Three Cationic, Nonporous CuI-Coordination Polymers: Structural Investigation and Vapor Iodine Capture

Article abstract of DOI:10.1021/acs.cgd.8b01446

Three cationic nonporous copper(I) coordination polymers containing bis-pyrazolyl flexible ligands have been prepared and characterized, namely, {[Cu(μ-bdb)_1.5](PF₆)}_n (1), {[Cu(μ-bpb)₂](PF₆)}_n

Full text of DOI:10.1021/acs.cgd.8b01446

Subscriber access provided by University of Sunderland
Article
I
Three Cationic Non-Porous Cu-Coordination Polymers:
Structural Investigation and Vapor Iodine Capture
Elham Baladi, Valiollah Nobakht, Abbas Tarassoli, Davide M. Proserpio, and Lucia Carlucci
Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.8b01446 • Publication Date (Web): 09 Oct 2018
Downloaded from http://pubs.acs.org on October 11, 2018
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 30
Crystal Growth & Design
1
2
3
4
5
6
Three Cationic Non-Porous CuI-Coordination Polymers: Structural
Investigation and Vapor Iodine Capture
7
8
Elham Baladi, [a] Valiollah Nobakht,*[a] Abbas Tarassoli,*[a] Davide M. Proserpio,[b],[c] Lucia Carlucci [b]
9
[a] Department of Chemistry, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Fax: +98 613
3331042 E-mail: v.nobakht@scu.ac.ir (V. Nobakht) and tarassoli@scu.ac.ir (A. Tarassoli)
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
[b] Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133, Milano, Italy.
[c] Samara Center for Theoretical Materials Science (SCTMS), Samara State Technical University, Samara 443100,
Russia.
ABSTRACT
Three cationic non-porous copper(I) coordination polymers containing bis-pyrazolyl flexible
ligands have been prepared and characterized, namely {[Cu(μ-bdb)1.5](PF6)}n (1), {[Cu(μ-
bpb)2](PF6)}n (2) and {[Cu(μ-bpmb)2](PF6)}n (3) (bdb = 1,4-bis(3,5-dimethylpyrazolyl)
methyl)benzene; bpb = 1,4-bis(pyrazolyl)butane; bpmb = 1,4-bis(pyrazolyl) methyl)benzene).
All compounds were characterized by IR, PXRD, elemental and thermal analyses, and single-
crystal X-ray diffraction. Compound 1, with methyl-substituted pyrazolyl ligand, forms a chain
of alternating rings and ribbons in which the copper(I) centers are three coordinated in distorted
trigonal planar geometry. In compounds 2 and 3 copper(I) atoms adopt distorted tetrahedral
geometries giving two dimensional sheet structures with 44-sql topology. Interestingly, iodine
sorption experiments show that colorless crystals of 2 and 3 remain unchanged in the presence of
iodine vapors, while the three coordinated compound 1 immediately absorb iodine and turn dark.
Anion exchange behavior of compounds 1 and 2 was also investigated both in solution and in
solid state.
Keywords: Copper(I), coordination polymer, non-porous, gaseous iodine capture, non-
coordinating anion.
INTRODUCTION
1
ACS Paragon Plus Environment

Crystal Growth & Design
Page 2 of 30
1
2
3
4
5
6
7
8
9
Coordination polymers (CPs) and their unique subclass of metal organic frameworks (MOFs),
belong to an interesting category of crystalline materials that is growning exponentially during
the past three decades.1-3 Their structures are composed of organic linkers and metal ions or
clusters nodes. Remarkable variety of structures and properties, ease of tailorability and wide
range of applications, ranging from gas storage and separation to catalytic processes, electronic
devices and biomedicine, made this category of materials one of the most exciting area of
research and attracted many scientists.4-6
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
Considering coordination ability of copper atoms, it can be observed that copper(II) ions often
form multinuclear Cu-carboxylate clusters trough coordination to oxygen atoms of carboxylic
ligands.7-9 On the other hand copper(I) ions often form copper halides aggregates and, among
them, especially CunIn clusters. A variety of copper(I) iodide-based structures with fascinating
building blocks have been reported so far.10-14 The intense investigation in this research field is
not only due to this structural variety, but also to the unique properties of copper(I) iodide
aggregates, such as luminescence,14-17 catalytic activity,18,19 iodine sorption12,20,21 and others.
Despite polymeric structures for copper(I) halides or pseudohalides are well known and
investigated, CPs or MOFs made of copper(I) in the presence of non-coordinating anions, such
-
-
-
-
as PF6 , BF4 , ClO4 , and SbF6 , are still rare and need to be explored more.22-26 Highly
coordinating halides often act as the structure directing factor in the assembly of polymeric
copper(I) halide compounds, thus preventing Cu(I) to fully exploit its coordination ability.
Hence, the use of non-coordinating anions, allow copper(I) to exhibit variable coordination
number and geometry.
Alongside the role of metal ions and coordinating ability of counterions, the structure of
coordination polymers are influenced also by other factors, such as the geometry of polydentate
linker ligands, crystallization solvent, metal to ligand ratio and synthetic procedure.27-29
Moreover, factors such as flexibility, steric hindrance, position of donor atoms, spacer group of
the linkers and participation of ligands in non-covalent ∙∙∙ stacking interactions and hydrogen
bonds also play important roles in the generation of novel structures and properties.30-32
Among possible applications for CPs and MOFs attractive is the adsorption of environmentally
harmful pollutants.33-35 In particular capture and isolation of radioactive iodine isotopes from the
waste of nuclear power plants is an important subject.36-38 Because the high fission yield of
2
ACS Paragon Plus Environment

Page 3 of 30
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
iodine, it can spread as volatile species in environment and readily accumulates in the thyroid.
The result is the major changes in human metabolic processes and may causes thyroid cancer.
Recently, adsorption of iodine into the pores of various MOFs have been reported by many
researchers, however, most of such investigations are conducted in solution only.39-43 Iodine
sorption studies in the vapor phase by non-porous coordination polymers are still rare and need
to be explored well.44 Our recent research results show that even non-porous CuI-based
coordination polymers can rapidly capture volatile iodine in the gas phase.45 On the basis of our
experience on the design and synthesis of copper(I) coordination polymers,23,27,46-49 here we
investigated the effect of different bispyrazolyl ligands (Scheme 1) on the assembly of non-
porous coordination polymers of copper(I) hexafluorophosphate, and characterized three novel
compounds. In addition, vapor iodine absorption ability by the synthetized compounds was
checked and related to their structure features.
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 1. Structure of the bispyrazolyl linker ligands.
EXPERIMENTAL SECTION
Materials and Instrumentation
All experiments were carried out in air. The starting materials were purchased from commercial
sources and used without further purification; [Cu(CH3CN)4]PF6 was prepared by published
method.50 The infrared spectra (4000-400 cm1) were recorded as KBr discs with BOMEN
MB102 FT-IR or Perkin Elmer Spectrum two spectrometers. The elemental analyses for C, H
3
ACS Paragon Plus Environment

