Three-Dimensional Co(II)-Metal-Organic Frameworks with Varying Porosities and Open Metal Sites toward Multipurpose Heterogeneous Catalysis under Mild Conditions

Article abstract of DOI:10.1021/acs.cgd.9b00823

In recent years, heterogeneous catalysis has become one of the most active domains in the research of metal-organic frameworks (MOFs). Here, two three-dimensional (3D) Co(II)-MOFs with open metal sites and exposed azo functionality on the MOF backbone hav

Full text of DOI:10.1021/acs.cgd.9b00823

Subscriber access provided by Nottingham Trent University
Article
3D Co(II)-MOFs with Varying Porosity and Open Metal Sites toward
Multipurpose Heterogeneous Catalysis under Mild Conditions
Santanu Chand, Shyam Chand Pal, Manas Mondal, Subrata
Hota, ARUN PAL, Rupam Sahoo, and Madhab C. Das
Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.9b00823 • Publication Date (Web): 15 Aug 2019
Downloaded from pubs.acs.org on August 15, 2019
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a service to the research community to expedite the dissemination
of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in
full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully
peer reviewed, but should not be considered the official version of record. They are citable by the
Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore,
the “Just Accepted” Web site may not include all articles that will be published in the journal. After
a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web
site and published as an ASAP article. Note that technical editing may introduce minor changes
to the manuscript text and/or graphics which could affect content, and all legal disclaimers and
ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or
consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W.,
Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the
course of their duties.

Page 1 of 23
Crystal Growth & Design
1
2
3
4
Revised Manuscript ID: cg-2019-00823x
5
6
7
8
3D Co(II)-MOFs with Varying Porosity and Open Metal Sites toward
Multipurpose Heterogeneous Catalysis under Mild Conditions
9
Santanu Chand‖, Shyam Chand Pal‖, Manas Mondal, Subrata Hota, Arun Pal, Rupam Sahoo
and Madhab C. Das*
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302,
WB, India.
E-mail: mcdas@chem.iitkgp.ac.in
Abstract: In recent years heterogeneous catalysis is becoming one of the most active domain
in the research of Metal-Organic Frameworks (MOFs). Here, two 3D Co(II)-MOFs with the
open metal sites and exposed azo functionality on the MOF backbone have been constructed
via mixed ligand assembly. Both the MOFs, 1 ({[Co2(1,4-NDC)2(L)(H2O)2(µ2-
H2O)]·(DMF)2(H2O)}n) and 2 {[Co(fma)(L)(H2O)2]·S}n [1,4-NDC = 1,4-naphthalene
dicarboxylic acid, fma = fumaric acid, L = 3,3' azobis pyridine and S = disordered solvents]
exhibit 3D frameworks with metal bound aqua ligands. These metal bound aqua ligands, as
well as the lattice solvent molecules, could simply be removed upon activation affording the
desolvated frameworks 1a and 2a respectively maintaining original crystallinity with varying
number of open metal sites. Although, crystallographic analysis revealed porous structure for
both the MOFs (34.4% and 14.3% void volume for 1 and 2 respectively), 1 showed
permanently microporous nature with BET surface area of 197 m2g-1 and moderate CO2
uptake capacity as established through gas sorption study. Both the MOFs exhibit efficient
catalytic activity for the chemical fixation of CO2 to cyclic carbonate in presence of a co-
catalyst, cyanosilylation reaction, Knoevenagel condensation under solvent free and mild
conditions and thus demonstrating their multipurpose heterogeneous catalytic nature. The
limited pore space decorated with the exposed metal sites and the functional azo groups were
efficient for size selective heterogeneous catalysis with varying catalytic efficiencies. A
systematic comparison in their catalytic performances could be made with the establishment
of structure-function relationship. Besides, both the MOFs can easily be separated out from
the reaction mixtures and reused for at least four cycles without any loss of catalytic activity
and structural integrity.
Page no:1
ACS Paragon Plus Environment

Crystal Growth & Design
Page 2 of 23
1
2
3
4
5
6
Introduction
7
8
9
Metal-organic framework (MOFs) have received extensive attention as porous hybrid
material owing to their unique structural features and useful application ranging from gas
storage, separation, catalysis, chemical sensing, drug delivery, magnetism, proton conduction,
and so on.1-33 Usually, MOFs are constructed from linear or bent polycarboxylic acid, which
acts as a linker between metal ions or their cluster to give the final three dimensional (3D)
porous structure.34,35 In general, the structural arrangement of the building unit and the
subsequent overall framework topology plays a key factor for the bulk property of the
particular system.36-38 In recent years, MOFs having well-defined crystal structures,
modifiable pore topology, excellent tailorability, high surface areas have presented huge
potential, especially in the field of heterogeneous catalysis.4-10, 39-54 The catalytic property of
MOFs can be readily controlled by the proper selection of metal ion and organic ligands.
Based on the literature reports, there are different types of the active sites in the MOF which
can catalyse the heterogeneous catalysis reactions (structural defect site, Lewis acid centre,
open metal site and MOFs with a functional linker).9,10
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
There are two fundamental aspects of CO2 related research: sequestration and its
utilization. While sequestration deals with CO2 gas separation and storage with porous
materials, utilization of CO2 is focused on its chemical reactions as C1 feedstock. The
increasing level of CO2 in the atmosphere has encouraged the researcher to find out ways to
selectively capture CO2 from various sources of gas mixtures, in particular, separation from
landfill or biogas (50% CO2 and 50% CH4) and flue gas (15% CO2 and 85% N2).55-57 On the
other hand, CO2 is an abundant C1 resource and its chemical conversion to a value-added
product such as dimethyl carbonate, N, Nꞌ disubstituted urea, cyclic carbonate, urethanes,
formic acid and so on are both environmentally and practically attractive.58 Therefore, the
formation of cyclic carbonates via metal-catalysed cycloaddition of CO2 and epoxide attracts
immense attention among the catalysis community.59 Cyclic carbonates are relatively
valuable as pharmaceutical/fine chemicals intermediate in addition to their several biomedical
applications.58 The 100% atom economic ring extension reaction of epoxide with CO2
generating cyclic carbonates is a conventional and well-known procedure catalyzed by a
collection of numerous homo and heterogeneous catalysis like Schiff base, simple metal
oxide, salen complex and supported ionic liquids catalyst.60,61 Although there are several
MOFs reported catalysing such reaction which required high pressure (>2M Pa) and high
Page no:2
ACS Paragon Plus Environment

Page 3 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
temperature (>80°C) and thus causes high energy cost. However, under milder condition,
only a handful of MOFs such as MMFC-2, MMPF-9 and HKUST-1 effectively catalyse such
reaction. Therefore, the development of MOFs as a heterogeneous catalyst to produce cyclic
carbonates under milder condition are highly desired.58,59
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Besides CO2 cycloaddition, cyanosilylation is another important organic reaction to
produce cyanohydrins from aldehydes, which are major organic compounds for both
biological processes and synthetic chemistry as well.62 They can readily be altered into
essential species such as β-amino alcohols or α-hydroxycarboxylic acids.63 On the other hand,
Knoevenagel condensation (condensation between carbonyl compounds and activated
methylene compounds) is one of the fundamental reactions in order to form carbon-carbon
bonds.64 This kind of reaction is extensively used for the production of vital drug
intermediates.64 The homogeneous catalysts such as metal oxides or amines are frequently
used to catalyse such reactions, however, they do have their inherent limitations. The problem
related to homogeneous catalyst essentially includes recycling of the catalyst and the
difficulty in separation of product.60,61 Hence, the development of efficient heterogeneous
MOF-catalysts featuring reusability and easier separation, together with non-leaching
property towards multipurpose reactions such as CO2 cycloaddition, cyanosilylation and
Knoevenagel condensation of aldehydes are of great interest that deserves to be explored.4-10,
39-54
On the other hand, it would be preferable to carry out the catalysis reactions without
the presence of solvents, simply by using liquid substrate and reagents. Solvent-free
environments are favourable not only from avoiding releases of organic vapours to the
atmosphere but also the solid catalyst become easily reusable without any byproduct.65
Considering all those points, we have designed and assembled two 3D Co(II)-based
MOFs bearing open metal sites, from mixed ligand assembly of two acid ligands and 3,3'
azobis pyridine spacer bearing azo functionality, for their potential usage in multipurpose
heterogeneous catalysis. Both the MOFs contain unsaturated Co(II) centre (s) to act as Lewis
acidic sites and the accessible azo groups of the spacer to serve as a Lewis base centre.
Interestingly, as ideal Lewis acid-base bifunctional catalyst, both the MOFs offer great
performance in various scope of substrates with satisfactory recyclability in three different
types of catalysis: CO2 to cyclic carbonate, cyanosilylation reaction and Knoevenagel
condensation in solvent-free condition. Varying the number of open metal sites, accessible
pore volumes, permanent porosity and CO2 sorption capability enabled us to establish a
structure-catalytic function relationship. Although a variety of MOFs has been explored for
Page no:3
ACS Paragon Plus Environment

