A Highly Stable Triazole-Functionalized Metal–Organic Framework Integrated with Exposed Metal Sites for Selective CO2 Capture and Conversion

Article abstract of DOI:10.1002/chem.201903912

A new triazole-functionalized tetracarboxylic acid ligand (H₄L) has been synthesized and utilized for the fabrication of a 3D Zn^II organic framework with a Zn₄(?COO)₆ cluster as the secondary building unit. The

Full text of DOI:10.1002/chem.201903912

A Journal of
Accepted Article
Title: A highly stable triazole functionalized metal organic framework
integrated with exposed metal sites for selective CO2 capture
and conversion
Authors: Vijay Gupta and Sanjay K Mandal
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Chem. Eur. J. 10.1002/chem.201903912
Link to VoR: http://dx.doi.org/10.1002/chem.201903912
Supported by

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
A highly stable triazole functionalized metal organic framework
integrated with exposed metal sites for selective CO2 capture and
conversion
Vijay Gupta and Sanjay K. Mandal*
Abstract: A new triazole functionalized tetracarboxylic acid ligand
(H4L) has been synthesized and utilized for the fabrication of a 3D
Zn(II) organic framework with a Zn4(-COO)6 cluster as the SBU. The
framework exhibits very good thermal stability and consists of dual
functionalities of exposed Lewis-acid metal sites and accessible
nitrogen-donor Lewis basic sites. The Lewis basic nitrogen sites into
the framework serve as CO2 binding sites for highly selective CO2
capture and the presence of exposed Lewis-acid metal sites into the
framework makes it an efficient heterogeneous catalyst for chemical
fixation of CO2 into value-added cyclic carbonates under ambient
conditions.
NO2, –NH2, , –OH, –COOH, –CONH–, –SO3H, –F, and –CF3, etc.)
in their pore surfaces.[7]
Among the MOF materials, zeolitic and zeolite-like metal
imidazolate frameworks (ZIFs) as special types of MOFs, are well
known for their amazing affinity for CO2 molecules due to aromatic
–N(H) donors on the imidazole moieties.[8] However, most of the
ZIF materials suffer from weak adsorption and separation ability
for CO2 because of the lack of active metal sites; the introduction
of additional N-donors and open metal sites into the framework
leads to much higher CO2 capture and selectivity than the un-
functionalized ones.[9] In this respect, various nitrogen-rich MOFs
containing triazolate and tetrazolate functionalized ligands have
been synthesized,[9,10] but the high affinity of these ligands
towards the metal ions limits the number of open donor sites
responsible for CO2 enhancement during adsorption process.
However, there are several examples of triazole-functionalized
Introduction
Carbon dioxide (CO2), as the major greenhouse gas, has been
cited as the leading culprit, causing global warming and
subsequent climate changes.[1] During the last 10 years, the mean
annual absolute CO2 concentration has increased by 2.21 ppm
per year and is responsible for about 82 % of the increase in
radiative forcing over the past 5 years.[2] Therefore, it is of
immense importance for developing such systems that can work
successfully in the process of carbon dioxide capture and
sequestration (CCS) and hence can help reduce the greenhouse
emission. Considerable effort has been made to develop effective
methods and materials capable of CCS.[1a,3] Recent works on
numerous materials including aqueous absorbents like
alkanolamine or ionic liquid-based wet scrubbing systems and
solid porous adsorbents such as zeolites and activated carbons
have demonstrated their potential for adsorption-based
separation.[3] But these CCS technologies still suffer from
reusability and gas selectivity issues.
MOFs,[11] but only
a few utilizes the tetratopic triazole
functionalized carboxylates as the organic linkers where all the
donor sites are available for interaction with the CO2 molecules. It
is also envisaged that the accessibility of the functional sites is
much more important rather than the electronic effects and any
hindrance to the functional site will limit its effect on the
improvement of CO2 uptake capacity and selectivity.
Metal organic frameworks (MOFs) as a new class of crystalline
porous organic−inorganic hybrid materials have emerged as
promising candidates for gas storage and separation applications,
particularly in the area of carbon capture,[4] and therefore have
received significant attention. Aiming at CO2 capture into the
MOFs, current efforts are largely devoted to enhancing the CO2
binding affinity in MOFs. Reported strategies include control over
the pore size and shape,[5] incorporation of open metal sites or
donor/basic sites,[6] and immobilizing polar functional groups (–
Figure 1. Chemical structure of the triazole functionalized tetracarboxylic acid
ligand (H4L) used for the MOF construction.
Based on the considerations and with the aim of incorporating
accessible nitrogen-donor Lewis-basic sites into the MOF
structure, herein, we report the rational design and synthesis of a
1,2,3-triazole functionalized bent tetracarboxylic acid ligand (H4L)
(Figure 1) via versatile click chemistry in good yield. The ligand
possesses dual functionalities of isophthalate as metal ion/cluster
binding sites and nitrogen-rich triazole moieties as Lewis basic
sites for CO2 interaction. Just as we expected, the reaction of H4L
with Zn(NO3)2.6H2O under solvothermal conditions, resulted in a
Dr. V. Gupta, Prof. Dr. S. K. Mandal
Department of Chemical Sciences
Indian Institute of Science Education and Research Mohali
Sector 81, Manauli PO, S.A.S. Nagar, Mohali, Punjab 140306, India.
E-mail: sanjaymandal@iisermohali.ac.in
Supporting information and the ORCID identification number(s) for the
author(s) of this article can be found under:
https://doi.org/10.1002/chem.2019xxxxx
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
thermally robust framework, {[Zn2(L)(H2O)].4H2O}n (1) with Zn4
cluster as secondary building units (SBUs). These multinuclear
SBUs are well known to impart high thermal stability and
permanent porosity to the framework.[12] The importance of SBU
in constructing such frameworks was first demonstrated in MOF-
2[13] and further established by isoreticular MOFs based on
tetranuclear zinc and other clusters.[14] A large number of
multinuclear (di-, tri-, tetra- and pentanuclear) zinc carboxylate
clusters are known,[15] where oxides or hydroxides as bridging
ligands are present in addition to the carboxylate linkers, e.g.
