Coordination polymers based on substituted terpyridine ligands: synthesis, structural diversity, and highly efficient and selective catalytic oxidation of benzylic c-h bonds

Article abstract of DOI:10.1021/acs.cgd.5b00008

Reaction of two related rigid terpyridine ligands, 4′-(4-cyanophenyl)-4,2′:6′,4-terpyridine (L¹) and its derivative, 4′-(4-carboxyphenyl)-4,2′:6′,4-terpyridine (L²), with transition metal ions (Co²⁺ or Cu²⁺/Cu⁺), afforded four novel coordination compounds: Co(L¹)Cl₂ (1), Co₃(L¹)₃Cl₆ (2), Cu^I₉(L¹)_4.5(CN)₉ (3), and [Cu^II₃(L²)₆(H₂O)₆]·4H₂O (4). Crystal structure analysis reveals that 1 is comprised of single-stranded 2₁ helical chains, and weak interactions involving C-H···Cl weak hydrogen bonding and stacking interactions exist in the structure. The structure of 2 is comprised of 3₂ helices, which is compared with the structure of compound 1. 3 shows a three-dimensional (3D) 4-fold interpenetration structure. 4 exhibits a one-dimensional gridlike belt structure, which further builds 3D supramolecular architecture via stacking interactions. These novel coordination compounds show exceptional catalytic activity for the oxidation of benzylic C-H bonds. Notably, compound 4 shows the best catalytic properties for the oxidation of benzylic hydrocarbons up to 99% conversion and 99% selectivity.

Full text of DOI:10.1021/acs.cgd.5b00008

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Article
Coordination Polymers based on Substituted Terpyridine
Ligands: Synthesis, Structural Diversity, and Highly Efficient
and Selective Catalytic Oxidation of Benzylic C-H Bonds
Ya-Ru Xi, Wei Wei, Yan-Qing Xu, Xianqiang Huang, Fanzhou Zhang, and Changwen Hu
Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.5b00008 • Publication Date (Web): 28 Apr 2015
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Coordination Polymers based on Substituted
Terpyridine Ligands: Synthesis, Structural
Diversity, and Highly Efficient and Selective
Catalytic Oxidation of Benzylic C-H Bonds
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Yaru Xi†, Wei Wei‡, Yanqing Xu†*, Xianqiang Huang†ǁ*,Fanzhou Zhang†, Changwen
Hu*†
† Key Laboratory of Cluster Science, Ministry of Education of China, Department of Chemistry, Beijing
Institute of Technology, Beijing 100081, P. R China. E-mail: xyq@bit.edu.cn; cwhu@bit.edu.cn. Fax:
+86-10-68912631; Tel: +86-10-68918468
‡ Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China.
ǁShandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, School
of Chemistry& Chemical Engineering Liaocheng University, Liaocheng, 252059, P. R. China
Abstract
Reaction
of
two
related
rigid
(L1)
terpyridine
and its
ligands,
4’-(4-cynaophenyl)-4,2’:6’,4-terpyridine
derivative
4’-(4-carboxyphenyl)-4,2’:6’,4-terpyridine (L2), with transition metal ions
(Co2+,Cu2+/Cu+) afforded four novel coordination compounds: Co(L1)Cl2 (1),
Co3(L1)3Cl6 (2), CuI9(L1)4.5(CN)9 (3), [CuII (L2)6(H2O)6]·4H2O (4). Crystal structure
3
analysis reveals that 1 is comprised of single-stranded 21 helical chains and weak
interactions involving C-H…Cl weak hydrogen bonding and π-π stacking interactions
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exist in the structure. The structure of 2 is comprised of 32 helices which is compared
with the compound 1. 3 shows a 3D 4-fold interpenetration structure. 4 exhibits a 1D
grid-like belt structure, which further builds 3D supramolecular architecture via π-π
stacking interactions. These novel coordination compounds show exceptional
catalytic activity for the oxidation of benzylic C-H bonds. Notably, compound 4 show
the best catalytic properties for the oxidation of benzylic hydrocarbons up to 99%
conv. and 99% sele..
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Keywords terpyridine compounds, crystal structure, catalytic oxidation
Introduction
Functionalization of C-H bonds is a powerful tool to generate high value chemical
feedstock from less expensive raw materials, and has become a central challenge in
modern organic chemistry.1-3 In this regard, conversion benzylic hydrocarbons into
valuable matters have received considerable attention in recent years.4-5 Despite of the
high conversion rate, many benzylic C-H bonds oxidation reactions reported to date
rely on homogeneous catalysts and thus recyclability and reusability of these
specially-designed catalysts can be problematic.6 Design of the heterogeneous
molecular catalysts containing catalytic active sites has proved to be the most valuable
strategy to solve this problem.
Copper and cobalt compounds has been extensively investigated as oxidation
catalyst for oxidation of benzylic C-H bonds.7-14In these catalysts, metal
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centers,which are usually coordinated to the N-donor or O-donor ligands such as
pyrimidine, imidazole, porphyrins, bipyridines, phenanthrolines and polycarboxylic
acids and acted as catalytic active sites, played a crucial role in the catalytical reaction.
