Spectroscopic and crystallographic investigations of novel Bodipy-derived metal-organic frameworks

Article abstract of DOI:10.1021/ic502219y

To explore new 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-derived metal-organic frameworks (MOFs), we employed 2,6-dicarboxyl-1,3,5,7-tetramethyl-8-phenyl-4,4-difluoroboradiazaindacene (H₂L) as a ligand to successfully synthesize five

Full text of DOI:10.1021/ic502219y

Article
pubs.acs.org/IC
Spectroscopic and Crystallographic Investigations of Novel BODIPY-
Derived Metal−Organic Frameworks
Ming Li,†,# Yi Yao,‡,# Jie Ding,*,† Lu Liu,† Jianhua Qin,† Yaopeng Zhao,*,‡ Hongwei Hou,*,†
and Yaoting Fan†
†College of Chemistry and Molecular Engineering, Zhengzhou University, Henan 450001, China
‡State Key Laboratory of Catalysis, , Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian
116023, China
S
* Supporting Information
ABSTRACT: To explore new 4,4-difluoro-4-bora-3a,4a-diaza-s-
indacene (BODIPY)-derived metal−organic frameworks
(MOFs), we employed 2,6-dicarboxyl-1,3,5,7-tetramethyl-8-
phenyl-4,4-difluoroboradiazaindacene (H2L) as a ligand to
successfully synthesize five coordination polymers, namely,
{[Zn2(L)2(bpp)]·2H2O·2EtOH}n (1), {[Cd2(L)2(bpp)]·2H2O·
EtOH}n (2), {[Cd2(L)(bpe)3(NO3)2]·2H2O·DMF·EtOH}n (3),
{[Cd(L)(bpe)0.5(DMF)(H2O)]}n (4), and {[Cd(L)(bpe)0.5]·
1.5H2O·DMF}n (5) (bpp = 1,3-bi(4-pyridyl)propane, bpe =
1,2-bi(4-pyridyl)ethane). Except for two 2D-layer coordination
polymers 3 and 4, the rest samples exhibit 3D metal−organic frameworks with certain pore sizes, especially MOFs 1 and 5.
Spectroscopic and crystallographic investigations demonstrate that the absorption and emission energies of the BODIPY
chromophores are sensitive to the coordination modes. Moreover, in case 2, the transition metal centers coordinated with the
dicarboxylate ligands L2− are capable of forming the two BODIPY units in coplanar arrangements (θ = 37.9°), simultaneously
suppressing the uncommon J-dimer absorption band centered at 705 nm with a long tail into the near-infrared region at room
temperature. On the other hand, in comparison with the ligand H2L, the emission of monomer-like BODIPY in case 3 is
enhanced in the solid state by a considerably long distance between the parallel BODIPY planes (about 14.0 Å).
shifts in absorption spectra relative to the monomers.15
Significantly, because small modifications of their structures
INTRODUCTION
■
During the past decade, metal−organic frameworks (MOFs),
enable tuning their photophysical features, BODIPY-derived
also called porous coordination polymers (PCPs), made by
materials have been widely employed as useful tools for many
reticular synthesis with polytopic organic struts and inorganic
different applications.16,17 Accordingly, the attachment of
nodes, have constituted an attractively versatile platform for
achieving long-range organization and order.1,2 Because of their
BODIPY units to a transition metal center is also highly
attractive, most of which are complex molecule examples.18−22
easily tailored structures and exploitable properties, MOFs have
Recently, Nitschke and co-workers have synthesized a series of
emissive metallo-supramolecular cages by incorporating
BODIPY fluorophores.20 Despite the intriguing properties,
the chemistry of BODIPY-derived coordination polymers has
remained relatively unexplored. In 2011, Hupp and co-workers
first reported two BODIPY-derived MOFs (BOB and BOP),
which are capable of harvesting light across the entire visible
spectrum by strut-to-strut energy transfer.21 As followed,
another two photoluminescent MOFs were obtained based
on a BODIPY-derived bipyridine ligand.22 Since such field is at
an early stage of development, we are very interested in
constructing new BODIPY-derived MOFs and exploring the
relationship between photophysical properties and the
structures in order to get a series of multifunctional materials
been one hot subject of research in the eyes of many chemists
and material scientists, which have aroused them with great
enthusiasm in different areas.3−5 In particular, the multifunc-
tional nature of these systems was used to explore the
applications in light-emitting devices,6 light-harvester,7 non-
linear optics,8 photoinduced hydrogen production,4e,9 chemical
sensor,10 and biomedicine11 by combining optical properties
with several other properties,3a,12 such as microporosity,
molecule and ion sensing, and catalysis.
4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY), one
kind of brilliant small molecule dye,13 shows distinctly
charming photophysical properties that include strong visible
absorption, relatively sharp fluorescence with efficient quantum
yield, relative insensitiveness to environment pH or polarity,
and reasonable stability to physiological conditions.14 In
addition, the packing of such a dye in aggregated solid states
may be engineered to facilitate the formation of J-type
aggregates (head-to-tail), which exhibit large bathochromic
Received: September 14, 2014
© XXXX American Chemical Society
A
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Scheme 1. Synthetic Procedure for Ligand H2L
state were conducted on a Hitachi 850 fluorescence spectropho-
tometer at room temperature. The quantum yield of sample emission
in the solid state was detected with an absolute photoluminescence
quantum yield measurement system (C11347-11, Hamamatsu
Photonics) under excitation at 450 nm at room temperature. The
gas sorption isotherms of coordination polymers 1 and 5 were
collected on a Micromeritics 3Flex surface area and pore size analyzer
under ultrahigh vacuum in a clean system, with a diaphragm and turbo
pumping system. Ultrahigh-purity-grade (>99.999%) N2 gas was
applied in all adsorption measurements. The experimental temperature
was maintained by liquid nitrogen (77 K). Prior to measurement, to
remove the solvent molecules, the bulk samples of complexes 1 and 5
were soaked in acetone for 2 days with the solvent refreshed every 12
h and then dried in a vacuum oven at 60 °C for 12 h. Moreover,
supercritical CO2 (SC−CO2) activation also was used to remove the
solvent molecules in sample 1 by a custom-built system. Typically, a
bulk sample of complex 1 was washed by absolute ethanol (EtOH)
three times, dried under a vacuum, and then transferred into a stainless
steel column. After 20 min of soaking and venting of supercritical CO2
by a DB-80 simplex pump, the column pressure regulator was set at
100 bar by soaking SC−CO2, and the column temperature was raised
to 55 °C. SC−CO2 in the column was gradually vented after 14 h. The
activation samples were placed in sealed containers for nitrogen
adsorption. TGA experiments and powder X-ray diffraction were
carried out to make sure that the solvent molecules were removed
completely and the framework structures retained crystallinity after
activation, respectively.
Syntheses. tert-Butyl 2-Hydroximino-3-oxobutyrate (8). tert-
Butyl 3-oxobutanoate (6, 40 mL, 241 mmol) was dissolved in acetic
acid (80 mL) in a round-bottomed flask, and the mixture was cooled in
an ice bath to about 10 °C. Sodium nitrite (18 g, 261 mmol) was
added over 1 h while the temperature was kept under 15 °C. The cold
bath was removed, and the mixture was allowed to stir for 3.5 h at
room temperature to give a crude solution of 8 which was used in the
next step without further purification.
3, 5-Dimethyl-1H-pyrrole-2, 4-dicarboxylic Acid 2-tert-Butyl Ester
4-Benzyl Ester (9). To a stirred mixture of benzyl 3-oxobutyrate (7,
13.7 mL, 79 mmol) and acetic acid (100 mL) in an oil bath, zinc dust
(50 g, 0.76 mol) was added portionwise. The mixture was heated to 60
°C. At this temperature, the crude 8 precipitated slowly. The
temperature was then increased to 75 °C for 1 h, and then the
with potential applications in optoelectronics, light-harvesting,
etc.
