A series of new mixed-ligand complexes based on 3,6-bis(imidazol-1-yl)pyridazine: Syntheses, structures, and catalytic activities

Article abstract of DOI:10.1039/c7ce00394c

Seven new mixed-ligand complexes based on L [L = 3,6-bis(imidazol-1-yl)pyridazine], namely, [Ni(L)₂(SCN)₂]_n (1), [Cu₅(L)(1,2-BDC)₄(μ₃-OH)₂]_n (2), {[Cu₄(L)₂(1,3-HBDC)(1,3-BDC)(μ₃-OH)₄]·ClO₄·2.6H₂O}_n (3), {[Ni(L)(1,4-BDC)H₂O]·0.25H₂O}_n (4), [Co(L)(1,3,5-H₂BTC)₂H₂O]_n (5), {[Cu₂(L)(2,6-PYDC)₂(H₂O)₂]·4.4H₂O}_n (6), and {[Co(L)(4,4′-OBA)]·3.725H₂O}_n (7) [1,2-benzenedicarboxylic acid (1,2-H₂BDC), 1,3-benzenedicarboxylic acid (1,3-H₂BDC), 1,4-benzenedicarboxylic acid (1,4-H₂BDC), 1,3,5-benzenetricarboxylic acid (1,3,5-H₃BTC), 2,6-pyridine dicarboxylic acid (2,6-H₂PYDC), and 4,4′-oxydibenzoic acid (4,4′-H₂OBA)], have been synthesized by solvothermal reactions. Complexes 1 and 2 possess a two-dimensional (2D) layered structure, and the 2D framework of complex 1 can be rationalized to be a four-connected {4⁴·6²} topological sql network, while 2 exhibits a similar topological network with pentanuclear [Cu₅(μ₃-OH)₂(μ₂-COO^-)₆]²⁺ secondary building units (SBUs). Complex 3 presents an 8-connected sqc3 3D framework based on a chair-shaped [Cu₄(μ₃-OH)₄]⁴⁺ SBU with a Schl?fli symbol of {4²⁴·6⁴}. Complex 4 displays a 3D framework with diamondoid topology, which includes L/Ni(ii)/L helical chains. Complex 5 features a 1D chain structure formed by L ligands. Complex 6 shows a dinuclear structure, which is arranged into a 1D supramolecular chain by hydrogen-bonding interactions. The 3D framework of 7 presents a 4-connected porous architecture with a Schl?fli symbol of {6⁶}, the same as that of complex 4. The powder X-ray diffraction spectra, IR spectra, UV-vis absorption spectra and thermal stabilities of 1-7 have been investigated. Moreover, in the complex-catalyzed homocoupling reaction of 4-substituted aryl iodides, the catalytic activities of 1-7 have also been studied and discussed.

Full text of DOI:10.1039/c7ce00394c

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Towards design strategies for anion–π interactions in crystal engineering
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DOI: 10.1039/C7CE00394C
A series of new mixed-ligand complexes based on
,6-bis(imidazol-1-yl)pyridazine: syntheses, structures,
and catalytic activities
3
a
a
a
a, b
b
Sheng-Bin Zhou , Xin-Fang Wang , Ceng-Ceng Du , Duo-Zhi Wang* , Dianzeng Jia
aCollege of Chemistry and Chemical Engineering, Xinjiang University, Urumqi Xinjiang, 830046,
P. R. China.
bKey Laboratory of Energy Materials Chemistry, Ministry of Education, Institute of Applied
Chemistry, Xinjiang University, Urumqi Xinjiang, 830046, P. R. China.
_
*
_______________________________________________________________
Corresponding authors. E-mail: wangdz@xju.edu.cn
To CrystEngComm

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Abstract: Seven new mixed-ligand complexes based on L [L=3,6-bis(imidazol-1-yl)py
D
ri
O
d
I:
a
1
z
0
i
.
n
10
e
39/C7CE00394C
]
,
namely,
[Ni(L)
(1,3-HBDC)(1,3-BDC)(μ
[Ni(L)(1,4-BDC)H O]·0.25H O}
[Cu (L)(2,6-PYDC) (H O) ]·4.4H
2
(SCN)
2
]
n
(1),
]·ClO
(4),
[Cu
O}
[Co(L)(1,3,5-H
5
(L)(1,2-BDC)
4
(μ
3
-OH)
2
]
n
(2),
(3),
(5),
(7)
{
{
{
[Cu
4
(L)
2
3
-OH)
4
4
·2.6H
2
n
2
2
n
2
BTC)
2
H
2
O]
n
2
2
2
2
2
O}
n
(6), and {[Co(L)(4,4′-OBA)]·3.725H
BDC), 1,3-benzenedicarboxylic acid (1,3-H
BDC), 1,3,5-benzenetricarboxylic acid (1,3,5-H
PYDC), and 4,4′-oxydibenzoic acid (4,4′-H OBA)], have
2
O}
n
[1,2-benzenedicarboxylic acid (1,2-H
2
2
BDC),
BTC),
1
,4-benzenedicarboxylic acid (1,4-H
,6-pyridine dicarboxylic acid (2,6-H
2
3
2
2
2
been synthesized by solvothermal reactions. Complexes 1 and 2 possess a two-dimensional (2D)
layered structure, and the 2D framework of complex 1 can be rationalized to be four-connected
4
2
{
4 ·6 } topological sql network, while 2 exhibits the similar topological network with a
]2+ secondary building units (SBUs). Complex 3 presents a
]4+ SBU with a Schläfli
pentanuclear [Cu
5
(μ
3
-OH)
2
(μ
2
-COOˉ)
6
8-connected sqc3 3D framework based on a chair-shaped [Cu
(μ
4 3
-OH)
4
24
4
symbol of {4 ·6 }. Complex 4 displays a 3D framework with diamondoid topology, which
includes L/Ni(II)/L helical chains. Complex 5 features a 1D chain structure formed by L ligands.
Complex 6 shows a dinuclear structure, which is arranged into 1D supramolecular chain by
hydrogen-bonding interactions. The 3D framework of 7 presents a 4-connected porous
6
architecture with a Schläfli symbol of {6 } as same as complex 4. The Powder X-ray diffraction,
IR spectra, UV−vis absorption spectra and thermal stabilities of 1–7 have been investigated.
Moreover, in the complexes-catalyzed homocoupling reaction of 4-substituted aryl iodides, the
catalytic activity of 1–7 have also been studied and discussed.

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Introduction
DOI: 10.1039/C7CE00394C
The rational design and syntheses of novel entangled networks have attracted particular
interest due to their intriguing aesthetic structures and potential application in nanoscale
magnetism, heterogeneous catalysis, gas storage and capture, photoluminescence, drug delivery
and so on.1-5 However, it is still a great challenge for chemists to develop efficient synthetic
strategies to synthesize metal–organic frameworks (MOFs) with targeted structures and expected
properties. From a synthetic view, MOFs structures can be controlled by the choice of appropriate
organic ligands and metal centers as well as reaction conditions such as solvent systems, pH
values, reaction temperatures, and so on.6-10 Among these, the design and selection of suitable
bridging ligands are quite critical in the construction of MOFs because of its characteristics such
as geometric configuration, rigidity/flexibility, coordination site/donor atom, symmetry and
substituent group.11-14
In the mixed-ligand assembly, a neutral imidazole-containing ligand and polycarboxylates
have been widely utilized for tunability of structural frameworks. Among the N-donor ligands,
rigid bis(imidazole)ligands as building blocks have been widely chosen in the construction of
coordination polymers due to their invariable coordination modes.15 Moreover, the multidentate
aromatic carboxylate ligands, which are grossly the most efficient organic ligands to connect
different metal ions, including main-group metals, transition metals, and rare-earth metals, have
been extensively employed to construct coordination polymers exhibiting various topological
structures.16,17
In recent years, a series of MOFs were studied as versatile supramolecular platforms to
develop heterogeneous catalysts for a variety of organic reactions, especially for liquid-phase
reactions,18 because of their unique physical and chemical properties, such as high level of
porosities, catalytic active centers, and precise structures and unique functionalities.19-21 Thus,
complexes with catalytic activities continue to be of extreme interest to scientists, since the
combination of organic linkers and metal cations in the framework could maximize the
opportunities for high dispersion and high loading of catalytically active sites. For example, Fan
and his coworkers used coordination polymers as heterogeneous catalysts to promote
homocoupling of aromatic halides,22 the experimental results show that the complexes with 2D
and 3D structures have good catalytic activity.

