Mixed-Ligand Metal-Organic Framework for Two-Photon Responsive Photocatalytic C-N and C-C Coupling Reactions

Article abstract of DOI:10.1021/acscatal.8b03537

A multiple-photon photochemical process breaks the existing energy limitation of visible-light photocatalysis. Through careful incorporation of both bis(3,5-dicarboxyphenyl)pyridine and bis(3,5-dicarboxyphenyl)methylpyridinium ligands into a single metal-

Full text of DOI:10.1021/acscatal.8b03537

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Article
A Mixed-Ligand Metal-Organic Framework for Two-Photon
Responsive Photocatalytic C-N and C-C Coupling Reactions
Hanning Li, Yang Yang, Cheng He, Le Zeng, and Chunying Duan
ACS Catal., Just Accepted Manuscript • DOI: 10.1021/acscatal.8b03537 • Publication Date (Web): 26 Nov 2018
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A Mixed-Ligand MetalOrganic Framework for
Two-Photon Responsive Photocatalytic CN and
CC Coupling Reactions
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Hanning Li, Yang Yang, Cheng He, Le Zeng and Chunying Duan*
State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian
University of Technology, Dalian 116024, China.
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KEYWORDS: two-photon photocatalysis, metalorganic framework, visible-light, coupling
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reactions, nonlinear optics
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ABSTRACT: Multiple-photon photochemical process breaks the existing energy limitation of
visible-light photocatalysis. Through careful incorporation of both bis(3,5-dicarboxyphenyl)-
pyridine and bis(3,5-dicarboxyphenyl)methylpyridinium ligands into a single metalorganic
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framework, we reported herein photocatalytic CN and CC oxidative coupling reactions that
evidenced the direct two-photon response process. Time-dependent luminescence decays studies
demonstrated that the framework reached the same excited state by a two-photon absorption
process as that reached via a single-photon absorption process, and the excited state could
activate substrates even under NIR light irradiation. Under a 660 nm LEDs irradiation, both the
photooxidative CN coupling reaction of benzylamine to form benzylidene-1-
phenylmethanamine, and the CC coupling reaction between nitromethane and N-phenyl-
trtrahydroisoquinoline were accelerated directly in a heterogeneous manner. Control experiments
suggested that the minimal by-products were formed under the NIR light irradiation comparing
to those of the UV light catalytic reactions. Importantly, photon intensity-dependent studies
exhibited a nonlinear correlation between catalytic efficiency of MTV-MOFs and photon power
intensity, verifying the two-photon responsive nature, which indicated that metalorganic
framework with high-density and ordered photoactive motifs could enhance the two-photon
absorption ability, thereby improve photocatalytic efficiency even under LEDs irradiation.
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INTRODUCTION
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Visible-light photocatalysis has emerged as a powerful tool in organic synthesis for preparing
valuable compounds owing to its unique advantages, i.e. under mild conditions with trace or no
by-products and affording unique products that cannot be obtained through other routes.1-6
Typical photocatalytic cycle only utilizes one photon for the forming or breaking the chemical
bonds, known as single electron transfer (SET) mechanism, which sets an energy limitation to
the photocatalytic process.7,8 Matching the energy levels of some low-reactivity substrates
requires the energy conferred by light excitation, which is limited to one single absorbed photon
being powerful enough.9 As high-energy photons, such as UV light, always lead to the over-
activation of the functional groups of the substrate, forming unexpected by-products in the
organic reactions, strategies for utilizing multiple photons in one catalytic cycle are highly
desirable for the development of visible-light photocatalytic transformations.
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On the other hand, multiphoton responsive materials, especially two-photon responsive
materials, are well known in the fields of (bio)imaging, (bio)sensing and nonlinear optical
materials.10-12 Noted that the consecutive photoinduced electron transfer (conPET) process
constitutes two sequential SET processes, it can break the energy limitation of visible light
photocatalysis and complete challenging reactions.13,14 Considering the difficulties on the
stabilization of the radical anion formed after the first PET process, direct absorption of two
photons to access a high-energy excited state for substrate activation is desirable to overcome the
restriction choice for the photocatalysts and organic reactions. However, the relatively low
quantum yield, short fluorescence lifetime, low efficiency of the multiphoton absorption and low
yield of the photochemical response restrict potential applications of two-photon responsive
materials as photocatalysts.15,16
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Scheme 1. Representation of the two-photon responsive metalorganic frameworks for the
coupling reactions of benzylamine or N-phenyl-tetrahydroisoquinoline under a 660 nm LEDs,
respectively.
Metalorganic frameworks (MOFs) are well-known porous crystalline materials, which have
been used as heterogeneous photocatalysts under clean and mild conditions to efficiently
promote organic transformations.17-25 A wide variety of building blocks were used to prepare
high-density photoactive catalytic sites through linking and isolating the organic dyes by the
metal ions to increase the light-harvesting ability, prevent the self-quenching processes, and
enhance the efficiency of multiphoton absorption.26-30 Recently Chen and Qian reported a novel
two-photon responsive metalorganic framework through the incorporation of two kinds of
photoactive linkers into a single metalorganic framework via a multivariate (MTV) strategy.31,32
It exhibits a significant one-photon and two-photon excited fluorescence change upon UV light
and infrared laser irradiation, enabling 3D modulation of the fluorescence of the MOFs.