Herein, by employing 2,6-dicarboxyl-BODIPY ligand H2L as
a chromophore linker, five coordination polymers
{[Zn2(L)2(bpp)]·2H2O·2EtOH}n (1), {[Cd2(L)2(bpp)]·
2H2O·EtOH}n (2), {[Cd2(L)(bpe)3(NO3)2]·2H2O·DMF·
EtOH}n (3), {[Cd(L)(bpe)0.5(DMF)(H2O)]}n (4), and {[Cd-
(L)(bpe)0.5]·1.5H2O·DMF}n (5) (bpp =1,3-bi(4-pyridyl)-
propane, bpe = 1,2-bi(4-pyridyl)ethane) have been formulated
by changing the metal ions and auxiliary pyridine ligands.
Except for two 2D-layer coordination polymers 3 and 4, the
rest of the samples exhibit 3D MOFs with certain pore sizes,
especially MOFs 1 and 5. Spectroscopic investigations
demonstrate that in case 2, the uncommon J-dimer absorption
band is observed at λmax = 705 nm with a long tail into the near-
infrared (NIR) region at room temperature. On the other hand,
in comparison with the ligand H2L, the emission of monomer-
liked BODIPY in case 3 is enhanced more than twice in the
solid state.
EXPERIMENTAL SECTION
■
Materials. All chemical reagents were purchased from commercial
suppliers and used without further purification, unless otherwise
indicated. Ligand H2L was synthesized by the procedure in Scheme 1.
Physical Measurements. 1H NMR (400 MHz) spectra were
measured on a Varian infinity-plas spectrometer with TMS as the
internal standard. FT-IR spectra were recorded on a Bruker-ALPHA
spectrophotometer using dry KBr disks in the range of 4000−400
cm−1. Elemental analyses for carbon, hydrogen, and nitrogen were
carried out on a FLASH EA 1112 analyzer. Thermogravimetric
analyses (TGA) were implemented on a Netzsch STA 449C thermal
analyzer, and the samples were heated at a rate of 10 °C min−1 under
the air atmosphere. The room-temperature powder X-ray diffraction
spectra were performed on a PANalytical X’Pert PRO diffractometer
using Cu Kα1 radiation. UV−vis absorption spectra in the solid state
were measured from 200 to 1100 nm by a Cary 5000
spectrophotometer equipped with a 110 nm diameter integrating
sphere. The measurements of steady-state emission spectra in the solid
B
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
reaction mixture was poured into water (40 mL). The precipitate was
collected by filtration to yield 9 in quantitative yield as a white solid.
1H NMR (400 MHz, CDCl3): 8.88 (br, s, 1H, NH), 7.47−7.33 (m,
5H, CCH), 5.29 (s, 2H, CH2), 2.53, 2.48 (2s, 6H, 2CH3), 1.56 (s,
9H, 3CH3).
2,4-Dimethyl-1H-pyrrole-3-carboxylic Acid Ester (10). A solution
of the product 9 (22.07 g, 67 mmol) dissolved in ethanol (78 mL) was
stirred vigorously as hydrochloric acid (10 N, 3.6 mL) was slowly
added at 20 °C. Then the reaction mixture was heated to 67 °C for 1
h, cooled to 5 °C, and poured into ice water. The solid was collected
by filtration and washed with water to yield 2, 4-dimethyl-1H-pyrrole-
3-carboxylic acid ester (8.10 g, 89% yield). 1H NMR (400 MHz,
CDCl3): 10.48 (br, s, 1H, NH), 7.47−7.33 (m, 5H, CCH), 6.35 (s,
1H, CH), 4.10 (q, 2H, CH2), 2.35, 2.15 (2s, 2CH3).
2,6-diCO2Bzl-BDP (11). The synthetic procedure is according to the
literature.23 1H NMR (400 MHz, CDCl3): 7.49 (m, 3H, CCH),
7.3−7.4 (m, 10H, CCH), 7.22 (m, 2H, CCH), 5.22 (s, 4H,
2CH2), 2.82 (s, 6H, 2CH3), 1.58 (s, 6H, 2CH3).
2,6-diCO2H-BDP (H2L). The synthetic procedure is according to the
literature.23 1H NMR (400 MHz, DMSO-d6): 12.73 (s, 2H, COOH),
7.56 (m, 3H, CCH), 7.40 (m, 2H, CCH), 2.68 (s, 6H, 2CH3),
1.55 (s, 6H, 2CH3).
{[Zn2(L)2(bpp)]·2H2O·2EtOH}n (1). A mixture of H2L (8.2 mg, 0.020
mmol), bpp (9.9 mg, 0.05 mmol), Zn(NO3)2·6H2O (14.9 mg, 0.05
mmol), DMF (2 mL), and an aliquot of HNO3 in EtOH (4 mL of a
0.03 M solution) was sealed in the autoclave at 80 °C for 2 days and
then cooled to room temperature. Orange-red crystals of 1 were
collected in a ca. 60% yield based on H2L ligand. Elemental analysis for
C59H64B2F4N6O12Zn2, calcd (%): C, 55.47; H, 5.05; N, 6.58. Found
(%): C, 55.51; H, 5.01; N, 6.49. IR data (KBr, ν/cm−1): 3435 (m),
2927 (w), 1621 (w), 1534 (m), 1430 (m), 1401 (w), 1343 (s), 1313
(m), 1144(s), 1072 (m), 1024 (s), 811 (m), 727 (m), 669 (w),
599(m).
{[Cd2(L)2(bpp)]·2H2O·EtOH}n (2). Dark red petal-shaped crystals of
2 were obtained using the same method as that for 1. The reagents
used were H2L (8.2 mg, 0.020 mmol), bpp (4.0 mg, 0.02 mmol),
Cd(NO3)2·4H2O (15.4 mg, 0.05 mmol). Yield: 45% based on H2L
ligand. Elemental analysis for C57H58B2Cd2F4N6O11, calcd (%): C,
51.65; H, 4.41; N, 6.34. Found (%): C, 51.59; H, 4.50; N, 6.28. IR
(KBr, ν/cm−1): 3430 (m), 2925 (m), 1617 (w), 1615 (w), 1532 (s),
1428 (m), 1399 (m), 1342 (s), 1312 (m), 1190 (s), 1142 (s), 1071
(m), 1022 (s), 822 (m), 785 (w), 727 (m), 667 (w), 598 (m), 572
(m).
{[Cd2(L)(bpe)3(NO3)2]·2H2O·DMF·EtOH} (3). A mixture of H2L (8.2
mg, 0.020 mmol), bpe (9.2 mg, 0.05 mmol), Cd(NO3)2·4H2O (15.4
mg, 0.05 mmol), DMF (2 mL), and an aliquot of HNO3 in EtOH (4
mL of a 0.03 M solution) was sealed in the autoclave at 80 °C for 2
days and then cooled to room temperature. Orange-red lamellar
crystals of 3 were obtained. Yield: 45% based on H2L ligand. Elem.
Anal. Calcd (Found) for C62H70BCd2F2N11O14: C, 50.76 (50.82); H,
4.81 (4.74); N, 10.50 (10.45). IR (KBr, ν/cm−1): 3422 (m), 2929 (w),
1655 (s), 1586 (w), 1539 (s), 1422 (m), 1397 (m), 1336 (s),
1312(m), 1258 (w), 1192 (s), 1142 (s), 1106 (w), 1074(m), 1022(m),
830 (w), 817 (m), 598 (m), 582 (m), 548 (m).
{[Cd(L)(bpe)0.5(DMF)(H2O)]} (4). Red blocklike crystals of 4 were
obtained using the same method as that for 3, except DMF and EtOH
in a volume ratio of 1:1. Yield: 75% based on H2L ligand. Elem. Anal.