MOF-5. The resulting framework in 1 is different from other
tetranuclear clusters for the fact that it forms a pure zinc
carboxylate cluster, where four zinc centers are bridged by six
carboxylates to form a Zn4(-COO)6 cluster as the SBU. The
framework possesses high density of exposed Lewis-acid metal
sites and nitrogen-donor Lewis-basic sites accessible for the
guest molecules.
lattice. The metal centers Zn1 and Zn2 are in distorted square
pyramidal and tetrahedral coordination environment, respectively.
Table 1. Crystallographic data and structure refinement parameters for 1.
Identification code
Empirical formula
Formula weight
Temperature/K
Crystal system
Space group
a/Å
1
C34H32N6O13SiZn2
891.48
100.15
monoclinic
P21/n
9.6578(6)
b/Å
40.024(2)
c/Å
9.7497(7)
α/°
90
β/°
100.403(4)
γ/°
Volume/Å3
90
3706.8(4)
Z
4
ρcalcg/cm3
1.597
1.401
μ/mm-1
F(000)
1824.0
Crystal size/mm3
Radiation
0.15 × 0.15 × 0.1
MoKα (λ = 0.71073)
4.368 to 50.034
-9 ≤ h ≤ 11, -39 ≤ k ≤ 47, -11 ≤ l ≤ 10
25033
6530 [Rint = 0.0861, Rsigma = 0.0846]
6530/6/526
1.059
Results and Discussion
2Θ range for data collection/°
Index ranges
Reflections collected
Independent reflections
Data/restraints/parameters
Goodness-of-fit on F2
Final R indexes [I>=2σ (I)]
Final R indexes [all data]
Largest diff. peak/hole / e Å-3
Single-crystal X-ray diffraction analysis reveals that 1 crystallizes
in the monoclinic P21/n space group (No. 14) (Table 1). As shown
in Figure 1a, the framework is assembled using the Zn4 cluster
secondary building units (SBUs) and organic ligands L4-, where
the inorganic SBU can be deconstructed as an 8-c node and the
organic tetratopic ligand as two 3-c branch points.[16] The
asymmetric unit consists of two crystallographically independent
Zn(II) atoms, one L4- ligand and five water molecules, one of which
is coordinated to one of the Zn(II) atom and other four are in the
R1 = 0.0608, wR2 = 0.1166
R1 = 0.1027, wR2 = 0.1301
0.63/-0.55
2
aR1 = Σ∥Fo| − |Fc∥/Σ|Fo|. bwR2 = [Σw(Fo – Fc2)2/Σw(Fo2)2]1/2, where w =
1/[σ2(Fo2) + (aP)2 + bP], P = (Fo2 + 2Fc2)/3.
Figure 2. Structure description of 1. (a) Tetranuclear Zn4 cluster and organic ligand L4- viewed as an 8-c node and a pair of 3-c branch points, respectively, (b)
perspective view of the framework showing 1D open channels lined with exposed Lewis-acid metal sites and accessible nitrogen-donor Lewis basic sites. Lattice
water molecules are not shown for clarity. (Colour codes: gray, C; red, O; blue, N; cyan, Si; green, Zn; white, H) and (c) overall 3,8-connected sqc topology.
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
An ORTEP view of the asymmetric unit with atom labelling
scheme is shown in Figure S1, supporting information. The 
parameter, which is an indicator[17] for the deviation from the ideal
square-pyramidal ( = 0) and trigonal bipyramidal ( = 1)
geometries for five coordinate metal centers, is found to be 0.2 for
Zn1 (Table S1, supporting information). The framework consists
of open channels along the c-axis (Figure 1b), with an
approximate diameter of 8.7 X 6.1 Å2 (regardless of the van der
Waals radii). The total solvent-accessible volume for 1 was
estimated to be 18% (692/3706 Å3 per unit cell volume) using
addition to the thermal stability, 1 was also found to be stable
towards water and various organic solvents as established by the
PXRD studies of 1, after soaking in different solvents for 2 days
followed by filtration and drying in air (Figure S6, supporting
information). Further, 1 exhibits very good stability in acidic and
alkaline medium based on the PXRD patterns of 1 after soaking
in 1N HCl and 1N NaOH for 24 h have been presented in Figure
S7, supporting information. The establishment of permanent
porosity in 1 was evaluated through N2 adsorption isotherm at 77
K. The Brunauer–Emmett–Teller (BET) and Langmuir surface
area were estimated to be 314 m2g-1and 447 m2g-1, respectively
(Figure S8-S10, supporting information). The properly oriented
accessible N-donor sites-enabled high CO2 uptake by 1 at low
temperature (Figure S11, supporting information) and inspired us
to explore the potential of 1 for selective CO2 capture and
separation from a gas mixture under ambient conditions. Single
component sorption isotherms for different gases (CO2, N2, and
CH4) were measured at 298 K and up to 1 bar pressure. As shown
in Figure 2a, 1 takes up very less amount of N2 (3.04 cm3g-1) and
CH4 (11.52 cm3g-1) compared to CO2 (41.75 cm3g-1), under
identical conditions. Although 1 presents comparatively low CO2
uptake than the MOFs derived from other triazole functionalized
ligands (Table S2, supporting information), it shows comparable
binding strength and good selectivity over N2 and CH4. The
quantitative binding strengths of CO2 molecules with the
framework was calculated based on the virial method,[20] from fits
of adsorption isotherms at different temperatures (Figure 2b and
Figure S12, supporting information). The enthalpy at zero
coverage of CO2 was calculated to give the value 32.7 KJmol-1,
which is better than the value reported for some well-known MOF
materials (Table S3, supporting information).
PLATON software.[18] From topological perspective,
1
corresponds 3,8-connected 3D porous framework with sqc
topology (Figure 1c), as determined by the TOPOS[19] program.
A broad band between 3400–3440 cm-1 in the FTIR spectrum
of 1 (Figure S2, supporting information) indicates the existence of
coordinated and lattice water molecules, whereas the sharp
peaks in the range of 1410–1630 cm-1 are due to the asymmetric
and symmetric stretching of the carboxylates coordinated to the
metal centers. A good agreement between the powder X-ray
diffraction (PXRD) pattern of the as-synthesized 1 and the
simulated PXRD pattern (Figure S3, supporting information)
confirms the bulk phase purity of 1. The thermal stability and
structural variation as a function of temperature were studied by
thermogravimetric analysis (TGA). 1 exhibits a weight loss of ~7%
in the temperature range 50-150 °C, followed by ~2% weight loss
in the temperature range 180-250 °C, which can be ascribed to
the loss of four lattice water (8%) and one coordinated water
(2.2%) molecules, respectively (Figure S4, supporting
information). The robustness and thermal stability of 1 were
further checked by in-situ variable temperature powder X-ray
diffraction (VT-PXRD) (Figure S5, supporting information). In
Figure 3. (a) CO2 adsorption isotherms for 1 at different temperatures, (b) comparison of uptake capacity of 1 for CO2, N2 and CH4 at 298 K, (c and d) binary mixture
adsorption isotherms and selectivities at 298 K for CO2/N2 (15/85) and CO2/CH4 (50/50) mixtures, respectively.