For example, Su et al. report a polycatenated 3D Cu(II) square-grid MOF,
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[CuII(bped)2(H2O)2(SiF6)](bped=meso-1,2-bis(4-pyridyl)-1,2-ethanediol)
display adsorption behaviors and efficient catalytic activities.10
which
Multipyridyl ligands of 4,2’:6’,4-terpyridine are a well-known class of ligands
which have some advantages for constructing metal-organic frameworks (MOFs),
especially the ligands with additional function such as (4-X-C6H4) (X: C≡CH, COOH,
Br, SMe, NMe2) groups incorporated into the 4’-position. The type of MOF had
potential applications in the area of catalysis, luminescence, gas uptake, magnetism
and biochemical activities.15-36 In this regard, Constable et al. have reported Co(SCN)2
reacted with 4’-C6H5- and 4’-(4-C≡CH-C6H4)- 4,2’:6’,4-terpyridine to offer two kinds
of cobalt frameworks, (4,4) and (6,3) nets, respectively.31 Wen and Ke et al. have
reported
two
porous
cadmium(II)
frameworks
with
a
polytopic
4-(4-carboxyphenyl)-4,2´:6´,4´´-terpyridine ligand, which show selective adsorption
of CO2 and display strong photoluminescence.32 Then following, this bridging
coligands coordinated with Zn(Ⅱ),Co(Ⅱ), Mn(Ⅱ) resulting different kinds of the
interpenetration,
polycatenane,
interdigitation,
polythread,
and
other
species.33-36However, coordination compounds with terpyridine ligands have rarely
been investigated in the oxidation catalytic reactions.37
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Herein, we successfully prepared four coordination polymers Co(L1)Cl2 (1),
Co3(L1)3Cl6 (2), Cu9(L1)4.5(CN)9 (3), [Cu3(L2)6(H2O)6]•4H2O (4) through
hydrothermal method. The dimensionalities of the entire architectures of the four
compounds vary from 1D to 3D, and we found that the solvent and subtle temperature
changes have a profound impact on the self-assembly of polymeric networks. We also
successfully employed the four coordination polymers as highly efficient catalyst for
the oxidation of benzylic hydrocarbons up to 99% conv.and 99% sele..
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Experimental Section
Materials and Methods. All of the chemicals and solvents were commercially
available without further purification. L1 was synthesized by a modification of the
literature methods.38 And L2 was readily obtained through the hydrolysis of L1. IR
spectra were recorded with KBr pellets on a Nicolet 170S Fourier transform infrared
spectrometer in 4000-400 cm-1 region. Powder X-ray diffraction data (PXRD) were
collected on Bruker SMART APEX-CCD using Cu-Kα radiation (λ = 1.54060 Å).
Thermal gravimetric analyses (TGA) were performed in a nitrogen atmosphere on a
Q50TGA with a heating rate of 10 °C min−1. The syntheses of compounds 1-4 are
shown in Scheme 1.
Synthesis of Ligand L1. Ligand L1 was prepared by the procedure of Beves with a
little modification.38 4-Acetylpyridine (4.84 g, 40.0 mmol) was added to a solution of
4-cyanobenzaldehyde (2.69 g, 20.5 mmol) in MeOH (100 cm3). KOH (2.70 g, 50
mmol) and aqueous NH3 (60 cm3, 25%) were added to the solution and the mixture
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was stirred at room temperature for 0.5 h. After refluxing for 12 h, the formed
off-white solid was collected by filtration and washed with EtOH (3 × 15 cm3).
Ligand L1 was isolated as white polycrystalline solid after recrystallization from
CHCl3-MeOH. Yield: 47.0%. Melting point: >250 °C. Anal.Calcd for C22H14N4 (%):
C, 79.02; H, 4.22; N, 16.76. Found: C, 78.03; H, 4.35; N, 16.52. FT-IR (KBr pellet,
cm-1): 3037(w), 2228(m), 1595(s), 1560(m), 1543(m), 1510(m), 1429(w),
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1396(m),819(s), 631(m), 620(w), 578(w); H NMR (d-DMSO, 600 MHz) δ(ppm):
8.10 (d, J = 8.2 Hz, 2H), 8.35(d, J = 8.2 Hz, 2H), 8.36(d, J = 6.0 Hz, 4H), 8.58(s, 2H),
8.79(d, J = 6.0 Hz, 4H).
Synthesis of Ligand L2. A mixture of L1 (1.07g, 3.2mmol), KOH (10.0g,
178.6mmol) and H2O (200 mL) were added to a round bottom flask and stirred at 100
ºC until dissolved. After cooled to room temperature, concentrated hydrochloric acid
was slowly dropwise added into the mixture under stirring until pH reached about 3.