Calcd (Found) for C30H32BCdF2N4O6: C, 51.05 (50.97); H, 4.57
(4.45); N, 7.94 (8.05). IR (KBr, ν/cm−1): 3440 (s), 2926 (w), 2169
(w), 1655 (m), 1534 (m), 1428 (m), 1384 (m), 1341 (s), 1311 (m),
1189 (s), 1142 (m), 1070 (m), 1020 (m), 809 (m), 785 (w), 727 (m),
664 (w), 597 (m), 571 (w).
(w), 1190 (s), 1144 (m), 1072 (m), 1017 (s), 827 (s), 728 (m), 598
(m), 577 (m).
Crystal Data Collection and Refinement. Single crystal X-ray
diffraction analyses of complexes 1 and 2 were carried out on a
SuperNova diffractometer with graphite monochromated Cu Kα
radiation (λ = 1.54178 Å) at 100(2) K, whereas the data of complexes
3−5 were collected on a Rigaku Saturn 724 CCD diffractometer with
Mo Kα radiation (λ = 0.71073 Å) at 20
1 °C. The empirical
absorption corrections were applied by the multiscan program. The
crystal data were corrected for Lorentz and polarization effects. The
structures were solved by direct methods and then refined for non-
hydrogen atoms by full-matrix least-squares techniques on the basis of
F2 using the SHELXL-97 program.24 There were large solvent
accessible pore volumes in complexes 1, 2, and 5, occupied by highly
disorded solvent molecules as well as those of complex 3. No
satisfactory disorder model could be achieved, and therefore the
SQUEEZE program implemented in PLATON was used to remove
these electron densities. The numbers of guest molecules for 1, 2, 3,
and 5 were calculated by the TGA and elemental analysis data.
Crystallographic processing parameter and selected bond lengths and
bond angles for 1−5 are listed in Tables S1 and S2 (in the Supporting
Information), respectively. Crystallographic data for 1−5 have been
deposited at the Cambridge Crystallographic Data Centre with CCDC
reference numbers 1023699−1023703.
RESULTS AND DISCUSSION
■
Synthetic Aspect. As we know, the luminescence was often
ascribed to the π-conjugated organic linker in many MOFs,
such as dicarboxylate-containing species. Because of the
excellent luminescent property of the BODIPY-based dicarbox-
ylic acid H2L in solution,23 it would be a novel platform to
construct functional high-dimensional coordination com-
pounds. As shown in Scheme 1, the chromophore linker,
H2L was synthesized by a simplified procedure compared to the
reported literature.23 At first, screening for simple and cheap
precursor 6 as the starting material, intermediate product 9 was
synthesized by the fast one-step cyclization reaction with very
high yield. Subsequently, complex 10 was obtained by 1 h
elimination reaction. Significantly, in comparison with the
reported procedure,23 this synthetic process was not only with
higher yield but also needed much less reaction time and softer
chemical condition.
Crystal Structure and Characterization. Five coordina-
tion polymers 1−5 were successfully obtained by the
solvothermal reactions with the chromophore linker H2L,
metal salts (M(NO3)2, M = Zn/Cd) and auxiliary pyridine
ligands (bpp and bpe) in DMF and HNO3 in ethanol media,
respectively. Single crystal X-ray diffraction analyses present all
the structures of coordination polymers 1−5, which are further
confirmed by the powder X-ray diffraction (PXRD),
thermogravimetric analyses (TGA), elemental analyses, and
infrared (IR) spectroscopy experiments.
In case 1, the single crystal X-ray diffraction pattern
demonstrates a 3D pillared-layer framework, which belongs to
the monoclinic system with C2/c space group. As shown in
Figures 1a and S1, two adjacent Zn ions, bridged by the
carboxylate groups of BODIPY-based ligands, form a paddle-
wheel type secondary building unit (SBU)−[Zn2(COO)4] with
Zn−Zn distance about 3.0 Å, which is connected by four
BODIPY-based dicarboxylic acid groups and further extended
into a 2D sheet-like layer. At the same time, these 2D layers are
pillared by the bpp linkers along the c axis to give rise to a 3D
pillared-layer porous framework with pore sizes of ∼14.8 × 14.8
Å2, while the structure induces 2-fold interpenetration of the
framework which reduces the void space with pore sizes of
{[Cd(L)(bpe)0.5]·1.5H2O·DMF}n (5). By adopting the preparative
method of 3, except at 100 °C for 2 days and then cooled to room
temperature, dark red block-shaped crystals of 5 were collected in a ca.
35% yield based on H2L ligand. Elem. Anal. Calcd (Found) for
C30H33BCdF2N4O6.5: C, 50.41 (50.37); H, 4.65 (4.74); N, 7.83 (7.75).
IR (KBr, ν/cm−1): 3442 (m), 3057 (w), 2927 (m), 1676 (s), 1612 (s),
1533 (m), 1506 (w), 1429 (m), 1385 (m), 1342 (s), 1311 (m), 1285
C
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
displayed that the crystal structure was totally representative
of the bulk sample (Figure S6). Moreover, TGA experiment
showed that coordination polymer 2 lost two lattice water
molecules and one EtOH molecule (obsd 6.05%, calcd 6.19%,
Figure S7) when the temperature was raised from 30 to 254 °C.
In addition, the resultant structure was stable up to 306 °C and
finally decomposed to CdO.
In consideration of interpenetration in MOF 1, we tried to
reduce the flexibility of pyridine ligand to construct 3D MOF
probably containing larger porosity. Surprisingly, when the bpe
linker was used instead of the bpp group, two 2D-layer
coordination polymers 3 and 4 were obtained by the similar
solvothermal method (Figure 2a,b). For coordination polymer
Figure 1. Schematic representation of the structures of complexes 1
(a) and 2 (b). Hydrogen atoms and solvent molecules have been
omitted for clarity.
∼11.5 × 11.5 Å2. Therefore, MOF 1 can be represented as a 6-
connected 2-fold interpenetration topology, and the point
symbol for the net is 412·63. A PXRD experiment for case 1 also
has been carried out to check its phase purity. As shown in
Figure S2, the peak positions of the experimental PXRD
spectrum match well with that of th esimulated one, indicating
that the crystal structure is truly representative of the bulk
sample. The differences in intensity may be due to the preferred
orientation of the crystal products. In addition, application of
the SQUEEZE routine in PLATON suggests that a void
volume is 35% in the total cell. These channels are occupied by
H2O and EtOH, which are confirmed by elemental analysis and
TGA. Furthermore, a TGA experiment was performed under
air atmosphere to check the thermal stability of MOF 1 (Figure
S3). For instance, it successively lost weight of 10.05% (calcd
10.03%) in the range of 30−277 °C due to one lattice water
molecule and one EtOH molecule, which also implies the
porosity. Over 277 °C, the framework of sample 1 was unstable
and decomposed gradually. Thus, gas sorption measurement
for the as-synthesized sample 1 after acetone exchange was
conducted up to a relative pressure (p/p0) of 1.0 on the
activated frameworks at STP. N2 adsorption isotherm
demonstrates that MOF 1 exhibits a small gas adsorption
value of 18 cm3/g with a Brunauer−Emmett−Teller (BET)
surface area of 27 m2/g (Figure S4). This result may be
attributed to the change from crystalline phase to amorphous
phase of MOF 1, on account of the broadening, or even
disappearing of some peaks in the PXRD spectrum (Figure
S2).22 Furthermore, the flowing SC−CO2 activation also has
been used to avoid collapse during volatile solvent evacuation.28
After SC−CO2 activation, as shown in Figure S4, the N2
adsorption isotherm of MOF 1 illustrates the BET surface area
of 257 m2/g with the gas adsorption value of 121 cm3/g.