Crystal Growth & Design
Page 4 of 30
1
2
3
4
5
6
7
8
9
and N were performed on a Costech-ECS 4010 CHNSO analyzer. X-ray powder diffraction
patterns were recorded on a Philips X’Pert Pro diffractometer (Cu Kα radiation, λ = 1.54184 Å)
in the 2θ range 5−35(50)°. Simulated XRD powder patterns, based on single crystal X-ray
diffraction data, were prepared using Mercury software.51 Energy dispersive X-ray (EDX)
spectroscopy was carried out using an EDX-coupled electron microscope (VEGA 3-TESCAN).
Thermogravimetric analyses (TGA) were carried out on a STA PT1600 (Linseis) thermal
analyzer between 50 and 600 °C under N2 atmosphere. UV-Vis spectra were recorded on a
Jenway 6715 spectrophotometer in EtOH solution in the range of 300–700 nm.
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
Synthetic Procedures
Preparation of bpmb, bdb, and bpb Ligands: The ligands were prepared according to
published methods.52-55 Typically, a mixture of pyrazole (1.36 g, 20 mmol) or 3,5-dimethyl-
pyrazole (1.92 g, 20 mmol) and finely powdered potassium hydroxide (2.24 g, 40 mmol) in
DMSO (12 mL) were vigorously stirred at 80 ºC for 2 h. Then, corresponding dihalides 1,4-
bis(chloromethyl)benzene (1.64 g, 10 mmol) or 1,4-dichlorobutane (1.11 mL, 10 mmol) in
DMSO (5 mL) was added dropwise to the slurry mixture. The mixture was stirred at 80 ºC until
completion of the reaction (checked by TLC), cooled to room temperature and then to 0°C in an
ice bath. 250 mL of cooled water was poured into the reaction mixture and a precipitate formed
immediately, which was collected by filtration, washed with water and dried under vacuum. In
the case of bpb, as the product is a liquid, the reaction mixture was poured into water (250 mL)
and extracted with chloroform (3×20 mL). The extract was washed with water (2×20 mL) and
dried over calcium chloride. After evaporation of chloroform under vacuum, the product was
isolated as a yellow oil.
Preparation of {[Cu(μ-bdb)1.5](PF6)}n (1)
A solution of bdb (0.02 g, 0.08 mmol) in CH3OH (5 mL) was gently layered on the top of a
solution of [Cu(CH3CN)4][PF6] (0.015 g, 0.04 mmol) in CH3CN (5 mL) in a test tube. Fern leaf-
shaped crystals of 1, suitable for X-ray crystallography, were obtained after a week. They were
collected and washed with small amounts of EtOH and Et2O and dried in air. (0.021g, 80.7%
yield based on Cu). Anal. Calcd for C27H33CuF6N6P: C 49.88, H 5.12, N 12.93; Found: C 50.74,
H 5.58, N 13.19%.
4
ACS Paragon Plus Environment

Page 5 of 30
Crystal Growth & Design
1
2
3
4
Preparation of {[Cu(μ-bpb)2](PF6)}n (2)
5
6
7
8
A solution of [Cu(CH3CN)4]PF6 (0.2 g, 0.54 mmol) in CH3CN (25 mL) was added to a solution
of bpb (0.2 g, 1.0 mmol) in CH3CN (25 mL). The reaction mixture was stirred at room
temperature for 6 h and the resulting mixture was filtered. Pale blue cubic single crystals of 2
suitable for X-ray crystallography were obtained at room temperature by slow evaporation of the
solvent after a week. The crystals were collected and dried in air. (0.17g, 53% yield based on
Cu). Anal. Calcd for C20H28CuN8F6P: C 40.78, H 4.79, N 19.03; Found: C 40.60, H 4.67, N
19.37%.
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
Preparation of {[Cu(μ-bpmb)2](PF6)}n (3)
A solution of [Cu(CH3CN)4]PF6 (0.2 g, 0.54 mmol) in CH3CN (20 mL) was added to a solution
of bpmb (0.254 g, 1.06 mmol) in CH3CN (20 mL). The reaction mixture was stirred at room
temperature for 6 h and then it was filtered. Colorless cubic single crystals of 3 suitable for X-ray
crystallography were obtained at room temperature by slow evaporation of the solvent after two
weeks. The crystals were collected and washed with small amounts of EtOH and Et2O and dried
in air. (0.31g, 85.0% yield based on Cu). Anal. Calcd for C28H28CuF6N8P: C 49.09, H 4.12, N
16.36; Found: C 49.43, H 4.18, N 16.52%.
Iodine Sorption Study
Crystals of coordination polymers 1-3 and {[Cu(µ-bbd)1.5](PF6)}n (refcode KEZXEU) and solid
iodine were added separately into small vials. The vials were placed into a large vessel, sealed,
and heated at 55°C for three different exposure times, 30 min, 50 min and 2 h. Color of the
crystals 1 and KEZXEU changed immediately to brown, while the color of samples 2 and 3
remained unchanged. The iodine adsorbed samples were collected, washed with cyclohexane,
dried in air, and weighed.
Iodine Release Study
Certain amounts of iodine-adsorbed samples 1-I2 and KEZXEU-I2 were suspended in 2 ml of
EtOH. The color of the solvent change gradually from light yellow to dark orange. To ensure the
completion of the release process, the samples were left in EtOH for 1 day. Solid materials of
compounds 1 and KEZXEU were recovered by filtration, washed with pure ethanol, Et2O, dried
5
ACS Paragon Plus Environment

Crystal Growth & Design
Page 6 of 30
1
2
3
4
5
6
in air and identified by FT-IR and PXRD analyses. To determine the iodine content of the
samples, released iodine solutions were diluted in 10 ml volumetric flasks and used for UV-Vis
spectroscopic measurements at 358 nm.
7
8
9
Anion Exchange in Solution
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
Finely powdered samples of 1 and 2 (0.1 mmol) were suspended in 30 mL of aqueous solutions
containing, respectively, KSCN (0.005 M), KI (1.0 M), NaClO4 (1.0 M) and NaBF4 (1.0 M) and
the mixtures were stirred at room temperature for 1 day. The resulting anion-exchanged solids
were separated by centrifugation and washed several times with water, EtOH and Et2O. After
drying in air the exchanged solids were identified by FT-IR and PXRD analysis.
Anion Exchange in the Solid State
Mixtures of colorless powder of compounds 1 or 2 (0.1 mmol) with, respectively, KSCN, KI,
NaClO4 or NaBF4 (0.1 mmol) were finely grinded in an agate mortar at room temperature for 30
min. The resulting products were washed several times with water, EtOH and Et2O, dried in air
and then identified by FT-IR and PXRD analysis.
X-ray Crystallographic Study
X-ray data were collected on a Bruker Apex II diffractometer using MoKα radiation. The
structures were solved using direct methods and refined using a full-matrix least squares
procedure based on F2 using all data.56 Hydrogen atoms were placed at geometrically estimated
positions. Details relating to the crystals and the structural refinements are presented in Table 1.
Full details of crystal data and structure refinements, in CIF format, are available as
Supplementary Information. CCDC reference numbers 1824721-1824723 for 1, 2, and 3,
respectively.
6
ACS Paragon Plus Environment

Page 7 of 30
Crystal Growth & Design
1
2
3
4
Table 1. Crystallographic data and structure refinement details for 1-3.
5
6
7
8
Compound
1
2
3
Formula
C27H33CuN6,F6P
650.10
C20H28CuN8,F6P
589.02
293
C28H28CuN8,F6P
685.09
293
Formula mass
9
293
T(K)
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
triclinic
P-1
tetragonal
P4/n
tetragonal
P4/n
Cryst syst
space group
10.3544(8)
11.5905(9))
13.8724(11)
70.766(1)
79.152(1)
89.788(1)
1540.8(2)
2
12.5954(7)
12.5954(7)
7.9766(9)
90.
13.616(3)
13.616(3)
7.984(3)
90.
a(Å)
b(Å)
c(Å)
α(°)
90.
90.
(°)
90.
90.
(°)
V(Å3)
1265.4(2)
2
1480.2(9)
2
Z
Dcalcd (g cm-3)
no. of reflns collected
no. of independentreflns
Rint
1.401
1.546
1.537
30990
19496
2079
18442
1685
7366
0.033
0.018
0.045
0.0509
0.0378
0.1115
0.0435
0.1246
R1[I> 2σ(I)]
wR2(all data)
0.1523
RESULTS AND DISCUSSION
Synthesis of Complexes 1-3. We set out to investigate the structural influence of the ligand
geometry on the topology of the resultant copper(I) coordination polymers. For this purpose, we
have prepared three bidentate pyrazolyl-based ligands and tuned their structures by varying the
spacer group and pyrazolyl ring substituents (Scheme 1). In addition, we also used our related
reported structure, {[Cu(μ-bbd)1.5](PF6)}n (refcode KEZXEU), for comparison.23 To accurately
evaluate the effect of the geometry of the linkers on the structure of the assembled products, and
to avoid side effects of the counter anion, we have used Cu(I) salt of the non-coordinating
-
hexafluorophosphate (PF6 ) anion. The reactions of [Cu(CH3CN)4][PF6] with bpb, bdb and bpmb
ligands in the 1:2 molar ratio produced three novel compounds which are almost stable in air and
moisture. Characterization by elemental analyses, FT-IR spectroscopy, PXRD and single-crystal
X-ray diffraction show one and two-dimensional polymeric structures for the three compounds.
7
ACS Paragon Plus Environment