Crystal Growth & Design
Page 4 of 23
1
2
3
4
5
6
their various highly efficient catalytic performances, most of them are reported to catalyze
single or at most two reactions simultaneously, however, to the best of our knowledge,
reports on MOFs toward multipurpose heterogeneous catalysis are yet to be reported.
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Experimental section
Materials and reagents
The spacer L was prepared according to a previously reported method.66,67 All the chemicals
used in this work were commercially available, and of reagent grade quality and used as
received without additional purifications.
Synthesis of {[Co2(1,4-NDC)2(L)(H2O)2(µ2-H2O)]·(DMF)2(H2O)}n, 1. A mixture of
Co(NO3)2·6H2O (0.1 mmol, 0.029 g), 1,4-NDC (0.1 mmol, 0.0216 g) and linker L (0.05
mmol, 0.009 g) was taken in a mixed solvent (DMF : MeOH : Water 1:2:1 ) was heated to
120 °C under autogenous pressure in a Teflon line stainless steel autoclave for 48 h,
followed by slow cooling to room temperature at 5 o/min to give 1 as pink colour block shape
crystals in 70% yield based on the metal. Elemental analysis for ‘C40H42CoN6O14’, calcd: C,
53.99%; H, 4.76%; N, 9.45%. Found: C, 54.01%; H, 4.75%; N, 9.43%. FT-IR (KBr pellet,
cm−1): 3350.1(br), 3070.2(w), 2920.6(w), 1613.2(s), 1453.7(m), 1425.9(s), 1355.2(s),
1251.4(m), 1083.7(m), 1014.3(m), 783.9(m), 686.1(m), 637.8(w), 588.4(m), 445.5(m).
Synthesis of {[Co(fma)(L)(H2O)2]·S}n, 2. A mixture of Co(NO3)2·6H2O (0.1 mmol, 0.029
g), fumaric Acid (fma) (0.1 mmol, 0.011 g) and linker L (0.05 mmol, 0.009 g) was taken in 3
ml DMF solution and stirred for 1 h at room temperature. The solution was filtered and kept
for slow evaporation at ambient temperature. Red crystals were obtained after fifteen days in
60% yield based on the metal. FT-IR (KBr pellet, cm−1): 3105.8(br), 1542.4(s), 1471.2(w),
1428.1(w), 1384.9(s), 1194.3(m), 1098.2(w), 1028.9(w), 976.7(m), 811.1(s), 687.4(s),
645.4(w), 519.6(m).
Results and Discussion
Single crystal X-ray analysis shows that 1 crystallizes in monoclinic crystal system with
space group P21/n constructing a 3D polymeric framework formulated as {[Co2(1,4-
NDC)2(L)(H2O)2(µ2-H2O)]·(DMF)2(H2O)}n. The primary building unit consists of two cobalt
(II) ions (Co (1) and Co (2)), two 1,4-NDC anions, one spacer (L), one bridging water
molecule (µ2-H2O), two coordinated water molecules, two lattice DMF molecules and one
water molecules. As illustrated in Figure 1a Co(1) is six-coordinated by four carboxyl oxygen
Page no:4
ACS Paragon Plus Environment

Page 5 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
atom from 1,4 NDC, one O atom from µ2-H2O and one pyridyl N atom from spacer L to
complete a distorted octahedral geometry. The bond distances and bond angles around the
metal centres in 1 are in the normal range and are listed in Table S2, SI. Co(2) is also six-
coordinated by two chelating carboxylate groups, two coordinated water molecules (Ow1 and
Ow2), one pyridyl N atom and one O atom from µ2-H2O. Two Co(II) ions are bridged by two
bis (monodentate) carboxyl groups and one aqua ligand with µ2 bridging mode forming a
dimeric {Co2(COO)4} unit with a 2D square shape layered network (Figure 1b). The 2D
layered network is further connected by the spacer (L) to generate an extended 3D network
(Figure 1c). The separation distance between the two Co(II) metal centres along
Co(1)···L···Co(1) and Co(2)···L···Co(2) are 10.832 and 12.007Å, respectively. The
framework contains a total 34.4% solvent-accessible volume (1484.0 Å3 of the unit cell
volume of 4308.9 Å3) as estimated through PLATON 68 calculation with the formation of a
channel (5.0 x 8.2 Å2 considering van der Waals radii) along the crystallographic ‘a’ axis
(Figure 1c). The Topological analysis of 1 using TOPOS revels that the framework of 1 can
be simplified to a 3D uninodal 6-connected rob topology with the point symbol {48.66.8} as
depicted in Figure 1d. Several H-bonding interactions among solvent molecules and the
constituent ligands further stabilize the framework (Table S3, SI).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 1. a)ꢀCoordination environment around Co(II) metal centre in 1. Color code: Co, pink;
O, red; N, blue; C, grey; H, cyan. b) Four coordinated NDC2− with a Co(II) unit generating a
2D {Co2(COO)4} layered network. c)ꢀRepresentation of the packing diagram showing 1D
Page no:5
ACS Paragon Plus Environment

Crystal Growth & Design
Page 6 of 23
1
2
3
4
5
6
channels along ‘a’ axis. d)ꢀA schematic illustration of the network presenting the ‘rob’
topology.
The single-crystal X-ray determination of the structure for 2 also reveals a 3D
7
8
9
coordination framework constituted by fma2- and a N, N'-donor spacer L. 2 crystallizes in
monoclinic crystal system with C2/c space group formulated as {[Co(fma)(L)(H2O)2]·S}n.
The asymmetric unit of 2 consists of one half of Co(II) metal ion, half deprotonated fumaric
acid, half of the L spacer and one coordinated water molecule. Each Co(II) atom is six-
coordinated with two N-atoms ligated from two different L spacer in axial position and four
O atoms, among them two from symmetry-related water molecules and two different fma2-
units and thus giving rise to a distorted octahedral configuration {CoO4N2} (Figure 2a). The
Co–O bond distances range from 2.067 to 2.075 Å whereas the Co–N bond distance is 2.173
Å which are in the normal range and are listed in Table S4, SI. The Co(II) ions are
coordinated by fumarate dianion and N, N'-donor spacer L in an alternating fashion to form a
2D [Co(fma)(L)] network (Figure 2b). These 2D layers are further pillared by spacer L,
generating a 3D pillar-layered framework that houses 1D channels with an approximate
diameter of 3.6 Å which is much smaller in size than found in 1 (Figure 2c). The PLATON68
calculation after removing disordered solvent molecule indicates that 2 affords a porosity of
14.3% of unit cell volume (254.6 Å3 per unit cell volume of 1776.5 Å3) which is again
substantially lower than the 34.4% porosity found in 1. The framework of 2 can be simplified
to a 3D uninodal, 4-connected ‘cds’ topology with the point symbol {65.8} as depicted in
Figure 2d. One H-bonding and one non-covalent intermolecular interactions among the
ligands further stabilized the framework (Table S5, SI).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 2. a)ꢀCoordination environment around Co(II) metal centre in 2. Color code: Co, pink;
O, red; N, blue; C, grey; H, cyan. b) Representation of a 2D view of [Co(fma)(L)] unit. c)ꢀ
Page no:6
ACS Paragon Plus Environment