Herein, we used this promising porous material to evidence the direct two-photon
photocatalytic CN and CC oxidative coupling reactions, through carefully investigating the
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factors that influence the efficiency of both the two-photon absorption and the catalytic reactions
(Scheme 1). We envisioned that the framework could reach the same excited state by a two-
photon absorption process as that reached via a single-photon absorption process, enabling the
activation of substrates even under NIR light irradiation. As the energy of the NIR light for the
two-photon excitation was quite lower, it could hardly activate other sensitive bonds, and
minimal by-products were expected under the NIR light irradiation comparing to those of the UV
light catalytic reactions. In addition, photon intensity-dependent studies exhibit a nonlinear
correlation between catalytic efficiency and photon power intensity, demonstrating the two-
photon process facilitates accumulation of sufficient energy for the visible light-driven
photocatalytic reactions. As metalorganic frameworks are fascinating materials with high-
density photoactive fragments within frameworks, the well-organized networks represent a
promising approach to overcome some restrictions of the homogeneous process especially to
enhance the two-photon absorption ability and improve photocatalytic efficiency even under
LEDs irradiation. Accompanied with the increasing proportion of pyridinium salts ligands, the
two-photon absorption ability of MTV-MOFs was enhanced. Importantly, the NIR-induced
photocatalytic efficiency also increased with the increasing proportion of pyridinium salts,
suggesting that the two-photon response process played an important role in the photocatalytic
system.
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RESULTS AND DISCUSSION
Synthesis and Characterization. Solvothermal reaction of zinc salt with bis(3,5-dicarboxy
phenyl)pyridine and bis(3,5-dicarboxyphenyl)methylpyridinium in different ratios gave a series
of metalorganic frameworks according to the literature method.32,33 Powder X-ray diffraction
(PXRD) demonstrated the phase purity of the porous materials and revealed that these materials
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were isostructural with the ZJU-56 framework. As revealed by single-crystal X-ray diffraction
of ZJU-56-0.2, two types of pores, irregular elongated pores of approximately 9.5 × 22.5 Å2 and
smaller pores approximately 10.5 Å in diameter, were found with the free volume calculated to
be approximately 70.6% by PLATON software.33 The BET (Brunauer–Emmett–Teller) surface
area and pore volume of the related isostructural framework were 2823 m2g-1 and 1.074 cm3g-1,
respectively.
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Figure 1. (a) The adsorption and release (round 1: black lines, round 2: red lines) curves of the
dye molecules with ZJU-56-0.2 in a methanol solution. Catalytic traces of the coupling reaction
of benzylamine performed under optimal conditions (blue line). (b) Confocal image of 2', 7'-
dichlorofluorescein-soaked ZJU-56-0.2 detected at λem = 510–610 nm, excited by λex = 488 nm
through a 405/488 nm filter. (c) UV-vis measurements of the methanol solution of 2', 7'-
dichlorofluorescein after adsorption by activated ZJU-56-0.2 at different time. (d) UV-vis
measurements of 2', 7'-dichlorofluorescein released from dye-adsorbed ZJU-56-0.2 at different
time.
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In the presence of bis(3, 5-dicarboxyphenyl)methylpyridinium (20%), the dye uptake
experiment was carried out by soaking activated ZJU-56-0.2 framework in a methanol solution
of 2',7'-dichlorofluorescein (Figure S7), yielding a dye uptake of 5.0% based on the solid weight.
The dye-uptake crystals were washed with methanol to remove the dye from the crystals surface
until the solution become colorless before UV-vis measurement. Confocal laser scanning
microscopy (CLSM)34,35 proved the successful uptake of the dye molecules into the channels of
ZJU-56-0.2 (Figure 1b). Meanwhile, the depth-scanning confocal laser scanning microscopy
studies further confirmed the thorough removal of the dye on the surface (Figure S8). It also
indicated that the dye molecules deeply penetrated the pores of the crystals rather than stayed on
the surface. Time-dependent adsorption of 2',7'-dichlorofluorescein suggested that the dye
molecules could ingress and egress freely, which was controlled by the diffusion kinetics (Figure
1a).36,37 It means that the pores of the ZJU-56-0.2 are sufficiently robust in the solution phase,
which allows this kind of porous materials to act as a heterogeneous catalyst for chemical
reactions.38
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Solid-state cyclic voltammogram of ZJU-56-0.2 showed a broad redox band centred at -0.97 V
with a scan rate of 100 mVs-1 (vs. Ag/AgCl) (Figure S4). When excited at 350 nm, the
suspension of ZJU-56-0.2 exhibited a strong emission peak at 470 nm, and upon addition of
benzylamine at concentration up to 0.56 mM to the suspension of the framework, the intensity of
the emission band decreased significantly (Figure S10), but the emission wavelength did not
change. This quenching process was attributed to the PET process from benzylamine to the
excited state of ZJU-56-0.2,39 suggesting that ZJU-56-0.2 was able to activate benzylamine for
photocatalytic reactions via a single-photon absorption process. Importantly, when excited at 672
nm, the suspension of ZJU-56-0.2 exhibited emission peak centered at 470 nm with a lifetime of
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0.64 ns, which decreased to 0.48 ns upon the addition of benzylamine. This result was consistent
with the lifetime of the emission peak at 470 nm (excitation at 405 nm) decreasing from 1.76 ns
to 1.14 ns upon addition of benzylamine (Figure 2a, 2b). Accordingly, the ZJU-56-0.2 could
reach the same excited state by a two-photon absorption process as that reached via a single-
photon absorption process, and the excited state could activate benzylamine even under NIR
light irradiation.
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Figure 2. Time-dependent luminescence decays of ZJU-56-0.2 suspension before and after the
addition of benzylamine (a, b) or N-phenyl-tetrahydroisoquinoline (c, d), respectively. The
intensity was recorded at 470 nm with an excitation wavelength at 405 nm (a, c). The intensity
was recorded at 470 nm with excitation at 672 nm (b, d).