Surprisingly, by the same solvothermal method except
changing metal salts into Cd(NO3)2·4H2O, coordination
polymer 2 features a totally different 3D framework, which
can be simplified into a 8-connected topology with the point
symbol 424·64 (Figures 1b and S5). Two carboxylic groups of
BODIPY-based ligands both adopt μ2-η2:η1-chelate/bridge
coordination fashions, which link Cd(II) ions to provide a
tetranuclear SBU− [Cd4(CO2)8]. Each tetranuclear SBU is
surrounded by eight L2− units and further furnish a complicated
3D MOF, while the bpp ligand just plays a role in connecting
Cd(II) ions from two adjacent SBUs to add the linking
numbers of the tetranuclear SBUs. Hence, a void volume of
22% in the total cell was indicated by the SQUEEZE routine in
PLATON. In case 2, the experimental PXRD data also
Figure 2. Schematic representation of the structures of complexes 3
(a), 4 (b) and 5 (c). Hydrogen atoms and solvent molecules were
omitted for clarity.
3, as shown in Figures S8 and 2a, the bpe groups connect
Cd(II) ions to form a 1D ladder-shape chain, and subsequently,
linked by BODIPY-based dicarboxylic acids in chelated
coordination modes, the chains are extended into a 2D wave-
like layer. Complex 3 illustrated very high phase purity detected
by the PXRD experiment (Figure S9). In contrast, while the
volume ratio of reaction solvent DMF/EtOH was turned into
1:1, the two carboxylic groups of ligand L2− adopt μ1-η1:η1 and
μ1-η0:η1 coordination modes in complex 4 (Figures S10 and
2b), respectively, which provide a 1D infinite chain by linking
Cd(II) ions. Interestingly, bridged by the bpe groups, the 1D
chains further form a graphene-like 2D layer. In each hexagonal
circle unit of such 2D layer, six Cd(II) ions are like the “C
atoms”, which are linked by four BODIPY-based dicarboxylic
acids and two bpe moieties. The experimental PXRD data also
exhibited that the crystal structure of complex 4 was totally
representative of the bulk sample (Figure S11). As shown in
Figure S7, from 90 to 230 °C, complex 3 lost two lattice water
molecules, one EtOH and one DMF (obsd 10.50%, calcd
10.58%) and became unstable beyond 260 °C. In comparison
with that of case 3, the thermal stability of coordination
polymer 4 was better, which lost one coordinated water
molecule and one coordinated DMF molecule in the scale of
90−330 °C (obsd 12.60%, calcd 12.91%), and above 330 °C,
complex 4 decomposed continuously until 800 °C.
Ultimately, under the same solvothermal reaction condition
except for raising the reaction temperature to 100 °C, a 3D
pillared-layer framework 5 was successfully synthesized, which
was the isoreticular framework of complex 1 deliberated by the
crystallographic analysis (Figure 2c). For instance, ligands L2−
chelate Cd1 ion and symmertry-related Cd1A ion to form a
[Cd2(CO2)4] binuclear SBU with Cd−Cd distance about 3.04
Å, which further gives rise to a 2D layer (Figure S12).
D
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Furthermore, the 2D networks are sustained by the bpe
moieties along the c direction to generate a pillared-layer 3D
framework. Structural topology analysis reveals that 412·63 is the
point symbol for this net. As a result of 2-fold interpenetration
with real pore sizes of ∼11.3 × 11.3 Å2, calculation by using
PLATON suggests the guest accessible void comprises 40% of
the total cell volume. Although complexes 1 and 5 are
isoreticular, the distances of two adjacent binuclear SBUs
bridged by pyridine ligands bpp or bpe in complexes 1 and 5
are 16.0286 and 16.675 Å, respectively, which may be attributed
to differences of the pillar molecules (bpp for complex 1 and
bpe for complex 5) and metal nodes (Zn for complex 1 and Cd
for complex 5). As shown in Figure S13, because the data of the
experimental PXRD spectrum is consistent with that of
simulated one, the crystal structure of 5 completely expressed
the bulk sample. For MOF 5, a weight loss of 14.33% in 20−
245 °C range was consistent with the removal of one DMF and
one and a half lattice water molecules (calcd 14.00%, Figure
S14), and the dehydrated compound was stable to 308 °C. To
consider the results of crystallographic analysis and TGA
measurement, 1D channels with considerable void spaces are
present in MOF 5. As shown in Figure S15, sample 5 shows a
type-I behavior in N2 adsorption isotherm at 77 K, which
indicates a gas uptake of 60 cm3/g with the BET surface area of
138 m2/g.
In this work, the UV−vis absorption spectra of ligand H2L,
bpe, bpp, and the coordination polymers 1−5 were recorded in
the solid state at room temperature (Table 1, Figure S17). As
Table 1. Absorption and Steady-State Fluorescence
Properties of Crystals 1−5 and Ligand bpe, bpp, and H2L in
Power State at Room Temperature
c
d
sample
λab/nm
λem/nm ΔυSt /cm−1
ϕF
a
1
212, 256, 354−391, 448, 489,
577
602
574
596
573
1360
1942
1662
1740
1170
0.0082
0.0067
0.017
535, 658
a
2
3
4
5
213, 254, 344−392, 447, 497,
539, 705
a
211, 257, 346−389, 458, 487,
524
a
210, 264, 344−395, 495, 520,
0.0099
0.0076
540, 654
a
210, 263, 341−393, 447, 489,
537, 677
bpe
bpp
210, 249, 282
210, 249, 274
b
b
b
b
b
b
H2L 213, 263, 373, 409, 562, 651
577
465
0.0073
a
b
Broad signal including multipeaks. Not measured in this paper.
c
d
Stokes shift = (1/λab − 1/λfl). Quantum yield was measured with an
absolute photoluminescence quantum yield measurement system
(C11347-11, Hamamatsu Photonics) upon excitation at 450 nm.
Photophysical Properties. Before the detailed spectro-
scopic investigations of the coordination polymers 1−5,
macroscopic images of 1−5 under natural light and 365 nm
UV irradiation would roughly manifest some photophysics
information. As shown in inset images of Figure 3, case 2
depicted in Figure 4a, ligand H2L exhibits several intense
absorption bands in the range of 210−570 nm. At the same
time, careful inspection of the spectrum on the low-energy side
reveals a small peak in the region of 600−800 nm. This could
indicate a weak transition centered at around 651 nm (15 360
cm−1) within the tail. The intense absorption band is at λmax
=
562 nm (17795 cm−1), which is ascribed to the π → π*
transition of the monomer-like BODIPY group, while the weak
band in lower energy range is possibly the transition of J-
aggregates based on dipole−dipole interaction in the
aggregate.23,25 Furthermore, the lowest energy absorption
band of ligand bpp or bpe is at λ < 285 nm (35090 cm−1,
Figure S17), which is distinctly higher than that of ligand H2L
in the energy level. As a result, the BODIPY group of ligand
H2L will play a key role as the chromophore after being
coordinated with the Zn(II)/Cd(II) metal ions.
Remarkably, compared to that of ligand H2L, the π → π*
transition of the monomer-like BODIPY group is visibly blue-
shifted in each of the samples 1−5 (Table 1, 1: 535 nm, 2: 539
nm, 3: 524 nm, 4: 540 nm, and 5: 537 nm), which might result
from the increasing electron-withdrawing character of carbox-
ylate groups at the 2,6-positions by being coordinated with the
transition metal ions.23 In addition, in comparison with the
inferred transition of powder sample H2L in lower energy level,
the relative intensity are enhanced in the coordination polymers
except for sample 3. Especially in case 2, such absorption band
grows into a strong shoulder peak centered at 705 nm (14 185
cm−1) with a long tail into the near-infrared (NIR) region.