Crystal Growth & Design
Page 8 of 30
1
2
3
4
5
6
Description of the Crystal Structures
7
8
{[Cu(μ-bdb)1.5](PF6)}n (1)
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
Compound 1 crystallizes in the triclinic P-1 space group with Z=2 (Table 1). Among all the
ligands considered in this work (Scheme 1) the bdb present in compound 1 results less flexible
and more sterically hindered being the two pyrazolyl groups spaced by the –CH2–Ph–CH2–
linker and decorated by methyl groups. As a result, the structure of 1 is a 1D coordination
polymer consisting of a sequence of metallocyclic rings and ribbons. The asymmetric unit of 1
-
contains one Cu(I) ion, one and a half µ-bdb ligand and a PF6 counter ion (Figure 1a). Each
copper atom is coordinated by three pyrazolyl nitrogen atoms from three µ-bdb ligands to form a
slightly distorted trigonal planar CuN3 environment with N–Cu–N angles and Cu–N bond
distances in the ranges 117.17(9)-124.20(9)° and 1.978(2)-1.998(2) Å, respectively (Table S1).
Although the ligands in the structure of 1 and {[Cu(μ-bbd)1.5](PF6)}n (KEZXEU) are different,
the overall structures are similar. Both are 1D, containing three coordinated copper centers and
alternating rings and ribbons along the chains. Two crystallographically different types of μ-bdb
ligands have been observed in the structure of 1. The ones that form the ribbons of the chains
(blue color in Figure 1b) are centrosymmetric with (Cu)N–to–N(Cu) distance of 9.22 Å, and
consequently the dihedral angle between the mean planes of two pyrazolyl rings is 0°. The other
ligand form the [Cu2(µ-bdb)2]+ metallocycles and is shown in red color in Figure 1b. In this case,
the dihedral angle between two pyrazolyl rings is 66.01° and the (Cu)N–to-N(Cu) distance is
8.38 Å. Due to the different linker lengths, two types of Cu···Cu distances have been observed in
the 1D structure of 1. The Cu···Cu separation in the ring motifs is shorter (8.26 Å) than the one
between the rings (10.19 Å) as also observed in the structure of KEZXEU, where, however,
such Cu···Cu distances are shorter of about 2 Å.23 The chains run along the [1 0 0] direction and
-
pack with an AAA sequence. Disordered PF6 counter-anions remain uncoordinated and are
located in the space between the chains.
8
ACS Paragon Plus Environment

Page 9 of 30
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
(a)
(b)
(c)
Figure 1. Crystal structure of 1: a) Asymmetric unit with a labeling scheme for non-C, H atoms.
b) 1D chain containing a sequence of metallocyclic rings (red) and ribbons (blue). c) Packing of
-
the chains with PF6 anions (left) and a closer view of the non-classic C–H···F interactions
(right).
9
ACS Paragon Plus Environment

Crystal Growth & Design
Page 10 of 30
1
2
3
4
5
6
7
8
{[Cu(µ-bpb)2]PF6}n (2)
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
Compound 2 crystallizes in the tetragonal P4/n space group with Z=2 (Table 1). Single-crystal
X-ray diffraction analysis reveals that 2 contain cationic two dimensional [Cu(µ-bpb)2]+ motifs
-
and PF6 counter anions (Figure 2). The Cu atom is coordinated by four nitrogen atoms from bpb
ligands, giving a CuN4 moiety with the N–Cu–N bond angles ranging from 96.74(8) to 116.19(4)
Å (Table S1). Deviations from ideal tetrahedral geometry can be specified by τ4 parameter57
which has values of 1.00 and zero for perfect tetrahedral and square planar geometries,
respectively. Calculated τ4 value of 0.905 for copper ions in 2 represents a deviation from ideal
tetrahedral towards square planar geometry, suggesting a distorted tetrahedral geometry for the
copper centers. The Cu–N distance is 2.0765(14) Å, comparable to those found in the
literature58,59 and longer than those found in the structure of 1 (1.978(2)-1.998(2) Å). Each
copper atom is connected to four adjacent Cu(I) atoms by µ-bpb ligands to form an infinite
cationic 2D sheet with 44-sql topology. The 2D sheets contain centrosymmetric 36-membered
[Cu4(bpb)4] metallocyclic units (Figure 2b) and extend in the crystallographic ab plane. The
-
layers are perfectly superimposed along [0 0 1] direction and disordered PF6 counter-anions
found place at the center of metallocycles and between adjacent layers. There are no significant
-
interactions between PF6 anions and copper(I) centers. However, closer inspection shows that
-
there are weak C-H∙∙∙F contacts between not disordered axial fluorine atoms of PF6 anions and
CH atoms of pyrazolyl rings (Figure 2c). Details of the hydrogen bonding geometry are given in
Table S2. No remarkable short contacts or π···π interactions were found between adjacent sheets.
10
ACS Paragon Plus Environment

Page 11 of 30
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
(a)
(b)
(c)
11
ACS Paragon Plus Environment

Crystal Growth & Design
Page 12 of 30
1
2
3
4
5
6
7
8
Figure 2. Crystal structure of 2: a) Coordination environment around copper(I) atom with
labeling scheme for the asymmetric unit part. b) View down c of a single layer with 44-sql net
-
-
and space-filling representation of the PF6 anions. c) View down a of a single layer and PF6
anions evidencing the weak C-H···F hydrogen bonds.
9
All the µ-bpb ligands are centrosymmetric and crystallographically equivalent exhibiting an anti-
anti-anti conformation for the C–C bonds of the –(CH2)4– spacer. The torsion angles NNCC,
NCCC, and CCCC, along the ligand, are -86.1(2), -178.35(16) and 180.00(16), respectively,
while the dihedral angle between the mean planes of the pyrazolyl rings is 0˚. As a result, the
(Cu)N···N(Cu) ligand length is 7.85 Å. The Cu∙∙∙Cu distance along the µ-bpb ligand is 8.906 Å,
which is longer than those observed in the structure of {[Cu(μ-bbd)1.5](PF6)}n (6.255 and 8.527
Å).23 The longer Cu∙∙∙Cu separation in 2 can be due to the fully extended anti-anti-anti
conformation of the bpb with respect to the gauche-anti-anti and gauche-anti-gauche
conformations of the bbd ligands in KEZXEU.
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
{[Cu(μ-bpmb)2](PF6)}n (3)
Single-crystal X-ray diffraction analysis reveals that the same as 2, compound 3 crystallizes in
the tetragonal P4/n space group with Z=2 (Table 1). The bpmb linker in the structure of 3 is
similar to the bdb (compound 1) without the methyl substituents on the pyrazolyl groups (see
Scheme 1). Compound 3 is a cationic 2D coordination polymer in which the coordination sites at
the copper atoms are occupied by four nitrogen atoms of four μ-bpmb linkers in a CuN4
coordination environment. The N–Cu–N bond angles are comprised in a smaller range
[101.12(9)-113.80(7)˚], compared to the values observed in 2. Calculated τ4 value of 1.03 for
copper(I) centers show almost an ideal tetrahedral geometry. The copper atoms are connected to
four adjacent Cu(I) atoms by μ-bpmb ligands, forming an infinite cationic 2-D sheet with 44-sql
topology. The structure is shown in Figure 3 and the atoms of the asymmetric unit, containing
one copper ion and half ligand (centrosymmetric), are labelled. The dihedral angle between two
pyrazolyl rings is 0˚ and the (Cu)N–to–N(Cu) distance is 8.78 Å. The Cu∙∙∙Cu distance (9.63 Å)
in the 2D structure of 3 is in between the values observed in 1 (8.26, 10.19 Å).
The Cu–N distance is 2.074(2) Å, comparable to that found in the structure of 2 and longer than
those found in the structure of 1 [1.980(3)-1.998(4) Å] and KEZXEU [1.983(2)-2.0022(19) Å].
12
ACS Paragon Plus Environment