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Photocatalytic CN Coupling Reaction. The selective oxidation of benzylamine and its
derivatives to imines is a fundamental transformation in chemical industry, and efforts were
made for catalyst functioning under ambient conditions with high efficiency.40-43 The
photooxidation of benzylamine was optimized to perform at 60 °C in acetonitrile (MeCN) with
1.0 mol % activated ZJU-56-0.2 as photocatalyst under the irradiation of a 660 nm NIR LEDs,
and 62% conversion was obtained after 24 hours irradiation using oxygen as the oxidizing agent
(Table 1, entry 1). Without catalyst ZJU-56-0.2, the conversion was very low under the same
conditions and almost no coupling product was obtained when the reaction was carried out in the
dark (Table S1). Under the same reaction conditions, the same loading of Zn salts, bis(3,5-
dicarboxy phenyl)pyridine and bis(3,5-dicarboxyphenyl)methylpyridinium ligands only gave the
conversion rate of 17%, highlighting the importance of ZJU-56-0.2 in the photocatalytic
oxidative coupling of benzylamine under NIR light (660 nm) irradiation. Upon the addition of 50
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mol % DABCO, a well-known O2 scavenger, the photocatalytic reaction was quenched
significantly (Table S1, entry 15).44,45 It proved that beside the activation of the amine substrate,
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the activation of O2 to form active oxygen species O2 is a key step in the oxidation of
benzylamine.46
The stability of photocatalyst ZJU-56-0.2 allowed it to be isolated from the reaction mixture
by a simple filtration and reused at least three times with no substantial decrease in conversion
(62%, 62% and 60%, respectively) (Table S1, entries 16, 17). The PXRD pattern of the ZJU-56-
0.2 isolated by filtration of the reaction mixture demonstrated that the structure of the
frameworks was maintained, which suggested that ZJU-56-0.2 was a true heterogeneous
photocatalyst (Figure S19). In addition, UV-vis measurement of dye released from ZJU-56-0.2
after catalysis exhibited that the dye uptake ability was almost identical to that of the fresh ZJU-
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56-0.2, which demonstrated the intactness of the framework (Figure S7). When the size of the
microcrystals was reduced to 0.5~1 μm by grinding the crystals for 20 min, the catalytic reaction
gave a conversion of 64% under the same conditions, which was almost the same comparing to
the original size (~100 μm), suggesting that the reaction occurred in the pores of ZJU-56-0.2.
Furthermore, the similar PXRD patterns of the ground ZJU-56-0.2 and the as-synthesized MOFs
confirmed that the framework was maintained at different sizes (Figure 3).
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Diffusion behavior is also one of the intrinsic characteristics of heterogeneous catalysis.47,48
The selective photooxidation of benzylamine exhibited a first order reaction kinetics. The quite
slower kinetics of the photocatalytic conversion, comparing to the time-dependent adsorption
and release kinetics of dye molecules, suggested that the diffusion of substrate and product was
not the rate-limiting step and the pores were large enough to allow the substrates diffusing quite
fast. While there are several examples of the photocatalytic oxidation of benzylamine to
benzylidene-1-phenylmethanamine under air, most of these systems need additives to achieve
efficient catalytic transformation. The ZJU-56-0.2 system is prominent because it is performed
under 660 nm NIR light source in mild conditions with molecular oxygen as oxidant, avoiding
the use of noble-metal and any additives as well as UV light to over-activate substrate.49-51
The photocatalytic system of ZJU-56-0.2 could be extended to other substrates with different
size and functional groups, which afforded slightly different conversions (61% to 6%) under the
same reaction conditions (Table 1, entries 2–7). Notably, in the presence of bulky benzylamine
(Table 1, entry 8), which is larger than the opening pores of MOFs, the reaction gave less than 1%
conversion. The size-selectivity of the substrates confirmed that the photocatalytic coupling
reactions occurred in the channels of ZJU-56-0.2.
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Table 1. Coupling reactions of benzylamine and derivatives with two-photon responsive
ZJU-56-0.2 as the photocatalyst.a
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a Reaction conditions: substrate (1 mmol), acetonitrile (2 mL), a 660 nm LEDs for 24 h, 333 K;
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conversions were determined by GC chromatogram. ZJU-56-0.6 instead of ZJU-56-0.2 as
photocatalyst.
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The integration of the H NMR spectrum of activated ZJU-56-0.2 solids that had been
immersed in a solution containing benzylamine indicated that ca. 6 mole equiv. of benzylamine
was present per ligand moiety (Figure S12). The IR spectrum of ZJU-56-0.2 impregnated with
benzylamine revealed a NH characteristic vibration at 3310~3240 cm-1, confirming the
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encapsulation of benzylamine in the pores and suggesting the possible activation of benzylamine
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in the pores of ZJU-56-0.2 (Figure S13).
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Figure 3. (a) SEM images of the initial crystals ZJU-56-0.2 with size about 100 μm, and the fine
crystalline materials with size about 0.5~1 μm by grinding ZJU-56-0.2 crystals. (b) PXRD
patterns based on the single-crystal simulation of ZJU-56-0.2 (black), fresh as-synthesized ZJU-
56-0.2 (red), and the ground sample of ZJU-56-0.2 (blue).