Page 7 of 23
Crystal Growth & Design
1
2
3
4
5
6
Representation showing channels along the crystallographic ‘c’ axis. d)ꢀ A schematic
representation of the network showing the cds topology.
To investigate the purity of the crystals in the bulk phase, PXRD experiment was
7
8
9
carried out for both the samples. The PXRD pattern of bulk samples of both the cases are in
good agreement with the as-synthesized ones, suggesting the phase purity in bulk synthesis
(Figure S1-S2, SI). It is well known that chemical stability is essential for the intended
practical applications. To illustrate the chemical stability of both the MOFs, the PXRD
patterns were recorded after immersing the MOFs in various solvents such as MeOH, THF,
acetone, acetonitrile, and water for 24 h. 1 shows high stability in common organic solvents,
however, when treated in water, change in peak positions in PXRD patterns is observed
suggesting formation of a different phase (Figure S3, SI) probably due to the partial
hydrolysis of metal-ligand bonds. On the other hand, for 2, the PXRD pattern of the dried
sample after soaking in different solvents including water reveals exact similarity with as-
synthesized pattern indicating its high chemical stability (Figure S4, Supporting Information).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
TGA profile of 1 shows a gradual weight loss up to 175 °C due to the removal of DMF
and H2O molecules (calc. 22.5 % for two lattice DMF and one water; three coordinated water
molecules). The network is stable until 270 °C and after that, a steady decomposition could be
observed. On the other hand, the framework of 2 shows a gradual weight loss up to 150 °C due to
the elimination of disordered lattice solvent as well as metal-bound H2O molecules followed by
steady weight loss corresponding to the degradation of the framework (Figure S5, Supporting
Information).
The permanent porosity of the MOFs was investigated by gas sorption studies. Before
gas sorption measurement, as synthesized MOFs were exchanged with dry chloroform for 48
h (10 times) and then subsequently activated at 373K under high vacuum for 14 h. The
activated frameworks retained the original crystallinity as confirmed through PXRD analysis
(Figure S1-S2, SI). It was found that the activated samples of 1 and 2 (1a and 2a
respectively) do not adsorb any N2 at 77K, indicating the energy of adsorbate and the thermal
energy of the framework are not high enough to permit the diffusion of the adsorbate
molecule through the pores.26 It is also well known that at this temperature the diffusion of
nitrogen through the micropores of the framework is very sluggish and diffusional limitation
at this temperature may influence the adsorption in ultramicropores.26 However, 1a adsorbed
84 cm3g-1 of CO2 at 195K/1 bar which corresponds to a BET surface area of 197 m2g-1
(Figure 3a) and thus establishing its permanent microporous nature. On the other hand, 2a did
Page no:7
ACS Paragon Plus Environment

Crystal Growth & Design
Page 8 of 23
1
2
3
4
5
6
7
8
9
not adsorb CO2 under similar condition confirming its non-microporosity and less affinity
towards CO2. 1a took up moderate CO2 uptake amount of 1.6 and 1.2 mmol at 273 and 295 K
respectively under 1 bar (Figure 3b) whereas 2a showed negligible uptake under such conditions
(Figure S6, SI).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 3. (a) CO2 adsorption of 1a at 195K at 1 bar. (b) CO2 sorption isotherms of 1a at 273
K and at 295 K. (Solid and open symbols represent adsorption and desorption, respectively).
Cycloaddition of CO2 to various epoxides
Given the open metal sites in both the MOFs and capacity to adsorb CO2 at ambient
conditions for 1, we decided to estimate its performances as Lewis acid based catalyst in the
wide range of heterogeneous catalysis such as, cycloaddition of CO2 and epoxides to form
cyclic carbonates, cyanosilylation reaction and Knoevenagel condensation under mild
conditions at 1 bar pressure.
The presence of open metal site in 1 is very important for CO2 fixation as it is already
established that CO2 molecules generally occupy positions near the unsaturated metal centers
at low pressure.55-57 Moderate CO2 uptake capacity on 1a, the exposed metal sites as well as
Lewis basic sites on both the frameworks of 1 and 2 make these MOFs potential
heterogeneous catalysts for cycloaddition reaction of CO2 with a various epoxides. The
reaction was performed with styrene oxide, activated catalyst 1a and tetrabutyl ammonium
bromide as co-catalyst in a two-neck round-bottom flask at room temperature with a pressure
of 1 bar CO2 for 24 h. However, the conversion of the corresponding carbonate was found to
be only ~ 20%, therefore, the temperature of the reaction mixture was increased stepwise and
finally 80 °C was selected as the optimum temperature. Keeping the temperature fixed at 80
°C, the reaction time was incresed successively from 1 h and finally optimised to 12 h (Figure
S7, SI). The conversion of the product from CO2 under this condition was found to be 93%.
Page no:8
ACS Paragon Plus Environment

Page 9 of 23
Crystal Growth & Design
1
2
3
4
5
6
The catalytic reaction was also investigated in the presence of both spacer and acid ligand;
however, no desired product could be obtained. Co(NO3)2·6H2O was also tested as a catalyst;
only 20% yield was obtained.
7
8
9
Scheme 1. Cycloaddition reaction of epoxide with CO2 catalysed by 1a and 2a
O
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Catalyst 1-2
(0.5 mol%)
TBAB
80 oC, 1 atm CO2
O
O
O
CO2
+
R
R
Entry
Catalyst(0.5 mol Epoxidation Cyanosilylation
Knovenagel
Reaction Conversion
(%)&
%)
Reaction
Conversion
(%)#
Recation
Conversion
(%) $
1
2
3
4
MOF1 (Un
activated)
55
52
60
52
MOF2 (Un
activated)
50
No
No
47
No
No
Spacer (L)
No
No
1,4 Napthlene
Dicarboxylic
Acid
5
6
7
Succinic Acid
No
20
No
28
-
No
30
-
Co(NO3)2·6H2O
TBAB (10
mol%)
<10
Table 1. Optimization of catalysis reaction and conditions 1a and 2a.
Reaction Condition [#]: 1,2-Epoxyethylbenzene (20 mmol, 1 equiv), catalyst (0.5 mol%
based on Co(II)) TBAB (10 mol%). No solvent was added. [$] 4-nitrobenzaldehyde (2 mmol,
1 equiv), catalyst (0.5 mol%) trimethylsilyl cyanide (6 mmol, 3equiv). No solvent was
added. [&] 4-nitrobenzaldehyde (2 mmol, 1 equiv), catalyst (0.5 mol%) malanonitrile (10
mol, 5 equiv) under neat condition. Conversion was evaluated from the 1H NMR spectra.
Definitely, the capacity of 1a to chemically convert CO2 into cyclic carbonates with
high efficiency under mild condition (i.e. 80 °C and 1 bar CO2 pressure) is highly beneficial.
It may be noted that high pressure and high temperature were used to achieve such efficiency
for some well-known MOFs.58,59,69-79 For example, conversions of 98%, 93%, 95%, 53% and
48% were achieved for MOF-5 (323 K, 60 bar pressure)75, ZIF-68 (393 K, 10 bar pressure)76,
Mg-MOF-74 (373 K, 20 bar pressure)77, UMCM-1-NH2 (300 K, 12 bar pressure)78 and
Page no:9
ACS Paragon Plus Environment