After filtration, the obtained white precipitate was washed with ethanol and then dried
in the air at 60ºC. Yield: 97.0%. Melting point: >250 °C. Anal.Calcd for C22H15N3O2
(%): C, 74.78; H, 4.28; N, 11.89. Found: C, 75.05; H, 4.06; N, 11.67. FT-IR (KBr
pellet, cm-1): 421 (s), 3071(w), 1707(m), 1631(s), 1598(s), 1508(m), 1395(m),
1
1120(m), 830(m), 773(m), 740(s), 615(s), 596(s), 530(s); H NMR (d-DMSO, 600
MHz) δ(ppm): 8.00 (d, J = 8.4 Hz, 2H), 8.27 (d, J = 8.4 Hz, 2H), 8.35 (s, 2H), 8.40 (d,
J = 6.0 Hz, 4H), 8.79 (d, J = 6.0 Hz, 4H).
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[Insert Scheme 1]
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Synthesis of Co (L1)Cl2 (1). A mixture of CoCl2·6H2O (7.14 mg, 0.03 mmol), L1
(10.0 mg, 0.03 mmol) and acetonitrile (5 mL) were sealed in a 10 ml Teflon-lined
autoclave and heated to 160 ºC for 3 days, followed by slowly cooling to room
temperature. After filtering the solution, blue strip crystalline products 1 were
obtained, washed with acetonitrile (2 mL) and dried in air. Yield: 20.0%. Anal.Calcd
for C22H14Cl2CoN4 (%): C, 56.89; H, 3.02; N, 12.06. Found: C, 57.02; H, 3.10; N,
12.15. FT-IR (KBr pellet,cm-1): 2990(w), 2226(w), 2065(m), 1637(m), 1617(s),
1489(m), 1397(m), 1174(m), 1137(w), 1002(s), 788(s), 620(m), 530(w).
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Synthesis of Co3(L1)3Cl6 (2). Blue hexagonal plate crystals 2 were prepared with
analogous procedure as 1, except that reaction temperature was decreased to 100 ºC.
Yield: 13.1%. Anal.Calcd forC66H42Cl6Co3N12 (%): C, 56.89; H, 3.02; N, 12.06.
Found: C, 57.12; H, 3.07; N, 12.11. FT-IR (KBr pellet, cm-1): 2990(w), 2227(m),
2065(m), 1637(m), 1617(s), 1488(m), 1396(m), 1174(m), 1137(w), 1002(s), 788(s),
622(m), 540(w).
Synthesis of CuI9(L1)4.5(CN)9 (3). A mixture of Cu(NO3)2·3H2O (7.25 mg,
0.03mmol), L1 (10.0 mg, 0.03mmol) and acetonitrile (8 mL) were sealed in a 16 mL
Teflon-lined autoclave and heated at 160 ºC for 3 days, followed by slowly cooling to
room temperature. After filtering the solution, long strip orange crystals 3 were
obtained. Yield: 24.2%. Anal.Calcd forC108H63Cu9N27 (%): C, 56.09; H, 2.73; N,
16.36. Found: C, 56.51; H, 3.07; N, 16.11. FT-IR (KBr pellet, cm-1): 2973(w),
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2225(w), 2126(m), 1599(s), 1541(w), 1394(m), 1061(w), 1011(w), 827(s), 672(m),
642(m), 544(m).
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Synthesis of [Cu3(L2)6(H2O)6]•4H2O (4). A mixture of Cu(CH3COO)2·H2O (6.0
mg, 0.03mmol), L2 (10.5 mg, 0.03mmol) and H2O (8mL) were sealed in a 16ml
Teflon-lined autoclave and heated at 160 ºC for 3 days, then cooled to room
temperature. After filtering the solution, blue strip crystals 4 were obtained. Yield:
10.2%. Anal.Calcd for C132H106Cu3N18O22 (%): C, 63.75; H, 4.30; N, 10.14. Found: C,
63.31; H, 4.37; N, 9.95. FT-IR (KBr pellet, cm-1): 3431(s), 1617(w), 1595(m), 1595(s),
1551(m), 1384(s), 1217(w), 1063(m), 847(w), 784(m), 696(m), 633(m), 512(m).
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General Procedure for Catalyzed Oxidation of benzylic hydrocarbons.
Benzylic hydrocarbons (0.1250 mmol), 70% tert-butyl hydroperoxide (TBHP)
(0.3125 mmol) and catalyst (4 µmol) were placed into a Schlenk Tube, and then
chlorobenzene (1 mL) was added to the mixture. Subsequently the reaction mixture
was heated to 80ºC in a Wattecs Parallel Reactor and maintained 24 h under stirring.
After the oxidation reaction, the mixture was cooled down to room temperature. Then
the resulting mixture was analyzed by GC-MS and GC using naphthalene as external
standard.
Crystal structure determination. The X-ray single-crystal data for compounds
was carried on a Bruker Smart CCD diffractometer with graphite-monochromated Mo
Kα radiation (λ = 0.71073 Å) at 293 K. The data sets were corrected by empirical
absorption correction using spherical harmonics, implemented in the ω-scaling
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algorithm. The structures of all compounds were solved by direct methods and refined
by full-matrix least-squares methods with SHELX-97. All non-hydrogen atoms were
refined anisotropically. All the hydrogen atoms are placed in calculated positions. For
2, we used the SQUEEZE command in the refine process as the solvent molecules
can’t be accurately determined owing to dispersibility of the electron cloud density.