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The coordination chemistry of rigid bis(imidazole)pyridazine ligand has been ex
D
t
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l
y
explored in our group, and they turned out to be good candidates for the construction of MOFs
23
with diversity structures. With the inspiration from the aforementioned points and as an ongoing
work, 3,6-bis(imidazol-1-yl)pyridazine (L) was chosen as the primary ligand owing to the
invariable building units, which is beneficial to adjust the coordination mode of auxiliary ligands.
In this article, we carried out the solvothermal reactions of M(II) (M = Ni, Cu, Co) salts with L
and seven auxiliary ligands including KSCN,24 1,2-benzenedicarboxylic acid (1,2-H
BDC),
BDC),
2
2
1
1
,3-benzenedicarboxylic acid (1,3-H
,3,5-benzenetricarboxylic acid (1,3,5-H
OBA) (Scheme 1), and successfully prepared isolated seven
2
BDC), 1,4-benzenedicarboxylic acid (1,4-H
3
BTC), 2,6-pyridine dicarboxylic acid (2,6-H
2
PYDC),
and 4,4′-oxydibenzoic acid (4,4′-H
2
new mixed-ligand complexes, [Ni(L)
2
(SCN)
2
]
n
(1), [Cu
O}
[Co(L)(1,3,5-H
5
(L)(1,2-BDC)
4
(μ
3
-OH)
2
]
n
(2),
(3),
(5),
{
{
{
[Cu
[Ni(L)(1,4-BDC)H
[Cu (L)(2,6-PYDC)
4
(L)
2
(1,3-HBDC)(1,3-BDC)(μ
O]·0.25H O}
(H O) ]·4.4H
3
-OH)
4
]·ClO
4
·2.6H
2
n
2
2
n
(4),
2 2
BTC) H
2
O]
n
2
2
2
2
2
O} (6), and {[Co(L)(4,4′-OBA)]·3.725H
2
O}
n
(7). All these
complexes have been characterized by single-crystal X-ray diffraction, elemental analyses, FT-IR
spectroscopy and powder X-ray diffraction (PXRD). In addition, photophysical properties and
thermal stability properties of those complexes were studied in detail. Furthermore, complexes
1–7 present good catalytic performances for the homocoupling reaction of 4-substituted aryl
iodides bearing electron-donating groups.
(Insert Scheme 1)
Experimental Section
Materials and General Methods All the other reagents used for the syntheses were commercially
available and employed without further purification. Elemental analysis of C, H and N were
determined with a Thermo Flash EA 1112-NCHS-O analyzer. IR spectra were measured as KBr
1
pellets using a Brucker Equinox 55 FT-IR spectrometer. H NMR data were collected using an
INOVA-400 NMR spectrometer and chemical shifts are reported in d relative to TMS. The X-ray
powder diffraction (PXRD) was recorded on a Rigaku D/Max-2500 diffractometer at 40 kV, 100
mA for a Cu-target tube and a graphite monochromator. Thermogravimetric analysis (TGA)
experiments were carried out on a PerkinElmer TG-7 analyzer heated from 25 to 1000 °C at a

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heating rate of 10 °C/min under Ar atmosphere. UV–Vis absorption spectra were obtaine
D
d
OI
u
:
s
10in.1
g
039/C7CE00394C
a
Hitachi UV-3010 UV–Vis Spectrophotometer.
Synthesis of complexes 1~7
[
Ni(L)
A mixture of Ni(CH
mg, 0.05 mmol) in 8 mL of H
2
(SCN)
2
]
n
(1)
3
COO)
2
·4H
2
O (12.5 mg, 0.05 mmol), KSCN (19.5 mg, 0.2 mmol) and L (10.6
2
O was placed in a Teflon vessel in a steel autoclave, heated at
–
1
1
30 °C for 72 h and then cooled to room temperature at a rate of 5 °C·h . The resulting green
block-shaped crystals of 1 were washed several times with water. The yield is 36% based on L.
Anal. Calcd(%) for C22
H
16
N
14
S
2
Ni: C, 44.09; H, 2.69; N, 32.72; Found: C, 44.18; H, 2.75; N,
-
1
3
1
6
2.89. IR (KBr pellets, cm ): 3126 m, 3080 w, 2090 s, 1579 m, 1530 m, 1493 s, 1453 s, 1326 m,
312 m, 1254 m, 1235 m, 1144 w, 1109 w, 1064 m, 1037 m, 970 m, 930 m, 836 m, 767 m, 649 m,
21 w.
[
Cu
A mixture of CuCl (29.7 mg, 0.3 mmol), 1,2-H
mmol), NaOH (8 mg, 0.2 mmol), and 8 mL H O was placed in a Teflon-lined stainless steel vessel
5
(L)(1,2-BDC)
4
(μ
3
-OH)
2
]
n
(2)
2
BDC (32.2 mg, 0.2 mmol), L (10.6 mg, 0.05
2
−
1
and heated to 140 °C for 48 h, followed by slow cooling (cooling rate of 5 °C·h ) to room
temperature. The pH value of the mixture before and after reaction was ~8. Blue-chip crystals of 2
were obtained in 42% based on L. Anal. Calcd(%) for C42
H
26
N
6
O
5
18Cu : C, 41.33; H, 2.15; N, 6.89;
-1
Found: C, 41.22; H, 2.03; N, 6.78. IR (KBr pellets, cm ): 3140 w, 2778 w, 2046 w, 1612 s, 1584 s,
1
547 s, 1450 m, 1395 s, 1311 m, 1236 m, 1151 m, 1121 m, 1064 m, 1030 m, 966 m, 949 m, 855 m,
32 m, 793 w, 758 s, 716 m, 698 m, 645 m, 620 w, 550 w, 511 m, 447 m.
8
{
[Cu
A mixture of Cu(ClO
.1 mmol), H O (8 mL) and NaOH (16 mg, 0.4 mmol) was sealed in a Teflon-lined stainless steel
4
(L)
2
(1,3-HBDC)(1,3-BDC)(μ
3
-OH)
4
]·ClO
4
·2.6H
2
O}
n
(3)
4 2
)
·6H O (74.1 mg, 0.2 mmol), 1,3-H
2
2
BDC (16.6 mg, 0.1 mmol), L (21.2 mg,
0
2
–
1
container and heated at 140 °C for 48 h and then cooled to room temperature at a rate of 5 °C·h .
The pH value of the mixture before and after reaction was ~9. Blue block crystals of 3 were
obtained in 28% based on L. Anal. Calcd(%) for C36
H
37.2
N
12
O
18.6ClCu
4
: C, 35.29; H, 3.06; N,
-1
1
3.72; Found: C, 35.38; H, 2.92; N, 13.86. IR (KBr pellets, cm ): 3605 m, 3400 m, 3215 w, 3080
w, 1607 s, 1584 m, 1559 s, 1534 m, 1498 s, 1396 s, 1452 s, 1396 s, 1369 s, 1316 m, 1306 m, 1265
w, 1244 w, 1224 w, 1149 w, 1090 s, 1062 s, 1031 m, 971 m, 945 m, 892 w, 835 m, 810 m, 767 w,

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748 m, 715 s, 644 m, 626 m.
DOI: 10.1039/C7CE00394C
{
[Ni(L)(1,4-BDC)H O]·0.25H
2
2
O}
n
(4)
2
A mixture of NiCl ·6H
2
O (23.8 mg, 0.1 mmol), 1,4-H
2
BDC (32.2 mg, 0.2 mmol), L (21.2 mg, 0.1
mmol), and 8 mL (H
2
O:CH
3
CN = 2:1) was placed in a Teflon-lined stainless steel vessel and
–
1
heated to 130 °C for 72 h, followed by slow cooling (cooling rate of 5 °C·h ) to room temperature.
Green block crystals of 4 were obtained in 43% based on L. Anal. Calcd(%) for C18
C, 47.25; H, 3.19; N, 18.37; Found: C, 47.33; H, 3.26; N, 18.29. IR (KBr pellets, cm ): 3342 w,
H
14.5
6
N O5.25Ni:
-
1
3
125 m, 3081 w, 1721 w, 1557 s, 1497 s, 1452 s, 1308 s, 1249 m, 1068 s, 1032 m, 968 s, 935 m,
85 w, 848 m, 828 m, 799 m, 747 s, 648 s, 616 m, 527 m, 497 m, 427 m.
8
[
Co(L)(1,3,5-H
2
BTC)
·6H
.1 mmol), and 8mL H
40 °C for 48 h and then cooled to room temperature at a rate of 5 °C·h . Pink block crystals of 5
14Co: C, 46.36; H, 3.06; N,
1.58; Found: C, 46.43; H, 3.17; N, 11.69. IR (KBr pellets, cm ): 3435 s, 3136 s, 3075 m, 2797 m,
2
H
2
O]
O (30.9 mg, 0.1 mmol), 1,3,5-H
O was sealed in a Teflon-lined stainless steel container and heated at
n
(5)
A mixture of CoSiF
6
2
3
BTC (42.0 mg, 0.2 mmol), L (21.2 mg,
0
1
2
–
1
were obtained in 21% based on L. Anal. Calcd(%) for C28
H
22
N O
6
-
1
1
2
1
643 m, 2541 m, 1697 s, 1613 s, 1537 s, 1458 s, 1399 s, 1324 m, 1305 m, 1270 s, 1181 m, 1103 m,
067 s, 1040 s, 968 m, 936 s, 841 m, 744 s, 708 m, 685 m, 650 m, 616 w, 531 m, 411 w.
{
[Cu
2
L(2,6-PYDC)
2
(H
·5H
.1 mmol), and 8 mL H
40 °C for 48h and then cooled to room temperature at a rate of 5 °C·h . Blue block crystals of 6
: C, 36.72; H, 3.44; N,
4.28; Found: C, 36.62; H, 3.36; N, 14.37. IR (KBr pellets, cm ): 3505 m, 3301 m, 3187 w, 3153
2
O)
O (25 mg, 0.1 mmol), 2,6-H
O was sealed in a Teflon-lined stainless steel container and heated at
2
]·4.4H
2
O} (6)
A mixture of CuSO
4
2
2
PYDC (16.7 mg, 0.1 mmol), L (21.2 mg,
0
1
2
–
1
were obtained in 41% based on L. Anal. Calcd(%) for C24
H
26.8
N
8
O
14.4Cu
2
-1
1
w, 3127 s, 3092 m, 1637 s, 1598 s, 1548 w, 1504 s, 1463 s, 1429 m, 1353 s, 1335 s, 1315 s, 1272
m, 1252 w, 1180 m, 1158 m, 1105 w, 1075 s, 1042 m, 973 m, 951 w, 914 w, 850 w, 821 w, 778 m,
7
38 m, 686 m, 649 w, 626 w, 594 w.
[Co(L)(4,4′-OBA)]·3.725H O} (7)
O (23.8 mg, 0.1 mmol), 4,4′-H
O was placed in a Teflon-lined stainless steel
{
2
n
A mixture of CoCl
2
·6H
2
2
OBA (26.3 mg, 0.21 mmol), L (21.2 mg,
0
.1 mmol), 2 mL 0.1 mol/L NaOH, and 8 mL H
2
–
1
vessel and heated to 130 °C for 72 h, followed by slow cooling (cooling rate of 5 °C·h ) to room