Crystal Growth & Design
Page 10 of 23
1
2
3
4
5
6
7
8
9
HKUST-1 (373 K, 20 bar pressure)79 respectively under relatively higher temperature and
higher CO2 pressure (Table S6, SI). On the other hand, Co-MOFs with open metal sites have
been found to achieve >95% conversion for styrene oxide with comparatively higher pressure
(2 MPa, 100°C, 4h for Co-MOF-74 and 0.8 MPa, 80°C, 12h for
[{Co(muco)(bpa)(2H2O)}·2H2O]n.80,81 In order to gain insight the scope of the catalysis
reactions for MOF 1 and 2, a systematic approach has been taken by varying the size of the
substrates. As shown in Table 2, the substrates with electron withdrawing group generally
showed better conversions. For example, the cycloaddition of CO2 with epichlorohydrin and
allylglycidyl ether were effectively catalyzed in high conversions (96% and 87%; 80% and
78%) (Figure S8-S9, SI). When propylene oxide, styrene oxide and 1,2-epoxy cyclohexane
were used the desired product were generated with 97% and 90%; 93% and 86%; and 42%
and 30% conversions for 1a and 2a respectively (Figure S10-S12, SI). Interestingly, the
smaller size substrate like propylene oxide (4.35 × 3.41Å2), styrene epoxide (4.28 × 7.26 Å2)
resulted the higher catalytic conversion. On the other side, aliphatic epoxide with long alkyl
chain (Table 2, entries 7 and 8) were converted to the cyclic carbonate with low conversion
due to larger size (8.19 × 3.39 and 13.32 × 3.39 Å2), respectively, compared to the pore size
(∼5.0 × 8.2 Å2) of 1.69-71,82 The results are in accordance with the fact that small substrates
can easily diffuse through the 1D channels which contain large numbers of open metal sites
for 1a59,69-71,80,81,83,84 suggesting the usefulness of 1a as a promising heterogeneous catalyst
for the cycloaddition of CO2. In addition, 2a exhibits systematically lower catalytic efficiency
than 1a, due to its non-affinity towards CO2 as evident from CO2 sorption studies (Figure S8-
S20, SI). Again, for the case of 2, the 1D channels with approximate diameter of 3.6 Å is
much smaller than the molecular sizes of most of the substrates used in the catalytic reaction
and therefore, it is assumed that the catalytic reaction for the case of 2a might proceed mainly
on the surface of the MOF. Although, 2a is nonporous to CO2, it showed surface adsorption
behavior (Figure S6, SI). In addition, presence of open metal sites also makes 2a a potential
catalyst for cycloaddition of CO2 to various epoxides with obvious lower efficiency than 1a.
The characterization of the desired carbonates was performed by the 1H spectra.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
In order to confirm the role of open metal sites onto the frameworks towards catalysis,
the catalysis reactions have been investigated without activating the MOFs i.e. 1 and 2. As
expected the yield of the catalytic conversion is very low for both of the MOFs (55% for 1;
50% for 2). Therefore, this phenomenon confirms the fact that the presence of open metal
sites is ultimately necessary to facilitate the catalytic reaction.69-71
Page no:10
ACS Paragon Plus Environment

Page 11 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
Table 2. Cycloaddition reaction of various substituted epoxides catalyzed by 1a and 2a.
Entry
Substrate
Conversion (%)
TON
194
Conversion (%)
TON
180
by 1a
97
by 2a
90
9
1.
2.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
96
93
192
186
87
86
174
172
3.
4.
5.
42
68
84
30
61
60
134
122
6.
80
160
78
156
7.
8.
52
49
104
98
35
30
70
60
Reaction conditions: epoxides (20 mmol, 1 equiv), catalyst (0.5 mol% based on Co(II)) TBAB
(10 mol%). No solvent was added. The conversion was evaluated from the 1H NMR spectra.
A tentative mechanism has been proposed for the formation of cyclic carbonates
catalysed by the strong Lewis acid based catalyst of 1a and 2a on the account of some earlier
reports, 85-87 as demonstrated in Scheme S1 (Supporting Information). Moreover, on the basis
of hot filtration test, the catalysts were found to be entirely heterogeneous revealing no
leaching of Co(II) ions (Figure S21 for 1a, S22 for 2a, SI).
Cyanosilylation Reaction
Taking into account the Lewis acidity and open metal sites, both the MOFs were also
explored as the heterogeneous catalysts in the cyanosilylation reaction under solvent free
condition. The results are summarized in the Table 3. Using 1a as catalyst the conversion
reached up to 96% while for 2a it was 81% for benzaldehyde (Figure S23-S24, SI). To
investigate the scope and limitation of this heterogeneous catalysis reaction, we studied the
Page no:11
ACS Paragon Plus Environment

Crystal Growth & Design
Page 12 of 23
1
2
3
4
5
6
7
8
9
influence of various substituents at the phenyl ring and found that conversion are very
sensitive to the electronic properties of the substituents attached to the phenyl ring (Table 3).
Aldehydes with electron withdrawing group attached to the phenyl ring are much more
reactive than electron donating group at the phenyl ring (Figure S25-S28, SI). On the other
hand, shape and size of the substrates influence the % conversion of the products to some
extent, for example, the longer hexanal showed significantly lower conversion (57% and
44%) than the other aromatic substrates. As given in Table 3, 1a exhibited higher
cyanosilylation catalytic activity than 2a. This can be attributed to the microporous nature of
1a as evident from BET surface area analysis as opposed to non-porous nature of 2a.
Although, the conversions are systematically lower for 2a than found in 1a as expected, but
still could be considered quite high for aromatic aldehydes. This might be due to porous
nature of 2 as determined through crystallographic analysis, although less compared to 1 as
estimated from void volume analysis with PLATON68 (34.4% vs 14.3%). Moreover, the
higher catalytic efficiency of 1a could also be correlated to the higher number of active metal
sites within the framework (three open metals sites in 1 vs two in 2 per unit formula). To the
best of our knowledge, only a few MOFs have been reported to be capable of efficiently
catalyzing cyanosilylation reaction with such efficiency under solvent free conditions.88-90
Furthermore, Table S7 (Supporting Information) provides the comparison of the catalytic
performances of MOF 1a and 2a with those for various other MOF-based catalytic systems
reported in the literature in terms of time, temperature and conversion. A proposed
mechanism for cyanosilylation reaction of aldehydes catalyzed by 1a is presented in Scheme
S2, SI. 90 Hot filtration test was performed to check the heterogeneity of the catalyst, showing
the catalysis reaction is entirely heterogeneous (Figure S29 for 1a, S30 for 2a, SI).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Scheme 2. Cyanosilylation reaction of aldehydes with TMSCN catalysed by 1a and 2a.
CN
O H
H
OTMS
Catalyst 1-2(0.5 mol%)
60 oC, 6h
+
TMSCN
R
R
Table 3.cyanosilylation reaction of various substituted aldehydes catalyzed by 1a and 2a.
Entry
Substrate
Conversion (%)
TON
Conversion (%)
TON
by 1a
by 2a
Page no:12
ACS Paragon Plus Environment

Page 13 of 23
Crystal Growth & Design
1
2
3
4
5
6
96
192
198
81
72
162
144
1.
2.
99
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
3.
4.
96
99
192
198
83
78
166
156
5.
6.
7.
90
98
57
180
196
114
68
89
44
136
178
88
Reaction conditions: aldehyde (2 mmol, 1 equiv), catalyst (0.5 mol% based on Co(II))
trimethylsilyl cyanide (6 mmol, 3equiv). No solvent was added. The conversion was
evaluated from the 1H NMR spectra.
Knoevenagel Condensation Reaction
Presence of moderate porosity as revealed through single crystal structure
determination, abundant Lewis basic and open metal sites for both the MOFs inspired us to
explore the catalytic reaction for Knoevenagel condensation of an aldehyde with active
methylene compound under solvent free condition. As shown in Table 4, the conversion
reached up to above 90% for 2-benzylidenemalonitrile catalyzed by both the MOFs (Figure
S31-S32, SI). To understand whether the catalysis reaction proceeds inside the pore or
surface of the MOFs, various substituted aldehyde groups as substrate were taken and
extended the scope of the study under similar condition. As shown in Table 4, in the case of
slightly elongated aldehyde, conversion for hexanal was decreased (33% and 31% for 1a and
2a respectively) significantly compared to smaller aldehydes for both the MOFs.
Furthermore, in
Page no:13
ACS Paragon Plus Environment