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
The variation of isosteric heat of adsorption with respect to
surface coverage is shown in Figure S13 (see supporting
information). The gas mixture selectivity was studied for CO2/CH4
and CO2/N2 mixture at a general feed composition of landfill gas
(CO2/CH4 = 50:50) and flue gas (CO2/N2 = 15:85) with pressure
up to 1 bar, by applying the well-known ideal adsorbed solution
theory (IAST) developed by Myers and Prausnitz for binary
mixtures.[21] Pure component adsorption data collected at 298 K
was taken as inputs to the IAST calculation, and the output
predicts the mixture adsorption equilibrium over the desired
pressure range. Mixture adsorption isotherms and adsorption
selectivity calculated by IAST (based on the dual-site Langmuir-
Freundlich model) for mixed CO2/N2 and CO2/CH4 in 1 as a
function of total bulk pressure is shown in Figure 2. The results
indicate that under 1 bar pressure the selectivity values for CO2/N2
(156.8) and CO2/CH4 (26.1) are much higher than the values
reported for some well-known examples (Table S5, supporting
information). At lower temperature (273 K) the selectivity values
for CO2/N2 and CO2/CH4 increased to 1416.8 and 52.7,
respectively. The highly selective CO2 capture further suggests
the cooperative effect of the dual functionalities into the
framework. In addition, the applicability of 1 for selective CO2
capture was further studied by recycling experiments; it was found
that 1 maintains about 100% adsorption capacity even after 3
cycles of adsorption experiments (Figure S17, supporting
information).
of the reaction was monitored by 1H NMR experiments; a
complete conversion (>99%) was obtained over 24 h, which
indicates excellent catalytic activity of 1. Furthermore, the
catalytic performance of 1 was also examined for different
functional groups substituted epoxides under identical conditions.
The results are summarized in Table 1.
Table 1 Various carbonates from different epoxides catalyzed by 1a.
From the simulation experiments,[22] it is also evident that 1
takes up comparatively high CO2 than N2 and CH4 (Figure S18,
supporting information), which is in accordance with the
experimental results. Further, the very strong interaction of the
CO2 with the framework was established by evaluating the binding
energies of CO2 (-11.27 kJ/mol), N2 (-4.8 kJ/mol) and CH4 (-
5.7kJ/mol) (Figure S18-S19, supporting information). Moreover,
the GCMC simulation was also accomplished for binary CO2/N2
(1:1) and CO2/CH4 (1:1) mixtures at 298 K and 1 bar pressure. As
shown in Figure S20 (see supporting information), the highly
selective CO2 uptake in the framework over N2 and CH4 in the
mixed gas compositions further corroborates to the IAST
selectivity obtained from the experimental adsorption isotherms.
In addition to the selective CO2 capture, another attractive
means of effective CO2 elimination is the direct chemical
conversion of CO2 into value-added chemicals (e.g. dimethyl
carbonates, cyclic carbonates, N,N’-disubstituted ureas or formic
acid).[23] Therefore, after the establishment of permanent porosity,
excellent stability and highly selective CO2 capture, the existence
of high density of Lewis-acid metal sites were further examined
for the catalytic activity of 1, towards chemical conversion of CO2
to cyclic carbonates. Although several MOFs as heterogeneous
catalysts have been demonstrated for chemical conversion of
CO2 into cyclic carbonates mostly under the conditions of high
temperature and high CO2 pressure.[24] Together with significant
uptake and limited reports for chemical conversion of CO2 into
cyclic carbonates at ambient conditions,[25] the catalytic activity
of1 was explored under milder conditions (30-40 °C and 1 atm.
pressure). Epichlorohydrin was taken as a standard substrate
aReaction conditions: epoxide (5 mmol), catalyst 1 (0.5 mol%), TBAB (1 mol%),
reaction time 24 h and temperature 30-40 oC. bAverage conversion for a set of
triplicate experiments calculated by 1H NMR experiment. cTON is the turnover
number (No. of moles of product per mole of the catalyst).
The high catalytic activity of 1 was also obtained for the larger-
sized 1,2-epoxyhexane substrate with a conversion of 84% (Table
1, entry 6). But for the bigger bulky styrene oxide and phenyl
glycidyl ether, the efficiency drops dramatically (Table 1, entry 9
and 10). This is perhaps due to, on one hand, the limited diffusion
of bulky epoxide substrates into the channels of 1, and on the
other hand, the low reactivity at the -carbon atom of large size
substrates.
The recyclability of 1, was assessed by taking the cycloaddition
of CO2 with epichlorohydrin as an example. After each catalytic
run, the catalyst was separated, washed with DCM, dried under
vacuum and reused for next catalytic experiments. Based on FTIR
spectra and PXRD data of the catalyst recorded before and after
five cycles, no loss of crystallinity or phase purity of the catalyst
was observed even after five cycles of reactions. In order to
further support the retention of crystallinity of 1 the nitrogen
adsorption isotherm of the recovered sample was collected. With
only a little drop in the gas uptake value, its adsorption isotherm
remains the same after use (Figure S21, supporting information).
Also, a product yield of 96% obtained in the fifth cycle indicate
a very little drop in the catalytic activity of 1. (Figure S22,
supporting information). The hot filtration test further reflects the
requisite role of 1 as a heterogeneous catalyst. After a certain time,
the reaction was stopped and the catalyst was separated from the
reaction mixture by centrifugation and the reaction was provided
with
1
as
a
catalyst in conjunction with tetra(n-tert-
butyl)ammonium bromide (TBAB) as a co-catalyst. The progress
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
with identical reaction conditions. Only a very little increase in the
product concentration was observed after 24 h (Figure S21 d,
supporting information).