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temperature. Purple black block-shaped crystals were obtained in 45% based on L. Anal.
8.725Co: C, 48.49; H, 3.97; N, 14.14; Found: C, 48.67; H, 3.85; N, 14.26. IR (KBr
pellets, cm ): 3625 w, 3406 m, 3139 m, 2006 w, 1919 w, 1598 s, 1557 s, 1499 s, 1452 s, 1382 s,
D
C
OI
a
:
l
1
c
0
d
.10(%39
)
/C7CE00394C
for C24
H
23.45
N O
6
-
1
1
305 s, 1237 s, 1158 s, 1068 s, 1033 s, 1010 s, 967 s, 941 m, 876 s, 833 s, 778 m, 653 m, 621 m,
49 m, 429 m.
6
Single-crystal X-ray studies The X-ray diffraction (XRD) data of complexes 1-7 were collected
on a Bruker APEX II Smart CCD diffractometer at 293(2) K with Mo-Kα radiation (λ = 0.71073
Å) by ω-φ scan mode. Semi-empirical absorption corrections were applied to the data using
SADABS program. The program SAINT was used for integration of the diffraction profiles. The
structures were solved by direct methods using the SHELXS program of the SHELXTL package
and refined by full-matrix least-squares methods with SHELXL-2014.25 Metal atoms in each
complex were located from the E-maps and other non-hydrogen atoms were located in successive
2
difference Fourier syntheses and refined with anisotropic thermal parameters on F . Hydrogen
atoms of carbon were located at calculated positions and refined with fixed thermal parameters
riding on their parent atoms. The highly disordered guest molecules of complexes 3, 6 and 7 are
2
6
difficult to model, so their contribution of densities was modeled using the SQUEEZE routine in
PLATON. The SQUEEZE program was used to remove the contributions of disordered solvent for
complexes 3, 6 and 7. The 104, 88, 149 electrons of complexes 3, 6 and 7 removed from the unit
cell by the squeeze process could correspond with 2.6, 4.4 and 3.725 water molecules, respectively.
The amount of water was determined by TGA and elemental analyses for complexes 3, 6 and 7.
The crystallographic data for complexes 1–7 were listed in Table 1, and selected bond lengths and
angles were given in Table S1 of Supplementary 1 and the IR spectra of complexes 1–7 have been
listed in the Figure S1 of Supplementary 2.
All crystal data file in CIF format was deposited in CCDC and reference numbers
1527995-1528001 (for complexes 1–7, respectively). This data can be obtained from the
Cambridge Crystallographic Data Center, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: +44
1223 336033; E-mail: deposit@ccdc.cam.ac.uk.
(Insert Table 1)
Results and Discussion
Synthesis and General Characterization

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It is well-known that the design and selection of suitable ligands are quite critic
D
a
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039/C7CE00394C
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formation of the metal-organic frameworks with intriguing different structures. A series of new
complexes based on 3,6-bis(imidazol-1-yl)pyridazine (L) have been studied by our research group
except for the mixed-ligand of it.
As described above, we selected L as the primary ligand, and SCNˉ or organic carboxylic
acid as auxiliary ligands to construct mixed-ligand complexes under different reaction conditions.
It is noteworthy that adjusting the hydrothermal/solvothermal synthetic conditions, either
changing pH values or temperature of the reaction systems, have immense influence on the
formation of coordination polymers, and interestingly, different types of ancillary ligands can
result in unexpected and completely different structures of complexes 1–7. At pH ~8 (adjusted
with NaOH), the auxiliary ligand 1,2-H BDC is deprotonated and coordinated to the central metal
2
Cu(II) ion to form 2D complex 2. Compared to 2, the hydrothermal system of 3 is almost the same
except a higher pH value of ~9, but 3 posesses a 3D framework, which is totally different from 2.
−
Interestingly, in the structures of both 2 and 3, high pH values turn these excessive OH anions to
act as a μ
system for complexes 5 and 6 are quite similar with complexes 2 and 3, except the presence of
different starting ancillary ligands (1,3,5-H BTC for 5; 2,6-H PYDC for 6) and without adding
3
-bridge and participate in the assembly process of MOFs. Furthermore, the reaction
3
2
NaOH for adjusting the pH value, while 5 shows a 1D chain structure and 6 presents a 0D
dinuclear structure, a far cry from higher dimensions of 2 and 3. When we utilized 0.1 mol/L
NaOH to adjust pH value, complex 7 was generated by completely deprotonated 4,4′-OBA2ˉ
ligands coordinating two Co(II) atoms. In addition, complexes 1, 4 and 7 were synthesized at the
same reaction temperature, while 4 was obtained using a decreased amount of water solvent along
with CH
3
CN. Moreover, without the participant of CH CN, the crystals of 4 can’t be formed,
3
which suggests that solvent also plays an important role during the assembly of MOFs. Although 1
and 7 were synthesized under similar reaction solvent and temperature, different starting metal
salts and ancillary ligands lead to unexpected and completely different construction of MOFs.
In the IR spectra of 2–7 showed strong peaks in the ranges of 1557–1637 cm−1 and
−
1
1
305–1399 cm , indicating that they all contained coordinated carboxylate groups. The strong
peak at 1697 cm−1 in 5 could be attributed to the uncoordinated carboxyl groups of the
BTC ligand. The broad medium intensity bands from about 3092 to 3505 cm−1 of 3–7
1,3,5-H
3

Page 9 of 39
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could be assigned to the water molecules. The absorption band at 2090 cm−1 indi
c
a
t
e
s
t
he
D
O
I
:
1
0.1
039/C7CE00394C
existence of the coordinated SCNˉ anion in 1. The bands at 1062 cm-1 and 1090 cm-1 were
assigned to the free ClO ˉ anion in 3.
4
Crystal Structures
[
Ni(L)
2
(SCN)
2
] (1) Single crystal X-ray diffraction analysis reveals that complex 1 crystallizes in
n
the monoclinic space group P2(1)/c and features a 2D layer structure, which contains one Ni(II)
center, two L ligands and two SCNˉ anions (Fig. 1a). The Ni(II) center is coordinated to four N
atoms of imidazole from distinct L ligands [Ni(1)−N(1)=2.140(3) Å, Ni(1)−N(6)=2.139(3) Å] in
the equatorial plane and another two N atoms from unique two SCNˉ anions [Ni(1)−N(7)=2.088(3)
Å] at the axial positions to complete its octahedral coordination geometry with the coordination
angles varying from 87.91(12)° to 180°. Each L ligand links two Ni(II) ions and in turn each Ni(II)
ion connects four L ligands to form a 2D layer structure with (4,4) network, in which all Ni(II)
ions are located in one plane as well as the Ni1 atom lies on an inversion centre. As shown in Fig.
1b, each (4,4) network is constructed by four ligands acting as four edges and four Ni(II) ions as
four vertices. Complex 1 exhibits a perfect rhombus with square dimensions of 13.1756×13.1756
2
Å . Two SCNˉ ions not only participate in coordination but also are used to balance the charge.
Topologically, if the central Ni(II) ions are viewed as 4-connected nodes and each L ligand
serves as the 2-connected spacers, the overall motif of 1 can be described as 4-connected net with
4
2
a Schläfli symbol of {4 ·6 } (Fig. 1c).
(Insert Fig. 1)
[Cu
5
(L)(1,2-BDC)
4
(μ
3
2 n
-OH) ]
(2) X-ray crystallography indicates that complex 2 crystallizes in
the triclinic with space group P-1 and exhibits a 2D framework based on pentanuclear structure
unit. The pentanuclear structure unit of 2 consists of five Cu(II) ions (2Cu1+Cu2+2Cu3), one L
2
ligand, four 1,2-BDC ˉ ions and a pair of μ
3
-OH groups. Cu1 centre is surrounded by four O atoms
2
(
O2, O3, O7 and O8) of carboxyl from three 1,2-BDC ˉ ions, one N atom (N1) from one L ligand
and one O atom (O9) from one μ
3
-OHˉ ion, thus forming a distorted octahedral [CuNO ] geometry
5
(Fig. 2a). Cu2 ion is located at the regular octahedron [CuO
6
] center and is six-coordinated by
#2
#3
2
four carboxyl O atoms (O3, O3 , O8 and O8 ) from four 1,2-BDC ˉ ions and two O atoms (O9
#
2
and O9 ) from two μ -OHˉ ions (Fig. 2b). The five-coordinated Cu3 centre adopts a distorted
3