Page 13 of 30
Crystal Growth & Design
1
2
3
4
5
6
These observations indicate stronger Cu–N bonds for three coordinated copper(I) centers and
nitrogen atoms of 3,5-dimethyl substituted pyrazolyl rings.
The 2D sheets extend in the crystallographic ab plane and pack as AAA along the c axis,
7
8
9
-
forming 1D channels across the 2D sheets that accommodate the PF6 counterions. In contrast to
the structure of 1, 2, and KEZXEU,23 significant π∙∙∙π stacking interactions occur in 3 (Figure
3c). The conformation of the bpmb ligands are such as to bring one pyrazolyl ring of a ligand
into close proximity of a phenyl ring of an adjacent bpmb ligand belonging to the same layer,
with a centroid∙∙∙centroid distance of 3.647(2) Å and a dihedral angle of 6.88(17)° between the
two rings.60 In addition, weak C-H∙∙∙F hydrogen interactions have also been observed between
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
-
one of the fluorine atoms of the PF6 anions and H atoms of the pyrazolyl rings (Table S2).61-64
(a)
(b)
13
ACS Paragon Plus Environment

Crystal Growth & Design
Page 14 of 30
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
(c)
Figure 3. Crystal structure of 3: a) Coordination environment around copper(I) atom with
labelling scheme for the asymmetric unit part. b) View down c of a single layer with 44-sql net
-
and space-filling representation of the PF6 anions. c) Intra-layer π∙∙∙π stacking interactions
between two pyrazolyl and one phenyl rings belonging to three different bpmb ligands.
Effect of the Geometry of the Linker Ligands
Tuning the structure of the linkers by varying the steric hindrance of pyrazolyl rings and/or the
flexibility of the spacer groups show interesting and remarkable effect on the assembled
coordination polymers. The bdb and bbd linkers with methyl decorated pyrazolyl rings (see
Scheme 1), form one-dimensional polymeric structures composed of three coordinate copper
centers in a trigonal planar geometry, while the bpmb and bpb linkers with un-substituted
pyrazolyl groups, resulted in almost similar 2D structures with four coordinated copper centers.
Changing the spacer group from a –(CH2)4– to –CH2–Ph–CH2– displays no meaningful effect on
the structure of the resultant polymers (Scheme 2).
Preference towards trigonal planar geometry by copper atoms in the structures of 1 and
KEZXEU and towards the four-coordinate tetrahedral one in the structures of 2 and 3 is most
likely due to the large steric hindrance induced by the 3,5-dimethylpyrazole rings of the bpb and
bpmb ligands. Moreover, the results clearly show the much more crucial role of the steric
hindrance of the pyrazolyl ring in orienting the final Cu(I) coordination compared to the effect
induced by the different nature of the pyrazolyl spacer groups. In the presence of non-
-
coordinating anions, such as PF6 , copper centers show their intrinsic nature to select three- or
four-coordinate geometry depending on the steric hindrance of the ligands.
14
ACS Paragon Plus Environment

Page 15 of 30
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
Interestingly, a significant relation between the structure of the coordination polymers and their
ability to capture volatile iodine was observed. So, the 1D structures with three coordinate Cu(I)
atoms act as an iodine sorbent, while 2D structures with four coordinate copper centers show no
ability of iodine sorption.
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: Schematic view of the effect of the different bis-pyrazolyl ligands on the structure of
cationic copper(I) coordination polymers.
Spectroscopic Characterization
Infrared spectra of coordination polymers 1, 2 and 3 are shown in Figure S1. Stretching vibration
of C=N bonds, typical of the pyrazolyl rings, are present at 1551 (bdb in 1), 1513 (bpb in 2) and
1519 (bpmb in 3) cm-1. The location of the peaks depends on the type of substituents on the
pyrazolyl rings. In compound 1, where the pyrazolyl rings bring two methyl substituents, this
vibration is shifted to higher wavenumber with respect to the values found for compounds 2 and
3 containing un–substituted pyrazolyl rings. The peaks with weak to medium intensity at 3142
(bdb in 1), 3149 (bpb in 2) and 3135 and 3150 cm-1 (bpmb in 3) are assigned to the stretching
vibration of aromatic C-H bonds of the coordinated ligands. Symmetric and asymmetric
stretching vibrations of the methylene (–CH2–) and methyl (–CH3) groups are observed in the
15
ACS Paragon Plus Environment

Crystal Growth & Design
Page 16 of 30
1
2
3
4
5
6
region of 2866-2950 cm-1. The infrared spectra of the compounds also show two sharp bands at
-
557 and 845 (multiple or broad) cm-1, attributed to the vibration bands of PF6 counter anion.24
7
8
9
Experimental and simulated powder X-ray diffraction (PXRD) patterns of the samples are shown
in Figures 4. The results show suitable phase purity of the bulk materials.
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
(a)
16
ACS Paragon Plus Environment

Page 17 of 30
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
(b)
(c)
17
ACS Paragon Plus Environment

Crystal Growth & Design
Page 18 of 30
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
(d)
Figure 4. Observed (black) and calculated from single-crystal structure (red) powder X-ray
diffraction patterns for compounds; a) 1, b) 2, c) 3, and d) KEZXEU. PXRD patterns of iodine
adsorbed samples of 1-I2 and KEZXEU-I2 (blue) and recovered 1 and KEZXEU (orange).
Iodine Sorption and Release
Most of the investigations on iodine sorption have been performed using porous coordination
polymers or metal-organic frameworks but in solution only.39-43 However, iodine sorption studies
in the gas phase by non-porous coordination polymers are still rare and need to be explored
well.44 Kawano et. al., reported CuI-based 3D porous coordination networks with outstanding
feature of iodine sorption in the gas phase12 and, by crystallographic evidence, showed both
chemi- and physi-sorption of iodine in these porous coordination networks. Our recent research
revealed iodine capture feature of non-porous CunIn-based coordination polymers in the gas
phase.45 Herein, we have explored this property by non-porous cationic Cu(I) CPs not containing
copper-iodide clusters moieties. Analysis of the structures by Platon65 confirms no accessible
void for guest molecules.
18
ACS Paragon Plus Environment