However, in case 3, such estimated dimer transition
disappeared as shown in Figure 4a. As we know, BODIPY
groups in J aggregates are arranged in a head-to-tail direction or
coplanar displacements with θ < 54.7°. Only the transition to
the lowest excited state is allowed, which is characterized by a
bathochromic shift of the absorption maximum compared to
the monomer.26 As exhibited in Figure 5a, the BODIPY
moieties in complex 2 can be arranged in coplanar displace-
ments with θ = 37.9°, and the center distance between the
BODIPYs is about 5.7 Å measured by the crystallographic
Figure 3. Macroscopic images of coordination polymers 1−5 under
365 nm UV irradiation; inset: macroscopic images of the
corresponding crystals under natural light, respectively.
exhibits the much deeper color comparing to the rest of the as-
synthesized samples and red ligand H2L (Figure S16),
indicating that the energy of S0 → S1 transition in 2 is
probably lower than those of the rest of the samples (1, 3, 4,
and 5) and ligand H2L. On the other hand, under irradiation of
365 nm UV light, all the samples show orange or red
photoluminescence with the naked eyes.
E
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Figure 4. (a, b) Diffuse-reflectance UV−vis and fluorescence spectra of ligand H2L and complexes 1−5 in the solid state at room temperature (λex
450 nm, the emission intensity in panel b corresponds to the result of absolute photoluminescence quantum yield measurement).
=
diagrams of the BODIPY units in 3 (Figure 5b). Herein, the
BODIPY units in complex 3 adopt parallel arrangements of the
transition dipoles with the slip angle of θ = 84°, and the
measured distance between the BODIPY-planes is about 14.0
Å. In such rigid frameworks, the BODIPY moieties could not
be allowed to form the dimers and also the concentration
quenching of fluorescent dyes was hindered by the considerably
long distance between the BODIPY-planes in the solid state.
Normally, the emission of monomer-liked BODIPY in case 3
will be enhanced.
Figure 5. Partial packing diagrams of the BODIPY units in sample 2
(a) and 3 (b), respectively. H atoms are omitted for clarity.
CONCLUSIONS
■
As a consequence, by using BODIPY-based dicarboxylic acid
H2L as a chromophore linker, five coordination polymers 1−5
were successfully obtained by the solvothermal reactions with
moderate-to-good yields in this work. By the metal center
Cd(II) instead of Zn(II), the 3D pillared-layer framework 1 was
replaced by a more compact coordination polymer 2, which
featured a totally different 3D framework with the point symbol
424·64. As the bpe linker instead of the bpp group reduces the
flexibility of pyridine ligand, two unanticipated 2D-layer
coordination polymers 3 and 4 were obtained, whereas 3D
pillared-layer framework 5 was prepared with larger porosity by
raising the reaction temperature at 100 °C. The combination of
spectroscopic investigation and crystallographic analysis dem-
onstrates that the absorption band of J-dimer can be observed
at λmax = 705 nm in the solid state since the BODIPY moieties
in complex 2 are arranged in coplanar displacements with θ =
37.9°. Furthermore, in comparison with the ligand H2L, the
emission of monomer-liked BODIPY in case 3 was enhanced in
the solid state, because the BODIPY moieties could not be
allowed to form the dimers, and also the concentration
quenching of fluorescent dyes was hindered by considerably
long distance between the parallel BODIPY-planes. These
results imply that, due to this BODIPY-based dicarboxylic acid
H2L as the novel chromophore linker, our study opens up
interest in this new platform to construct excellently
luminescent BODIPY-derived MOFs for exploring applications
in optoelectronics and light-harvesting.
analysis. Hence, in case 2, such absorption band centered at 705
nm is clearly assigned by the transition of J-dimer based on
dipole−dipole interaction.
Furthermore, to prove the hypothesis for the evidence in
absorption spectroscopic measurement, some information was
observed in the luminescence studies of the ligand H2L and as-
synthesized coordination polymers 1−5. The room temper-
ature emission spectra of the ligand H2L and samples 1−5 in
the solid state are shown in Figure 4b. Upon excitation at λ >
590 nm, ligand H2L has no emission observed, although such S0
→ S1 transition would result in a potential luminescence in the
NIR, as the associated long radiative lifetime of the
corresponding emission is easily quenched by the surrounding
environment in solid state or suffered by the self-quenching due
to the high concentration. Interestingly, upon excitation at 450
nm, it exhibited an emission at λmax = 577 nm (17330 cm−1) at
room temperature with a small absolute quantum yield of
0.0073. Moreover, due to the small Stokes shift of 465 cm−1
1
(Table 1), this fluorescence is derived from the ππ* excited
state of the monomer-like BODIPY group in nature.
Similar to ligand H2L, there are also no emissions in the
spectra of complexes 1, 2, 4, and 5 upon excitation at 600 nm.
In contrast, upon excitation at λ > 430 nm, complexes 1−5 still
1
display the emissions assigned to the ππ* excited state of
BODIPY group (1: 577 nm, 2: 602 nm, 3: 574 nm, 4: 596 nm,
and 5: 573 nm), although in cases 2 and 4, the emission bands
are distinctly red-shifted. As shown in Table 1, the quite large
Stokes shifts in complexes 1−5 (1170−1942 cm−1) comparing
to the ligand H2L suggest a geometrical rearrangement between
the ground and excited states,27 which may be explained by the
influence of the coordinated transition metal ions. Significantly,
the emission quantum yield is increased more than twice in
complex 3 (ϕF = 0.017). This result is in accordance with the
absorption study, which is further proved by the partial packing
ASSOCIATED CONTENT
■
S
* Supporting Information
Details of crystal structures, TGA, and PXRD experiments of
1−5, the gas sorption measurements of 1 and 5, the
macroscopic image of H2L and the diffuse-reflectance UV−vis
F
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
(5) (a) Yi, F.-Y.; Yang, W. T.; Sun, Z.-M. J. Mater. Chem. 2012, 22,
23201−23209. (b) Kent, C. A.; Liu, D. M.; Meyer, T. J.; Lin, W. B. J.
Am. Chem. Soc. 2012, 134, 3991−3994. (c) He, Y. B.; Zhou, W.;
Krishna, R.; Chen, B. L. Chem. Commun. 2012, 48, 11813−11831.
(d) Zhan, W.-W.; Kuang, Q.; Zhou, J.-Z.; Kong, X.-J.; Xie, Z.-X.;
Zheng, L.-S. J. Am. Chem. Soc. 2013, 135, 1926−1933. (e) Meilikhov,
M.; Furukawa, S.; Hirai, K.; Fischer, R. A.; Kitagawa, S. Angew. Chem.,
Int. Ed. 2013, 52, 341−345. (f) Sun, C.-Y.; Wang, X.-L.; Qin, C.; Jin, J.-
L.; Su, Z.-M.; Huang, P.; Shao, K.-Z. Chem.Eur. J. 2013, 19, 3639−
3645. (g) Li, Y.-W.; Li, J.-R.; Wang, L.-F.; Zhou, B.-Y.; Chen, Q.; Bu,
spectra of ligand bpe and bpp This material is available free of
charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Authors
■
*(J.D.) E-mail: jieding@zzu.edu.cn.
*(Y.Z.) E-mail: ypzhao@dicp.ac.cn.
*(H.H.) E-mail: houhongw@zzu.edu.cn. Fax: (86)371-
67761744.
X.-H. J. Mater. Chem. A 2013, 1, 495−499. (h) Lu, Y. Y.; Zhan, W. W.;
̈
Author Contributions
#(M.L., Y.Y.) The authors contributed equally to the work and
should be considered co-first authors.
He, Y.; Wang, Y. T.; Kong, X. J.; Kuang, Q.; Xie, Z. X.; Zheng, L. S.
ACS Appl. Mater. Interfaces 2014, 6, 4186−4195. (i) Yoon, S. M.;
Warren, S. C.; Grzybowski, B. A. Angew. Chem., Int. Ed. 2014, 53,
4437−4441.
Notes
The authors declare no competing financial interest.
(6) (a) D’Andrade, B. W.; Forrest, S. R. Adv. Mater. 2004, 16, 1585−
1595. (b) Wang, P.; Ma, J.-P.; Dong, Y.-B.; Huang, R.-Q. J. Am. Chem.