CrystEngComm
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[CuO
5
] trigonal bipyramid geometry, filled by four carboxyl O atoms (O1, O4, O6 and
D
O
O
7
I:
)
10
f
.
r
1039/C7CE00394C
o
m
2
four 1,2-BDC ˉ ions and one O atom (O9) from one μ
3
-OHˉ ion (Fig. 2c). Furthermore, the five
Cu(II) ions are bridged by two μ
3
-OHˉ groups and six μ
2
-COOˉ ions to form pentanuclear
-OH
]2+ (Fig. 2d). The intermetllic distance formed by μ
5
3
2
2
structure unit [Cu (μ -OH) (μ -COOˉ)
6
3
groups is 2.8793(6), 3.5026(7), and 3.0034(8) Å for Cu1∙∙∙Cu2, Cu2∙∙∙Cu3, and Cu1∙∙∙Cu3,
respectively. In addition, it is worth noting that the L ligand lies about an inversion centre and that
Cu2 lies on another inversion centre. The bond lengths of Cu−O are in the range of 1.916(3) to
2.285(3) Å, and the distance of Cu−N is 1.940(3) Å. In complex 2, [Cu
5
(μ
3
-OH)
2
(μ
2
-COOˉ)
]2+
6
2
pentanuclear structure units are interlinked by 1,2-BDC ˉ ions to generate the 1D chains (Fig. 2e),
which are further connected by L ligands to generate a 2D net (Fig. 2f).
To get a better insight into the structure of complex 2, we used the TOPOS software to
conduct topological analysis of the 2D framework. Topologically, both L ligands and 1,2-BDC2ˉ
ions can be considered as 2-connected linkers, and the [Cu
(μ
5 3
-OH)
2
(μ
2
-COOˉ)
]2+ SBUs can be
6
4
2
considered as 4-connected nodes. Hence, a similar 2D 4-connected {4 ·6 } topological sql
network was obtained, which is the same as complex 1 (Fig. 2g).
(Insert Fig. 2)
{
[Cu
4 2
(L) (1,3-HBDC)(1,3-BDC)(μ
3
-OH)
4
]·ClO ·2.6H O}
4
2
n
(3) Complex 3 exhibits a 3D
framework based on tetranuclear structure unit and belongs to the monoclinic system with space
group C2/c. The structure unit of 3 consists of four Cu(II) ions (2Cu1+2Cu2), two L ligands, one
2
1
,3-HBDCˉ ion, one 1,3-BDC ˉ ion, four μ
3
-OHˉ ions, one ClO ˉ ion, and 2.6 lattice water
4
molecules. It is worth noting that the perchlorate chlorine atom Cl1 lies on a twofold axis. As
illustrated in Figure. 3a, Cu1 is five-coordinated by two O atoms (O5, O2) from 1,3-HBDCˉ ion
2
and 1,3-BDC ˉ ion, another two O atoms (O3, O4) from two μ
3
-OHˉ ions, one N atom (N1) from
L ligand to form a distorted trigonal bipyramid [CuNO
surrounded by one carboxyl O atom (O1) from 1,3-HBDCˉ ion, three O atoms (O3, O4 and O3 )
from three μ -OHˉ ions, and one N atom (N3) from one L ligand, indicating that the geometry of
4
] coordination geometry. Each Cu2 ion is
#
3
3
Cu2 also is a distorted trigonal bipyramid. Furthermore, the four Cu(II) ions are bridged by four
]4+ SBU (Fig. 3b). The intermetllic distance
μ
3
-OH groups to form chair-shaped [Cu
4
(μ
3
-OH)
4
#
5
generated by μ
3
-OH groups is 6.0833(6), 3.0285(6), 3.7054(5), and 2.9653(7) Å for Cu1∙∙∙Cu1 ,
#3
#3
Cu1∙∙∙Cu2, Cu1∙∙∙Cu2 , and Cu2∙∙∙Cu2 , respectively. The angle of Cu−O−Cu is 90.26(9)°,

Page 11 of 39
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#
5
9
0.75(9)°, and 98.76(10)° for Cu1−O3−Cu2, Cu1−O4−Cu2, and Cu2−O3−Cu2 , res
D
p
O
e
I
c
:
t
1
i
0
v
.1
e
0
l
39/C7CE00394C
y
.
The bond lengths of Cu−O and Cu−N are in the range of 1.928(2) to 2.310(2) Å and 1.970(3) to
2
1
.981(3) Å, respectively. Cu1 and Cu2 ions are interlinked by 1,3-HBDCˉ and 1,3-BDC ˉ ions to
generate the 2D layers (Fig. 3c), which are further connected by L ligands to generate a 3D
framework (Fig. 3d).
To better understand the 3D framework, topological analysis is necessary. Regarding the
structural features of 3, the [Cu
(μ
4 3
-OH)
]4+ SUBs can be regarded as 8-connected nodes, and the
4
2
ligands (L, 1,3-HBDCˉ and1,3-BDC ˉ) can be reduced to 2-connected spacers. Thus, complex 3
2
4
4
can be classified as a 8-connected net with a Schläfli symbol of {4 ·6 } (Fig. 3e).
Insert Fig. 3)
(4) Structural analysis indicates that complex 4 crystallizes in
(
{
2 2
[Ni(L)(1,4-BDC)H O]·0.25H O}
n
the triclinic system with space group P-1 and shows a 3D fascinating architecture. As shown in
Fig. 4a, the structure unit of 4 is composed of one crystallographically independent Ni(II) ion, one
2
L ligand, one 1,4-BDC ˉ ion, one coordinated water molecule and as well as a lattice water
2
molecule which was assigned 0.25 occupancy. In complex 4, the L and (1,4-BDC ˉ) ligands lie
about inversion centres so that only a half of these components are in the asymmetric unit. Each
Ni(II) center is coordinated by two N atoms (N1 and N5) from two different L ligands, three
2
carboxylate O atoms (O1, O2 and O4) from two 1,4-BDC ˉ ions and one O atom (O3) from one
water molecule to give a slightly distorted [CdN
2
4
O ] octahedral geometry [Ni−N,
2.053(4)−2.065(4) Å; Ni−O, 2.031(3)−2.178(3) Å]. The coordination angles of O−Ni−O and
N−Ni−O are in the range of 61.11(13) to 168.25(15)° and 88.39(15) to 174.20(16)°, respectively.
Around Ni(II) centre, three O atoms (O1, O2 and O4) and one N atom (N5) are located on the
equatorial sites, while one O atom (O3) and one N atom (N1) occupy the axial positions with the
O4−Ni−O1 bond angle of 168.3°. Compared with aforementioned complexes, each L also acts as
a bis(dimonodentate) ligand, while the left- and right-handed helical chains come into being where
two Ni(II) ions and one L ligand are connected in a L/Ni(II)/L fashion (Fig. 4b). The adjacent
2
Ni(II) centers are interlinked by 1,4-BDC ˉ ions and L ligands to generate the 2D layers, which
2
are further connected by 1,4-BDC ˉ ions to form a 3D framework (Fig. 4d).
2
In complex 4, the ten Ni(II) ions are bridged by 1,4-BDC ˉ ions and L ligands to form 3D
adamantane skeleton structure (Fig. 4c). From a topological view, each 2-connected bridging L

CrystEngComm
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2
ligand and 1,4-BDC ˉ ions can be regarded as a linear linker. Ni(II) center can be t
D
r
O
eaI:
t
1
e
0
d
.1039/C7CE00394C
as
4-connected nodes. Therefore, the 3D framework of 4 is a 4-connected connected net with a
6
Schläfli symbol of {6 } (Fig. 4e).
(Insert Fig. 4)
[
Co(L)(1,3,5-H
2
BTC) H O]
2 2 n
(5) Complex 5 crystallizes in the triclinic system with space group
P-1 and exhibits a 1D chain structure. As shown in Figure. 5, the structure unit contains one
crystallographically independent Co(II) ion, one L ligand, two incompletely-deprotonated
1,3,5-H
2
BTCˉ ions, and one coordinated water molecule. The asymmetric unit contains two half
cobalt atoms, Co1, Co2, each lying on independent inversion centres. Co1 ion is six-coordinated
#1
#1
to two N (N1 and N1 ) atoms from two L ligands, two carboxylate O atoms (O5 and O5 ) from
#
1
two 1,3,5-H
2
BTCˉ ions, and another two O atoms (O7 and O7 ) from two coordinated water
molecules [Co1−N = 2.109(2) Å; Co1−O, 2.098(18)−2.1916(16) Å]. The Co2 centre is surrounded
#2
#2
by four carboxyl O (O12, O12 , O13 and O13 ) atoms from two 1,3,5-H
2
BTCˉ ions, and two N
#2
(
N6 and N6 ) atoms from two L ligands [Co2−N = 2.129(2) Å; Co2−O, 2.1398(16)−2.1916(16)
Å]. The O−Co−O coordination angles vary from 60.40(6) to 119.61(6)°, while the N−Co−O bond
angles are in the 87.58(7)−92.42(7)° ranges. The Co1 and Co2 atoms are six-coordinated and
exhibit octahedral geometries, in which four O atoms (O5, O5#1, O7 and O7 for Co1; O12, O13,
#1
O12#2 and O13#2 for Co2) take the equatorial sites, whereas the N1 (N1 ) and N6 (N6 ) atoms
occupy the axial positions for Co1 and Co2 centers. In complex 5, the L ligand bridges Co1 and
Co2 to form a 1D chain structure with a Co∙∙∙Co separation of 13.1994(6) Å.
#1
#1
(Insert Fig. 5)
{
[Cu
2
L(2,6-PYDC)
2
2 2 2
(H O) ]·4.4H O} (6) Single crystal X-ray study reveals that complex 6
crystallizes in the triclinic system with space group P-1. The dinuclear structure unit, which is
shown in Figure. 6a, displays the coordination environments of Cu1 and Cu2, two
2
crystallographically independent Cu(II) ions, one L ligand, two 2,6-PYDC ˉ ions, two coordinated
2
H O molecules and 4.4 lattice water molecules. Both Cu1 and Cu2 cations are five-coordinated in
a distorted tetragonal pyramid geometry (τ=0.11 for Cu1 and Cu2). Cu1 and Cu2 have similar
coordination environments, coordinating with one N atom and two carboxylate O atoms from the
2
same tridentate (-ONO-) 2,6-PYDC ˉ ion, one N atom from L ligand and one O atom from one
coordinated water molecule. In complex 6, the bond distances of Cu−N and Cu−O are in the range