Considering the two-photon absorption ability is closely related to the photon density, the
intensity-dependent experiments were conducted to investigate the impact of photon density on
the photocatalytic behavior of ZJU-56-0.2 using a 660 nm LEDs as the light source but with
different photon power density controlled by changing the distance between the LEDs and the
reactor. With 1.0 mol % loading of ZJU-56-0.2 as photocatalyst under 24 h NIR irradiation,
experiments results suggested a nonlinear correlation between the conversions of the
benzylamine oxidation and photon power density, verifying the two-photon responsive nature
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and demonstrating the two-photon process could facilitate accumulation of sufficient energy for
the visible light-driven photoredox reactions (Figure 5c). When the light intensity was lower, no
coupling products were found expect for background conversions. The nonlinear behavior was
also a significant evidence for the two-photon absorption process caused by ZJU-56-0.2 during
photocatalytic process, indicating metalorganic framework with high-density and ordered
photoactive motifs can enhance the two-photon absorption ability, thereby improve
photocatalytic efficiency even under LEDs irradiation.
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Figure 4. (a) H NMR spectra of a series of ZJU-56 MOFs. (b) PXRD patterns of a series of
ZJU-56 MOFs. (c) Conversions achieved in the photocatalytic coupling reactions of
benzylamine (black bars) and N-phenyl-tetrahydroisoquinoline (red bars) with a series of ZJU-
56 MOFs as catalysts.
When the proportion of bis(3,5-dicarboxyphenyl)methylpyridinium was increased, the
obtained MOFs (ZJU-56-0.4 and ZJU-56-0.6) exhibited increasing efficiency in photocatalytic
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reaction (Figure 4a, 4c). In the presence of ZJU-56-0.4 and ZJU-56-0.6, the corresponding
coupling products were obtained in 75% and 84% conversions, respectively. Whereas the ZJU-
56 itself gave a conversion of 24% under the same conditions (Figure 4c). As the increasing
proportion of pyridinium salts enhanced the two-photon absorption ability, it demonstrated that
the two-photon absorption ability played an important role in the photocatalytic process.
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Figure 5. (a) The recycling experiments of the coupling reaction of benzylamine (black bars)
and N-phenyl-tetrahydroisoquinoline (red bars) with ZJU-56-0.2 as the photocatalyst. (b)
Conversions achieved in the photocatalytic coupling reactions of benzylamine (black bars) and
N-phenyl-tetrahydroisoquinoline (red bars) with ZJU-56-0.6 as the photocatalyst under LEDs
irradiation with different wavelengths. (c) The conversions of the coupling reaction of
benzylamine under the 660 nm LEDs as the light source but with different photon power density
(inside: the nonlinear relationship between the conversions of the photooxidation and the photon
power density).
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Importantly, using LEDs with different wavelengths but equivalent power gave interesting
results in the catalytic reaction. With 1.0 mol % loading of ZJU-56-0.6 as photocatalyst, the
conversions of the benzylamine coupling reaction were 94%, 84%, and 60% under 360 nm, 660
nm, and 455 nm LEDs irradiation, respectively (Figure 5b). The lowest conversion of the
reaction under a 455 nm LEDs suggested the conversion was dependent on the absorption
wavelength, but it did not decrease directly with the red shift of wavelength. Clearly, the
excitation at 660 nm could reach the same excited state by a two-photon absorption process as
that reached via a single-photon absorption process, from which the excited state could activate
benzylamine even under NIR light irradiation and the photocatalytic reaction was dominated by
the two-photon responsive process under NIR irradiation.
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Photocatalytic CC Coupling Reaction. The CC oxidative coupling reactions are the most
critical steps in many important chemical syntheses,52,53 thus, developing new methods for these
reactions that optimize the balance between resource and energy efficiency is very meaningful.
N-phenyl-tetrahydroisoquinoline, one of the most common substrates in CC coupling reactions,
is also an efficient quencher for the luminescence of the suspension of ZJU-56-0.2. When
excited at 672 nm, the fluorescence lifetime of 0.68 ns at 470 nm was reduced to 0.54 ns upon
the addition of N-phenyl-tetrahydroisoquinoline at concentration up to 0.8 mM (Figure 2d). The
typical PET quenching process demonstrated that the excited state of ZJU-56-0.2 could activate
N-phenyl-tetrahydroisoquinoline in the photocatalytic chemical reaction.
The photocatalytic CC coupling reaction involving N-phenyl-tetrahydroisoquinoline was
optimized to perform at 50 °C in dioxane and nitromethane (1:1, v/v) with 4.0 mol % activated
ZJU-56-0.2 as photocatalyst under the irradiation of a 660 nm LEDs, and 54% conversion for
the coupling reaction of N-phenyl-tetrahydroisoquinoline and nitromethane was obtained after 32
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hours irradiation using oxygen as the oxidizing agent (Table 2). Control experiments (Table S2)
revealed that only a small amount of product was generated in the dark, and low conversion
(21%) of the background reaction was observed in the absence of catalyst. When the reaction
system contained the metal salts, the ligands, or the mixture of metal salts with the ligands, low
conversions (< 30%) were observed under the same conditions, which confirmed that ZJU-56-
0.2 played an important role in the two-photon photocatalysis.
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Table 2. Coupling reaction of N-phenyl-tetrahydroisoquinoline and derivatives with ZJU-
56-0.2 as the photocatalyst.a
a
Reaction conditions: substrate (0.125 mmol), nitromethane/dioxane (2 mL, 1:1), irradiation by
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660 nm LEDs for 32 h, 323 K, conversions were determined by H NMR analysis of the crude
products. b ZJU-56-0.6 instead of ZJU-56-0.2 as photocatalyst.