Soc. 2007, 129, 10620−10621. (c) Wang, M.-S.; Guo, S.-P.; Li, Y.; Cai,
L.-Z.; Zou, J.-P.; Xu, G.; Zhou, W.-W.; Zheng, F.-K.; Guo, G.-C. J. Am.
Chem. Soc. 2009, 131, 13572−13573. (d) Sun, C.-Y.; Wang, X.-L.;
Zhang, X.; Qin, C.; Li, P.; Su, Z.-M.; Zhu, D.- X.; Shan, G.-G.; Shao,
K.-Z.; Wu, H.; Li, J. Nat. Commun. 2013, 4, 2716−2717.
(7) (a) Kent, C. A.; Mehl, B. P.; Ma, L. Q.; Papanikolas, J. M.; Meyer,
T. J.; Lin, W. B. J. Am. Chem. Soc. 2010, 132, 12767−12769.
(b) Zhang, X. D.; Ballem, M. A.; Hu, Z.-J.; Bergman, P.; Uvdal, K.
Angew. Chem., Int. Ed. 2011, 50, 5729−5733. (c) Streit, H. C.; Adlung,
M.; Shekhah, O.; Stammer, X.; Arslan, H. K.; Zybaylo, O.; Ladnorg,
ACKNOWLEDGMENTS
■
This work was financially supported by the National Natural
Science Foundation (Nos. 21371155 and 21301157) and
Research Found for the Doctoral Program of Higher Education
of China (20124101110002).
REFERENCES
■
(1) (a) Yaghi, O. M.; Li, G. M.; Li, H. L. Nature 1995, 378, 703−706.
(b) Venkataraman, D.; Gardner, G. B.; Lee, S.; Moore, J. S. J. Am.
Chem. Soc. 1995, 117, 11600−11601. (c) Kondo, M.; Yoshitomi, T.;
Seki, K.; Matsuzaka, H.; Kitagawa, S. Angew. Chem., Int. Ed. Engl. 1997,
36, 1725−1727. (d) Kitagawa, S.; Kitaura, R.; Noro, S.-I. Angew. Chem.,
Int. Ed. 2004, 43, 2334−2375. (e) Rowsell, J. L. C.; Yaghi, O. M.
Microporous Mesoporous Mater. 2004, 73, 3−14. (f) Long, J. R.; Yaghi,
O. M. Chem. Soc. Rev. 2009, 38, 1213−1214.
T.; Gliemann, H.; Franzreb, M.; Woll, C.; Wickleder, C.
̈
ChemPhysChem 2012, 13, 2699−2702. (d) Suresh, V. M.; George, S.
J.; Maji, T. K. Adv. Funct. Mater. 2013, 23, 5585−5590. (e) Sun, L. B.;
Xing, H. Z.; Liang, Z. Q.; Yu, J. H.; Xu, R. R. Chem. Commun. 2013,
49, 11155−11157.
(8) (a) Evans, O. R.; Lin, W. B. Acc. Chem. Res. 2002, 35, 511−522.
(b) Zang, S. Q.; Su, Y.; Li, Y. Z.; Ni, Z. P.; Meng, Q. J. Inorg. Chem.
2006, 45, 174−180. (c) Yang, J.; Li, G. D.; Cao, J. J.; Yue, Q.; Li, G.-
H.; Chen, J. S. Chem.Eur. J. 2007, 13, 3248−3261. (d) Wang, C.;
Zhang, T.; Lin, W. B. Chem. Rev. 2012, 112, 1084−1104. (e) Huang,
K. X.; Song, Y. L.; Pan, Z. R.; Li, Y. Z.; Zhuo, X.; Zheng, H. G. Inorg.
Chem. 2007, 46, 6233−6235. (f) Xu, C.; Zhang, Z.-Y.; Ren, Z.-G.;
Zhou, L.-K.; Li, H.-X.; Wang, H.-F.; Sun, Z.-R.; Lang, J.-P. Cryst.
Growth Des. 2013, 13, 2530−2539. (g) Wei, Z.-H.; Ni, C.-Y.; Li, H.-X.;
Ren, Z.-G.; Sun, Z.-R.; Lang, J.-P. Chem. Commun. 2013, 49, 4836−
4838. (h) Zhang, Z.-Y.; Gong, W.-G.; Wang, F.; Chen, M.-M.; Zhou,
L.-K.; Ren, Z.-G.; Sun, Z.-R.; Lang, J.-P. Dalton Trans. 2013, 42, 9495−
9504.
(9) (a) Kataoka, Y.; Sato, K.; Miyazaki, Y.; Masuda, K.; Tanaka, H.;
Naito, S.; Mori, W. Energy Environ. Sci. 2009, 2, 397−400. (b) Silva, C.
G.; Luz, I.; Xamena, F. X. L. I; Corma, A.; García, H. Chem.Eur. J.
2010, 16, 11133−11138. (c) Krafft, K. E.; Wang, C.; Lin, W. B. Adv.
Mater. 2012, 24, 2014−2018. (d) He, J.; Yan, Z. Y.; Wang, J. Q.; Xie,
J.; Jiang, L.; Shi, Y. M.; Yuan, F. G.; Yu, F.; Sun, Y. J. Chem. Commun.
2013, 49, 6761−6763. (e) Fateeva, A.; Chater, P. A.; Ireland, C. P.;
Tahir, A. A.; Khimyak, Y. Z.; Wiper, P. V.; Darwent, J. R.; Rosseinsky,
M. J. Angew. Chem., Int. Ed. 2012, 51, 7440−7444. (f) Wang, C.;
deKrafft, K. E.; Lin, W. B. J. Am. Chem. Soc. 2012, 134, 7211−7214.
(g) Zhou, T. H.; Du, Y. H.; Borgna, A.; Hong, J. D.; Wang, Y. B.; Han,
J. Y.; Zhang, W.; Xu, R. Energy Environ. Sci. 2013, 6, 3229−3234.
(10) (a) Zhao, B.; Chen, X.-Y.; Cheng, P.; Liao, D.-Z.; Yan, S.-P.;
Jiang, Z.-H. J. Am. Chem. Soc. 2004, 126, 15394−15395. (b) Lee, E. Y.;
Jang, S. Y.; Suh, M. P. J. Am. Chem. Soc. 2005, 127, 6374−6381.
(c) Zhu, W.-H.; Wang, Z.-M.; Gao, S. Inorg. Chem. 2007, 46, 1337−
1342. (d) Lu, W.-G.; Jiang, L.; Feng, X.-L.; Lu, T.-B. Inorg. Chem.
́
(2) (a) Paz, F. A. A.; Klinowski, J.; Vilela, S. M. F.; Tome, J. P. C.;
Cavaleiro, J. A. S.; Rocha, J. Chem. Soc. Rev. 2012, 41, 1088−1110.
(b) Furukawa, H.; Cordova, K. E.; O’Keeffe, M.; Yaghi, O. M. Science
2013, 341, 1230444. (c) Cook, T. R.; Zheng, Y.-R.; Stang, P. J. Chem.
Rev. 2013, 113, 734−777. (d) Lu, W. G.; Wei, Z. W.; Gu, Z.-Y.; Liu,
T.-F.; Park, J.; Park, J.; Tian, J.; Zhang, M. W.; Zhang, Q.; Gentle, T.
III; Bosch, M.; Zhou, H.-C. Chem. Soc. Rev. 2014, 43, 5561−5593.
(e) Lin, Z.-J.; Lu, J.; Hong, M. C.; Cao, R. Chem. Soc. Rev. 2014, 43,
̈
5867−5895.
(3) (a) Allendorf, M. D.; Bauer, C. A.; Bhakta, R. K.; Houk, R. J. T.
Chem. Soc. Rev. 2009, 38, 1330−1352. (b) Lee, J. Y.; Farha, O. K.;
Roberts, J.; Scheidt, K. A.; Nguyen, S. B. T.; Hupp, J. T. Chem. Soc.