Page 13 of 39
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of 1.905(2) to 1.944(2) Å and 2.0303(19) to 2.340(2) Å, respectively. The coordination
D
a
O
n
I:
g
1
l
0
e
.
s
10
o
39/C7CE00394C
f
N−Cu−N, N−Cu−O, and O−Cu−O are in the range of 171.38(9) to 174.15(9)°, 80.04(8) to
00.45(8)° and 90.29(8) to 160.35(8)°, respectively. One L ligand bridges Cu1 and Cu2 to form a
1
dinuclear structure unit with a Cu∙∙∙Cu separation of 13.1994(6) Å. Around Cu(II) centre, two O
atoms (O2 and O4 for Cu1, O7 and O9 for Cu2) and two N atoms (N1 and N2 for Cu1, N7 and N8
for Cu2) are located on the equatorial sites, while one O atom (O5 for Cu1, O6 for Cu2) occupies
the vertex of square pyramid. The coordinated H O molecules act as hydrogen bonding donors,
2
while carboxylates are acceptors, generating intermolecular hydrogen bonds. The discrete
dinuclear structure units of 6 are interlinked by the strong O−H∙∙∙O hydrogen bonds to form a 1D
ladder structure (Fig. 6b and Table S2 of Supplementary 1).
(Insert Fig. 6)
{
[Co(L)(4,4′-OBA)]·3.725H
2
O}
n
(7) Crystal structure analysis of 7 indicates a 3D framework
crystallize in the orthorhombic system with space group P2
1
2 2 and consists of one Co(II) ion, one
1
2
L ligand, one 4,4′-OBA ˉ anion and 3.725 lattice water molecules. Each Co(II) ion is coordinated
by two N atoms [Co1−N1 = 2.053(11) Å and Co1−N4=2.022(11) Å] from two L ligands and three
carboxylate O atoms [Co1−O1 = 1.926(11), Co1−O4 = 2.011(10) and Co1−O5 = 2.4582(99) Å]
2
from two different 4,4′-OBA ˉ anions, showing a distorted trigonal bipyramid [CoN
2
O ]
3
coordination mode with the coordination angles varying from 93.6(5)° to 119.0(5)°. It can be
considered that the O1, O4 and O5 atoms are located on the equatorial sites, whereas the N1 and
N4 atoms occupy the axial positions with the N1−Co−N4 bond angle of 107.7(4)° (Fig. 7a).
2
Moreover, the adjacent Co(II) atoms are bridged by 4,4′-OBA ˉ ions linker with a Co∙∙∙Co
separation distance of 14.9418(28) Å, thus furnishing a 3D metal–organic framework (Fig.7b). We
2
can consider each L ligand and 4,4′-OBA ˉ anion to be one connecting rod. So each Co(II) is
linked to four different Co(II) ions, resulting in the formation of an adamantane type cage unit
(Fig.7c). Furthermore, it is interesting that 1-D channels in the 3D framework can be observed
along the c axis, and the channels’ inner surface is decorated by guest H O molecules.
2
Furthermore, the accessible solvent volume is 18.6% per unit cell volume as calculated by
PLATON (Fig.7d).
2
From a topological view, each 2-connected bridging L ligand and 4,4′-OBA ˉ can be
regarded as a linear linker and Co(II) center ion can be treated as 4-connected. Therefore, the 3D

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6
framework of 7 is a 4-connected net with a Schläfli symbol of {6 } (Fig.7e), which is th
D
e
O
s
I
a
: 1
m
0.
e
1039/C7CE00394C
as
complex 4.
(
Insert Fig. 7)
Effect of aromatic carboxylates on the structures of the complexes
In this work, we selected one rigid ligand L, five rigid carboxylate ligands
,2-benzenedicarboxylic acid (1,2-H BDC), 1,3-benzenedicarboxylic acid (1,3-H BDC),
,4-benzenedicarboxylic acid (1,4-H BDC), 1,3,5-benzenetricarboxylic acid (1,3,5-H BTC) and
,6-pyridine dicarboxylic acid (2,6-H PYDC), and one flexible carboxylate ligand
,4′-oxydibenzoic acid (4,4′-H OBA) to synthesis six new mixed-ligand complexes 2−7, aiming to
1
1
2
4
2
2
2
3
2
2
examine the effect of aromatic carboxylates on the architecture of MOFs. In complexes 2−7, all
the rigid ligands L have the same coordination mode connecting six divalent metal ions. The
2
1
,2-BDC ˉ ligands as linkers connect two adjacent metal ions to form a 2D structure based on
pentanuclear structure unit [Cu
(μ
5 3
-OH)
2
(μ
2
-COOˉ)
6
]2+ for 2. For 3, the μ
3
-OHˉ ions bridge four
4
+
Cu atoms forming a tetranuclear cluster [Cu
4
(μ -OH)
3
4
] , which is interlinked by 1,3-HBDCˉ and
2
1
1
,3-BDC ˉ ions to generate the 2D layers, and further lead to a 3D 8-connected sqc3 net. The
2
2
,4-BDC ˉ and the 4,4′-OBA ˉ ligands as linkers connect two adjacent metal ions to form a 3D
adamantane skeleton structure for complexes 4 and 7, while 7 contains 1D channels with the
accessible solvent volume of 18.6%. However, each incompletely-deprotonated 1,3,5-H BTCˉ ion
2
2
doesn’t play a role to bridge two different metal centers in 5. For 6, the 2,6-PYDC ˉ ligand shows
a tridentate coordination mode which makes it difficult to form high dimensional coordination
polymers. This indicates that the different aromatic carboxylates have a great influence on the
architecture of frameworks.27
Powder X-ray diffraction and thermal stability
Powder X-ray diffraction (PXRD) patterns of complexes 1−7 were essentially in accordance
with the simulated patterns, indicating the pure samples of complexes 1−7 (Figure S2 of
Supplementary 2).
To further estimate the stabilities of complexes 1−7, their thermal behaviors were studied by
thermogravimetric analyses (TGA) under argon environment with a heating rate of 10 °C·min-1
from 25 to 1000 °C as shown in Figure S3 of Supplementary 2. Complexes 1 and 2 showed high
thermal stability below 220 °C. When the temperature was elevated, the products gradually lost

Page 15 of 39
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2
their ancillary ligands (two SCNˉ anions for 1; four 1,2-BDC ˉ ions and a pair of μ
) and primary ligands (two L ligands for 1; one L ligand for 2). For 3, the 12.10% (calculated
1.93%) weight loss in the range of 25 to 249 °C may be attributed to the removal of one
uncoordinated ClO ˉ ion and 2.6 lattice water molecules, the second weight loss corresponding to
3
-OH g
D
r
O
o
I
u
: 1
p
0
s
.10fo39
r
/C7CE00394C
2
1
4
the release of organic ligands occurred at about 250 °C. Complex 4 was stable up to 190 °C and
then lost 6.46% (calculated 5.90%) of its weight in the first stage from 190 to 380°C, which can be
assigned to the release of a quarter of lattice water molecules and one coordinated water molecule.
After that, the structure began to collapse above 380 °C. Complex 5 lost its coordinated water
molecule below 200 °C with the weight loss of 2.81% (calculated 2.48%). When the temperature
increased, it began to decompose gradually. For 6, it exhibited a loss of 14.54% between 25 and
264 °C, matching well with the removal of two coordinated water molecules and 4.4 lattice water
molecules (calculated 14.67%), and then the pyrolysis of the framework took place. The first
weight loss of 7 is 10.29% (calculated 11.27%) owing to the dissociation of guest water molecules
from 25 to 330 °C, and then the framework disintegrated until 330 °C.
Photophysical properties and optical band gaps
The research on the photophysical properties and optical band gaps of metal–organic
2
8
structures have been reported in the former literature. The solid state UV−vis absorption spectra
of 1–7 were measured at room temperature. As depicted in the Fig. 8, several characteristic
absorption peaks can be detected, such as 245 nm, 281 nm and 601 nm for 1; 243 nm, 264 nm,
3
09 nm and 701 nm for 2; 256 nm, 263 nm, 339 nm and 735 nm for 3; 240 nm, 295 nm, 387 nm
and 649 nm for 4; 266 nm, 499 nm and 715 nm for 5; 240 nm, 251 nm, 271 nm and 754 nm for 6;
40 nm, 304 nm and 583 nm for 7. Complexes 1–7 show the analogous absorption bands with
2
maxima more than 499 nm, which can be principally ascribed to the d−d transition of the divalent
metal ion. Meanwhile, the band gap energy of these complexes can be calculated according to the
formula: E
g
= 1240/λ
g
(eV), where E
g
is the band gap energy (eV) and λ
values are 3.46 eV for 1, 2.98 eV for 2,
.11 eV for 3, 3.50 eV for 4, 3.61 eV for 5, 3.47 eV for 6 and 3.36 eV for 7, singly. The
g
is the absorption edge
wavelength (nm) (Figure S4 of Supplementary 2). The E
g
3
corresponding E values are in favor of the electron transition, which may be beneficial to
g
catalysis.
(Insert Fig. 8)

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Catalytic activity
DOI: 10.1039/C7CE00394C
In order to investigate the catalytic activity of these complexes, the homocoupling reactions
of aryl iodides were explored under the condition of complexes as heterogeneous catalysts and
metallic magnesium served as reaction substrate. Compared with orthodox catalysts for this
reaction, complexes as catalysts have some advantages, such as the smaller amount of catalysts,
mild reaction conditions, nonpoisonous, environmental friendliness and so on. Firstly, the catalytic
activity of complex 1 was tested for the direct cross-coupling of iodobenzene with metallic
magnesium (1.2 equiv) was used as a model reaction for the screening of optimum reaction
conditions, and the results were summarized in Table 2. To explore the optimal reaction conditions,
a series of reactions were performed via using several time durations, solvents, and catalyst
amount to obtain the best possible combination. According to the evaluated results: 10% mmol is
found to be the most effective catalyst loading, the best reaction time is 8 h, and anhydrous
tetrahydrofuran (THF) is the best solvent.
(Insert Table 2)
With the optimized reaction conditions in hand, the scope of the complexes-catalyzed
homocoupling reactions was investigated by employing various substituted aryl iodides. The most
relevant results in terms of conversion were obtained by using 4-substituted aryl iodides bearing
electron-donating groups (-CH
3
, -OCH
3
) (entries 5-18, Table 3), but for the substrates bearing
electron-withdrawing group (-NO
2
) target product has not been detected (entry 19, Table 3).
Furthermore, the diversity structural 1−7 based on the same N-donor ligand, different ancillary
ligands, and different metal ions [Ni(II), Cu(II), and Co(II)] will help to identify the relation
between the central metals and catalytic performances. As shown in Table 3, complexes 1, 4, and 7
can promote the catalytic homocoupling reaction of all tested aromatic iodides except for the
substrates bearing electron-withdrawing group (-NO ), leading to the corresponding biaryls in
2
good yields without byproducts. Moreover, the complexes 2, 3, 5 and 6 also have high catalytic
activity to obtain the desired products when the reaction substrates bearing electron-donating
groups such as -CH
3
and -OCH .
3
(Insert Table 3)
On the basis of above results, we propose a mechanism for this homocoupling reaction of
aryl iodide. Aryl iodide Grignard reagents are formed in THF by the reaction of aryl iodide with