Based on the studies described above, a possible mechanism
for cycloaddition of CO2 with epoxides is presented in Figure 4,
on the basis of previous reports.[24-25] First, epoxides are activated
by the Lewis-acid metal sites, when O atom of epoxide interacts
with the Lewis-acid metal site. Second, the less-hindered C atoms
of the epoxides are attacked by Br- nucleophiles from TBAB to
open the epoxy ring. Finally, the opened epoxy ring adds up with
CO2 to produce the cycloaddition product. The mechanism can be
further supported by GCMC simulations (Figure S23, supporting
information).
Figure 4. A plausible mechanism for the cycloaddition reactions of CO2 with epoxides catalyzed by 1.
dichlorodimethylsilane (≥ 98%, Sigma-Aldrich), bis(triphenylphosphine)
palladium(II) dichloride (Pd(PPh3)2Cl2, ≥ 98%, Sigma-Aldrich), copper(I)
iodide (CuI, 98%, Sigma-Aldrich), zinc(II) nitrate hexahydrate
Conclusions
≥
In summary, we elaborately designed a triazole functionalized
tetracarboxylate ligand and subsequently utilized for the
construction of a dual functionalized Zn(II) organic framework with
a Zn4(-COO)6 cluster as the SBU. The MOF with exposed Lewis-
acid metal sites and accessible nitrogen-donor Lewis basic sites
presents a highly selective CO2 capture and its chemical
conversion under ambient conditions. The GCMC simulations
further support the contributions of dual active sites for
preferential strong interactions with the CO2 as well as epoxide
molecules. This work presents the versatility of triazole
functionalized organic linkers to fabricate a MOF meeting the dual
goal of the selective capture and chemical conversion of carbon
dioxide under ambient conditions.
(Zn(NO3)2•6H2O, purified, Merck), copper(II) sulphate pentahydrate
(Cu(SO4)2•5H2O, purified, Merck), triethylamine (TEA AR Grade, CDH),
N,N’-diethylacetamide (DEA, 99%, Alfa Aeser), dimethyl
5
aminoisophthalate (98%, Alfa Aeser), hydrochloric acid (HCl, 37 wt%,
Finar), sodium L-ascorbate (≥98%, Sigma-Aldrich), sodium azide (NaN3,
≥99.5%, Sigma-Aldrich), sodium nitrite (NaNO2, ≥97%, Sigma-Aldrich),
triphenylphosphine
(Ph3P,
≥98.5%,
Sigma-Aldrich),
and
(trimethylsilyl)acetylene (TMSA, 98%, Alfa Aesar).
The 1H NMR spectra on a BrukerARX-400 spectrometer at ambient
temperature. All 1H NMR spectra were reported as chemical shift δ in units
of parts per million (ppm) downfield with reference to deuterated solvents.
Multiplicities were presented as: s (singlet); d (doublet); t (triplet); and m
(multiplet). Coupling constants J values were expressed in Hz and the
number of protons was expressed as nH. 13C NMR spectra were obtained
from a BrukerARX-400 spectrometer at ambient temperature. Spectra
were reported as chemical shift δ in units of parts per million (ppm)
downfield with reference to deuterated solvents. High-resolution mass
spectra (HRMS) was carried out on a Waters Q-TOF Premier mass
spectrometry. The elemental analysis (C, H, N) was carried out using Leco
TruSpec Micro CHNS analyzer, thermogravimetric analysis was carried
out from 30 to 500 °C (at a heating rate of 10 °C/min) under dinitrogen
atmosphere on a Shimadzu DTG-60H instrument. IR spectra were
measured in the 4000-400 cm-1 range on a Perkin-Elmer Spectrum I
spectrometer with samples prepared as KBr pellets.
Experimental Section
Materials and methods
All starting materials are commercially available and were used as
received unless specifically mentioned: 1,4-dibromobenzene (98%, Alfa
Aeser), n-butyl lithium (1.6
M solution in hexane, Sigma-Aldrich),
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
Powder X-ray diffraction data were recorded on a Rigaku Ultima IV
diffractometer equipped with a 3 KW sealed tube Cu Kα X-ray radiation
(generator power settings: 40 kV and 40 mA) and a DTex Ultra detector
using parallel beam geometry (2.5° primary and secondary solar slits, 0.5°
divergence slit with 10 mm height limit slit). Each sample grounded into a
fine powder using a mortar and a pestle was placed on a glass sample
holder for room temperature measurement while on a copper sample
holder for variable temperature measurement. The data were collected
over an angle range 5° to 50° with a scanning speed of 2° per minute with
0.02° step. Gas sorption experiments were performed using a BELSORP
MAX (BEL JAPAN) volumetric adsorption analyzer at different
temperatures. Ultrapure (99.995%) N2, He, H2, and CO2 gases were used
for the adsorption measurements. Prior to adsorption measurement, the
sample was grounded to powder and evacuated at 393 K for 24 h and
purged with ultrapure nitrogen gas on cooling. The measurement
temperatures for sorption isotherms at 273 and 298 K were maintained
with a circulating water bath connected to a chiller. Solid-state UV−Vis
reflectance was recorded on a Cary 6000 UV−Vis spectrophotometer from
Agilent Technologies using a solid-state sample holder.
Single crystal X-ray data collection and refinements. A suitable
single crystal of 1 was placed inside a nylon loop on a goniometer head.
Initial crystal evaluation (unit cell determination) and data collection at 100
K (using an Oxford LT device) were performed on a fully automated Kappa
APEX II diffractometer equipped with a CCD detector (with the crystal-to-
detector distance fixed at 60 mm) and sealed-tube monochromated MoKα
radiation through the program APEX2.[26] By using the program SAINT[26]
for the integration of the data, reflection profiles were fitted, and values of
F2 and σ(F2) for each reflection were obtained. Data were also corrected
for Lorentz and polarization effects. The subroutine XPREP was used for
the processing of data that included determination of space group,
application of an absorption correction (SADABS),[26] merging of data, and
generation of files necessary for solution and refinement. The crystal
structure was solved by the direct method using SHELXS program of
SHELXTL package and refined by full-matrix least-square methods with
SHELXL-2014[27] within the OLEX2 crystallographic software suite.[28] In
each case, the space group was chosen based on systematic absences
and confirmed by the successful refinement of the structure. The potential
solvent accessible area or void space was calculated using the PLATON[18]
software. Positions of most of the non-hydrogen atoms were obtained from
a direct methods solution. Several full-matrix least-squares/difference
Fourier cycles were performed, locating the remainder of the non-
hydrogen atoms. In the final difference Fourier map in each case there was
no other significant peaks >1 e/Å3. All non-hydrogen atoms were refined
with anisotropic displacement parameters. Crystallographic parameters
and basic information pertaining to data collection and structure refinement
for all compounds are summarized in Table 3. All figures were drawn using
MERCURY V 3.10[29] and DIAMOND V 3.2.[30] The final positional and
thermal parameters of the non-hydrogen atoms for all structures are listed
in the CIF files. CCDC-1936341 for 1, contains the supplementary
crystallographic data for this paper. These data can be obtained free of
charge from the Cambridge Crystallographic Data Centre.
sulphate and evaporated to get the crude oily solution which after
recrystallization at -20 ºC gave white crystalline product. (4.8 g, yield 68%).