Electrospray ionization mass (ESI-MS) of the reaction solution after 4 hours LEDs irradiation
showed an intense peak at m/z = 208, which was assigned to the corresponding imine ion (Figure
S18).54,55 The imine ion intermediate, which was valuable and highly reactive in
functionalization reactions, confirmed that the oxidative activation of the CH bonds occurred
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adjacent to the nitrogen atom in tertiary amines (Figure S31). ZJU-56-0.2 could be separated
from the reaction system by simple filtration and reused at least three times without a substantial
decrease in conversions (54%, 52% and 51%, respectively) (Figure 5a). The stability of ZJU-56-
0.2 in the coupling reaction was verified by the maintenance of the PXRD pattern of the
framework after being isolated from the reaction mixture by filtration (Figure S20). The dye
adsorption experiment of ZJU-56-0.2 after reaction also proved the intactness of the frameworks
(Figure S7). When the size of ZJU-56-0.2 microcrystals was reduced to 0.5~1 μm, the catalytic
reaction gave a conversion of 55% under the same conditions (Figure 3a), demonstrating that the
reaction occurred in the pores of the catalyst.
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The IR spectrum of ZJU-56-0.2 impregnated with N-phenyl-tetrahydroisoquinoline showed
the characteristic vibration peaks of the substrate, and the red shift of these peaks suggested that
the substrate was encapsulated and activated in channels of ZJU-56-0.2 (Figure S15). In
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conjunction with the H NMR spectrum of desolvated ZJU-56-0.2 immersed in the solution of
N-phenyl-tetrahydroisoquinoline, these results revealed the encapsulation and possible activation
of the substrate as well as the formation of the iminium intermediate in the pores under the
irradiation of 660 nm LEDs. The scope of substrates was expanded and moderate conversions
were achieved under the same reaction conditions (Table 2). The photocatalytic activities of a
series of catalysts, ZJU-56, ZJU-56-0.4, and ZJU-56-0.6, were also measured under the same
conditions (33%, 65% and 78%, respectively) (Figure 4c). The results indicated that the catalytic
efficiency of the catalysts improved as the increasing proportion of bis(3,5-
dicarboxyphenyl)methylpyridinium, verifying that the two-photon response played a vital role in
the photocatalytic process.
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Control experiments using light sources with different wavelengths were conducted with ZJU-
56-0.6 as the catalyst under the same conditions (Figure 5b). Unexpectedly, no product was
detected in the coupling reaction of N-phenyl-tetrahydroisoquinoline with 360 nm or 455 nm
LEDs irradiation and the substrate 1a was converted to other by-products. The HPLC-MS
experiments of the reaction solution revealed that the by-product 2-Phenyl-3,4-
dihydroisoquinolin-1(2H)-one 3a was formed under the irradiation of high energy photons
(Figure S31).56 While there are several examples on the photocatalytic transformation using
multiphoton to activate substrate and drive the reaction smoothly, our results show that the over
activation of substrates with several sensitive groups under UV light or even visible light could
lead to unwanted activation or unwanted by-products. It also revealed the unexplored advantage
of the two-photon responsive photocatalyst for light-sensitive transformations, besides the
photocatalytic reaction under NIR light irradiation enhanced the utilization efficiency of the solar
energy on the photocatalytic transformations.
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CONCLUSION
In summary, we developed a promising two-photon responsive photocatalytic path by using
porous crystalline materials as photocatalysts, which has not been reported previously in our
literatures review. Under a 660 nm LEDs irradiation, the porous catalysts featured heterogeneous
photocatalytic properties and promoted both the oxidative CN coupling reaction of
benzylamine to form benzylidene-1-phenylmethanamine, and CC coupling of N-phenyl-
tetrahydroisoquinoline with nitromethane. The formation of excited state via unique two-photon
absorption process under NIR light irradiation could activate substrates as well as avoid the over
activation of the substrates with sensitive groups comparing with that under UV light or even
visible light, preventing unwanted activation and the formation of unwanted by-products. The
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efficiency of the multi-photon absorption and the conversions of coupling reactions were all
enhanced with the increasing proportion of pyridinium salts ligands in catalysts. Importantly, the
intensity-dependent experiments suggested a nonlinear correlation between the photocatalytic
efficiency of MTV-MOFs and photon power density, which indicated that metalorganic
framework containing high-density and ordered photoactive motifs could enhance the
photocatalytic efficiency under NIR LEDs irradiation via a two-photon absorption process.
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EXPERIMENTAL SECTION
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Materials and Methods: All chemicals were of reagent grade quality obtained from
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commercial sources and used without further purification. The ligands 2,5-bis(3,5-
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dicarboxyphenyl)-1-methylpyridinium
hydroxide
(H4L1•OH)
and
bis(3,5-dicarboxy
phenyl)pyridine (H4L2) were synthesized according to the methods in the literature and
characterized by 1H NMR.32,33
Powder X-ray diffraction (PXRD) measurements were obtained on a Rigaku Smart Lab XRD
instrument with a sealed Cu tube (λ = 1.54178 Å). Thermogravimetric analyses were performed
on a Mettler-Toledo TGA/SDTA851 instrument and recorded under N2 followed by a ramp of
10 °C min-1 up to 800 °C. Fourier transform infrared spectroscopy spectra were recorded using
KBr pellets on a JASCO FT/IR-430. Liquid UV-vis spectra were performed on a TU-1900
spectrophotometer. The solid UV-vis spectra were recorded on a Hitachi U-4100 UV-VIS-NIR
Spectrophotometer. Scanning electron microscopy (SEM) images were taken with a HITACHI
UHR FE-SEM SU8200 microscope. The fluorescent spectra were measured on JASCO FP-6500.