Page 17 of 39
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metallic magnesium. Then, the fast electrophilic complex with Grignard reagent af
D
fo
O
r
I:
d
1
s
0.1
t
039/C7CE00394C
h
e
monosubstituted species I, which further reacts with Grignard reagent to produce the
diaryl-substituted intermediate II, reductive elimination of II produces the homocoupling products
and revives the catalytically active species (Scheme 2). Although this reaction mechanism is same
as Fan’s report, but our complexes catalysts do not only include the 2D complexes but also contain
0D, 1D and 3D complexes.
(
Insert Scheme 2)
Finally, the durability is another important factor for catalysts when involved in practical
applications. Herein, the recyclability of 1 has been tested for the homocoupling reaction of
-methyl-iodobenzen in the presence of metallic magnesium, and the results were summarized in
4
Table 4. In the recycled and reused experiments, 1 was readily regained from the catalytic reaction
by filtration and washing with methanol. The yield of target product was slightly decreased after
five cycles (Fig. 9a), which indicates that 1 has the excellent stability. Moreover, the PXRD
pattern of 1 after the fifth catalytic reactions closely matches that of single crystals 1 and shows
the same as the skeleton structure, which shows that the structure remains intact after at least five
runs (Fig. 9b).
(Insert Table 4, Fig. 9a and Fig. 9b)
Influence of the structures of the complexes on catalytic activity
According to the above study, the catalytic performance of complexes-based heterogeneous
catalysts is strongly dependent on the structures of the complexes. Frist of all, the E values of
g
complexes 1–7 are in the 2.98–3.61 eV range, which indicates that they have the similar catalytic
activity. Secondly, the experimental results show that 2D and 3D coordination polymers have
higher catalytic activity than 0D and 1D complexes, which is attributed to the higher net structure
prompt the metal center have a stronger ability to accept electrons. As mentioned in the reaction
mechanism, easy to accept electronic complexes are beneficial to form reaction intermediates I
and II. In complexes 1, 2, 4 and 5, although the metal ions are six-coordinated, the weak
coordination groups (coordinated SCNˉ ions for 1, μ -OHˉions for 2 and coordinated water
3
molecules for 4 and 5) are easy to leave, which provide the empty coordination sites to combine
with the Grignard reagent. However, complexes 1 and 7 exhibit preeminent catalytic performance
than others, which is attributes to their unique structure. In addition, the 2D structure of 1 to

CrystEngComm
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2
possess numerous large open channels (dimensions of 13.1756×13.1756 Å ), and these
D
b
O
i
I
g
: 10
o
.1
p
039/C7CE00394C
e
n
channels can promote the transportation of organic substrates and products, taking great advantage
of the touch of the substrates and the catalytic active sites. It is worth noting that the existence of
the 1D channel (the porosity of complex 7 is 18.6%) will be conducive to the transmission of the
reaction substrates in 7, further facilitating the catalytic reaction.
Conclusion
In this article, seven new mixed-ligand complexes are prepared from reactions of metal salts
with L ligands and various auxiliary ligands under solvothermal conditions. The complexes show
diverse structures varying from 0D to 3D networks. The variety of the structures indicates that the
polycarboxylate anions and pH values play dominant roles in the assembly of the final structure.
Moreover, complexes 1–7 exhibit specific photophysical properties which may have potential
applications in heterogeneous catalysis. Noteworthily, the complexes 1–7 can be regarded as a
highly active heterogeneous catalyst for the homocoupling reaction of 4-substituted aryl iodides
bearing electron-donating groups (-CH
3
, -OCH ).
3
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (No.
1361026).
References
2
1
2
3
(a) Y. F. Zeng, X. Hu, F. C. Liu and X. H. Bu, Chem. Soc. Rev., 2009, 38, 469; (b) E. Q. Gao,
Y. F. Yue, S. Q. Bai, Z. He and C. H. Yan, J. Am. Chem. Soc., 2004, 126, 1419; (c) D. M. Chen,
X. Z. Ma, X. J. Zhang, N. Xu and P. Cheng, Inorg. Chem., 2015, 54, 2976; (d) S. D. Jiang, B.
W. Wang, H. L. Sun, Z. M. Wang and S. Gao, J. Am. Chem. Soc., 2011, 133, 4730.
(a) T. Zhang, F. J. Song and W. B. Lin, Chem. Commun., 2012, 48, 8766; (b) J. W. Liu, L. F.
Chen, H. Cui, J. Y. Zhang, L. Zhang and C. Y. Su, Chem. Soc. Rev., 2014, 43, 6011; (c) G. L.
Fan, F. Li, D. G. Evans and X. Duan, Chem. Soc. Rev., 2014, 43, 7040; (d) S. Horike, M.
Dinca, K. Tamaki and J. R. Long, J. Am. Chem. Soc., 2008, 130, 5854.
(a) J. R. Li, R. J. Kuppler and H. C. Zhou, Chem. Soc. Rev., 2009, 38, 1477; (b) P. Q. Liao, D.
D. Zhou, A. X. Zhu, L. Jiang, R. B. Lin, J. P. Zhang and X. M. Chen, J. Am. Chem. Soc., 2012,
134, 13780; (c) J. P. Zhang, Y. B. Zhang, J. B. Lin and X. M. Chen, Chem. Rev., 2012, 112,
1001; (d) H. He, H. Ma, D. Sun, L. Zhang, R. Wang and D. Sun, Cryst. Growth Des., 2013, 13,

Page 19 of 39
CrystEngComm
View Article Online
3
154; (e) X. J. Gu, Z. H. Lu, H. L. Jiang, T. Akita and Q. Xu, J. Am. Chem. Soc., 2
1822; (f) F. L. Li, H. X. Li and J. P. Lang, CrystEngComm, 2016, 18, 1760.
(a) Y. J. Cui, Y. F. Yue, G. D. Qian and B. L. Chen, Chem. Rev., 2012, 112, 1126; (b) M. J. Yan,
D
0
O
1
I
1
: 1
,
0
1
.1
3
039/C7CE00394C
3
,
1
4
Q. Feng and H. H. Song, J. Mol. Struct., 2016, 147, 1112; (c) L. Z. Yang, R. Fang, W. Dou, A.
M. Kirillov, C. L. Xu and W. S. Liu, CrystEngComm, 2015, 17, 3117; (d) Y. L. Shao, Y. H.
Cui, J. Z. Gu, A. M. Kirillov, J. Wu and Y. W. Wang, RSC Adv., 2015, 5, 87484; (e) Y. L. Gai,
F. L. Jiang, L. Chen, Y. Bu, M. Y. Wu, K. Zhou, J. Pan and M. C. Hong, Dalton Trans., 2013,
42, 9954; (f) Z. Su, Y. Zhao, M. Chen and W. Y. Sun, CrystEngComm, 2011, 13, 1539; (f) H.
Deka, R. Sarma, S. Kumari, A. Khare, J. B. Baruah, J. Solid State Chem., 2011, 184, 1726.
(a) J. Q. Liu, X. F. Li, C. Y. Gu, J. C. S. D. Silva, A. L. Barros, S. Alves-Jr, B. H. Li, F. Ren, S.
R. Batten and A. Thereza, Dalton Trans., 2015, 44, 19370; (b) K. M. L. Taylor-pashow, J. D.
Rocca, Z. G. Xie, S. Tran and W. B. Lin, J. Am. Chem. Soc., 2009, 131, 14261.
5
6
(a) X. L. Tong, D. Z. Wang, T. L. Hu, W. C. Song, Y. Tao and X. H. Bu, Cryst. Growth Des.,
2009, 9, 2280; (b) J. Q. Chen, Y. P. Cai, H. C. Fang, Z. Y. Zhou, X. L. Zhan, G. Zhao and Z.
Zhang, Cryst. Growth Des., 2009, 9, 1605; (c) B. Ding, P. Yang, Y. Y. Liu, Y. Wang and G. X.
Du, CrystEngComm, 2013, 15, 2490; (d) L. Wang, Z. H. Yan, Z. Y. Xiao, D. Gou, W. Q. Wang
and Y. Yang, CrystEngComm, 2013, 15, 5552; (e) W. Chen, J. F. Chu, N. Mutikainen, J.
Reedijk, U. Turpeinen and Y. F. Song, CrystEngComm, 2011, 13, 7299.
7
(a) Y. B. Wang, D. S. Liu, T. H. Pan, Q. Liang, X. H. Huang, S. T. Wu and C. C. Huang,
CrystEngComm, 2010, 12, 3886; (b) D. Niu, J. Yang, J. Guo, W. Q. Kan, S. Y. Song, P. Du and
J. F. Ma, Cryst. Growth Des., 2012, 12, 2397; (c) Y. Y. Liu, J. F. Ma, J. Yang and Z. M. Su,
Inorg. Chem., 2007, 46, 3027; (d) R. Sarma and J. B. Baruah, J. Coord. Chem., 2008, 61,
3329.
8
9
(a) Z. X. Xu, Y. Xiao, Y. Kang, L. Zhang and J. Zhang, Cryst. Growth Des., 2015, 15, 4676; (b)
L. Li, T. L. Hu, J. R. Li, D. Z. Wang, Y. F. Zeng and X. H. Bu, CrystEngComm, 2007, 9, 412;
(c) Y. H. Liu, L. P. Lu, M. L. Zhu, S. S. Feng and F. Su, Dalton Trans., 2016, 45, 9267; (d) M.
Aricl, O. Z. Yesilel and M. Tas, Cryst. Growth Des., 2015, 15, 3024.
(a) K. Liu, B. H. Ma, X. L. Guo, D. X. Ma, L. K. Meng, G. Zeng, F. Yang, G. H. Li, Z. Shi and
S. H. Feng, CrystEngComm, 2015, 17, 5054; (b) D. C. Zhong, W. G. Lu and J. H. Deng,
CrystEngComm, 2014, 16, 4633; (c) Y. X. Ye, S. S. Xiong, X. N. Wu, L. Q. Zhang, Z. Y. Li, L.