1H NMR (400 MHz, CDCl3): 7.52 (d, J = 8 Hz, 4H), 7.37 (d, J = 8 Hz, 4H),
0.56 (s, 6H) (Figure S24, supporting information). 13C NMR (100 MHz,
CDCl3): 136.45, 135.72, 131.12, 124.27, 2.52 (Figure S25, supporting
information).
dimethylbis(4-((trimethylsilyl)ethynyl)phenyl)silane (II). Compound II
was synthesized according to the literature reported method with slight
modifications.[11b] In an oven-dried 25 mL round bottom flask 3.7 g (10
mmol) of bis(4-bromophenyl)dimethylsilane (I), 280 mg (0.4 mmol) of
[Pd(PPh3)2Cl2], 150 mg (0.8 mmol) of copper(I) iodide and 260 mg (1
mmol) of triphenyphosphine was taken along with 5 mL of dry THF and 20
mL triethylamine. To this solution, 4.2 mL (30 mmol, 2.5 eq.) of TMS-
acetylene was added and the reaction mixture was stirred at room
temperature under N2 environment. The reaction was monitored by TLC.
After 24 hours the spot due to the starting material was completely
disappeared. The insoluble substance was filtered off and washed with
ethyl acetate. The combined filtrate was dried over sodium sulphate and
evaporated to give the crude solid which was purified by column
chromatography over silica gel using ethyl acetate/hexane (0-5 %) as
1
eluent to give compound II as a pale yellow solid (2.8 g, yield: 70%). H
NMR (400 MHz, δ ppm, CDCl3): 7.45 (d, J = 8 Hz, 4H), 7.42 (d, J = 8 Hz,
4H), 0.55 (s, 6H), 0.27 (s, 18 H) (Figure S26, supporting information). 13
C
NMR (100 MHz, δ ppm, CDCl3): 138.57, 133.91, 131.11, 123.85, 105.05,
94.98, -0.02, -2.60(Figure S27, supporting information).
bis(4-ethynylphenyl)dimethylsilane (III). The terminal alkyne was
obtained by the deprotection of the TMS bond using potassium carbonate.
In a 250 mL round bottom flask a solution of 2g (4.95 mmol) of TMS
protected alkyne, dimethylbis(4-((trimethylsilyl)ethynyl)phenyl)silane (II) in
150 mL DCM/Methanol (1:1) mixture was made and 1.5g (10 mmol) of dry
K2CO3 was added to this solution. The reaction mixture was stirred at room
temperature for 5-6 hrs. The reaction was monitored by TLC using hexane
as eluent. The deprotected product was obtained after 5 h. The solvent
was evaporated and 30 mL of water was added to the crude solid. The
product was extracted with DCM (40 + 20 mL). The organic layer was
collected and dried over sodium sulphate and evaporated to give the pure
product as a white solid. (1.2 g, yield: 93%). 1H NMR (400 MHz, δ ppm,
CDCl3): 7.49 (d, J = 8 Hz, 4H), 7.47 (d, J = 8 Hz, 4H), 3.13 (s, 2H), 0.57 (s,
6H) (Figure S28, supporting information). 13C NMR (100 MHz, δ ppm,
CDCl3): 138.90, 134.00, 131.35, 122.90, 83.62, 77.87, 2.64(Figure S29,
supporting information).
dimethyl-5-azidoisophthalate (IV). To a 250 mL round bottom flask 2g
(9.56 mmol) of dimethyl-5-aminoisophthalate was added along with 100
mL of 6N HCl solution. The suspension thus obtained was cooled to 0 ºC.
To this solution, a previously cooled aqueous solution of 700 mg (10 mmol)
of sodium nitrite (NaNO2) was slowly added and stirred at this temperature
for 30 minutes. An aqueous solution of 650 mg (10 mmol) of sodium azide
(NaN3) was then slowly added to the reaction mixture at 0 ºC. After the
complete addition, the temperature was allowed to rise slowly to room
temperature and the reaction mixture was stirred overnight. The white ppt.
thus formed was filtered and washed with copious water and dried in air to
get the pure product as white solid (2.1 g, yield: 93%). 1H NMR (400 MHz,
δ ppm, CDCl3): 8.46 (s, 1H), 7.89 (s, 2H), 3.98 (s, 6H) (Figure S30,
supporting information). 13C NMR (100 MHz, δ ppm, CDCl3): 165.41,
141.26, 132.28, 126.90, 124.04, 52.66(Figure S31, supporting information).
tetramethyl-5,5'-(4,4'-((dimethylsilanediyl)bis(4,1-phenylene))bis(1H-
1,2,3-triazole-4,1-diyl))diisophthalate (Me4L). To a solution containing
350 mg (1.35 mmol) of the terminal alkyne (3) and 820 mg (3.5 mmol) of
the dimethyl-5-azidophthlate (4) in 50 mL THF and 15 mL water in a 100
mL round bottom flask, 125 mg (0.5 mmol) of Copper sulphate
pentahydrate and an excess of sodium ascorbate 500 mg (2.5 mmol) was
added. The reaction mixture was heated to 60 ºC and stirred for 3 days
under a nitrogen atmosphere. Then 50 mL of DCM and 50 mL water was
added to the reaction mixture and the organic layer was separated. The
aqueous layer was again extracted with 20 mL DCM. The combined
Synthesis of H4L: The ligand H4L was synthesized following the scheme
S1 (see supporting information).