Confocal Laser Scanning Microscopy (CLSM) micrographs were collected by Olympus
1
Fluoview FV1000 with λex = 488 nm. H NMR spectra were recorded on a Varian INOVA-
400MHz type spectrometer, TMS as internal standard. The light source is a 660 nm LEDs, which
was purchased from the Beijing China Education Au-light Co., Ltd. The range of the photon
power density is from 0 – 390 mW/cm2 measured by PL-MW2000 Photoradiometer from Perfect
Light Company. The photocatalytic coupling reactions were all performed under the photon
power density being 330 mW/cm2.
Solid-state cyclic voltammogram was measured on ZAHNER ENNIUM Electrochemical
Workstation by using a carbon-paste working electrode; a well-ground mixture of each bulk
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sample and carbon paste (graphite and mineral oil) was set in the channel of a glass tube and
connected to a copper wire. A platinum-wire counter electrode and an Ag/AgCl reference
electrode were used in an aqueous solution of KPF6 at a scan rate of 100 mVs−1.
Preparation:
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Synthesis of ZJU-56: A mixture of H4L2 (10 mg, 0.025 mmol) and Zn(NO3)2•6H2O (48 mg,
0.16 mmol) were dissolved in 5 mL mixed solution of DMF and acetonitrile (4:1) in a autoclave
with trace amount of formic acid. The resulting mixture was kept in an oven at 80 °C for 24 h.
After cooling the autoclave to room temperature, colorless block-shaped crystals ZJU-56 were
obtained. Yield: 73%.
Synthesis of ZJU-56-0.2: A mixture of Zn(NO3)2•6H2O and H4L1•OH (0.005 M for H4L1•OH
and 0.020 M for Zn(NO3)2) were dissolved in DMF, and denoted as solution A. A mixture of
Zn(NO3)2•6H2O and H4L2 (0.005 M for H4L2 and 0.020 M for Zn(NO3)2) were dissolved in DMF,
and denoted as solution B. According to reaction stoichiometry, 1.0 mL of solution A, 4.0 mL of
solution B and another 1.0 mL of acetonitrile were mixed and heated at 80 °C for 24 h. After
cooling the autoclave to room temperature, colorless block-shaped crystals ZJU-56-0.2 were
obtained. Yield: 66%.
Synthesis of ZJU-56-0.4: ZJU-56-0.4 with same structure was synthesized according to the
similar method with changing the ratio of solution A and B, respectively. According to reaction
stoichiometry, 5.0 mL of mixed solution (2.0 mL of A and 3.0 mL of B) and another 1.0 mL of
acetonitrile were mixed and heated at 80 °C for 24 h. After cooling the autoclave to room
temperature, small block-shaped crystals ZJU-56-0.4 were obtained. Yield: 20%.
Synthesis of ZJU-56-0.6: ZJU-56-0.6 with same structure was synthesized according to the
similar method with changing the ratio of the solution A and B, respectively. According to
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reaction stoichiometry, 5.0 mL of mixed solution (3.0 mL of A and 2.0 mL of B) and another 1.0
mL of acetonitrile were mixed and heated at 80 °C for 24 h. After cooling the autoclave to room
temperature, small block-shaped crystals ZJU-56-0.6 were obtained. Yield: 7%.
Catalysis Details:
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Typical Photocatalysis Procedure for CN Coupling Reaction of Benzylamine: A glass
tube was filled with substrate amines (1 mmol), ZJU-56-0.2 (1.0 mol %) and acetonitrile (2 mL).
The resulting mixture was degassed with O2 bubbling for 10 minutes and then the reaction
mixture was maintained at 60 °C, and 0.1 MPa O2 atmosphere for 24 h under a 660 nm LEDs.
After reaction, the mixture was centrifuged to remove ZJU-56-0.2. The conversions were
calculated by GC measurements.
Typical Photocatalysis Procedure for the CC Coupling Reaction of N-phenyltetrahydro-
isoquinoline: A glass tube was filled with substrates (0.125 mmol), ZJU-56-0.2 (4.0 mol %),
nitromethane (1 mL) and 1,4-dioxane (1 mL). The resulting mixture was degassed with O2
bubbling for 10 minutes and then the reaction mixture was maintained at 50 °C and 0.1 MPa O2
atmosphere for 32 h under 660 nm LEDs. After reaction, the mixture was centrifuged to remove
ZJU-56-0.2. Removal of the solvent in vacuo yielded N-phenyl-tetrahydroisoquinoline
derivatives. The conversions were directly determined by 1H NMR analyses of crude products.
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ASSOCIATED CONTENT
Supporting Information
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Experimental details and additional catalytic informations.
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AUTHOR INFORMATION
Corresponding Author
cyduan@dlut.edu.cn
Notes
The authors declare no competing financial interests.
Author Contributions
The manuscript was written through contributions of all authors. All authors have given approval
to the final version of the manuscript.
ACKNOWLEDGMENT
This work was supported by the National Natural Science Foundation of China (No. 21231003
and 21171029).
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REFERENCES
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(1) Schultz, D. M.; Yoon, T. P. Solar Synthesis: Prospects in Visible Light Photocatalysis.
Science. 2014, 343, 1239176.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
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40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(2) Su, C. L.; Tandiana, R.; Tian, B. B.; Sengupta, A.; Tang, W.; Su, J.; Loh, K. P. Visible-Light
Photocatalysis of Aerobic Oxidation Reactions Using Carbazolic Conjugated Microporous
Polymers. ACS Catal. 2016, 6, 3594–3599.
(3) Lang, X. J.; Zhao, J. C.; Chen, X. D. Cooperative Photoredox Catalysis. Chem. Soc. Rev.
2016, 45, 3026–3038.
(4) Hou, J.; Ee, A.; Feng, W.; Xu, J. H.; Zhao,Y.; Wu, J. Visible-Light-Driven Alkyne Hydro-
/Carbocarboxylation Using CO2 via Iridium/Cobalt Dual Catalysis for Divergent Heterocycle
Synthesis. J. Am. Chem. Soc. 2018, 140, 5257–5263.