Rev. 2009, 38, 1450−1459. (c) Shekhah, O.; Liu, J.; Fischerb, R. A.;
Woll, C. Chem. Soc. Rev. 2011, 40, 1081−1106. (d) Kreno, L. E.;
̈
Leong, K.; Farha, O. K.; Allendorf, M.; Duyne, R. P. V.; Hupp, J. T.
Chem. Rev. 2012, 112, 1105−1125. (e) Sumida, K.; Rogow, D. L.;
Mason, J. A.; McDonald, T. M.; Bloch, E. D.; Herm, Z. R.; Bae, T.-H.;
Long, J. R. Chem. Rev. 2012, 112, 724−781. (f) Horcajada, P.; Gref, R.;
́
Baati, T.; Allan, P. K.; Maurin, G.; Couvreur, P.; Ferey, G.; Morris, R.
E.; Serre, C. Chem. Rev. 2012, 112, 1232−1268. (g) Makal, T. A.; Li, J.-
R.; Lu, W. G.; Zhou, H.-C. Chem. Soc. Rev. 2012, 41, 7761−7779.
(h) Liu, J. W.; Chen, L. F.; Cui, H.; Zhang, J. Y.; Zhang, L.; Su, C.-Y.
Chem. Soc. Rev. 2014, 43, 6011−6061.
(4) (a) Hu, A. G.; Ngo, H. L.; Lin, W. B. J. Am. Chem. Soc. 2003, 125,
11490−11491. (b) Alkordi, M. H.; Liu, Y. L.; Larsen, R. W.; Eubank, J.
F.; Eddaoudi, M. J. Am. Chem. Soc. 2008, 130, 12639−12641.
(c) Allendorf, M. D.; Houk, R. J. T.; Andruszkiewicz, L.; Talin, A. A.;
Pikarsky, J.; Choudhury, A.; Gall, K. A.; Hesketh, P. J. J. Am. Chem. Soc.
2008, 130, 14404−14405. (d) Furukawa, H.; Yaghi, O. M. J. Am.
Chem. Soc. 2009, 131, 8875−8883. (e) Dan-Hardi, M.; Serre, C.; Frot,
2009, 48, 6997−6999. (e) Harbuzaru, B. V.; Corma, A.; Rey, F.; Jorda,
́
́
T.; Rozes, L.; Maurin, G.; Sanchez, C.; Ferey, G. J. Am. Chem. Soc.
J. L.; Ananias, D.; Carlos, L. D.; Rocha, J. Angew. Chem., Int. Ed. 2009,
48, 6476−6479. (f) Xie, Z. G.; Ma, L. Q.; deKrafft, K. E.; Jin, A.; Lin,
W. B. J. Am. Chem. Soc. 2010, 132, 922−923. (g) Guo, Z.; Xu, H.; Su,
S.; Cai, J.; Dang, S.; Xiang, S.; Qian, G.; Zhang, H.; O’Keeffe, M.;
Chen, B. Chem. Commun. 2011, 47, 5551−5553.
2009, 131, 10857−10859. (f) Gascon, J.; Kapteijn, F. Angew. Chem.,
Int. Ed. 2010, 49, 1530−1532. (g) McKinlay, A. C.; Morris, R. E.;
́
Horcajada, P.; Ferey, G.; Gref, R.; Couvreur, P.; Serre, C. Angew.
Chem., Int. Ed. 2010, 49, 6260−6266. (h) Liu, Y.; Xuan, W. M.; Cui, Y.
Adv. Mater. 2010, 22, 4112−4135.
G
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
(11) (a) Rieter, W. J.; Taylor, K. M. L.; An, H. Y.; Lin, W. L.; Lin, W.
B. J. Am. Chem. Soc. 2006, 128, 9024−9025. (b) Zhang, P.; Steelant,
W.; Kumar, M.; Scholfield, M. J. Am. Chem. Soc. 2007, 129, 4526−
4527. (c) Taylor, K. M. L.; Rieter, W. J.; Lin, W. B. J. Am. Chem. Soc.
2008, 130, 14358−14359. (d) Rowe, M. D.; Thamm, D. H.; Kraft, S.
L.; Boyes, S. G. Biomacromolecules 2009, 10, 983−993. (e) Huxford, R.
C.; Rocca, J. D.; Lin, W. B. Curr. Opin. Chem. Biol. 2010, 14, 262−268.
(f) Jung, S.; Kim, Y.; Kim, S.-J.; Kwon, T.-H.; Huh, S.; Park, S. Chem.
Commun. 2011, 47, 2904−2906.
5537. (c) Whited, M. T.; Djurovich, P. I.; Roberts, S. T.; Durrell, A. C.;
Schlenker, C. W.; Bradforth, S. E.; Thompson, M. E. J. Am. Chem. Soc.
2011, 133, 88−96. (d) Ryu, J. H.; Eom, Y. K.; Bunzli, J.-C. G.; Kim, H.
̈
K. New J. Chem. 2012, 36, 723−731. (e) Sozmen, F.; Oksal, B. S.;
Bozdemir, O. A.; Buyukcakir, O.; Akkaya, E. U. Org. Lett. 2012, 14,
5286−5289. (f) Zhou, Q.-X.; Lei, W.-H.; Hou, Y.-J.; Chen, Y.-J.; Li, C.;
Zhang, B.-W.; Wang, X.-S. Dalton Trans. 2013, 42, 2786−2791.
(g) Bartelmess, J.; Weare, W. W.; Sommer, R. D. Dalton Trans. 2013,
42, 14883−14891.
(19) (a) Wu, W. H.; Sun, J. F.; Cui, X. N.; Zhao, J. Z. J. Mater. Chem.
C 2013, 1, 4577−4589. (b) Sun, J. F.; Zhong, F. F.; Yi, X. Y.; Zhao, J.
Z. Inorg. Chem. 2013, 52, 6299−6310. (c) Shi, W.-J.; Menting, R.;
(12) (a) Binnemans, K. Chem. Rev. 2009, 109, 4283−4374.
(b) Rocha, J.; Carlos, L. D.; Paza, F. A. A.; Ananias, D. Chem. Soc.
Rev. 2011, 40, 926−940. (c) Cui, Y. J.; Yue, Y. F.; Qian, G. D.; Chen,
B. L. Chem. Rev. 2012, 112, 1126−1162. (d) Zhang, W.; Xiong, R.-G.
Ermilov, E. A.; Lo, P.-C.; Roder, B.; Ng, D. K. P. Chem. Commun.
̈
2013, 49, 5277−5279. (d) Majumdar, P.; Yuan, X. L.; Li, S. F.;
Guennic, B. L.; Ma, J.; Zhang, C. S.; Jacquemin, D.; Zhao, J. Z. J.
Mater. Chem. B 2014, 2, 2838−2854. (e) Manton, J. C.; Long, C.; Vos,
J. G.; Pryce, M. T. Phys. Chem. Chem. Phys. 2014, 16, 5229−5236.
(f) Bartelmess, J.; Francis, A. J.; Roz, K. A. E.; Castellano, F. N.; Weare,
Chem. Rev. 2012, 112, 1163−1195. (e) Heine, J.; Muller-Buschbaum,
̈
K. Chem. Soc. Rev. 2013, 42, 9232−9242. (f) Meyer, L. V.; Schonfeld,
̈
F.; Muller-Buschbaum, K. Chem. Commun. 2014, 50, 8093−8108.
̈
(g) Liu, D.; Ren, Z.-G.; Li, H.-X.; Lang, J.-P.; Li, N.-Y.; Abrahams, B. F.
Angew. Chem., Int. Ed. 2010, 49, 4767−4770. (h) Lang, J.-P.; Xu, Q.-F.;
Chen, Z.-N.; Abrahams, B. F. J. Am. Chem. Soc. 2003, 125, 12682−
12683.