bis(4-bromophenyl)dimethylsilane (I). Compound I was synthesized
according to the reported method.[31] A solution of 24mL (1 eq.) of n-BuLi
(1.6M in hexane) in 20 mL of dry diethyl ether was added dropwise to a
solution of 9 g (0.038 mol) of 1,4-dibrolmobenzene in 100 mL of dry diethyl
ether at 0 ºC. The solution was stirred at this temperature for 1-2 hours at
this temperature. Then
a
solution of 2.5 mL (0.02 mol) of
dichlorodimethylsilane in 10 mL of dry diethyl ether was added dropwise
to the reaction mixture at 0 ºC. The reaction mixture was maintained at this
temperature for 1 hour and then the temperature was allowed to rise slowly
to room temperature. After overnight stirring at room temperature, the
reaction was quenched by adding 50 mL of 1N HCl solution. The organic
layer was separated and washed with brine solution, dried over sodium
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
organic layer was collected and dried over sodium sulphate and
concentrated under reduced pressure to get the yellow solid which was
used as obtained for the next step. (0.90 g, yield: 91%). 1H NMR (400 MHz,
δ ppm, CDCl3): 8.77 (s, 2H), 8.70 (s, 4H), 8.38 (s, 2H), 7.96 (d, J = 8 Hz,
4H), 7.69 (d, J = 8 Hz, 4H), 4.04 (s, 12H), 0.66 (s, 6H) (Figure S32,
supporting information). 13C NMR (100 MHz, δ ppm, CDCl3): 165.05,
148.86, 138.81, 137.41, 134.88, 132.50, 130.49, 130.35, 125.30, 125.00,
117.61, 52.92, 2.39(Figure S33, supporting information). ESI-TOF-HRMS:
m/z calcd. for C38H34N6O8Si: 731.2285, found: 731.2316 [M+H]+ (Figure
S36, supporting information).
5,5'-(4,4'-((dimethylsilanediyl)bis(4,1-phenylene))bis(1H-1,2,3-
triazole-4,1-diyl))diisophthalic acid (H4L). The corresponding acid was
obtained by the hydrolysis of the ester group. 1 g (1.36 mmol) of Me4L was
dissolved in 50 mL THF and 100 mL water mixture and 400 mg of sodium
hydroxide were added to the solution. The reaction mixture was stirred at
room temperature overnight. THF was removed under reduced pressure
and the remaining solution was filtered and acidified to pH 1 with dilute HCl.
The yellow ppt. formed was filtered and washed with water and air-dried.
(0.87 g, yield: 94%). 1H NMR (400 MHz, δ ppm, CDCl3): 13.80 (s, 4H), 9.69
(s, 2H), 8.73 (s, 4H), 8.53 (s, 2H), 8.01 (d, J = 8 Hz, 4H), 7.70 (d, J = 8 Hz,
4H), 0.63 (s, 6H) (Figure S34, supporting information). 13C NMR (100 MHz,
δ ppm, CDCl3): 166.17, 147.99, 138.46, 137.55, 135.06, 133.66, 131.25,
129.80, 125.24, 124.88, 120.63, 2.22(Figure S35, supporting information).
ESI-TOF-HRMS: m/z calcd for C34H26N6O8Si: 675.1659, found: 675.1628
[M+H]+ (Figure S37, supporting information). Selected FTIR peaks (KBr,
cm-1): 3382, 1722, 1682, 1603, 1463, 1427, 1247, 1173, 1090, 812, 760,
663, 522.
H. Arakawa, M. Aresta, J. N. Armor, M. A. Barteau, E. J. Beckman, A. T.
Bell, J. E. Bercaw, C. Creutz, E. Dinjus, D. A. Dixon, K. Domen, D. L.
DuBois, J. Eckert, E. Fujita, D. H. Gibson, W. A. Goddard, D. W.
Goodman, J. Keller, G. J. Kubas, H. H. Kung, J. E. Lyons, L. E. Manzer,
T. J. Marks, K. Morokuma, K. M. Nicholas, R. Periana, L. Que, J.
Rostrup-Nielson, W. M. H. Sachtler, L. D. Schmidt, A. Sen, G. A.
Somorjai, P. C. Stair, B. R. Stults, W. Tumas, Chem. Rev. 2001, 101,
953–996; c) R. S. Lindzen, Proc. Natl. Acad. Sci. 1997, 94, 8335–8342.
WMO, Greenhouse Gas Bulletin, 2018, no. 14.
[2]
[3]
M. Bui, C. S. Adjiman, A. Bardow, E. J. Anthony, A. Boston, S. Brown, P.
S. Fennell, S. Fuss, A. Galindo, L. A. Hackett, J. P. Hallett, H. J. Herzog,
G. Jackson, J. Kemper, S. Krevor, G. C. Maitland, M. Matuszewski, I. S.
Metcalfe, C. Petit, G. Puxty, J. Reimer, D. M. Reiner, E. S. Rubin, S. A.
Scott, N. Shah, B. Smit, J. P. M. Trusler, P. Webley, J. Wilcox, N. Mac
Dowell, Energy Environ. Sci. 2018, 11, 1062–1176.
[4]
a) J. Liu, P. K. Thallapally, B. P. McGrail, D. R. Brown, J. Liu, Chem. Soc.
Rev. 2012, 41, 2308–2322; b) A. Schoedel, Z. Ji, O. M. Yaghi, Nat.
Energy 2016, 1, 16034; c) Z. Zhang, Z.-Z. Yao, S. Xiang, B. Chen,
Energy Environ. Sci. 2014, 7, 2868.
[5]
[6]
Q. Wang, J. Bai, Z. Lu, Y. Pan, X. You, Chem. Commun. 2016, 52, 443–
452.
a) Z. Zhang, Y. Zhao, Q. Gong, Z. Li, J. Li, Chem. Commun. 2013, 49,
653–661; b) H. Furukawa, U. Müller, O. M. Yaghi, Angew. Chem. Int. Ed.
2015, 54, 3417–3430; c) Y. Liu, Z. U. Wang, H.-C. Zhou, Greenhouse
Gas Sci Technol. 2012, 2, 239-259.
[7]
a) A. Das, D. M. D’Alessandro, CrystEngComm 2015, 17, 706–718; b) Z.
Lu, J. Bai, C. Hang, F. Meng, W. Liu, Y. Pan, X. You, Chem. Eur. J. 2016,
22, 6277–6285.