(5) Xie, J.; Jin, H. M.; Hashmi, A. S. K. The Recent Achievements of Redox-Neutral Radical C–
C Cross-Coupling Enabled by Visible-Light. Chem. Soc. Rev. 2017, 46, 5193–5203.
(6) Yoon, T. P.; Ischay, M. A.; Du, J. Visible Light Photocatalysis as a Greener Approach to
Photochemical Synthesis. Nat. Chem. 2010, 2, 527–532.
(7) Prier, C. K.; Rankic, D. A.; MacMillan, D. W. C. Visible Light Photoredox Catalysis with
Transition Metal Complexes: Applications in Organic Synthesis. Chem. Rev. 2013, 113, 5322–
5363.
(8) Bartling, H.; Eisenhofer, A.; König, B.; Gschwind, R. M. The Photocatalyzed Aza-Henry
Reaction of N-Aryltetrahydroisoquinolines: Comprehensive Mechanism, H•-versus H+-
Abstraction, and Background Reactions. J. Am. Chem. Soc. 2016, 138, 11860–11871.
(9) Ravelli, D.; Dondi, D.; Fagnoni, M.; Albini, A. Photocatalysis. a Multi-Faceted Concept for
Green Chemistry. Chem. Soc. Rev. 2009, 38, 1999–2011.
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1
2
3
4
5
6
7
8
9
(10) Medishetty, R.; Zaręba, J. K.; Mayer, D.; Samoć, M.; Fischer, R. A. Nonlinear Optical
Properties, Upconversion and Lasing in Metal–Organic Frameworks. Chem. Soc. Rev. 2017, 46,
4976–5004.
10
11
12
13
14
15
16
17
18
19
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21
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53
54
55
56
57
58
59
60
(11) Yu, J. C.; Cui, Y. J.; Xu, H.; Yang, Y.; Wang, Z. Y.; Chen, B. L.; Qian, G. D. Confinement
of Pyridinium Hemicyanine Dye within an Anionic Metal–Organic Framework for Two-Photon-
Pumped Lasing. Nat. Commun. 2013, 4, 2719.
(12) He, H. J.; Ma, E.; Cui, Y. J.; Yu, J. C.; Yang, Y.; Song, T.; Wu, C. D.; Chen, X. Y.; Chen,
B. L.; Qian, G. D. Polarized Three-Photon-Pumped Laser in a Single MOF Microcrystal. Nat.
Commun. 2016, 7, 11087.
(13) Ghosh, I.; Ghosh, T.; Bardagi, J. I.; König, B. Reduction of Aryl Halides by Consecutive
Visible Light-Induced Electron Transfer Processes. Science 2014, 346, 725.
(14) Zeng, L.; Liu, T.; He, C.; Shi, D. Y.; Zhang, F. L.; Duan, C. Y. Organized Aggregation
Makes Insoluble Perylene Diimide Efficient for the Reduction of Aryl Halides via Consecutive
Visible Light-Induced Electron-Transfer Processes. J. Am. Chem. Soc. 2016, 138, 3958–3961.
(15) Karotki, A.; Khurana, M.; Lepock, J. R.; Wilson, B. C. Simultaneous Two-Photon
Excitation of Photofrin in Relation to Photodynamic Therapy. Photochem. Photobiol. 2006, 82,
443–452.
(16) Khurana, M.; Collins, H. A.; Karotki, A.; Anderson, H. L.; Cramb, D. T.; Wilson, B. C.
Quantitative In Vitro Demonstration of Two-Photon Photodynamic Therapy Using Photofrin and
Visudyne. Photochem. Photobiol. 2007, 83, 1441–1448.
(17) Cook, T. R.; Zheng, Y. R.; Stang, P. J. Metal–Organic Frameworks and Self-Assembled
Supramolecular Coordination Complexes: Comparing and Contrasting the Design, Synthesis,
and Functionality of Metal–Organic Materials. Chem. Rev. 2013, 113, 734–777.
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7
8
9
(18) Li, B.; Wen, H. M.; Cui, Y. J.; Zhou, W.; Qian, G. D.; Chen, B. L. Emerging
Multifunctional Metal–Organic Framework Materials. Adv. Mater. 2016, 28, 8819–8860.
(19) Lustig, W. P.; Mukherjee, S.; Rudd, N. D.; Desai, A. V.; Li, J.; Ghosh, S. K. Metal–Organic
Frameworks: Functional Luminescent and Photonic Materials for Sensing Applications. Chem.
Soc. Rev. 2017, 46, 3242–3285.
10
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44
45
46
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53
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55
56
57
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59
60
(20) Yu, X.; Cohen, S. M. Photocatalytic Metal–Organic Frameworks for Selective 2,2,2-
Trifluoroethylation of Styrenes. J. Am. Chem. Soc. 2016, 138, 12320–12323.
(21) Zeng, L.; Guo, X. Y.; He, C.; Duan, C. Y. Metal−Organic Frameworks: Versatile Materials
for Heterogeneous Photocatalysis. ACS Catal. 2016, 6, 7935–7947.
(22) Leng, F. C.; Liu, H.; Ding, M. L.; Lin, Q. P.; Jiang, H. L. Boosting Photocatalytic Hydrogen
Production of Porphyrinic MOFs: The Metal Location in Metalloporphyrin Matters. ACS Catal.
2018, 8, 4583–4590.