Page 19 of 30
Crystal Growth & Design
1
2
3
4
5
6
Fixed iodine vapor pressure strategy was employed, and vials containing colorless crystals of
23
compounds 1-3 and that of the already reported structure {[Cu(µ-bbd)1.5](PF6)}n were left in a
capped vessel containing crystals of iodine and then heated at 55 °C for three different exposure
times, 30 min, 50 min and 2 h (Table S3). Monitoring by naked eye revealed that the color of
samples 1 and KEZXEU immediately changed to deep brown, while that of samples 2 and 3
remained unchanged. Photographs of the samples before and after vapor iodine sorption are
shown in Figure 5. Surprisingly, compounds having similar crystal structures, indifferently with
respect to the ligands, behave in the same way. Hence, 1 and KEZXEU, with the same 1D chain
structure and trigonal geometry of the copper atoms, showed vapor I2 adsorption. On the
contrary, no iodine adsorption was evidenced for 2 and 3, with 2D structures and tetrahedral
copper atoms. On the other hand, none of the four compounds showed the ability to adsorb
iodine in cyclohexane solution.
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
To evaluate the maximum amount of volatile iodine adsorbed by 1 and KEZXEU, the adsorbed
crystals, taken after a given exposure time, were washed with cyclohexane to remove deposited
iodine on their surface, dried and weighed. After 2h of exposure time the maximum of adsorbed
I2 was reached for both samples and, as determined gravimetrically, it was of 47.0 and 58.2 wt %
for 1 and KEZXEU, respectively (Table S3). In terms of moles this means that 1.20 and 1.33
moles of I2 are adsorbed per formula unit of 1 and KEZXEU, respectively.
19
ACS Paragon Plus Environment

Crystal Growth & Design
Page 20 of 30
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
Figure 5. Photographs of samples of compounds 1-3 and KEZXEU before and after iodine
sorption.
To investigate the vapor iodine uptake process in 1 and KEZXEU, IR spectra and PXRD
patterns on adsorbed samples 1-I2 and KEZXEU-I2 were acquired. FT-IR spectra of 1 and 1-I2
are almost the same (Figure S1 a,b). PXRD patterns of 1-I2 and KEZXEU-I2 were recorded and
compared with that of the relative pristine materials, and no substantial differences were found
(Figure 4a,d). These may confirm that the structures of the two compounds are maintained
during iodine sorption process. Thermal stability of the compounds before and after I2 sorption
was also investigated by thermogravimetry under nitrogen atmosphere. The results (Figure S2)
°
showed that the structures are stable up to about 250 C and start to collapse at higher
20
ACS Paragon Plus Environment

Page 21 of 30
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
°
temperatures, except for 1 that is stable up to about 200 C. Comparison between the
thermogravimetric traces of 1 and 1-I2 showed that iodine release occurs at temperature close to
the decomposition point of 1. To understand whether thermal iodine release from 1-I2 can be
attained with retention of the framework, powder of 1-I2 was heated at 200°C for 20 min in N2
atmosphere. A color change from brown to yellow was visible after the first 5 min (Figure S3a)
while the FT-IR spectrum, acquired on the sample heated for 20 min, (Figure S3 b) is
comparable to that of the pristine samples. These results confirm that iodine in 1-I2 can be
thermally released at 200°C without destruction of the framework. The TG trace of KEZXEU-I2
show that iodine release occurs at lower temperatures (ca. 110°C) with respect to the
decomposition temperature of KEZXEU. This may imply a weaker interaction of iodine
molecules with the structure of KEZXEU compared to that of 1. The results are consistent with
faster release of adsorbed iodine from KEZXEU-I2 in pure EtOH (vide infra).
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 get a better insight on the iodine sorption behavior, energy dispersive X-ray (EDX)
analyses have also been performed on 1-I2 and KEZXEU-I2. The EDX maps reveal uniform
distribution of adsorbed iodine over the samples (Figure 6). Moreover, EDX elemental analysis
predict average iodine content of about 51 and 60 wt% for 1-I2 and KEZXEU-I2, respectively,
(Figure S4) which are almost consistent with the values obtained gravimetrically (Table S3).
(a)
21
ACS Paragon Plus Environment

Crystal Growth & Design
Page 22 of 30
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
(b)
Figure 6. EDX mapping of a) 1-I2 and b) KEZXEU-I2. Black (C), red (N), green (F), violet (P),
orange (Cu) and blue (I).
Iodine release was also investigated in polar EtOH and non-polar CCl4 solvents. The results
show faster iodine release in polar EtOH with respect to CCl4. Probably, the interactions of
iodine species with the polar molecules of EtOH provides sufficient energy to overcome the
weak supramolecular interactions between adsorbed iodine molecules and the skeleton of the
coordination polymers and set off the release of iodine by the polar solvent.66,67 Photographs of
iodine release tests in ethanol and of recovered solid materials of compounds 1 and KEZXEU
are shown in Figure S5. The iodine release from 1-I2 and KEZXEU-I2 in EtOH was also
monitored by time-dependent UV-Vis measurements (Figure S5) following the increase in the
intensity of the band at 358 nm. The results show faster release of iodine from KEZXEU-I2 with
respect to 1-I2 confirming what observed in the TG analysis. Moreover, UV-Vis quantitative
analysis of the iodine content of 1-I2 and KEZXEU-I2 obtained at 2 h exposure time gave values
of 45.0 and 62.0 wt%, respectively, which are almost consistent with that obtained
gravimetrically and comparable to that reported for porous coordination networks.12
22
ACS Paragon Plus Environment

Page 23 of 30
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
Encapsulation of iodine by MOFs and CPs could be ascribed to various supramolecular
interactions between iodine and ligand moieties, such as, π···I and O/N/C–H···I hydrogen
bonding66,67 or to interaction of iodine with open coordination sites in the skeleton of the
structures.68 Another way to iodine capture is the formation of I–I halogen bond between I2
molecules and [CuI]n moieties in the structure of copper iodide-coordination networks.12 In the
present work, as compounds 2 and 3 with 2D sheet structures, that are containing aromatic rings
and C–H groups, show no tendency to capture iodine, the most rational factor for iodine capture
by the 1D CPs 1 and KEZXEU may be assigned to the presence of three coordinated trigonal
planar copper atoms with open coordination sites.
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
Anion Exchange Properties of 1 and 2
As revealed by the crystal structure analyses of 1-3, the hexafluorophosphate anions are loosely
connected to the cationic skeleton of the structures through weak C-H∙∙∙F interactions. To
-
investigate whether the PF6 anions can be exchanged by other anions, anion exchange reactions
were carried out on 1 and 2 as representative of 1D and 2D structural type, respectively. Anion
exchange processes were investigated both in solution and in the solid state and the anion-
exchanged products were identified by FT-IR and PXRD techniques. Hence, a certain amount of
finely powdered samples of 1 or 2 were added to aqueous solutions containing, respectively,
-
-
SCN- (0.005 M), I-, ClO4 or BF4 (1 M) and the resulting mixtures were stirred at room
-
temperature for one day. The results show that PF6 anions of 1 or 2 were replaced only by the
strongly coordinating SCN- anion (Figure S1 a, c; 1-SCN and 2-SCN). The presence of SCN- in
the anion-exchanged products is established from the appearance of a sharp band at 2113 cm-1,
which is assigned to the CN stretching mode of the thiocyanate groups23 and the disappearance
-
of vibrations bands due to PF6 anions in the FT-IR spectra. Anion exchange experiments in the
solid state were also investigated by grinding certain amount of 1 or 2 with solid KSCN, KI,
NaClO4 and NaBF4 in an agate mortar (molar ratio 1:1). Anion exchange in the solid state for 2
-
-
is the same as that in solution and only SCN- is able to replace PF6 . Differently, the PF6 anions
in the structure of 1 were also replaced by iodide ions (Figure S1 b). This phenomenon could be
put in relation to the presence of an additional accessible coordination site on the three
-
-
coordinated copper(I) centers in the structure of 1. The anions ClO4 and BF4 resulted not able to
23
ACS Paragon Plus Environment