Crystal Growth & Design
Page 14 of 23
1
2
3
4
5
Scheme 3. Knoevenagel condensation reaction of substituted aldehyde with malononitrile
catalyzed by 1a and 2a.
6
7
8
9
CN
O H
H
CN
Catalyst 1-2(0.5 mol%)
60 oC, 6h
NC CN
+
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
R
R
Table 4. Knoevenagel condensation of various substituted aldehyde catalyzed by 1a and 2a.
Entry
Substrate
Conversion (%) by
TON
Conversion ( %) by
TON
1a
2a
1.
95
190
93
186
2.
3.
94
97
188
194
92
95
184
190
4.
5.
92
90
184
180
78
80
156
160
6.
7.
99
33
198
66
96
31
192
62
Reaction conditions: aldehyde (2 mmol, 1 equiv), catalyst (0.5 mol% based on Co(II))
malanonitrile (10 mol, 5 equiv) under neat condition. The conversion was evaluated from the
1H NMR spectra.
the presence of electron withdrawing group i.e p-chloro benzaldehyde and p-nitro
benzaldehyde, excellent conversions are achived (97% and 95%; 99% and 96%) (Figure S33-
S34, SI), however, for electron donating groups i.e. p-anisaldehyde and p-methyl
benzaldehyde the conversions were systematically lower (92% and 78% ; 94% and 92%)
(Figure S35-S36, SI), which suggests that the electrophilicity of carbonyl group increases in
Page no:14
ACS Paragon Plus Environment

Page 15 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
the former case and suppresses in the latter case. As ensembled in Table 4, 1a exhibited
higher catalytic activity than 2a, due to more porous nature of 1a compared to 2a as
determined through crystallographic and BET surface area analysis in conjunction with more
accessible open metal sites in 1a compared to 2a. A systematic comparison on catalytic
performances between 1a and 2a along with various other literature reports are given in the
Table S8 (Supporting Information). Interestingly, both the MOFs offer superior catalytic
activity with minimal catalytic loadings under mild and solvent free condition and thus
making them as potential heterogeneous catalysts for Knoevenagel condensation reaction. A
proposed mechanism for 1a-catalyzed knoevenagel condensation reaction is shown in
Scheme S3, Suporting Information.91-93 It is assumed that the interaction between Lewis
acidic sites (coordinatively unsaturated cobalt center) and the carbonyl group of the aldehyde
improves the electrophilic character of the carbonylic carbon atom and thus assisting the
attack by malononitrile.91-93 Furthermore, hot filtration data supported the heterogeneous
nature of the catalyst for Knoevenagel reaction (Figure S37 for 1a, S38 for 2a SI).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
The recyclability is a very important issue for heterogeneous catalytic systems. The
catalysts could be completely recovered and reused without showing any significant loss of
activity at least for four catalytic cycles by simple filtration followed by washing with DMF,
ethyl acetate, DCM and subsequently drying in oven as shown in Figure S39-S41 (Supporting
Information). The integrity of frameworks is also retained during multiple cycles as confirm
by PXRD analysis (Figure S42-S43, SI) and thus demonstrating their potential to act as
multipurpose heterogeneous catalysts under milder conditions.
Conclusion
In conclusion, two new 3D Co(II)-MOFs with Lewis acid-Lewis base bi-
functionalities were successfully developed based on organic dicarboxylic acids and azo
linked N, N donor spacer and structurally characterized with varying porosities. The limited
pore spaces decorated with exposed metal sites and N-rich functional azo groups were
efficient for size selective chemical transformation of CO2 with epoxide into cyclic carbonate
under solvent free and mild condition. The MOFs also showed excellent heterogeneous
catalytic behaviour toward the cyanosilylation reactions and Knoevenagel condensation. A
systematic comparison in their catalytic performances could be made based on their available
open metal site concentrations, porosities and CO2 sorption capabilities. Apart from these, the
catalysts can be easily be separated and reused for at least four cycles without any loss of
Page no:15
ACS Paragon Plus Environment

Crystal Growth & Design
Page 16 of 23
1
2
3
4
5
6
7
8
9
activity and structural integrity. Given the enormous library of organic polycarboxylic acids
and N,N' donor spacer and less numbers of reported Co(II)-based MOFs with permanent
porosity and open metal sites, this study may contribute to broaden the scope of Co(II)-based
microporous MOFs for their potential applications in heterogeneous catalysis under mild
conditions.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ASSOCIATED CONTENT
Supporting Information (SI):
Crystallographic data table, PXRD patterns, TGA profile, calculation details, selectivity
comparison table, related catalytic reactions plots (PDF). CCDC 1896926 and 1896927
contains the supplementary crystallographic data for this paper.
AUTHOR INFORMATION
Corresponding Author
*E-mail: mcdas@chem.iitkgp.ac.in
ORCID iD
Madhab C. Das: 0000-0002-6571-8705
Notes
‖These authors contributed equally to this work
Acknowledgements
S.C. and S.C.P. thanks IIT KGP for fellowship. M.C.D. gratefully acknowledges the financial
support received from SERB, New Delhi as Early Carrier Research Award
(ECR/2015/000041).
Conflicts of Interest
The authors declare no competing financial interest.
References
1. Themed collection on MOF: Li, J. -R.; Kuppler, R. J.; Zhou, H.-C. Selective Gas
Adsorption and Separation in Metal–Organic Frameworks. Chem. Soc. Rev. 2009, 38,
1477-1504.
Page no:16
ACS Paragon Plus Environment

Page 17 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
2. Li, J. R.; Sculley, J.; Zhou, H. C. Metal-Organic Frameworks for Separations. Chem.
Rev. 2012, 112, 869-932.
3. (c) Cui, Y.; Li, B.; He, H.; Zhou, W.; Chen, B.; Qian, G. Metal–Organic Frameworks
as Platforms for Functional Materials. Acc. Chem. Res. 2016, 49, 483-493.
4. Lee, J.; Farha, O. K.; Roberts, J.; Scheidt, K. A.; Nguyen, S. T.; Hupp, J. T.
Metal−Organic Framework Materials as Catalysts. Chem. Soc. Rev. 2009, 38,
1450−1459.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
5. Yoon, M.; Srirambalaji, R.; Kim, K. Homochiral Metal−Organic Frameworks for
Asymmetric Heterogeneous Catalysis. Chem. Rev. 2012, 112, 1196−1231.
6. Aresta, M.; Dibenedetto, A.; Angelini A. Catalysis for the Valorization of Exhaust
Carbon: from CO2 to Chemicals, Materials, and Fuels. Technological Use of CO2.
Chem. Rev. 2014, 114, 1709−1742.
7. Zhu, L.; Liu, X. Q.; Jiang, H. L.; Sun, L. B. Metal−Organic Frameworks for
Heterogeneous Basic Catalysis Chem. Rev. 2017, 117, 8129−8176.
8. Gole, B.; Bar, A. K.; Mallick, A.; Banerjee, R.; Mukherjee, P. S. Electron Rich
Porous Extended Framework as Heterogeneous Catalyst for Diels-Alder Reaction.
Commun. 2013, 49, 7439-7441.
9. Maina, J. W.; Gonzalo, C. P.; Kong, L.; Schütz, J.; Hill, M. Dumée L. F. Metal
organic framework based catalysts for CO2 conversion Mater. Horiz., 2017,4, 345-
361.
10. Beyzavi, M. H.; Stephenson, C. J.; Liu, Y.; Karagiaridi, O.; Hupp, J. T.; Farha,
O. K. Metal–organic framework-based catalysts: Chemical fixation of CO2 with
epoxides leading to cyclic organic carbonates. Front. Energy Res. 2:63.
doi:10.3389/fenrg.2014.00063.
11. Cui, Y.; Yue, Y.; Qian, G.; Chen, B. Luminescent Functional Metal−Organic
Frameworks. Chem. Rev. 2012, 112, 1126−1162.
12. Lustig, W. P.; Mukherjee, S.; Rudd, N. D.; Desai, A. V.; Li, J.; Ghosh, S. K. Metal-
Organic Frameworks: Functional Luminescent and Photonic Materials for Sensing
Applications. Chem. Soc. Rev. 2017, 46, 3242-3285.
13. Khatua, S.; Goswami, S.; Biswas, S.; Tomar, K.; Jena, H. S.; Konar, S. Stable
Multiresponsive Luminescent MOF for Colorimetric Detection of Small Molecules in
Selective and Reversible Manner. Chem Mat. 2015, 27, 5349-5360.
14. Horcajada, P.; Gref, R.; Baati, T.; Allan, P. K.; Maurin, G.; Couvreur, P.; Férey, G.;
Morris, R. E.; Serre, C. Metal–Organic Frameworks in Biomedicine. Chem. Rev.,
2012, 112, 1232–1268.
15. Kurmoo, M. Magnetic Metal–organic Frameworks. Chem. Soc. Rev. 2009, 38, 1353–
1379.
16. Chand. S.; Elahi, S. M.; Pal, A.; Das, M. C. Metal Organic Frameworks and Other
Crystalline Materials for Ultrahigh Superprotonic Conductivities of 10-2 S cm‐1 or
Higher. Chem. Eur. J.2019, 25 6259-6269.
17. Ramaswamy, P.; Wong, N. E.; Shimizu, G. K. H. MOFs as Proton Conductors
Challenges and Opportunities. Chem. Soc. Rev. 2014, 43, 5913−5932.
18. Yamada, T.; Otsubo, K.; Makiura, R.; Kitagawa, H. Designer Co-ordination
Polymers: Dimensional Crossover Architectures and Proton Conduction. Chem. Soc.
Rev. 2013, 42, 6655-6669.
19. Elahi, S. M.; Chand, S.; Deng, W.-H.; Pal, A.; Das, M. C. Polycarboxylates
Templated Coordination Polymers: Role of Templates for Superprotonic
Conductivities up to 10‐1 S cm‐1. Angew. Chem. Int. Ed. 2018, 57, 6662-6666;
Page no:17
ACS Paragon Plus Environment