The crystallographic data are collected in Table 1. Important bond lengths and bond
angles are listed in Table S1 in the ESI.†.
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[Insert Table 1]
Results and Discussion
Syntheses. The ligand L1 was synthesized according to the reaction
cyanobenzaldehyde with two equivalents of 4-acetylpyridine under the basic
condition. Then, L1 was hydrolyzed to the ligand L2 with carboxyl group under acidic
conditions. The ligands are poorly soluble in solvent at room temperature so we
adopted a solvothermal method which can promote the solubility of ligands. In this
system, the self-assembly process is obviously affected by various factors such as
reaction temperature, metal ions and coordinated disposition of the ligands. As we
expected, the benzonitrile group of L1 is not coordinated in the assembly process,
whereas the carboxyphenyl of L2 is connected with metal ions through oxygen atoms,
which greatly affects the resulting structures and properties.
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Structure description of Co (L1)Cl2(1). Single crystal X-ray diffraction analysis
reveals that compound 1 crystallizes in the monoclinic space group P21/n. In the
asymmetric unit there are one cobalt ion, one L1 ligand and two bound Cl- anion. As
shown by Figure 1a, Co2+ is surround by two nitrogen atoms from two L1 and two
chloride anion to furnish a distorted CoN2Cl2 tetrahedral geometry. Significantly, each
L1 is connected to two Co2+via the terminal N-donors of pyridyl groups leaving the
nitrile group uncoordinated, thus L1 acts as a bidentate-bridging linker, leading to a
one-deimensional 21 helical chain with the a pitch of 16.7Å and the distance of
Co···Co along the chain being 12.727(1) Å (Figure 1b). Various weak interactions
are also found in the packing structure, involving π π interactions among pyridyl
rings of L1 from adjacent helices in an offset face-to-face stacking fashion
(centroid-to-centroid distances of 3.619 Å and 3.708 Å), weak interactions of the
nitrile groups and pyridyl rings of L1 via face-to-face stacking interaction (distance:
3.589 Å) and C-H…N weak hydrogen bonding interaction (distance: 3.260 and 3.284
Å), as are shown in Figure 1c and 1d.
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[Insert Figure 1]
[Insert Figure 2]
Structure description of Co1.5(L1)1.5Cl3 (2). Compound 2 crystallizes in the
trigonal space group P3221 with its asymmetric unit consisting of two
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crystallographically independent cobalt ions, one and a half ligand L2, and three Cl-
anions, shown in Figure 2a. In this structure, the cobalt centers also adopts four
coordinated tetragonal geometry defined by two Cl- anions and two pyridyl nitrogen
atoms from L1 to form helical chains with the distance of Co···Co 12.540(1) Å
(Figure 2c). For the reason that the procedure of 1 and 2 are almost the same expect
the temperature, they seem to show the comparable chain-like structure. But in fact
they are distinct from each other. Compound 2 shows more complicated helical
structure. A 32 axis in 2 instead of 21 axis in 1 runs along oc direction(Figure 2c). In 1,
two neighboring L1 arrange in the same orientations and positions, while the spatial
directions of alternate L1 in 2 are different, which can be ascribed to two types of
crystallographically independent cobalt ions and L2 in 2. Similar to 1, the π⋯π
stacking interactions between the pyridyl rings or C≡N (centroid-to-centroid distance
of 3.801 and 3.960 Å) in neighboring chains sustain the interdigitated structure
(Figure 2b).
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[Insert Figure 3]
Structure description of Cu9(L1)4.5(CN)9 (3). As is shown in Figure 3a,
compound 3 crystallizes in the orthorhombic Pbcn space group with its asymmetric
unit comprising nine CuI ions, four and a half L1 ligands and nine cyanide ions. The
existence of cyanide ions can be proved by 2126 cm-1 of the bridged CN- stretching in
IR, which is in agreement with the previously reported result.39 Despite the absence of
CN- anions in the reactant system, they probably originate from the decomposition of
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solvent acetonitrile and/or L1 at high temperature, and simultaneously reduced Cu2+ to
Cu+.40 Similarly, the XPS experiments were carried out for testing the charge of
cooper in the compounds 3. Thus, Figure S2 show plots of the Cu2p3/2 (931.14eV) and
Cu2p1/2 (950.97eV) photoelectron being in agreement with those previously reported
and discussed in the literature for Cu+.41 In this structure, each copper ion is bridged
by two C/N of CN- and one pyridyl nitrogen atoms of L1 to form distorted triangular
coordination geometry. As a rigid “V” type connector, each L1 ligand combines with
two CuI ions via two pyridyl groups, leaving the nitrile group uncoordinated. Also,
CN- anion acts as a linear ꢀ2- ligand bridging cuprous ions. As shown by Figure 3b
and 3c, ꢀ2-L1/CN- connectors and three-connected cuprous node construct two types
of ring motif: tetranuclear and octanuclear cuprous rings. Tetranuclear cuprous ring is
comprised of two L1, two CN- and four cuprous ions, and the distance of Cu···Cu is
4.857 Å along the CN- and 13.136 Å along L1. Meanwhile, two L1, six CN- and eight
cuprous ions construct an elliptical octanuclear ring, whose longest Cu···Cu distance
is 23.485 Å. In this way, the two ring motifs connect with each other to construct a 3D
network with large hexagonal channels (see Figure S3).† Notably, the large size void
in the layer structure provide the possibility for the ultimate generation of the
entanglement. As shown in the Figure 3d, the structure is reinforced by a 4-fold
interpenetration to a resultant stable close structures.