Crystal Growth & Design
Page 24 of 30
1
2
3
4
5
6
7
8
9
-
replace PF6 in 1 and 2 either in solution or in the solid state, this may be due to their weakly
coordinating character. To investigate structural change during anion exchange process, PXRD
analyses were performed on anion- exchanged products 1-SCN, 1-I, and 2-SCN (Figure S6). The
results indicate structural change during anion exchange. Concerning the anion exchange product
1-I in the solid state, the results show structural transformation to a corresponding CuI
coordination polymer [CuI(μ-bdb)]n (ACITAK)45 (Figure S6 a).
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
CONCLUSION
We reported the facile syntheses of three cationic Cu(I) coordination polymers with flexible
bispyrazolyl linker ligands and investigated the effect of the geometry of the linkers on their
structures and iodine sorption behavior. Due to the known structure-directing effects of halides
-
and pseudo-halides on the structure of Cu(I) CPs, non- or weakly-coordinating PF6 anion has
been selected as counter anion. Crystal structure analysis on the isolated compounds show no
clear effect of the pyrazolyl spacer groups but an evident influence of pyrazolyl ring steric
hindrance. The relation of the structures with their capability in the capture of volatile iodine is
also attractive. Ligands containing methyl-substituted bulky pyrazolyl rings form low
dimensional coordination polymers of three coordinated copper centers and are good iodine
sorbents. Ligands with non-substituted rings give rise to higher dimensional CPs with four
coordinated copper centers with any ability of iodine sorption. Therefore, the results show that
even non-porous copper(I) coordination polymers have potential application in sorption of
gaseous iodine and that such ability can be tuned by changing the coordination geometry of
copper(I) ions.
SUPPORTING INFORMATION AVAILABLE
Selected bond lengths (Å) and bond angles (˚) for compounds 1-3 (Table S1) and hydrogen
bonds for compounds 2 and 3 (Table S2); Gravimetric and UV-Vis determination of iodine
contents for compounds 1 and KEZXEU in different I2(g) exposure time (Table S3). FT-IR
spectra for complexes and anion exchanged products (Figures S1,S3), TGA curves (Figure S2),
EDX spectra and iodine contents information for iodine-adsorbed samples (Figure S4),
24
ACS Paragon Plus Environment

Page 25 of 30
Crystal Growth & Design
1
2
3
4
5
6
Photographs of iodine release tests (Figure S5), PXRD patterns for anion exchanged products
(Figure S6). This material is available free of charge via the Internet at http://pubs.acs.org.
7
8
9
AUTHOR 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
Corresponding Author
* E-mail: v.nobakht@scu.ac.ir Fax: +98 613 3331042
Notes
The authors declare no competing financial interest.
ACKNOWLEDGEMENT
The authors thank Shahid Chamran University of Ahvaz (Grant No.: 31400) and the Università
degli Studi di Milano for financial support.
REFERENCES
(1) Furukawa, H.; Cordova, K. E.; O’Keeffe, M.; Yaghi, O. M. The chemistry and applications
of metal-organic frameworks. Science. 2013, 341, 974-986.
(2) Lu, W.; Wei, Z.; Gu, Z.; Liu, T.; Park, J.; Park, J.; Tian, J.; Zhang, M.; Zhang, Q.; Gentle, T.;
Bosch, M.; Zhou, H. Tuning the structure and function of metal–organic frameworks via
linker design. Chem. Soc. Rev. 2014, 43, 5561-5593.
(3) Leong, W. L.; Vittal, J. J. One-dimensional coordination polymers: complexity and diversity
in structures, properties, and applications. Chem. Rev. 2011, 111, 688-764.
(4) Guillerm, V.; Kim, D.; Eubank, J. F.; Luebke, R.; Liu, X.; Adil, K.; Lah, M. S.; Eddaoudi, M.
A supermolecular building approach for the design and construction of metal–organic
frameworks. Chem. Soc. Rev. 2014, 43, 6141-6172.
(5) 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.
(6) Bhattacharya, B.; Ghoshal, D. Selective carbon dioxide adsorption by mixed-ligand porous
coordination polymers. CrystEngComm. 2015, 17, 8388-8413.
(7) Meng, X.; Song, S.-Y.; Song, X.-Z.; Zhu, M.; Zhao, S.-N.; Wu, L.-L.; Zhang, H.-J. A
tetranuclear copper cluster-based MOF with sulfonate–carboxylate ligands exhibiting high
proton conduction properties. Chem. Commun. 2015, 51, 8150- 8152.
(8) Zhu, S.-L; Ou, S.; Zhao, M.; Shen, H.; Wu, C.-D. A porous metal–organic framework
containing multiple active Cu2+ sites for highly efficient cross dehydrogenative coupling
reaction. Dalton Trans., 2015, 44, 2038-2041.
(9) Liu, L.; Peng, Y.-F.; Lv, X.-X.; Li, K.; Li, B.-L.; Wua, B. Construction of three coordination
polymers based on tetranuclear copper(II) clusters: syntheses, structures and photocatalytic
properties. CrystEngComm. 2016, 18, 2490-2499.
25
ACS Paragon Plus Environment

Crystal Growth & Design
Page 26 of 30
1
2
3
4
5
6
(10) Peng, R.; Li, M.; Li, D. Copper(I) halides: A versatile family in coordination chemistry and
crystal engineering. Coord. Chem. Rev. 2010, 254, 1-18.
(11) Graham, P. M.; Pike, R. D.; Sabat, M.; Bailey, R. D.; Pennington, W. T. Coordination
polymers of copper(I) halides. Inorg. Chem. 2000, 39, 5121-5132.
7
(12) Kitagawa, H.; Ohtsu, H.; Kawano, M. Kinetic assembly of a thermally stable porous
coordination network based on labile CuI units and the visualization of I2 sorption. Angew.
Chem. Int. Ed. Engl. 2013, 52, 12395.
(13) Braga, D.; Grepioni, F.; Maini, L.; Mazzeo, P.; Ventura, B. Solid-state reactivity of
copper(I) iodide: luminescent 2D-coordination polymers of CuI with saturated
bidentatenitrogen bases. New J. Chem. 2011, 35, 339-344.
(14) Yuan, S.; Wang, H.; Wang, D.; Lu, H.-F.; Fenga, S.-Y.; Sun, D. Reactant ratio-modulated
six new copper(I)–iodide coordination complexes based on diverse [CumIm] aggregates and
biimidazole linkers: syntheses, structures and temperature-dependent luminescence
properties. CrystEngComm. 2013, 15, 7792-7802.
(15) Yadav, A.; Srivastava, A. K.; Balamurugana, A.; Boomishankar, R. A cationic copper(I)
iodide cluster MOF exhibiting unusual ligand assisted thermochromism. Dalton Trans. 2014,
43, 8166-8169.
(16) Knorr, M.; Khatyr, A.; Aleo, A. D.; Yaagoubi, A. E.; Strohmann, C.; Kubicki, M. M.;
Rousselin, Y.; Aly, S. M.; Fortin, D.; Lapprand, A.; Harvey, P. D. Copper(I) halides (X = Br,
I) coordinated to bis(arylthio)methane ligands: aryl substitution and halide effects on the
dimensionality, cluster size, and luminescence properties of the coordination polymers.
Cryst. Growth Des. 2014, 14, 5373-5387.
(17) Benito, Q.; Goff, X. F. L.; Maron, S.; Fargues, A.; Garcia, A.; Martineau, C.; Taulelle, F.;
Kahlal, S.; Gacoin, T.; Boilot, J.; Perruchas, S. Polymorphic copper iodide clusters: Insights
into the mechanochromic luminescence properties. J. Am. Chem. Soc. 2014, 136, 11311-
11320.
(18) Li, M.; Li, Z.; Li, D. Unprecedented cationic copper(I)–iodide aggregates trapped in
“click” formation of anionic-tetrazolate-based coordination polymers. Chem. Commun. 2008,
0, 3390-3392.
(19) Wen, T.; Li, M.; Zhou, X.-P.; Li, D. Unprecedented copper(I)-catalyzed in situ double
cycloaddition reaction based on 2-cyanopyrimidine. Dalton Trans. 2011, 40, 5684-5686.
(20) Xin, B.; Zeng, G.; Gao, L.; Li, Y.; Xing, S.; Hua, J.; Li, G.; Shi, Z.; Feng, S. An unusual
copper(I) halide-based metal–organic framework with a cationic framework exhibiting the
release/adsorption of iodine, ion-exchange and luminescent properties. Dalton Trans. 2013,
42, 7562-7568.
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
(21) Wang, J.; Luo, J.; Luo, X.; Zhao, J.; Li, D.-S.; Li, G.; Huo, Q.; Liu, Y. Assembly of a three-
dimensional metal–organic framework with copper(I) iodide and 4-(pyrimidin-5-yl) benzoic
acid: controlled uptake and release of iodine. Cryst. Growth Des. 2015, 15, 915-920.
(22) Haldón, E.; Delgado-Rebollo, M.; Prieto, A.; Álvarez, E.; Maya, C.; Nicasio, M. C.; Pérez,
P. J. Synthesis, structural characterization, reactivity, and catalytic properties of copper(I)
complexes with a series of tetradentate tripodal tris(pyrazolylmethyl)amine ligands. Inorg.
Chem. 2014, 53, 4192-4201.
(23) Beheshti, A.; Nobakht, V.; Carlucci, L.; Proserpio, D.M.; Abrahams, C. Influence of the
counter ion on the structure of two new copper(I) coordination polymers: Synthesis,
structural characterization and thermal analysis. J. Mol. Struct. 2013, 1037, 236-241.
26
ACS Paragon Plus Environment