CrystEngComm
Page 20 of 39
View Article Online
H. Wang, X. L. Ma, Q. H. Chen, Z. J. Zhang and S. C. Xiang, Inorg. Chem., 2016, 5
D
5
O
,
I
2
:
9
10
2
.1
;
0
(
39/C7CE00394C
d
)
C. Ren, L. Hou, B. Liu, G. P. Yang, Y. Y. Wang and Q. Z. Shi, Dalton Trans., 2011, 40, 793.
1
0 (a) A. Aijaz, E. Barea and P. K. Bharadwaj, Cryst. Growth Des., 2009, 9, 4480; (b) K. H. Cui,
S. Y. Yao, H. Q. Li, Y. T. Li, H. P. Zhao, C. J. Jiang and Y. Q. Tian, CrystEngComm, 2011, 13,
3
432; (c) A. Aijaz, P. Lama, E. C. Sanudo, R. Mishra and P. K. Bharadwaj, New J. Chem.,
010, 34, 2502.
2
1
1 (a) S. T. Yan, L. X. Shi, F. F. Sun and C. D. Wu, CrystEngComm, 2010, 12, 3437; (b) K. Wang,
Z. L. Chen, H. H. Zou, Z. Zhang, W. Y. Sun and F. P. Liang, Cryst. Growth Des., 2015, 15,
2883; (c) Y. Deng, C. T. Hou, R. I. Walton, J. Q. Tang, P. Z. Zhu, K. L. Zhang and S. W. Ng,
Dalton Trans., 2013, 42, 12468; (d) J. Z. Gu, Y. H. Cui, X. X. Liang, J. Wu, D. Y. Lv and A.
M. Kirillov, Cryst. Growth Des., 2016, 16, 4658.
12 (a) N. Chen, M. X. Li, P. Yang, X. He, M. Shao and S. R. Zhu, Cryst. Growth Des., 2013, 13,
2650; (b) X. He, X. P. Lu, M. X. Li and R. E. Morris, Cryst. Growth Des., 2013, 13, 1649; (c)
J. S. Hu, Y. J. Shang, X. Q. Yao, L. Qin, Y. Z. Li, Z. J. Guo, H. G. Zheng and Z. L. Xue, Cryst.
Growth Des., 2010, 10, 4135; (d) B. Wu, W. H. Zhang and J. P. Lang, CrystEngComm, 2016,
18, 3048.
13 (a) Q. Yang, X. F. Zhang, J. P. Zhao, B. W. Hu and X. H. Bu, Cryst. Growth Des., 2011, 11,
2
9
839; (b) J. F. Wang, S. Y. Liu, C. Y. Liu, Z. G. Ren and J. P. Lang, Dalton Trans., 2016, 45,
294; (c) T. Huang, Y. L. Wang, Q. Yin, B. Karadeniz, H. F. Li, J. Lu and R. Cao,
CrystEngComm, 2016, 18, 2742; (d) R. Sarma and J. B. Baruah, Inorg. Chim. Acta., 2009,
62, 1681.
4 (a) Y. Y. Yang, Z. J. Lin, J. Liang, Y. B. Huang and R. Cao, CrystEngComm, 2015, 17, 4547;
b) Y. Cheng, M. L. Yang, H. M. Hu, B. Xu, X. F. Wang and G. L. Xue, J. Solid State Chem.,
3
1
(
2016, 239, 121; (c) T. T. Fan, J. J. Li, X. L. Qu, H. L. Han and X. Li, CrystEngComm, 2015,
17, 9443; (d) D. Z. Wang, J. Z. Fan, D. Z. Jia and C. C. Du, CrystEngComm, 2016, 18, 6708.
1
5 (a) K. Chen, Y. S. Kang, L. Luo, Y. Zhao, P. Wang, Q. Liu, Y. Lu and W. Y. Sun, Polyhedron,
014, 79, 239; (b) S. L. Wang, F. L. Hu, J. Y. Zhou, Y. Zhou, Q. Huang and J. P. Lang, Cryst.
2
Growth Des., 2015, 15, 4087; (c) L. P. Xue, X. H. Chang, S. H. Li, L. F. Ma and L. Y. Wang,
Dalton Trans., 2014, 43, 7219; (d) M. Arici, O. Z. Yesilel, M. Tas, H. Demiral and H. Erer,
Cryst. Growth Des., 2016, 16, 5448; (e) L. M. Fan, W. L. Fan, B. Li, X. Zhao and X. T. Zhang,

Page 21 of 39
CrystEngComm
View Article Online
CrystEngComm, 2015, 17, 9413.
DOI: 10.1039/C7CE00394C
16 (a) X. Y. Li, M. Liu, K. F. Yue, Y. P. Wu, T. He, N. Yan and Y. Y. Wang, CrystEngComm, 2015,
17, 8273; (b) J. Park, Y. P. Chen, Z. Perry, J. R. Li and H. C. Zhou, J. Am. Chem. Soc., 2014,
136, 16895; (c) X. L. Zhang, Y. Z. Zhang, D. S. Zhang, B. Y. Zhu and J. R. Li, Dalton Trans.,
2015, 44, 15697; (d) D. C. Hu, Y. Fan, C. D. Si, Y. J. Wu, X. Y. Dong, Y. X. Yang, X. Q. Yao
and J. C. Liu, J. Solid State Chem., 2016, 241, 198; (e) R. Sarma, H. Deka, A. K. Boudalis,
and J. B. Baruah, Cryst. Growth Des., 2011, 11, 547.
1
1
1
2
2
7 (a) Y. L. Shao, Y. H. Cui, J. Z. Gu, J. Wu, Y. W. Wang and A. M. Kirillov, CrystEngComm,
2
4
016, 18, 765; (b) J. A. Hua, Y. Zhao, Y. S. Kang, K. Chen and W. Y. Sun, RSC Adv., 2015, 5,
3268; (c) M. Dai, X. R. Su, X. Wang, B. Wu, Z. G. Ren, X. Zhou and J. P. Lang, Cryst.
Growth Des., 2014, 14, 240; (d) R. Sarma, P. Chowdhury, C. Bikkina, S. Gumma and J. B.
Baruah, J. Chem. Crystallogr., 2010, 40, 892.
8 (a) D. J. Xiao, J. Oktawiec, P. J. Milner and J. R. Long, J. Am. Chem. Soc., 2016, 138, 14371;
(b) J. S. Wang, F. Z. Jin, H. C. Ma, X. B. Li, M. Y. Liu, J. L. Kan, G. J. Chen and Y. B. Dong,
Inorg. Chem., 2016, 55, 6685; (c) G. H. Dang, H. Q. Lam, A. T. Nguyen, D. T. Le, T. Truong
and N. T. S. Phan, J. Catal., 2016, 337, 167; (d) W. Y. Gao, H. F. Wu, K. Y. Leng, Y. Y. Sun
and S. Q. Ma, Angew. Chem. Int. Ed., 2016, 55, 5472.
9 (a) T. Toyao, K. Miyahara, M. Fujiwaki, T. Kim, S. Dohshi, Y. Horiuchi and M. Matsuoka, J.
Phys. Chem. C, 2015, 119, 8131; (b) B. Y. Li, K. Y. Leng, Y. M. Zhang, J. J. Dynes, J. Wang,
Y. F. Hu, D. X. Ma, Z. Shi, L. K. Zhu, D. L. Zhang, Y. Y. Sun, M. Chrzanowski and S. Q. Ma,
J. Am. Chem. Soc., 2015, 137, 4243; (c) W. Q. Zhou, B. H. Zou, W. N. Zhang, D. B. Tian, W.
Huang and F. W. Huo, Nanoscale, 2015, 7, 8720.
0 (a) A. W. Augustyniak, W. Zawartka, J. A. R. Navarro and A. M. Trzeciak, Dalton Trans.,
2016, 45, 13525; (b) H. T. H. Nguygen, O. T. K. Nguyen, T. Truong and N. T. S. Phan, RSC
Adv., 2016, 6, 36039; (c) K. C. Wang, X. L. Lv, D. W. Feng, J. Li, S. M. Chen, J. L. Sun, L.
Song, Y. B. Xie, J. R. Li and H. C. Zhou, J. Am. Chem. Soc., 2016, 138, 914; (d) M. H. Xie, X.
L. Yang and C. D. Wu, Chem. Commun., 2011, 47, 5521.
1 (a) L. Bromberg, X. Su and T. A. Hatton, Chem. Mater., 2014, 26, 6257; (b) J. A. Johnson, J.
Luo, X. Zhang, Y. S. Chen, M. D. Morton, E. Echeverria, F. E. Torres and J. Zhang, ACS
Catal., 2015, 5, 5283; (c) Y. H. Han, Z. Y. Zhou, C. B. Tiana and S. W. Du, Green Chem.,

