, Green Chem., 16 (2014) 4223-4233.
[27] D. Yadav, S.K. Awasthi, An unsymmetrical covalent organic polymer for catalytic amide
synthesis, Dalton Trans., 49 (2020) 179-186.
[28] R. Rajput, A.P. Mishra, A review on biological activity of quinazolinones, Int. J. Pharm.
Sci., 4 (2012) 66-70.
[29] J. Miao, X. Sang, Y. Wang, S. Deng, W. Hao, Synthesis of thiazolo[2,3-b]quinazoline
derivatives via base-promoted cascade bicyclization of o-alkenylphenyl isothiocyanates with
propargylamines, Org. Biomol. Chem., 17 (2019) 6994-6997.
[30] K. Chakrabarti, M. Maji, S. Kundu, Cooperative iridium complex-catalyzed synthesis of
quinoxalines, benzimidazoles and quinazolines in water, Green Chem., 21 (2019) 1999-2004.
[31] N. Shcherban, P. Mäki-Arvela, A. Aho, S. Sergiienko, P. Yaremov, K. Eränen, D.Y.
Murzin, Melamine-derived graphitic carbon nitride as a new effective metal-free catalyst for
Knoevenagel condensation of benzaldehyde with ethylcyanoacetate, Catal. Sci. & Technol., 8
(2018) 2928-2937.
[32] L. Shao, S. Wang, M. Liu, J. Huang, Y.-N. Liu, Triazine-based hyper-cross-linked polymers
derived porous carbons for CO2 capture, Chem. Eng. J., 339 (2018) 509-518.
[33] S.K. Das, S. Chatterjee, S. Mondal, A. Bhaumik, A new triazine-thiophene based porous
organic polymer as efficient catalyst for the synthesis of chromenes via multicomponent
21

coupling and catalyst support for facile synthesis of HMF from carbohydrates, Mol. Catal., 475
(2019) 110483.
[34] J. Yu, S. Wang, B. Cheng, Z. Lin, F. Huang, Noble metal-free Ni (OH) 2–gC 3 N 4
composite photocatalyst with enhanced visible-light photocatalytic H 2-production activity,
Catal. Sci. & Technol., 3 (2013) 1782-1789.
[35] J. Yu, X. Sun, X. Xu, C. Zhang, X. He, Donor-acceptor type triazine-based conjugated
porous polymer for visible-light-driven photocatalytic hydrogen evolution, Appl. Catal. B,
Environ., 257 (2019) 117935.
[36] P. Bhanja, S.K. Das, K. Bhunia, D. Pradhan, T. Hayashi, Y. Hijikata, S. Irle, A. Bhaumik, A
new porous polymer for highly efficient capacitive energy storage, ACS Sustain. Chem. Eng., 6
(2017) 202-209.
[37] R. Xue, H. Guo, T. Wang, X. Wang, J. Ai, L. Yue, Y. Wei, W. Yang, Synthesis and
characterization of a new covalent organic framework linked by NH linkage, Mater. Lett., 209
(2017) 171-174.
[38] S.-P. Lee, N. Mellon, A.M. Shariff, J.-M. Leveque, Geometry variation in porous covalent
triazine polymer (CTP) for CO 2 adsorption, New J. Chem., 42 (2018) 15488-15496.
[39] X. Wu, B. Wang, Z. Yang, L. Chen, Novel imine-linked covalent organic frameworks:
preparation, characterization and application, J. Mater. Chem. A, 7 (2019) 5650-5655.
[40] Y. Zhao, Z. Liao, Z. Xiang, Microfluidics for synthesis and morphology control of
hierarchical porous covalent organic polymer monolith, Chem. Engg. Sci., 195 (2019) 801-809.
[41] S. Kanti Das, S. Mishra, K. Manna, U. Kayal, S. Mahapatra, K. Das Saha, S. Dalapati, G.P.
Das, A.A. Mostafa, A. Bhaumik, A new triazine based π-conjugated mesoporous 2D covalent
organic framework: its in vitro anticancer activities, Chem. Commun., 54 (2018) 11475-11478.