Page 27 of 30
Crystal Growth & Design
1
2
3
4
5
6
(24) Beheshti, A.; Soleymani Babadi, S.; Nozarian, K.; Heidarizadeh, F.; Ghamari, N.; Mayer,
P.; Motamedi, H. Crystal structure, microbiological activity and theoretical studies of Ag(I)
and Cu(I) coordination polymers with 1,1′-(butane-1,4-diyl)bis(3-methylimida- zoline-2-
thione) ligand. Polyhedron. 2016, 110, 261-273.
7
(25) Plasseraud, L.; Maid, H.; Hampel, F.; Saalfrank, R. W. A meso-helical coordination
8
9
polymer
from
achiral
dinuclear
[Cu2(H3CCN)2(μ-pydz)3][PF6]2
and
1,3-
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
Bis(diphenylphosphanyl)propane—synthesis and crystal structure of equation image {[Cu(μ-
pydz)2][PF6]} (pydz=pyridazine). Chem. Eur. J. 2001, 7, 4007-4011.
(26) Shi, H.-Y.; Huang, Y.-L.; Sun, J.-K.; Jiang, J.-J.; Luo, Z.-X.; Ling, H.-T.; Lama, C.-K.;
−
−
−
Chao, H.-Y. Assembly of BF4 , PF6 , ClO4 and F− with trinuclear copper(I) acetylide
complexes bearing amide groups: structural diversity, photophysics and anion binding
properties. RSC Adv. 2015, 5, 89669-89681.
(27) Beheshti, A.; Clegg, W.; Nobakht, V.; Harrington, R.W. Metal-to-ligand ratio as a design
factor in the one-pot synthesis of coordination polymers with [MS4Cun] (M = W or Mo, n = 3
or 5) cluster nodes and a flexible pyrazole-based bridging ligand. Cryst. Growth Des. 2013,
13, 1023-1032.
(28) Huang, F.-P.; Yang, C.; Li, H.-Y.; Yao, P.-F.; Qin, X.-H.; Yanb, S.-P.; Kurmoo, M. Solvent
effects on the structures and magnetic properties of two doubly interpenetrated metal-organic
frameworks. Dalton Trans. 2015, 44, 6593-6599.
(29) Li, X.-Y.; Liu, X.-X.; Yue, K.-F.; Wu, Y.-P.; He, T.; Yana, N.; Wang, Y.-Y. Solvent-
controlled formation of four Ni(II) coordination polymers based on a flexible bis(imidazole)
ligand: syntheses, structural diversification, properties. RSC Adv. 2015, 5, 81689-81695.
(30) Nobakht, V.; Beheshti, A.; Proserpio, D. M.; Carlucci, L.; Abrahams, C. T. Influence of the
counter anion and steric hindrance of pyrazolyl and imidazolyl flexible ligands on the
structure of zinc-based coordination polymers. Inorg. Chim. Acta. 2014, 414, 217-225.
(31) Dong, M.-M.; He, L.-L.; Fan, Y.-J.; Zang, S.-Q.; Hou, H.-W.; Mak, T. C. W. Seven copper
coordination polymers based on 5-iodo-isophthalic acid: halogen-related bonding and N-
donor auxiliary ligands modulating effect. Cryst. Growth Des. 2013, 13, 3353-3364.
(32) Dong, X.-Y.; Si, C.-D.; Fan, Y.; Hu, D.-C.; Yao, X.-Q.; Yang, Y.-X.; Liu, J.-C. Effect of N-
donor ligands and metal ions on the coordination polymers based on a semirigid carboxylic
acid ligand: structures analysis, magnetic properties, and photoluminescence. Cryst. Growth
Des. 2016, 16, 2062–2073.
(33) Barea, E.; Montoro, C.; Navarro, J. A. R. Toxic gas removal – metal–organic frameworks
for the capture and degradation of toxic gases and vapours. Chem. Soc. Rev. 2014, 43, 5419-
5430.
(34) Britt, D.; Tranchemontagne, D.; Yaghi, O. M. Metal-organic frameworks with high capacity
and selectivity for harmful gases. PNAS. 2008, 105, 11623-11627.
(35) Khan, N.A.; Hasan, Z.; Jhung, S. H. Adsorptive removal of hazardous materials using
metal-organic frameworks (MOFs): A review. J. Hazard. Mater. 2013, 244, 444-456.
(36) Saiz-Lopez, Plane, A.; J. M. C.; Baker, A. R.; Carpenter, L. J.; Glasow, R.; Martin, L. C. G.;
McFiggans, G.; Saunders, R. W. Atmospheric chemistry of iodine. Chem. Rev. 2012, 112,
1773-1804.
(37) Hoeve, J. E. T.; Jacobson, M. Z. Worldwide health effects of the Fukushima Daiichi nuclear
accident. Energy Environ. Sci. 2012, 5, 8743-8757.
27
ACS Paragon Plus Environment