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[Insert Figure 4]
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Structure description of [Cu3(L2)6(H2O)6]•4H2O (4).The reaction between L2 and
Cu(CH3COO)2•H2O afforded blue strip crystals 4 that crystallize in the triclinic space
group P-1. In the asymmetric unit, there are one and a half cooper ions and three L2.
As shown in the Figure 4a, each Cu1 forms a distorted CuN2O3 tetragonal pyramid
geometry with two nitrogen atoms and two oxygen atoms from four L2 ligands
occupying the equatorial positions and one oxygen atom from a coordinated H2O
filling the axial position; While the Cu2 center adopts a distorted octahedral geometry
defined by two pyridyl nitrogen atoms and two carboxylate oxygen atoms from two
non-equivalent L2 ligands, two oxygen atoms from water molecule occupying the
axial position. It’s noted worthy that the axial position is occupied by water molecule
via the weak coordination interaction for the Jahn-Tellar effect of Cu (with the Cu-O
distance being 2.305 and 2.481 Å), which makes them potential active sites for further
catalytic property.
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In this structure, each L2 ligand acts as a bridging linker to connect Cu(II) centers
using one of the pyridine terminal nitrogen atoms and the carboxylate oxygen atom to
form a grid-like infinite 1D chain with a minimum Cu…Cu distance of 14.288 Å
(Figure 4a). Unlike compound 3, (a) the introduce of -COOH instead of -C≡N bring
new bridging mode of this ligand; (b) without the acetonitrile in the reaction system,
the oxidation state of Cu is +2 in 4. As depicted in Figure 4b and 4c, although the
residual pyridyl rings and phenyl rings are not engaged in coordination, it bears the
offset face-to-face π...π stacking interactions with their corresponding rings of
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adjacent chains with centroid-to-centroid distance of 3.537, 3.883 and 3.811 Å, which
further aggregated 3D network.
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Thermal stability and Powder XRD. In order to investigate the thermal stability
of compounds 1-4, the thermal gravimetric analyses (TGA) were carried out in the
temperature range of 25-800 °C under nitrogen atmosphere (in Figure S4) (ESI).†
Their main skeletons are stable till 300-500 °C and show excellent thermal stability.
The collapse temperature is about 460°C for 1, 440 °C for 2, 360°C for 3, and 290°C
for 4, respectively. Specially, for compound 4, there’s a weight loss before 79°C
(observed 7.41 %, theoretical 7.85 %), which can be attributed to the release of lattice
water molecules.
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Furthermore, the powder X-ray diffraction patterns of compounds 1-4 are
illustrated in Figure S5 (ESI)† which confirm the purities of the bulky crystalline
samples 1-4 between the simulated ones and as-synthesized products.
Oxidation Catalytic test. With the aim to understand the catalytic property of
these coordination polymers for developing a new oxidation system in organic
chemistry, the oxidation of diphenylmethane to benzophenone was selected as a
model reaction (Scheme 2).
[Insert Scheme 2]
[Insert Figure 5]
The primary results suggest that, all four compounds can promote the catalytic
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oxidation of diphenylmethane, leading to benzophenone and diphenylmethanol with
preferable selectivity of the carbonyl product. Optimization of the reaction conditions
were carried out by selectively evaluating effects of different diphenylmethane-to-4
molar ratios, oxidant-to-4 molar ratios, and solvents (Supporting Information Table
S2). As depicted in Table S2, on the basis of the oxidation of diphenylmethane, 2.5
equiv of TBHP and 4 µmol of catalyst in chlorobenzene for 24h are appropriate
conditions for all catalytic reactions. Under the same conditions, we note that
compounds 1, 2 and 3 showed moderate activities while 4 presented superior activity
toward the oxidation reaction, giving a 94.5% conversion and 92.6% selectivity in
chlorobenzene at 80°C for 24h (Figure 5). These results exhibit that compound 4 can
facilitate the oxidation of diphenylmethane and serve as highly efficient and selective
catalyst. And indeed, yield of the compound 4 outperforms many effective catalysts
reported to date, i.e. nano-sized coordination cages [CuII(bped)2(H2O)2(SiF6)],10
[Cu4L4]4X (L= 1,3,5-tris(1-benzylbenzimidazol-2-yl)benzene, X= ClO4, OTs, OTf),11
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NHPI/Cu@PILC12,
[Co3(BTC)2(HCOO)4(DMF)]•H2O13
and
even
noble
Pd@N-doped carbon14, etc.