Crystal Growth & Design
Page 18 of 23
1
2
3
4
5
6
7
8
9
20. Chand, S.; Pal, S. C.; Pal, A.; Ye, Y.; Lin, Q.; Zhang, Z.; Xiang, S.; Das, M. C.
Metalo Hydrogen-Bonded Organic Frameworks (MHOFs) as New Class of
Crystalline Materials for Protonic Conduction. Chem. Eur. J. 2019, 25, 1691–1695.
21. Shen, K.; Chen, J.; Chen, X.; Long, J.; Luque, R.; Zhang, L.; Li, Y.; Chen, B. Ordered
Macro-Microporous Metal-Organic Framework Single Crystals. Science 2018, 359,
206-210.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
22. Ghosh, T. K.; Chakraborty, S.; Chowdhury, B.; Ghosh, P. Bis-Heteroleptic
Ruthenium(II) Complex of Pendant Urea Functionalized Pyridyl Triazole and
Phenathroline for Recognition, Sensing, and Extraction of Oxyanions. Inorg. Chem.
2017, 56, 5371−5382.
23. Zhang, M.; Feng, G.; Song, Z.; Zhou, Y.-P.; Chao, H.-Y.; Yuan, D.; Tan, T. T. Y.;
Guo, Z.; Hu, Z.; Tang, B. Z.; Liu, B.; Zhao, D. Two-Dimensional Metal−Organic
Framework with Wide Channels and Responsive Turn-On Fluorescence for the
Chemical Sensing of Volatile Organic Compounds. J. Am. Chem. Soc. 2014, 136,
7241−7244.
24. Maity, D. K.; Halder, A.; Pahari, G.; Haque, F.; Ghoshal, D. Hydrogen Uptake by an
Inclined Polycatenated Dynamic Meta-Organic Framework Based Material. Inorg.
Chem. 2017, 56, 713–716.
25. Wang, B.; Yang, Q.; Guo, C.; Sun, Y.; Xie, L.-H.; Li, J.-R. Stable Zr(IV)-Based
Metal−Organic Frameworks with Predesigned Functionalized Ligands for Highly
Selective Detection of Fe(III) Ions in Water. ACS Appl. Mater. Interfaces 2017, 9,
10286−10295.
26. Maji, T. K.; Matsuda, R.; Kitagawa, S. A flexible interpenetrating coordination
framework with a bimodal porous functionality. Nat. Mater., 2007, 6, 142–148.
27. Zhang, J. –P.; Zhang, Y.–B.; Lin, J.–B.; Chen, X.–M. Metal Azolate Frameworks:
From Crystal Engineering to Functional Materials. Chem. Rev. 2012, 112, 1001–1033.
28. Nandi, S.; Collins, S.; Chakraborty, D.; Banerjee, D.; Thallapally, P. K.; Woo, T. K.;
Vaidhyanathan, R. Ultralow Parasitic Energy for Postcombustion CO2 Capture
Realized in a Nickel Isonicotinate Metal−Organic Framework with Excellent
Moisture Stability. J. Am. Chem. Soc. 2017, 139, 1734-1737.
29. Gao, M. L.; Wang, W.-J.; Liu, L.; Han, Z.-B.; Wei, N.; Cao, X.-M.; Yuan, D.-Q.
Microporous Hexanuclear Ln(III) Cluster-Based Metal–Organic Frameworks: Color
Tunability for Barcode Application and Selective Removal of Methylene Blue. Inorg.
Chem. 2017, 56, 511–517.
30. Panda, T.; Pachfule, P.; Chen, Y.; Jiang, J.; Banerjee, R. Amino Functionalized
Zeolitic Tetrazolate Framework (ZTF) with High Capacity for Storage of Carbon
Dioxide. Chem. Commun. 2011, 47, 2011-2013.
31. Chand, S.; Elahi, S. M.; Pal, A.; Das, M. C. A New Set of Cd(II)˗coordination
Polymers with Mixed Ligands of Dicarboxylate and Pyridyl Substituted
Diaminotriazine: Selective Sorption towards CO2 and Cationic Dyes. Dalton Trans.
2017, 46, 9901-9911.
32. Klein, N.; Senkovska, I.; Gedrich, K.; Stoeck, U.; Henschel, A.; Mueller, U.; Kaskel,
S. A Mesoporous Metal–Organic Framework. Angew. Chem. Int. Ed. 2009, 48, 9954–
9957; Angew. Chem. 2009, 121, 10139–10142.
33. Krause, S.; Bon, V.; Senkovska, I.; Tobbens, D. M.; Wallacher, D.; Pillai, R. S.;
Maurin, G.; Kaskel, S. The effect of crystallite size on pressure amplification in
switchable porous solids. Nat Commun, 2018, 9, 1573.
34. Special Issue on MOF: Zhou, H. -C.; Long, J. R.; Yaghi, O. M. Introduction to
Metal−Organic Frameworks. Chem. Rev. 2012, 112, 673-674.
Page no:18
ACS Paragon Plus Environment