Synthesis of {[Zn2(L)(H2O)].4(H2O)}n (1). 102 mg (0.15 mmol) of the
tetracarboxylic acid, H4L was taken in a Teflon vessel and dissolved in 5
mL diethylacetamide (DEA). To this solution 90 mg (0.3 mmol) of zinc
[8]
[9]
A. Phan, C. J. Doonan, F. J. Uribe-Romo, C. B. Knobler, M. O’Keeffe, O.
M. Yaghi, Acc. Chem. Res. 2010, 43, 58–67.
.
nitrate hexahydrate (Zn(NO3)2 6H2O) was added along with 5 mL water.
a) H.-P. Li, S.-N. Li, H.-M. Sun, M.-C. Hu, Y.-C. Jiang, Q.-G. Zhai, Cryst.
Growth Des. 2018, 18, 3229–3235; b) T. Panda, P. Pachfule, Y. Chen,
J. Jiang R. Banerjee, Chem. Commun. 2011, 47, 2011–2013; c) J.-P.
Zhang, A.-X. Zhu, R.-B. Lin, X.-L. Qi, X.-M. Chen, Adv. Mater. 2011, 23,
1268–1271; d) J. Lin, J. Zhang, X. Chen, J. Am. Chem. Soc. 2010, 132,
6654–6656.
The Teflon vessel was sealed in a stainless-steel reactor and heated to
120 °C for 3 days followed by slow cooling to room temperature at a rate
of 1.5 °C/h. A colorless plate-like crystal of 1 thus obtained was filtered and
washed with fresh DMA for three times and then with ethanol and air-dried
at room temperature to get the as-synthesized compound. (105 mg, 78 %).
Analysis Calculated for C34H32N6O13SiZn2 (MW 891.50): % C, 45.81; % H,
3.62; % N, 9.43. Found: % C, 45.23; % H, 4.46; % N, 10.23. Selected FTIR
peaks (KBr, cm-1): 3413(br), 1624(s), 1583(s), 1566(s), 1452(m), 1415(s),
1386(m), 1246(m), 1121(m), 1093(m), 1059(m), 1033(m), 814(s), 776(s),
757(m), 728(w), 511(w) (Figure S2, supporting information).
[10] a) R.-B. Lin, D. Chen, Y.-Y. Lin, J.-P. Zhang, X.-M. Chen, Inorg. Chem.
2012, 51, 9950–9955; b) S. Jeong, X. Song, S. Jeong, M. Oh, X. Liu, D.
Kim, D. Moon, M. S. Lah, Inorg. Chem. 2011, 50, 12133–12140; c) S.-M.
Zhang, Z. Chang, T.-L. Hu, X.-H. Bu, Inorg. Chem. 2010, 49, 11581–
11586.
[11] a) P.-Z. Li, X.-J. Wang, Y. Zhao, Coord. Chem. Rev., 2019, 380, 484–
518; b) P.-Z. Li, X.-J. Wang, J. Liu, J. S. Lim, R. Zou, Y. Zhao, J. Am.
Chem. Soc. 2016, 138, 2142–2145; c) B. Liu, S. Yao, C. Shi, G. Li, Q.
Huo, Y. Liu, Chem. Commun. 2016, 52, 3223–3226; d) S. Seth, G.
Savitha, J. N. Moorthy, Inorg. Chem. 2015, 54, 6829–6835; e) X.-J.
Wang, P.-Z. Li, Y. Chen, Q. Zhang, H. Zhang, X. X. Chan, R. Ganguly,
Y. Li, J. Jiang, Y. Zhao, Sci. Rep. 2013, 3, 1149.
Acknowledgments
We gratefully acknowledge IISER Mohali, India for financial
support (to S.K.M.) and SRF from UGC New Delhi, India (to V.G.).
The use of the X-ray facility at IISER Mohali is gratefully
acknowledged.
[12] a) M. J. Kalmutzki, N. Hanikel, N, O. M. Yaghi, Sci. Adv. 2018, 4, 1-16;
b) M. Eddaoudi, D. B. Moler, H. Li, B. Chen, T. M. Reineke, M. O’Keeffe,
O. M. Yaghi, Acc. Chem. Res. 2001, 34, 319-330.
[13] H. Li, M. Eddaoudi, T. L. Groy, O. M. Yaghi, J. Am. Chem. Soc. 1998,
120, 8571-8572.
[14] a) H. Li, M. Eddaoudi, M. O’Keeffe, O. M. Yaghi, Nature, 1999, 408, 276-
279; b) M. Eddaoudi, J. Kim, N. Rosi, D. Vodak, J. Wachter, M. O’Keeffe,
O. M. Yaghi, Science, 2002, 295, 469-472; c) H. Furukawa, K. E.
Cordova, M. O’Keeffe, O. M. Yaghi, Science, 2013, 1230444.
[15] (a) J. Kim, B. Chen, T. M. Reineke, H. Li, M. Eddaoudi, D. B. Moler, M.
O’Keeffe, O. M. Yaghi, J. Am. Chem. Soc. 2001, 123, 8239-8247.
[16] a) M. O’Keeffe, O. M. Yaghi, Chem. Rev. 2012, 112, 675–702; b) M. Li,
D. Li, M. O’Keeffe, O. M. Yaghi, Chem. Rev. 2014, 114, 1343-1370.
[17] A. W. Addison, T. N. Rao, J. Reedijk, J. van Rijn, G. C. Verschoor, Dalton
Trans. 1984, 1349–1356.
Conflict of interest
The authors declare no conflict of interest.
Keywords: metal organic framework • highly stable • dual
functionalized • selective CO2 capture • heterogeneous catalyst
[1]
a) K. Sumida, D. L. Rogow, J. A. Mason, T. M. McDonald, E. D. Bloch,
[18] A. L. Spek, Acta Crystallogr. Sect. C Struct. Chem. 2015, 71, 9-18.
Z. R. Herm, T.-H. Bae, J. R. Long, Chem. Rev. 2012, 112, 724–781; b)
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
[19] V. A. Blatov, A. P. Shevchenko, D. M. Proserpio, Cryst. Growth Des.
2014, 14, 3576-3586.
Huang, R. Cao, Chem. Sci., 2017, 8, 1570–1575; n) Wei Jiang, J. Yang,
Y. Y. Liu, Shu-Yan Song, J. F. Ma, Chem. Eur. J. 2016, 22, 16991 –
16997.