Furthermore, control catalytic experiments of the catalytic oxidation of
diphenylmethane were performed on L2 and Cu(CH3COO)2·H2O under the same
reaction conditions, respectively. The conversion was 8.71% for the former and 75.8%
for the latter. Based on the above-mentioned facts, we conclude that the introduce of
L2 into the catalytic system changes the coordination environment of the Cu ions and
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the cooperation between CuII centers and organic ligands in catalyst of 4 probably
produces synergistic effect; and thus enhances the oxidative capacity of copper
centers in the catalytic process.
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[Insert Table 2]
Following the success of diphenylmethane oxidation and evaluating the scope and
limitations of the current procedure, oxidation reactions with an array of benzylic
hydrocarbons were examined using compound 4. A compilation of results for the
oxidation of various benzyl-alkanes with large molecules, along with the
corresponding ketones is presented in Table 2. It is noteworthy that, without any
further optimization, the oxidation of fluorene, the derivatives of the fluorene and
xanthene proceeded smoothly with a high catalytic activity (>99% conversion, >99%
selectivity for ketones). These preliminary results exhibit that these coordination
polymers based on substituted terpyridine, especially compound 4, can facilitate the
oxidation of benzyl-alkanes and serve as highly efficient and selective catalysts.
Conclusions
In this paper, four coordination compounds were successfully synthesized by two
types of substituted terpyridine ligands L1 and L2 with transition metal ions of Co and
Cu ions under solvothermal conditions. These compounds possess different
architectures such as 1D helix or grid-like chain and 3D interpenetration network,
whichdemonstrates that a change of temperature and metal ions have played a crucial
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role in the self-assembly process. Meanwhile, all the compounds show good thermal
stabilities. In addition, the compound 4 exhibits excellent oxidation catalytic
properties towards benzyl-alkanes. The good catalytic properties along with the high
thermal stability make these compounds potential applicable under more rigorous
reactions specially as the heterogeneous catalysts.
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Acknowledge
We are grateful to the National Natural Science Foundation of China (Project No.
21271025, 11474204; 21401094), Beijing Higher Education Young Elite Teacher
Project (Project No. 1209 and 1628) and Beijing Municipal Natural Science
Foundation (Project No. 2143039).
Associated content
Supporting Information Available
Crystallographic data in CIF format, PXRD for simulated and as-synthesized samples,
TG curves for all compounds, XPS for compound 3 and selective oxidation of
diphenylmethane by 4 using TBHP oxidant. This material is available free of charge
via the Internet at http://pubs.acs.org.
References
(1) Brodsky, B. H.; Du Bois, J.J. Am. Chem. Soc. 2005, 127, 15391-15393.
(2) Lee, S. M.; Fuchs, P. L. J. Am. Chem. Soc. 2002, 124,13978-13979.
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1
2
3
4
(3) Genuine,J.; Lutz, S.;Sames, D.;Toure, B. B. J. Am.Chem. Soc. 2013, 135,
5
6
7
12346-12352.
8
9
(4) George, S. D.;Sherman, S. C.;Iretskii, A. V.; White, M. G. Catal. Lett.2000,65,
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
181-183.
(5) Delgiacco, T.;Baciocchi, E.;Steenken, S. J. Phys.Chem. 1993, 97, 5451-5456.
(6) Hemeon, I.; Barnett, N. W.;Gathergood, N.;Scammells, P. J.; Singer, R. D. Aust. J.
Chem. 2004, 57, 125-128.
(7) Velusamy, S.; Punniyamurthy, T. Tetrahedron Lett.2003, 44, 8955-8957.
(8) Ma, Y.; Zeng, M.; He, J.; Duan, L.; Wang, J.; Li, J.; Wang. J. Appl.Catal. A:
Gen.2011, 396, 123-128.
(9) Luz, I.; León, A.; Boronat, M.; LlabrésiXamena, F. X.; Corma, A. Catal. Sci.
Technol. 2013, 3, 371-379.
(10) Wang, S.; Li, L.; Zhang, J.; Yuan, X.; Su, C.-Y. J. Mater. Chem.2011, 21,
7098-7104.
(11) He, Q.-T.; Li, X.-P.; Chen, L.-F.; Zhang, L.; Wang, W.; Su, C.-Y.ACS Catal.2013,
3, 1-9.
(12) Zhao, Q.; Zhang, P.; Antonietti, M. Yuan, J. J. Am. Chem. Soc.2012, 134,
11852-11855.
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1
2
3
4
(13) Hamidipour, L.; Farzaneh, F.Reac.Kinet. Mech. Cat.2013, 109, 67-75.
5
6
7
8
(14) Zhang,P.-F.;Gong, Y.-T.;Li, H.-R.;Chen, Z.-R.;Wang, Y. Nat. Commun.2013, 4,
9
1593-1603.
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
(15) Yoshizawa, M.; Miyagi, S.; Kawano, M.; Ishiguro, K.; Fujita, M. J. Am. Chem.
Soc.2004, 126, 9172-9173.