Page 19 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
35. Zhou, H.-C.; Kitagawa, S. Metal-Organic Frameworks (MOFs), Chem. Soc. Rev.,
2014, 43, 5415-5418.
36. Perry, J. J.; Perman, J. A.; Zaworotko, M. J. Design and synthesis of metal-organic
frameworks using metal-organic polyhedral as supermolecular building blocks. Chem.
Soc. Rev., 2009, 38, 1400-1417.
37. Eddaoudi, M.; Moler, D. B.; Chen, B.; Reineke, T. M.; Keeffe, M. O.; Yaghi, O. M.
Modular chemistry: Secondary building units as a basis for the design of highly
porous and robust metal-organic carboxylate frameworks. Acc. Chem. Res. 2001, 34,
319-330.
38. Zhai, Q.-G.; Bu, X.; Zhao, X.; Li, D.-S.; Feng, P. Pore Space Partition in Metal–
Organic Frameworks Acc. Chem. Res. 2017, 50, 407-417.
39. Das, S. K.; Chatterjee, S.; Bhunia, S.; Mondal, A.; Mitra, P.; Kumari, V.; Pradhan, A.;
Bhaumik, A. A new strongly paramagnetic cerium-containing microporous MOF for
CO2 fixation under ambient conditions. Dalton Trans. 2017, 46, 13783−13792.
40. Markad, D.; Khullar, S.; Mandal, S. K. Engineering a Nanoscale Primary Amide-
Functionalized 2D Coordination Polymer as an Efficient and Recyclable
Heterogeneous Catalyst for the Knoevenagel Condensation Reaction. ACS Appl. Nano
Mater. 2018, 1, 5226−5236.
41. Li, B.; Ju, Z.; Zhou, M.; Su, K.; Yuan, D. A Reusable MOF-Supported Single-Site
Zinc(II) Catalyst for Efficient Intramolecular Hydroamination of o –Alkynylanilines.
Angew. Chem. Int. Ed. 2019, 58 7687-7691; Angew.Chem.2019, 131, 7769–7773.
42. Nguyen, K. D.; Kutzscher, C.; Drache, F.; Senkovska, I.; Kaskel, S. Chiral
Functionalization of a Zirconium Metal-Organic Framework (DUT-67) as a
Heterogeneous Catalyst in Asymmetric Michael Addition Reaction. Inorg. Chem.
2018, 57, 1483−1489.
43. Jiao, L.; Wang, Y.; Jiang, H.-L.; Xu, Q. Metal-Organic Frameworks as Platforms for
Catalytic Applications. Adv. Mater. 2018, 30, 1703663.
44. Gao, W.Y.; Chen, Y.; Niu, Y.; Williams, K.; Cash, L.; Perez, P. J.; Wojtas, L.; Cai,
J.; Chen, Y. S.; Ma, S. Crystal Engineering of an nbo Topology Metal–Organic
Framework for Chemical Fixation of CO2 under Ambient Conditions. Angew. Chem.,
Int. Ed. 2014, 53, 2615-2619.
45. Fujita, M.; Kwon, Y. J.; Washizu, S.; Ogura, K. Preparation, Clathration Ability, and
Catalysis of a Two-Dimensional Square Network Material Composed of Cadmium
(II) and 4,4'-Bipyridine. J. Am. Chem. Soc. 1994, 116, 1151-1152.
46. Haldar, R.; Reddy, S. K.; Suresh, V. M.; Mohapatra, S.; Balasubramanian, S.; Maji,
T. K. Flexible and Rigid Amine‐Functionalized Microporous Frameworks Based on
Different Secondary Building Units: Supramolecular Isomerism, Selective
CO2 Capture, and Catalysis. Chem. Eur. J. 2014, 20, 4347-4356.
47. Sasan, K.; Lin, Q.; Maob, C.; Feng, P. Open framework metal chalcogenides as
efficient photocatalysts for reduction of CO2 into renewable hydrocarbon fuel.
Nanoscale, 2016, 8, 10913–10916.
48. Liang, L.; Liu, C.; Jiang, F.; Chen, Q.; Zhang, L.; Xue, H.; Jiang, H. L.; Qian, J.;
Yuan, D.; Carbon dioxide Capture and Conversion by an Acid-Base Resistant Metal-
Organic Framework. Hong, M. Nat. chem. 2017, 8, 1233;
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
49. De, D.; Pal, T. K.; Neogi, S.; Senthilkumar, S.; Das, D.; Gupta, S. S.; Bharadwaj P. K.
A Versatile Cu(II) Metal–Organic Framework Exhibiting High Gas Storage Capacity
with Selectivity for CO2 : Conversion of CO2 to Cyclic Carbonate and Other Catalytic
Abilities. Chem. Eur. J. 2016, 22, 3387–3396.
Page no:19
ACS Paragon Plus Environment

Crystal Growth & Design
Page 20 of 23
1
2
3
4
5
6
7
8
9
50. Li, P. Z.; Wang, X. J.; Liu, J.; Phang, H. S.; Li, Y.; Zhao, Y. Highly Effective
Carbon Fixation via Catalytic Conversion of CO2 by an Acylamide-Containing
Metal−Organic Framework. Chem. Mater. 2017, 29, 9256-9261.
51. Sharma, M. K.; Singh, P. P.; Bharadwaj, P. K. Two-Dimensional Rhombus Grid
Coordination Polymer Showing Heterogeneous Catalytic Activities. J. Mol. Catal. A:
Chem. 2011, 342, 6−10.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
52. Burgoyne, A. R.; Meijboom, R. Knoevenagel Condensation Reactions Catalysed by
Metal-Organic Frameworks. Catal. Lett. 2013, 143, 563−571.
53. Fang, Q.-R.; Yuan, D.-Q.; Sculley, J.; Li, J.-R.; Han, Z.-B.; Zhou, H.-C. Functional
Mesoporous Metal−Organic Frameworks for the Capture of Heavy Metal Ions and
Size-Selective Catalysis. Inorg. Chem. 2010, 49, 11637−11642.
54. Zhu, Q. L.; Xu, Q. Immobilization of Ultrafine Metal Nanoparticles to High-Surface-
Area Materials and Their Catalytic Applications. Chem, 2016, 1, 220–245.
55. Sumida, K.; Rogow, D. L.; Mason, J. A.; McDonald, T. M.; Bloch, E. D.; Herm, Z.
R.; Bae, T.; Long, J. R. Carbon Dioxide Capture in Metal-Organic Frameworks.
Chem. Rev. 2012, 112, 724−781.
56. Lin, R.-B.; Xiang, S.; Xing, H.; Zhou, W.; Chen, B. Exploration of Porous Metal–
organic Frameworks for Gas Separation and Purification. Coord. Chem. Rev. 2019,
378, 87–103.
57. Pal, A.; Chand, S.; Das, M. C. A Water-Stable Twofold Interpenetrating Microporous
MOF for Selective CO2 Adsorption and Separation. Inorg. Chem. 2017, 56, 13991-
13997.
58. Darensbourg, D. J.; Holtcamp, M. W. Catalysis for the Reaction of Epoxide and
Carbon dioxide. Coord. Chem. Rev. 1996, 115, 155-174.
59. He, H.; Perman, J. A.; Zhu, G.; Ma, S. Metal-Organic Frameworks for CO2 Chemical
Transformations. Small 2016, 12, 6309-6324.
60. Paddock, R. L.; Nguyen, S. T. Chemical CO2 Fixation: Cr(III) Salen Complexes as
Highly Efficient Catalysts for the Coupling of CO2 and Epoxides. J. Am. Chem. Soc.
2001, 123, 11498−11499.
61. He, Q.; O’Brien, J. W.; Kitselman, K. A.; Tompkins, L. E.; Curtis, G. C. T.; Kerton,
F. M. Synthesis of Cyclic Carbonates from CO2 and Epoxides Using Ionic Liquids
and Related Catalysts Including Choline Chloride−metal Halide Mixtures. Catal. Sci.
Technol. 2014, 4, 1513−1528.
62. (a) Gregory, R. J. H. Cyanohydrins in Nature and the Laboratory:ꢁ Biology,
Preparations, and Synthetic Applications Chem Rev. 1999, 99, 3649-3682.
63. Brunel, J. –M.; Holmes, I. P. Chemically Catalyzed Asymmetric Cyanohydrin
Syntheses. Angew. Chem. Int. Ed. 2004, 43, 2752–2778.
64. Fleming, F. F.; Wang, Q. Unsaturated Nitriles:ꢁConjugate Additions of Carbon
Nucleophiles to a Recalcitrant Class of Acceptors. Chem Rev. 2003, 103, 2035-2077.
65. Dhakshinamoorthy, A.; Asiri, A. M.; Alvaro, M.; Garcia, H. Metal Organic
Frameworks as Catalysts in Solvent-free or Ionic Liquid Assisted Conditions. Green
Chem. 2018, 20, 86-107.
66. Chand. S.; Pal, A.; Das, M. C. A Moisture Stable 3D Microporous Co(II)-MOF with
Potential for Highly Selective CO2 Separation under Ambient Conditions. Chem.
Eur. J. 2018, 24, 5982 –5986.
67. Chand. S.; Pal, A.; Pal, S. C.; Das, M. C. A Trifunctional Luminescent 3D
Microporous MOF with Potential for CO2 Separation, Selective Sensing of a Metal
Ion, and Recognition of a Small Organic Molecule. Eur. J. Inorg. Chem. 2018, 2785–
2792.
Page no:20
ACS Paragon Plus Environment