[20] a) H. Alawisi, B. Li, Y. He, H. D. Arman, A. M. Asiri, H. Wang, B. Chen,
Crys. Growth Des. 2014, 14, 2522-2526; b) S. Xiang, Z. Zhang, C. G.
Zhao, K. Hong, X. Zhao, D. R. Ding, M. H. Xie, C. D. Wu, M. C. Das, R.
Gill, K. M. Thomas, B. Chen, Nat. Commun. 2011, 2, 204.
[25] a) N. Sharma, S. S. Dhankhar, C. M. Nagaraja, Sustainable Energy Fuels,
2019, 3, 2977-2982; b) B. Ugale, S. Kumar, T. J. Dhilip Kumar, C. M.
Nagaraja, Inorg. Chem., 2019, 58, 3925-3936; c) L. Liang, C. Liu, F.
Jiang, Q. Chen, L. Zhang, H. Xue, H.-L. Jiang, J. Qian, D. Yuan M. Hong,
Nat. Commun. 2017, 8, 1233; d) X.-Y. Li, Y. Li, Y. Yang, L. Hou, Y. Wang,
Z. Zhu, Chem. Commun. 2017, 53, 12970–12973; e) P.-Z. Li, X.-J. Wang,
J. Liu, J. S. Lim, R. Zou, Y. Zhao, J. Am. Chem. Soc. 2016, 138, 2142–
2145; f) R. Babu, A. C. Kathalikkattil, R. Roshan, J. Tharun, D.W. Kim,
D. W. Park, Green Chem., 2016, 18, 232–242; g) W.-Y. Gao, L. Wojtas,
S. Ma, Chem. Commun. 2014, 50, 5316–5318; h) W. Y. Gao, Y. Chen,
Y. Niu, K. Williams, L. Cash, P. J. Perez, L. Wojtas, J. Cai, Y. S. Chen,
S. Ma, Angew. Chem. Int. Ed. 2014, 53, 2615 –2619.
[21] A. L. Myers, J. M. Prausnitz, AIChE J. 1965, 11, 121-127.
[22] Accelrys Software Inc., Materials Studio 2018 R2, San Diego: Accelrys
Software Inc., 2018.
[23] P. Bhanja, A. Modak, A. Bhaumik, Chem. Eur. J. 2018, 24, 7278 – 7297.
[24] a) M. Ding, R. W. Flaig, H. L. Jiang, O. M. Yaghi, Chem. Soc. Rev.,
2019,48, 2783-2828; b) M. Ding, H. L. Jiang, ACS Catal., 2018, 8,
3194−3201; c) L. L. Zhang, S. Yuan, L. Feng, B. Guo, J. S. Qin, B. Xu,
C. Lollar, D. Sun, H. C. Zhou, Angew. Chem. Int. Ed. 2018, 57, 5095-
5099; d) P. T. K. Nguyen, H. T. D. Nguyen, H. N. Nguyen, C. A. Trickett,
Q. T. Ton, E. Gutiꢀrrez-Puebla, M. A. Monge, K. E. Cordova, F. Gꢁndara,
ACS Appl. Mater. Interfaces, 2018, 10, 733−744; e) N. Sharma, S. S.
Dhankhar, S. Kumar; T. J. Dhilip Kumar, C. M. Nagaraja, Chem. Eur. J.,
2018, 24, 16662-1669; f) H. F. Zhou, B. Liu, L. Hou, W. Y. Zhang, Y. Y.
Wang, Chem. Commun. 2018, 54, 456–459; g) J. Liang, Y.-Q. Xie, X. S.
Wang, Q. Wang, T.-T. Liu, Y.-B. Huang, R. Cao, Chem. Commun. 2018,
54, 342–345; h) Q. Wu, L. Tang, H. Wu, Z. Jiang, X. Wang, S. Zhang, J.
Mater. Chem. A 2017, 6, 2964–2973; i) B. B. Lu, W. Jiang, J. Yang, Y. Y.
Liu, J. F. Ma, ACS Appl. Mater. Interfaces 2017, 9, 39441–39449; j) P. Z.
Li, X. J. Wang, J. Liu, H. S. Phang, Y. Li, Y. Zhao, Chem. Mater. 2017,
29, 9256–9261; k) J. W. Maina, C. Pozo-Gonzalo, L. Kong, J. Schütz, M.
Hill, L. F. Dumée, Mater. Horizons 2017, 4, 345–361; l) X. Y. Li, Y. Z. Li,
Y. Yang, L. Hou, Y. Y. Wang, Z. Zhu, Chem. Commun., 2017,53, 12970-
12973; m) J. Liang, R. P. Chen, X. Y. Wang, T. T. Liu, X. S. Wang, Y. B.
[26] APEX2, SADABS, and SAINT, Bruker AXS Inc., Madison, WI, USA, 2008.
[27] G. M. Sheldrick, SHELXTL Version 2014/7. https://shelx.uni-
ac.gwdg.de/SHELX/index.php.
[28] O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard, H. J.
Puschmann, J. Appl. Crystallogr. 2009, 42, 339-341.
[29] C. F. Macrae, I. J. Bruno, J. A. Chisholm, P. R. Edington, P. McCabe, E.
Pidcock, L. Rodriguez-Monge, R. Taylor, J. van de Streek, P. A. Wood,
J. Appl. Crystallogr. 2008, 41, 466-470.
[30] H. Putz, K. Brandenburg, Diamond - Crystal and Molecular Structure
Visualization. http://www.crystalimpact.com/diamond
[31] R. P. Davies, R. J. Less, P. D. Lickiss, K. Robertson, A. J. P. White, Inorg.
Chem. 2008, 47, 9958–9964.
This article is protected by copyright. All rights reserved.

10.1002/chem.201903912
Chemistry - A European Journal
FULL PAPER
A dual functionalized robust
and highly stable metal-
organic framework containing
Vijay Gupta and Sanjay K.
Mandal*
Page No. – Page No.
triazole
functionalized
tetracarboxylate and Lewis-
acidic open metal sites
exhibiting highly selective
CO2 capture and its chemical
fixation at ambient conditions
is reported.
A highly stable triazole
functionalized metal
organic framework
integrated with exposed
metal sites for selective
CO2 capture and
conversion.
This article is protected by copyright. All rights reserved.