(16) Furusawa, T.; Kawano, M.; Fujita, M. Angew. Chem., Int. Ed.2007, 46,
5717-5719.
(17) Kumazawa, K.; Biradha, K.; Kusukawa, T.; Okano, T.; Fujita, M. Angew. Chem.,
Int. Ed.2003, 42, 3909-3913.
(18) Ohmori, O.; Kawano, M.; Fujita, M. Angew. Chem., Int. Ed.2005, 44, 1962-1964.
(19) Li, X.-Z.; Li, M.; Li, Z.; Hou, J.-Z.; Huang, X.-C.; Li, D.Angew. Chem., Int.
Ed.2008, 47, 6371-6374.
(20) Constable, E. C.; Zhang, G.; Housecroft, C. E.; Neuburger, M.; Zampese, J. A.
CrystEngComm2009, 11, 2279-2281.
(21) Wang, B.-C.; Wu, Q.-R.; Hu, H.-M.; Chen, X.-L.; Yang, Z.-H.; Shangguan, Y.-Q.;
Yang, M.-L.; Xue, G.-L. CrystEngComm2010, 12, 485-492.
(22) Wang, B.-C.; Chen, X.-L.; Hu, H.-M.; Yao, H.-L.; Xue, G.-L. Inorg. Chem.
Commun.2009, 12, 856-859.
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1
2
3
4
5
6
(23) Liu, C.; Ding, Y.-B.; Shi, X.-H.; Zhang, D.; Hu, M.-H.; Yin, Y.-G.; Li. D. Cryst.
Growth.Des.2009, 9, 1275-1277.
7
8
9
(24) Constable, E. C.; Zhang, G.; Coronado, E.; Housecraft, C. E.; Neuburger, M.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
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41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
CrystEngComm2010, 12, 2139-2135.
(25) Constable, E. C.; Zhang, G.; Housecroft, C. E.; Neuburger, M.; Zampese, J. A.
CrystEngComm2010, 12, 2146-2152.
(26) Constable, E. C.; Zhang, G.; Housecroft, C. E.; Zampese, J. A.
CrystEngComm2011, 13, 6864-6870.
(27) Constable, E. C.; Zhang, G.; Housecroft, C. E.; Neuburger, M.; Zampese, J. A.
CrystEngComm2010, 12, 3733-3739.
(28) Yuan, F.; Xie, J.; Hu, H.-M.; Yuan, C.-M.; Xu, B.; Yang, M.-L.; Dong, F.-X.; Xue,
G.-L. CrystEngComm2013, 15, 1460-1467.
(29) Liu, Q.-X.; Wei, Q.; Zhao, X.-J.; Wang, H.; Li, S.-J.; Wang, X.-G. Dalton Trans.
2013, 42, 5902-5915.
(30) Li, N.; Zhu, Q.-E.; Hu, H.-M.; Guo, H.-L.; Xie, J.; Wang, F.; Dong, F.-X.; Yang,
M.-L.; Xue, G.-L. Polyhedron2013, 49, 207-215.
(31) Constable, E. C.; Housecroft, C. E.;Neuburger, M.; Vujovic, S.; Zampese, J. A.
Zhang, G. CrystEngComm2012, 14, 3554-3563.
(32) Wen, L.; Ke, X.; Qiu, L.; Zou, Y.; Zhou, L.; Zhao, J.; Li, D. Cryst.
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Growth.Des.2012, 12, 4083-4089.
5
6
7
8
(33) Gai, Y.-L.; Jiang, F.-L.; Chen,-L.; Bu, Y.; Wu, M.-Y.; Zhou, K.; Pan, J.; Hong,
9
M.-C. Dalton Trans. 2013, 42, 9954-9965.
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55
56
57
58
59
60
(34) Yang, J.; Liu, J.; Wang, X.; Chi, X.; Zhang, J.; Zhang, H.; Xiao, D.; Luo, Q.
CrystEngComm2013, 15, 10435-10439.
(35) Yang, P.; Wang, M.-S.; Shen, J.-J.; Li, M.-X.; Wang, Z.-X.; Shao, M.; He, X.
Dalton Trans. 2014, 43, 1460-1470.
(36) Xu, B.; Xie, J.; Hu, H.-M.; Yang, X.-L.; Dong, F.-X.; Yang, M.-L.; Xue, G.-L.
Cryst.Growth.Des.2014, 14, 1629-1641.
(37) Ma, Z.; Wei, L. J.; Alegria, E. C. B. A.; Martins, L. M. D. S.; Guedes da Silva, M.
F.; Pombeiro, A. J. L. Dalton Trans. 2014, 43, 4048-4058.
(38) Beves, J. E.; Dunphy, E. L.; Constable,E. C.; Housecroft, C. E.; Kepert, C. J.;
Neuburger, M.; Price, D. J.; Schaffner, S. Dalton Trans.2008, 386-396.
(39) Lang, J.-P.; Xu, Q.-F.; Chen, Z.-N.; Abrahams. B. F. J. Am. Chem. Soc. 2003, 125,
12682-12683.