CrystEngComm
Page 22 of 39
View Article Online
2
016, 18, 4086; (d) S. L. Zhu, X. Xu, S. Ou, M. Zhao, W. L. He and C. D. Wu, Inor
D
g
O
.
I
C
: 1
h
0
e
.1
m
039/C7CE00394C
.
,
2016, 55, 7295.
2
2
2
2 (a) L. Liu, C. Huang, X. Xue, M. Li, H. W. Hou and Y. T. Fan, Cryst. Growth Des., 2015, 15,
4507; (b) L. A. Guo, C. Huang, L. Liu, Z. C. Shao, Y. Tong, H. W. Hou and Y. T. Fan, Cryst.
Growth Des., 2016, 16, 4926.
3 (a) J. P. Li, J. Z. Fan and D. Z. Wang, J. Solid State Chem., 2016, 239, 251; (b) D. Z. Wang, J.
P. Li, J. Z. Fan and D. Z. Jia, Polyhedron, 2016, 111, 123; (c) X. F. Wang, C. C. Du, S. B.
Zhou and D. Z. Wang, J. Mol. Struct., 2017, 1128, 103.
4 (a) J. Chen, M. Z. Li, N. Sun and J. H. Guo, J. Mol. Struct., 2016, 1105, 273; (b) X. Li, Y. K.
Gu, X. B. Deng, K. Zhao and L. P. Jin, CrystEngComm, 2011, 13, 6665; (c) B. Guo, X. Zhang,
Y. N. Wang, J. J. Huang, J. H. Yu and J. Q. Xu, Dalton Trans., 2015, 44, 5095; (d) X. R. Wu,
X. Yang, R. J. Wei, J. Li, L. S. Zheng and J. Tao, Cryst. Growth Des., 2014, 14, 4891.
5 (a) Bruker AXS, SAINT Software Reference Manual, Madison, WI, 1998; (b) G. M.
Sheldrick, Acta Crystallogr. Sect. A: Found. Crystallogr., 2008, 64, 112; (c) G. M. Sheldrick,
SHELX-2014, Programs for the Refinement of Crystal Structures, University of Göttingen,
Göttingen, Germany, 2014.
2
26 (a) A. L. Spek, Acta Cryst. Sect. D, 2009, 65, 148; (b) A. L. Spek, Acta Cryst. Sect. C, 2015,
71, 9.
2
7 (a) T. P. Hu, B. H. Zheng, X. Q. Wang and X. N. Hao, CrystEngComm, 2015, 17, 9348; (b) Y.
L. Li, Y. Zhao, Y. S. Kang, X. H. Liu and W. Y. Sun, Cryst. Growth Des., 2016, 16, 7112; (b) Y.
Y. Yang, Z. J. Lin, T. T. Liu, J. Liang and R. Cao, CrystEngComm, 2015, 17, 1381; (d) L. P.
Zhang, J. F. Ma, J. Yang, Y. Y. Liu and G. H. Wei, Cryst. Growth Des., 2009, 9, 4660.
28 (a) G. S. Yang, H. Y. Zang, Y. Q. Lan, X. L. Wang, C. J. Jiang, Z. M. Su and L. D. Zhu,
CrystEngComm, 2011, 13, 1461; (b) J. H. Liao, J. S. Juang and Y. C. Lai, Cryst. Growth Des.,
2006, 6, 354.

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Captions to Figures
DOI: 10.1039/C7CE00394C
Fig. 1. View of (a) coordination environment of the Ni(II) ion (symmetry codes: #2:-x+1,-y+1,-z;
4
2
#
4:x+1,-y+1/2,z-1/2); (b) 2D structure of complex 1; (c) the 4-connected framework with {4 ·6 }
topology (Hydrogen atoms have been omitted for clarity).
Fig. 2. View of (a) the coordination environment of the Cu1 center in 2; (b) the coordination
environment of the Cu2 center in 2 (symmetry codes: #2:-x-1,-y,-z+1; #3:-x,-y,-z+1); (c) the
coordination environment of the Cu3 center in 2; (d) the pentanuclear structure unit
2+
[Cu
5
(μ
3
-OH)
2
(μ
2
-COOˉ)
6
] formed by two μ
3
-OHˉ groups and six μ
2
-COOˉ ions (symmetry codes:
2
#
1:x-1,y,z; #2:-x-1,-y,-z+1; #3:-x,-y,-z+1); (e) the 1D chain of 2 interlinked by 1,2-BDC ˉ ions
based on [Cu
Cu (μ -OH) (μ -COOˉ)
pentanuclear [Cu (μ -OH)
5
(μ
3
-OH)
2
(μ
2
-COOˉ)
6
]2+ SUBs; (f) the 2D net formed by the
4
2
[
5
3
2
2
6
]2+ SUBs; (g) the 4-connected {4 ·6 } topological structure with a
2+
5
3
2
(μ
2
-COOˉ) ] SUBs (Hydrogen atoms have been omitted for clarity).
6
Fig. 3. View of (a) coordination environment of the the Cu(II) ion (symmetry codes: #3:
-x+1/2,-y+5/2,-z+1); (b) the chair-shaped [Cu
4
(μ
3
-OH)
4
]4+ SBU formed by four μ
-OH groups
3
(symmetry codes: #3: -x+1/2,-y+1/2,-z+1; #5: x,-y+2,z-1/2 ); (c) 2D layers formed by 1,3-HBDCˉ
2
]4+ SBUs; (e) the 8-connected
and 1,3-BDC ˉ ions. (d) the 3D framework formed by [Cu
(μ
4 3
-OH)
4
2
4
4
]4+ SBUs (Hydrogen atoms have been
{
4 ·6 } topological structure based on [Cu
4
(μ
3
-OH)
4
omitted for clarity).
Fig. 4. View of (a) the coordination environment of the Ni center in 4; (b) the left- and
right-handed helix chains composed of Ni(II) ions and L ligands; (c) the 3D adamantane skeleton
6
structure of complex 4; (d) the 3D framework of 4; (e) 4-connected framework with {6 } topology
(Hydrogen atoms have been omitted for clarity).
Fig. 5. View of the 1D chain structure formed by L ligands in 5 (symmetry codes: #1:-x,-y+1,-z;
2:-x+2,-y,-z) (Hydrogen atoms have been omitted for clarity).
#
Fig. 6. View of (a) the coordination environment of the Cu center in 6; (b) the 1D ladder structure

CrystEngComm
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formed by O-H∙∙∙O hydrogen bonds (Hydrogen atoms have been omitted for clarity).
DOI: 10.1039/C7CE00394C
Fig. 7. View of (a) the coordination environment of the Co center in 7; (b) the 3D adamantane
skeleton structure of complex 7; (c) the 3D framework of 7; (d) the space filling model of the
6
framework; (e) the 3D 4-connected net with {6 } topology of 7 (Hydrogen atoms have been
omitted for clarity).
Fig. 8. View of UV−vis absorption spectra at room temperature for complexes 1−7.
Fig. 9. (a) Recycling test for 1 as catalysts; (b) compared with the PXRD of 1 before and after
catalysis.
Table 1. Crystal Data and Structure Refinement Summary for complexes 1~7
1
2
3
4
formula
C
22
H
16
N
14
S
2
Ni
C
42
H
26
N
6
O
18Cu
5
C
36
H
37.2
N
12
O
18.6ClCu
4
C
18
H
14.50
N
6
O
5.25
N
i
formular wt
crystal system
space group
T/K
599.32
1120.39
Triclinic
P-1
1225.19
Monoclinic
C2/c
457.57
Monoclinic
P2(1)/c
296(2)
7.409(2)
16.144(5)
10.837(3)
90
Triclinic
P-1
273(2)
296(2)
296(2)
a/Å
7.6597(11)
11.1980(16)
13.3076(18)
110.824(4)
95.302(4)
104.344(4)
1012.9(2)
1
29.8816(12)
7.7255(3)
21.4941(9)
90
8.4549(3)
9.6723(4)
12.4874(6)
b/Å
c/Å
a/deg
111.4130(10)
90.1010(10)
101.5080(10)
928.48(7)
2
β/deg
γ/deg
107.531(9)
90
117.245(2)
90
V/Å3
1236.0(6)
2
4411.4(3)
4
Z
D/g cm-3
µ/mm-1
F(000)
1.610
2.001
1.842
1.637
0.999
2.676
2.056
1.093
612
609
2472
469
messured reflns
obsd reflns
7649
6636
14470
4083
6135
2137
3611
3360

Page 25 of 39
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Ra/wRb
View Article Online
0.0604/0.1401
DOI: 10.1039/C7CE00394C
0.0447/0.1063
0.0406/0.0901
0.0358/0.0983
5
6
7
formula
C
28
H
22
N
6
O
14Co
C
24
H
26.8
N
8
O
14.4Cu
2
C
24
H
23.45
N
6
O8.725Co
formular wt
crystal system
space group
T/K
725.44
784.81
Triclinic
P-1
594.46
Orthorhombic
P2
Triclinic
P-1
1
1
2 2
296(2)
296(2)
273(2)
16.979(3)
24.792(5)
6.1089(11)
90
a/Å
10.5905(5)
11.7646(5)
13.5378(6)
6.8758(3)
10.5245(5)
21.6313(9)
80.5010(10)
84.0300(10)
72.1610(10)
1467.26(11)
2
b/Å
c/Å
a/deg
105.3360(10)
105.4280(10)
106.8560(10)
1445.46(11)
2
β/deg
90
γ/deg
90
V/Å3
2571.4(8)
4
Z
D/g cm-3
µ/mm-1
F(000)
1.667
1.780
1.525
0.681
1.538
0.730
742
802
1216
messured reflns
obsd reflns
Ra/wRb
9549
9723
16566
4597
5219
5243
0.0372/0.1068
0.0332/0.0916
0.0724/0.2980
a
b
|2−|F
2 2
2)]1/2
R = Σ(||F
0
|−|F
C
||)/Σ|F
0
|; wR = [Σw(|F
0
C
| ) /Σw(F
0
COOH
COOH
N
N
N
N
HOOC
COOH
N N
HOOC
COOH
L
2BDC
2BDC
1,3-H BDC
1,4-H
1,2-H
2
COOH
O
HOOC
N
COOH
HOOC
HOOC
COOH
COOH
3BTC
2,6-H PYDC
2BOA
4,4'-H
1
,3,5-H
2
Scheme 1 Structures of L and auxiliary polycarboxylates ligands used in this work.

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Page 26 of 39
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DOI: 10.1039/C7CE00394C
(a)
(b)
(c)
Fig. 1

Page 27 of 39
CrystEngComm
View Article Online
DOI: 10.1039/C7CE00394C
(a)
(b)
(c)

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DOI: 10.1039/C7CE00394C
(d)
(e)
(f)
(g)
Fig. 2

Page 29 of 39
CrystEngComm
View Article Online
DOI: 10.1039/C7CE00394C
(a)
(b)
(c)