Page 21 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
68. Spek, A. L. Single-crystal Structure Validation with the Program PLATON. J. Appl.
Crystallogr. 2003, 36, 7−13.
69. Zhao, D.; Liu, X. H.; Shi, Z. Z.; Zhu, C. D.; Zhao, Y.; Wang, P.; Sun, W.Y. Three
powerful dinuclear metal–organic catalysts for converting CO2 into organic
carbonates. Dalton Trans. 2016, 45, 14184-14190.
70. Zhao, D.; Liu, X. H.; Guo, J. H.; Xu, H. J.; Zhao, Y.; Lu, Y.; Sun, W.Y. Porous
Metal–Organic Frameworks with Chelating Multi amine Sites for Selective
Adsorption and Chemical Conversion of Carbon Dioxide. Inorg. Chem. 2018, 57,
2695−2704.
71. Zhao, D.; Liu, X. H.; Zhu, C.; Kang, Y. S.; Wang, P.; Shi, Z.; Lu, Y.; Sun, W.Y.
Efficient and Reusable Metal–Organic Framework Catalysts for Carboxylative
Cyclization of Propargyl amines with Carbon Dioxide. ChemCatChem 2017, 9, 4598
– 4606.
72. Miralda, C. M.; Macias, E. E.; Zhu, M.; Ratnasamy, P.; Carreon, M. A. Zeolitic
Imidazole Framework-8 Catalysts in the Conversion of CO2 to Chloropropene
Carbonate. ACS Catal. 2012, 2, 180−183.
73. Guillerm, V.; Weseliński, Ł. J.; Belmabkhout, Y.; Cairns, A. J.; D’Elia, V.; Wojtas,
Ł.; Adil, K.; Eddaoudi, M. Discovery and introduction of a (3,18)-connected net as an
ideal blueprint for the design of metal-organic framework Nat. Chem. 2014, 6,
673−680.
74. Senthilkumar, S.; Maru, M. S.; Somani, R. S. Bajaj, H. C.; Neogi, S. Unprecedented
NH2-MIL-101(Al)/n-Bu4NBr System as Solvent-Free Heterogeneous Catalyst for
Efficient Synthesis of Cyclic Carbonates via CO2 Cycloaddition. Dalton Trans. 2018,
47, 418-428 and the references therein.
75. Song, J.; Zhang, Z.; Hu, S.; Wu, T.; Jiang, T.; Han, B. MOF-5/n-Bu4NBr: an
efficient catalyst system for the synthesis of cyclic carbonates from epoxides and
CO2 under mild conditions. Green. Chem. 2009, 11, 1031-1036.
76. Yang, L.; Yu, L.; Diao, G.; Sun, M.; Cheng, G.; Chen, S. Zeolitic imidazolate
framework-68 as an efficient heterogeneous catalyst for chemical fixation of carbon
dioxide. J. Mol. Catal. A: Chem. 2014, 392, 278-283.
77. Yang, D. A.; Cho, H. Y.; Kim, J.; Yang, S. T.; Ahn, W. S. CO2 capture and
conversion using Mg-MOF-74 prepared by a sonochemical method Energy Environ.
Sci. 2012, 5, 6465.
78. Babu, R.; Kathalikkattil, A. C.; Roshan, R.; Tharun, J.; Kim, D. W.; Park D. W.
Dual-Porous Metal-Organic Framework for Room Temperature CO2 Fixation via
Cyclic Carbonate Synthesis. Green Chem. 2016, 18, 232–242.
79. Kim, J.; Kim, S.-N.; Jang, H. G.; Seo, G.; Ahn, W. S. CO2 Cycloaddition of Styrene
Oxide over MOF catalysts. Applied Catalysis A: General, 2013, 453, 175-180.
80. Cho, H.-Y.; Yang, D.-A.; Kim, J.; Jeong, S.-Y.; Ahn, W.-S. CO2 adsorption and
catalytic application of Co-MOF-74 synthesized by microwave heating. Catal. Today,
2012, 185, 35–40.
81. Ugale, B.; Dhankhar, S. S.; Nagaraja, C. M. Interpenetrated Metal−Organic
Frameworks of Cobalt(II): Structural Diversity, Selective Capture, and Conversion of
CO2. Cryst. Growth Des.2017, 17, 3295−3305.
82. Li, P. Z.; Wang, X. J.; Liu, J.; Lim, J. S.; Zou, R.; Zhao, Y. A Triazole-Containing
Metal−Organic Framework as a Highly Effective and Substrate Size-Dependent
Catalyst for CO2 Conversion. J. Am. Chem. Soc. 2016, 138, 2142-2145.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Page no:21
ACS Paragon Plus Environment

Crystal Growth & Design
Page 22 of 23
1
2
3
4
5
6
7
8
9
83. Zhou, Z.; He, C.; Xiu, J.; Yang, L.; Duan, C. Metal–Organic Polymers Containing
Discrete Single-Walled Nanotube as a Heterogeneous Catalyst for the Cycloaddition
of Carbon Dioxide to Epoxides. J. Am. Chem. Soc. 2015, 137, 15066-15069.
84. Shaikh, R. R.; Pornpraprom, S.; D’Elia, V. Catalytic Strategies for the Cycloaddition
of Pure, Diluted, and Waste CO2 to Epoxides under Ambient Conditions. ACS Catal.
2018, 8, 419-450.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
85. (a) North, M.; Pasquale, R. Mechanism of Cyclic Carbonate Synthesis from Epoxides
and CO2. Angew. Chem., Int. Ed. 2009, 48, 2946−2948.
86. Feng, D.; Chung, W.-C.; Wei, Z.; Gu, Z.-Y.; Jiang, H.-L.; Chen, Y.-P.; Darensbourg,
D. J.; Zhou, H.-C. Construction of Ultrastable Porphyrin Zr Metal−Organic
Frameworks through Linker Elimination. J. Am. Chem. Soc. 2013, 135, 17105–17110.
87. Verma, A.; De, D.; Tomar, K.; Bharadwaj, P. K. An Amine Functionalized Metal–
Organic Framework as an Effective Catalyst for Conversion of CO2 and Biginelli
Reactions. Inorg. Chem. 2017, 56, 9765−9771.
88. Kumar, G.; Das, S. K. Coordination Frameworks Containing Compounds as
Catalysts. Inorg. Chem. Front. 2017, 4, 202-233 and the references therein.
89. Mo, K.; Yang, Y.; Cui, Y. A Homochiral Metal−Organic Framework as an Effective
Asymmetric Catalyst for Cyanohydrin Synthesis. J. Am. Chem. Soc. 2014, 136,
1746−1749.
90. Zhang, Z.; Chen, J.; Bao, Z.; Chang, G.; Xing, H.; Ren, Q. Insight into the Catalytic
Properties and Applications of Metal Organic Frameworks in the Cyanosilylation of
Aldehydes. RSC Adv. 2015, 5, 79355-79360.
91. Hasegawa, S.; Horike, S.; Matsuda, R.; Furukawa, S.; Mochizuki, K.; Kinoshita, Y.;
Kitagawa, S. Three-Dimensional Porous Coordination Polymer Functionalized with
Amide Groups Based on Tridentate Ligand: Selective Sorption and Catalysis. J. Am.
Chem. Soc. 2007, 129, 2607-2614.
92. Yao, C.; Zhou, S.; Kang, X.; Zhao, Y.; Yan, R.; Zhang, Y.; Wen, L. A Cationic
Zinc–Organic Framework with Lewis Acidic and Basic Bifunctional Sites as an
Efficient Solvent-Free Catalyst: CO2 Fixation and Knoevenagel Condensation
Reaction. Inorg. Chem. 2018, 57, 11157−11164.
93. Almáši, M.; Zeleňák, V.; Gyepes, R.; Bourrelly, S.; Opanasenko, M. V.; Llewellyn
P. L.; Čejka J. Robust Bifunctional Lanthanide Cluster Based Metal−Organic
Frameworks (MOFs) for Tandem Deacetalization−Knoevenagel Reaction. Inorg.
Chem. 2018, 57, 1774−1786.
Page no:22
ACS Paragon Plus Environment

Page 23 of 23
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Table of Content
3D Co(II)-MOFs with Varying Porosity and Open Metal Sites toward
Multipurpose Heterogeneous Catalysis under Mild Conditions
Santanu Chand‖, Shyam Chand Pal‖, Manas Mondal, Subrata Hota, Arun Pal, Rupam Sahoo
and Madhab C. Das*
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302,
WB, India.
E-mail: mcdas@chem.iitkgp.ac.in
___________________________________________________________________________
Two new 3D Co(II)-MOFs with varying porosities and open metal sites have been
constructed for three different types of heterogeneous catalysis such as CO2 to cyclic
carbonate, cyanosilylation reaction and Knoevenagel condensation under solvent free and
mild conditions.
Page no:23
ACS Paragon Plus Environment