Crystal Growth & Design
Page 28 of 30
1
2
3
4
5
6
7
8
9
(38) Taghipour, F.; Evans, G. J. Radiolytic organic iodide formation under nuclear reactor
accident conditions. Environ. Sci. Technol. 2000, 34, 3012-3017.
(39) Parshamoni, S.; Sanda, S.; Jena, H. S.; Konar, S. Tuning CO2 uptake and reversible iodine
adsorption in two isoreticular MOFs through ligand functionalization. Chem. Asian J. 2015,
10, 653-660.
(40) Chaudhari, A. K.; Mukherjee, S.; Nagarkar, S. S.; Joarder, B.; Ghosh, S. K. Bi-porous
metal–organic framework with hydrophilic and hydrophobic channels: selective gas sorption
and reversible iodine uptake studies. CrystEngComm. 2013, 15, 9465-9471.
(41) Hashemi, L.; Morsali, A. A new lead(II) nanoporous three-dimensional coordination
polymer: pore size effect on iodine adsorption affinity. CrystEngComm. 2014, 16, 4955-
4958.
(42) Falaise, C.; Volkringer, C.; Facqueur, J.; Bousquet, T.; Gasnotb, L.; Loiseaua, T. Capture of
iodine in highly stable metal–organic frameworks: a systematic study. Chem. Commun. 2013,
49, 10320-10322.
(43) Safarifard, V.; Morsali, A. Influence of an amine group on the highly efficient reversible
adsorption of iodine in two novel isoreticular interpenetrated pillared-layer microporous
metal–organic frameworks. CrystEngComm. 2014, 16, 8660-8663.
(44) Miyao, K.; Funabiki, A.; Takahashi, K.; Mochida, T.; Uruichi, M. Reversible iodine
absorption of nonporous coordination polymer Cu(TCNQ). New J. Chem. 2014, 38, 739-743.
(45) Tarassoli, A.; Nobakht, V.; Baladi, E.; Carlucci, L.; Proserpio D. M. Capture of volatile
iodine by newly prepared and characterized non-porous [CuI]n-based coordination polymers.
CrystEngComm. 2017, 19, 6116-6126.
(46) Beheshti, A.; Clegg, W.; Nobakht, V.; Harrington, R. W. Design, synthesis, and structures
of two-dimensional copper (I) coordination polymers by variation of co-ligands in a facile
one-pot reaction. Polyhedron. 2014, 81, 256-260.
(47) Beheshti, A.; Clegg, W.; Khorramdin, R.; Nobakht, V. Synthesis and structural
characterization of mixed-metal complexes of CuI with MOS3 cores (M = Mo, W) and of an
unusual polymeric AgI/mercaptoimidazole complex with five different AgI coordination
environments. Russob, L. Dalton Trans. 2011, 40, 2815-2821.
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
(48) Beheshti, A.; Clegg, W.; Nobakht, V.; Panahi Mehr, M.; Russo, L. Complexes of copper(I)
and silver(I) with bis(methimazolyl)borate and dihydrobis(2-mercaptothiazolyl)borate
ligands. Dalton Trans. 2008, 6641-6646.
(49) Beheshti, A.; Nobakht, V.; Karimi Behbahanizadeh, S.; Abrahams, C. T.; Bruno, G.; Amiri
Rudbarid, H. Mo (W)/Cu/S coordination polymers based on tetranuclear cubane-like cluster
nodes and 1, 4-bis (3, 5-dimethypyrazol-1-yl) butane flexible ligand. Inorg. Chim. Acta.
2015, 437, 20-25.
(50) Kubas, G. J. Tetrakis(acetonitirile)copper(I) hexaflurorophosphate. Inorg. Synth. 1990, 28,
68-70.
(51) Mercury 3.0, Copyright Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge, CB2 1EZ, UK, 2012.
(52) Huang, Y. J.; Song, Y. L.; Chen, Y.; Li, H. X.; Zhang, Y.; Lang, J. P. Formation of dimeric
and polymeric W/Cu/S clusters via degradation or expansion of the cluster core in
[Et4N]4[WS4Cu4I6]. Dalton Trans. 2009, 0, 1411-1421.
28
ACS Paragon Plus Environment

Page 29 of 30
Crystal Growth & Design
1
2
3
4
5
6
7
8
9
(53) Ma, J. F.; Liu, J. F.; Xing, Y.; Jia, H. Q.; Lin, Y. H. Networks with hexagonal circuits in co-
ordination polymers of metal ions (ZnII, CdII) with 1,1′-(1,4-butanediyl)bis(imidazole).
Dalton Trans. 2000, 0, 2403-2407.
(54) Wang, X. Y.; Liu, S. Q.; Zhang, C. Y.; Song, G.; Bai, F. Y.; Xing, Y. H.; Shi, Z. Synthesis,
structural, and biological evaluation of the arene-linked pyrazolyl methane ligands and their
d9/d10 metal complexes. Polyhedron. 2012, 47, 151-164.
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
(55) Potapov, A. S.; Domina, G. A.; Khlebnikov, A. I.; Ogorodnikov, V. D. Facile synthesis of
flexible bis(pyrazol-1-yl)alkane and related ligands in a superbasic medium. Eur. J. Org.
Chem. 2007, 5112-5116.
(56) Sheldrick, G. M. SHELX97-Programs for Crystal Structure Analysis, release 97-2; Institut
fur Anorganische Chemie der Universitat Gottingen, Gottingen, Germany (1998).
(57) Yang, L.; Powell, D. R.; Houser, R. P. Structural variation in copper(I) complexes with
pyridylmethylamide ligands: structural analysis with a new four-coordinate geometry index,
τ4. Dalton Trans. 2007, 0, 955- 964.
(58) Cariati, E.; Bu, X.; Ford, P. C. Solvent- and vapor-induced isomerization between the
luminescent solids [CuI(4-pic)]4 and [CuI(4-pic)]∞ (pic = methylpyridine). The Structural
basis for the observed luminescence vapochromism. Chem. Mater. 2000, 12, 3385-3391.
(59) Li, G. H.; Shi, Z.; Liu, X. M.; Dai, Z. C.; Feng, S. H. Low-dimensional hybrid copper
halides with novel D6R Cu6I6 cores. Inorg. Chem. 2004, 43, 6884–6886.
(60) Janiak, C. A critical account on π–π stacking in metal complexes with aromatic nitrogen-
containing ligands. J. Chem. Soc., Dalton Trans. 2000, 0, 3885-3896.
(61) Arunan, E.; Desiraju, G. R.; Klein, R. A.; Sadlej, J.; Scheiner, S.; Alkorta, I.; Clary, D. C.;
Crabtree, R. H.; Dannenberg, J. J.; Hobza, P.; Kjaergaard, H. G.; Legon, A. C.; Mennucci,
B.; Nesbitt, D. J. Definition of the hydrogen bond. J. Pure Appl. Chem. 2011, 83, 1637-
1641.
(62) Brooker, S.; White, N.G.; Bauza, A.; Deya, P. M.; Frontera, A. Understanding the forces
that govern packing: A density functional theory and structural investigation of anion−π–
anion and nonclassical C–H···anion interactions. Inorg. Chem. 2012, 51, 10334-10340.
(63) Carlucci, L.; Ciani, G.; Maggini, S.; Proserpio, D. M. CrystEngComm. 2008, 10, 1191-1203.
(64) White, N.G.; Kitchen, J. A.; Brooker, S. A structural investigation of anion–triazole
interactions: observation of “π-pockets” and “π-sandwiches”. Eur. J. Inorg. Chem. 2009,
1172-1180.
(65) Spek, A. L. Single-crystal structure validation with the program PLATON. J. Appl.
Crystallogr. 2003, 36, 7-13.
(66) Rachuri, Y.; Bisht, K. K.; Suresh, E. Two-Dimensional Coordination Polymers Comprising
Mixed Tripodal Ligands for Selective Colorimetric Detection of Water and Iodine Capture,
Cryst. Growth Des. 2014, 14, 3300-3308.
(67) Rachuri, Y.; Bisht, K. K.; Parmar B., Suresh, E. Luminescent MOFs comprising mixed
tritopic linkers and Cd(II)/Zn(II) nodes for selective detection of organic nitro compounds
and iodine capture, J. Solid State Chem. 2015, 223, 23–31.
(68) Sava, D. F.; Chapman, K. W.; Rodriguez, M. A.; Greathouse, J. A.; Crozier, P. S.; Zhao,
H.; Chupas, P. J.; Nenoff, T. M. Competitive I2 Sorption by Cu-BTC from Humid Gas
Streams, Chem. Mater. 2013, 25, 2591–2596.
29
ACS Paragon Plus Environment