(40) Feng, S. G.; Templeton, J. L.J. Am. Chem. Soc.1989,111, 6477-6478.
(41) Espinós, J. P.; Morales, J.; Barranco, A.; Caballero, A.; Holgado, J. P.;
González-Elipe, A. R. J. Phys. Chem. B. 2002, 106, 6921-6929.
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Scheme 1. Synthesis of compounds 1−4
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Scheme 2. The oxidation of diphenylmethane
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Table 1.Crystallographic data for compounds 1-4.
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Compound
formula
1
2
3
4
C22H14Cl2CoN4 C66H42Cl6Co3N12
C108H63Cu9N27 C132H106Cu3N18O22
9
Formula
mass
464.20
1392.61
Trigonal
P3221
2310.71
2486.97
Triclinic
P-1
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Crystal
system
Monoclinic
P21/n
Orthorhombic
Pbcn
Space
group
a/Å
b/Å
c/Å
10.150(3)
16.699(5)
12.184(4)
90
13.6428(12)
13.6428(12)
31.625(3)
90
21.238(2)
14.4083(16)
64.699(7)
90
10.4718(13)
13.5124(16)
21.992(3)
75.334(2)
86.167(2)
71.784(2)
2859.3(6)
296(2)
α/°
β/°
94.644(6)
90
90
90
γ/°
120
90
V/Å3
T/K
Z
2058.3(11)
296(2)
4
5097.6(8)
293(2)
3
19798(4)
296(2)
8
1
ꢀ/mm−1
F(000)
1.109
1.007
1.957
9288
0.639
940
2115
1305
Reflection
s collected
/ unique
10256/3623
0.1141
25548/5974
95776/17479
14326/9903
Rint
0.1221
0.0651
0.1500
0.1192
0.0683
0.1761
0.0373
0.0843
0.2252
R1(I>2δ(I)) 0.0448
wR(F2)
0.1116
(I>2δ(I))
R1(all
0.0746
0.1075
0.1395
0.1473
data)
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wR(F2) (all 0.1527
0.1695
0.2099
0.3263
data)
6
7
S
1.054
0.927
1.029
1.123
8
9
CCDC
.No
1033132
1033133
1033134
1033135
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Table 2 The oxidation of various benzyl hydrocarbons catalyzed by 4
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Sele.
(%)b
Entry Substrates
Products
Conv.(%)
94.5
9
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12
13
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21
22
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1
92.6
>99
>99
95.8
96.2
2
3
4
5
>99
>99
96.2
97.1
[a] Reaction conditions: benzylic hydrocarbons (0.125mmol), compound 4 (4 µmol), TBHP
(0.3125mmol), chlorobenzene (1 mL), 80 ºC, 24h. [b] Selectivity to ketones. The by-products are
corresponding alcohols.
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FIGURE CAPTIONS
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Figure 1. a) The coordination mode of the L1ligand and the coordination geometries
of the CoIIcations in compound 1 (Symmetry code: A 3/2-x, y-1/2, 1/2-z). b) Scheme
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of the one-dimensional helical chain of 1 with 21axis (in yellow). c) The
interactions between the pyridyl rings of neighboring ligands. d) the weak interactions
of interactions and hydrogen bonding interactions between C N and the pyridyl
π-π stacking
π-π
≡
or benzene rings in 1. Color scheme: Co, light blue; N, dark blue; Cl, green; C, black.
H atoms are omitted for clarity.
Figure 2. a) The coordination mode of the L1 ligand and the coordination geometries
of the CoII cations in compound 2. b) The
pyridyl rings and C N of neighboring ligands. c) The one-dimensional helix topology
π-π stacking interactions between the
≡
in 2 runs along the oc axis.Color scheme: Co, light blue; N, blue; Cl, green; C, black.
H atoms are omitted for clarity.
Figure 3. a) The scheme of assymetric unit in 3 showing the coordination mode of the
L1 ligand and the coordination geometries of the CuIcations in compound 3. b) The
tetranuclear cuprous ring. c) The octanuclear cuprous ring. d) A perspective view of
the quadruple interdigitated architecture in 3 along the oc axis(The connectivity of
neighboring Cu is drawn by a line and the ligands are omitted). Color scheme: Cu,
light blue; C, black; H atoms was omitted for clarity. The ꢀ2-CN- bonds are
highlighted in pink.
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Figure 4. a) The grid-like chain of 4 showing its coordination mode of L2 ligand and
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the coordination geometries of two types of CuIIcations. b)
schematic along the oc axis. c) View of the 1D +1D
3D architecture of 4.(Color
π-π stacking interactions
→
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scheme: Cu, light blue; N, blue; O, red; C, black; H atoms are omitted for clarity.)
Figure 5. Conversion and selectivity of diphenylmethane to benzophenone with
compounds 1-4. Reaction conditions: diphenylmethane (0.125 mmol), as-synthesized
compound (4 µmol), TBHP (0.3125 mmol), chlorobenzene (1 mL), 80 ºC, 24h.
[b]Selectivity to ketones. The by-product was benzhydrol.
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Figure 1.
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