22

[42] Subodh, N.K. Mogha, K. Chaudhary, G. Kumar, D.T. Masram, Fur-Imine-Functionalized
Graphene Oxide-Immobilized Copper Oxide Nanoparticle Catalyst for the Synthesis of Xanthene
Derivatives, ACS Omega, 3 (2018) 16377-16385.
[43] R. Peng, G. Chen, F. Zhou, R. Man, J. Huang, Catalyst-free synthesis of triazine-based
porous organic polymers for Hg2+ adsorptive removal from aqueous solution, Chem. Eng. J.,
371 (2019) 260-266.
[44] L. Shao, Y. Li, J. Huang, Y.-N. Liu, Synthesis of triazine-based porous organic polymers
derived N-enriched porous carbons for CO2 capture, Ind. Eng. Chem. Res., 57 (2018) 2856-
2865.
[45] M.-N. Chen, L.-P. Mo, Z.-S. Cui, Z.-H. Zhang, Magnetic nanocatalysts: synthesis and
application in multicomponent reactions, Curr. Opin. Green Sustain. Chem., 15 (2018) 27-37.
[46] B.B. Toure, D.G. Hall, Natural product synthesis using multicomponent reaction strategies,
Chem. Rev., 109 (2009) 4439-4486.
[47] A. Shaabani, R. Afshari, S.E. Hooshmand, M. Keramati Nejad, Molecularly Imprinted
Polymer as an Eco-Compatible Nanoreactor in Multicomponent Reactions: A Remarkable
Synergy for Expedient Access to Highly Substituted Imidazoles, ACS Sustain. Chem. Eng., 5
(2017) 9506-9516.
[48] R.M. Cherian, N.A. Harry, S. Saranya, K. Rohit, G. Anilkumar, Copper‐ Catalysed
Multicomponent Syntheses of Heterocycles, Asian J. Org. Chem., 8 (2019) 197-233.
[49] R.D. Dennington, T.A. Keith, J.M. Millam, GaussView 5.0. 8, Gaussian Inc, 340 (2008).
[50] N. Xu, R.-L. Wang, D.-P. Li, X. Meng, J.-L. Mu, Z.-Y. Zhou, Z.-M. Su, A new triazine-
based covalent organic polymer for efficient photodegradation of both acidic and basic dyes
under visible light, Dalton Trans., 47 (2018) 4191-4197.
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Author’s Biography
Subodh
Mr. Subodh received his bachelor’s degree in Chemistry from Hansraj College, University of Delhi, in
2013. Afterwards, he had completed his M.Sc (Chemistry) from the same university. He is currently
pursuing PhD from University of Delhi with Dr. Dhanraj T. Masram. His major research interests include
the design and development of polymeric functional materials.
Kunal Prakash
Kunal Prakash received a laureate in chemistry with hons. from Hansraj College, University of Delhi.
Later, he received a degree of M. Tech in Chemical Synthesis & Process Technologies from University of
Delhi. He had completed his master’s thesis work under the enlightened guidance of Dr. Satish Kumar.
Kunal Prakash is co-authoring several manuscripts in a variety of reputed journals. Currently, he is doing
advanced research training with Dr. D.T. Masram and working as an intern with research interests in
porous materials.
Karan Chaudhary
Karan Chaudhary is a Ph.D. candidate at the Department of Chemistry, University of Delhi, under the
supervision of Dr. Dhanraj T. Masram. In 2015, he completed his B.Sc. (Hons)Chemistry as a topper from
Dyal Singh College, University of Delhi. In 2017, he completed his M.Sc. Chemistry with second topper
from Hansraj college, University of Delhi. Currently, he is working in the field, synthesis of carbon
nanocomposites and their applications in the field of catalysis and biosensors.
Dhanraj T. Masram
Dr. Dhanraj T. Masram is working in the Department of Chemistry, University of Delhi as Assistant
Professor. He has served as Lecturer in Department of Chemistry, R.T.M. Nagpur University (2004-2009)
and obtained his Ph.D. degree from the same University. He has also worked as researcher at school of
Material Science, JAIST, Japan. Dr. Masram has received young scientist award from DST-SERB,
Government of India. His research focuses on the development of synthetic methodologies for materials
and their systematic understanding for application as catalysts, biosensors and in bioinorganic
chemistry.
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