W. W.; Sommer, R. D. Inorg. Chem. 2014, 53, 4527−4534. (g) Chu, G.
́
M.; Guerrero-Martínez, A.; Fernan
́
dez, I.; Sierra, M. A. Chem.Eur. J.
2014, 20, 1367−1375.
(13) (a) Loudet, A.; Burgess, K. Chem. Rev. 2007, 107, 4891−4932.
(b) Ziessel, R.; Ulrich, G.; Harriman, A. New J. Chem. 2007, 31, 496−
501. (c) Ulrich, G.; Ziessel, R.; Harriman, A. Angew. Chem., Int. Ed.
2008, 47, 1184−1201. (d) Benniston, A. C.; Copley, G. Phys. Chem.
Chem. Phys. 2009, 11, 4124−4131.
(20) Neelakandan, P. P.; Jimen
́
ez, A.; Nitschke, J. R. Chem. Sci. 2014,
5, 908−915.
(21) Lee, C. Y.; Farha, O. K.; Hong, B. J.; Sarjeant, A. A.; Nguyen, S.
B. T.; Hupp, J. T. J. Am. Chem. Soc. 2011, 133, 15858−15861.
(22) Zhou, L.; Xue, Y.-S.; Xu, Y.; Zhang, J.; Du, H.-B. CrystEngComm
2013, 15, 7315−7320.
(23) Komatsu, T.; Urano, Y.; Fujikawa, Y.; Kobayashi, T.; Kojima,
H.; Terai, T.; Hanaoka, K.; Nagano, T. Chem. Commun. 2009, 7015−
7017.
(14) (a) Karolin, J.; Johansson, L. B.-A.; Strandberg, L.; Ny, T. J. Am.
Chem. Soc. 1994, 116, 7801−7806. (b) Wan, C.-W.; Burghart, A.;
Chen, J.; Bergstrom, F.; Johansson, L. B.-Å.; Wolford, M. F.; Kim, T.
̈
G.; Topp, M. R.; Hochstrasser, R. M.; Burgess, K. Chem.Eur. J.
2003, 9, 4430−4441. (c) Yogo, T.; Urano, Y.; Ishitsuka, Y.; Maniwa,
F.; Nagano, T. J. Am. Chem. Soc. 2005, 127, 12162−12163. (d) Baruah,
(24) Sheldrick, G.-M. Acta Crystallogr., Sect. A 2008, 64, 112−122.
(25) Bergstrom, F.; Mikhalyov, I.; Hagglof, P.; Wortmann, R.; Ny, T.;
Johansson, L. B.- A. J. Am. Chem. Soc. 2002, 197, 196−204.
(26) Vu, T. T.; Dvorko, M.; Schmidt, E. Y.; Audibert, J.-F.; Retailleau,
P.; Trofimov, B. A.; Pansu, R. B.; Clavier, G.; Renault, R. M. J. Phys.
Chem. C 2013, 117, 5373−5385.
́
M.; Qin, W. W.; Vallee, R. A. L.; Beljonne, D.; Rohand, T.; Dehaen,
W.; Boens, N. Org. Lett. 2005, 7, 4377−4380. (e) Goud, T. V.; Tutar,
A.; Biellmann, J.-F. Tetrahedron 2006, 62, 5084−5091. (f) Tahtaoui,
́
C.; Thomas, C.; Rohmer, F.; Klotz, P.; Duportail, G.; Mely, Y.;
Bonnet, D.; Hibert, M. J. Org. Chem. 2007, 72, 269−272. (g) Oleynik,
P.; Ishihara, Y.; Cosa, G. J. Am. Chem. Soc. 2007, 139, 1842−1843.
(27) Vu, T. T.; Badre,
Audebert, P.; Senotrusova, E. Y.; Schmidt, E. Y.; Trofimov, B. A.;
Pansu, R. B.; Clavier, G.; Meallet-Renault, R. J. Phys. Chem. C 2009,
113, 11844−11855.
́
S.; Dumas-Verdes, C.; Vachon, J.-J.; Julien, C.;
(15) (a) Mikhalyov, I.; Gretskaya, N.; Bergstrom, F.; Johansson, L.
̈
́
B.-Å. Phys. Chem. Chem. Phys. 2002, 4, 5663−5670. (b) Liao, Y. Y.;
́ ́
Genot, V.; Meallet-Renault, R.; Vu, T. T.; Audibert, J.-F.; Lemaistre, J.-
(28) Liu, B. J.; Wong-Foy, A. G.; Matzger, A. J. Chem. Commun.
2013, 49, 1419−1421.
P.; Clavier, G.; Retailleaub, P.; Pansu, R. B. Phys. Chem. Chem. Phys.
2013, 15, 3186−3195. (c) Choi, S.; Bouffard, J.; Kim, Y. Chem. Sci.
2014, 5, 751−755.
(16) (a) Nepomnyashchii, A. B.; Bard, A. J. Acc. Chem. Res. 2012, 45,
1844−1853. (b) Awuah, S. G.; You, Y. RSC Adv. 2012, 2, 11169−
11183. (c) Boens, N.; Leen, V.; Dehaen, W. Chem. Soc. Rev. 2012, 41,
1130−1172. (d) Kamkaew, A.; Lim, S. H.; Lee, H. B.; Kiew, L. V.;
Chung, L. Y.; Burgess, K. Chem. Soc. Rev. 2013, 42, 77−88.
(e) Culzoni, M. J.; Pena, A. M. D. L.; Machuca, A.; Goicoechea, H.
̃
C.; Babiano, R. Anal. Methods 2013, 5, 30−49. (f) Ni, Y.; Wu, J. S. Org.
Biomol. Chem. 2014, 12, 3774−3791.
(17) (a) Yee, M.-c.; Fas, S. C.; Stohlmeyer, M. M.; Wandless, T. J.;
Cimprich, K. A. J. Biol. Chem. 2005, 280, 29053−29059. (b) Hattori,
S.; Ohkubo, K.; Urano, Y.; Sunahara, H.; Nagano, T.; Wada, Y.;
Tkachenko, N. V.; Lemmetyinen, H.; Fukuzumi, S. J. Phys. Chem. B
2005, 109, 15368−15375. (c) Yuan, M. J.; Li, Y. L.; Li, J. B.; Li, C. H.;
Liu, X. F.; Lv, J.; Xu, J. L.; Liu, H. B.; Wang, S.; Zhu, D. B. Org. Lett.
2007, 9, 2313−2316. (d) Ziessel, R.; Allen, B. D.; Rewinska, D. B.;
Harriman, A. Chem.Eur. J. 2009, 15, 7382−7393. (e) Zhang, G. Q.;
Palmer, G. M.; Dewhirst, M. W.; Fraser, C. L. Nat. Mater. 2009, 8,
747−751. (f) Bozdemir, O. A.; Guliyev, R.; Buyukcakir, O.; Selcuk, S.;
Kolemen, S.; Gulseren, G.; Nalbantoglu, T.; Boyaci, H.; Akkaya, E. U.
J. Am. Chem. Soc. 2010, 132, 8029−8036. (g) Suk, J.; Omer, K. M.;
Bura, T.; Ziessel, R.; Bard, A. J. J. Phys. Chem. C 2011, 115, 15361−
15368. (h) Zhang, X. J.; Xu, Y. F.; Guo, P.; Qian, X. H. New J. Chem.
2012, 36, 1621−1625.
(18) (a) Nastasi, F.; Puntoriero, F.; Campagna, S.; Olivier, J.-H.;
Ziessel, R. Phys. Chem. Chem. Phys. 2010, 12, 7392−7402.
(b) Rosenthal, J.; Lippard, S. J. J. Am. Chem. Soc. 2010, 132, 5536−
H
DOI: 10.1021/ic502219y
Inorg. Chem. XXXX, XXX, XXX−XXX