(23) Dhakshinamoorthy, A.; Asiri, A. M.; Garcia, H. Metal–Organic Framework (MOF)
Compounds: Photocatalysts for Redox Reactions and Solar Fuel Production. Angew. Chem. Int.
Ed. 2016, 55, 5414–5445.
(24) Nasalevich, M. A.; Becker, R.; Ramos-Fernandez, E. V.; Castellanos, S. Veber, S. L.; Fedin,
M. V.; Kapteijn, F. Reek, J. N. H.; van der Vlugt, J. I.; Gascon, J. Co@NH2-MIL-125(Ti):
Cobaloxime-Derived Metal–Organic Framework-Based Composite for Light-Driven H2
Production. Energy Environ. Sci., 2015, 8, 364–375.
(25) Wu, P. Y.; He, C.; Wang, J.; Peng, X. J.; Li, X. Z.; An, Y. L.; Duan, C. Y. Photoactive
Chiral Metal–Organic Frameworks for Light-Driven Asymmetric α.-Alkylation of Aldehydes. J.
Am. Chem. Soc. 2012, 134, 14991–14999.
ACS Paragon Plus Environment
27

ACS Catalysis
Page 28 of 32
1
2
3
4
5
6
(26) Gao, C.; Wang, J.; Xu, H. X.; Xiong, Y. J. Coordination Chemistry in the Design of
Heterogeneous Photocatalysts. Chem. Soc. Rev. 2017, 46, 2799–2823.
7
8
9
(27) Wu, X. P.; Gagliardi, L.; Truhlar, D. G. Cerium Metal−Organic Framework for
Photocatalysis. J. Am. Chem. Soc. 2018, 140, 7904–7912.
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
(28) Wang, C.; Xie, Z. G.; Krafft, K. E.; Lin, W. B. Doping Metal−Organic Frameworks for
Water Oxidation, Carbon Dioxide Reduction, and Organic Photocatalysis. J. Am. Chem. Soc.
2011, 133, 13445–13454.
(29) Xia, Z. Q.; He, C.; Wang, X. G.; Duan, C. Y. Modifying Electron Transfer between
Photoredox and Organocatalytic Units via Framework Interpenetration for β-carbonyl
Functionalization. Nat. Commun 2017, 8, 361.
(30) Xu, H. Q.; Hu, J. H.; Wang, D. K.; Li, Z. H.; Zhang, Q.; Luo, Y.; Yu, S. H.; Jiang, H. L.
Visible-Light Photoreduction of CO2 in a Metal−Organic Framework: Boosting Electron−Hole
Separation via Electron Trap States. J. Am. Chem. Soc. 2015, 137, 13440–13443.
(31) Deng, H.; Doonan, C. J.; Furukawa, H.; Ferreira, R. B.; Towne, J.; Knobler, C. B.; Wang,
B.; Yaghi, O. M. Multiple Functional Groups of Varying Ratios in Metal−Organic Frameworks.
Science 2010, 327, 846–850.
(32) (a) Yu, J. C.; Cui, Y. J.; Wu, C. D.; Yang, Y.; Chen, B. L.; Qian, G. D. Two-Photon
Responsive Metal−Organic Framework. J. Am. Chem. Soc. 2015, 137, 4026–4029. (b) Yu, J. C.
Design, Preparation and Nonlinear Optical Properties of Ionic Metal−Organic Frameworks and
Host-Guest Systems. Doctoral Dissertation of Zhejiang University, Zhejiang, China, 2013.
(33) Rao, X.T.; Cai, J. F.; Yu, J. C.; He, Y. B.; Wu, C. D.; Zhou, W.; Yildirim, T.; Chen, B. L.;
Qian, G. D. A Microporous Metal–Organic Framework with both Open Metal and Lewis Basic
ACS Paragon Plus Environment
28

Page 29 of 32
ACS Catalysis
1
2
3
4
5
6
Pyridyl Sites for High C2H2 and CH4 Storage at Room Temperature. Chem. Commun. 2013, 49,
6719–6721.
7
8
9
(34) Helmchen, F.; Denk, W. Deep Tissue Two-Photon Microscopy. Nat. Methods 2005, 2, 932–
940.
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
(35) Han, S. B.; Hermans, T. M.; Fuller, P. E.; Wei, Y.; Grzybowski, B. A. Transport into
Metal–Organic Frameworks from Solution Is Not Purely Diffusive. Angew. Chem., Int. Ed.
2012, 51, 2662–2666.
(36) Chen,Y.; Hong, S.; Fu, C. W.; Hoang, T.; Li, X.; Valencia, V.; Zhang, Z. J.; Perman, J. A.;
Ma, S. Q. Investigation of the Mesoporous Metal–Organic Framework as a New Platform To
Study the Transport Phenomena of Biomolecules. ACS Appl. Mater. Interfaces 2017, 9, 10874–
10881.
(37) Shin, S. M.; Lee, M. S.; Han, J. H.; Jeong, N. Assessing the Guest-Accessible Volume in
MOFs using Two-Photon Fluorescence Microscopy. Chem. Commun. 2014, 50, 289–291.
(38) Farrusseng, D.; Aguado, S.; Pinel, C. Metal–Organic Frameworks: Opportunities for
Catalysis. Angew. Chem. Int. Ed. 2009, 48, 7502–7513.
(39) Johnson, J. A.; Luo, J.; Zhang, X.; Chen, Y. S.; Morton, M. D.; Echeverría, E.; Torres, F. E.;
Zhang, J. Porphyrin-Metalation-Mediated Tuning of Photoredox Catalytic Properties in Metal–
Organic Frameworks. ACS Catal. 2015, 5, 5283–5291.
(40) Jeon, S. J.; Kang, T. W.; Ju, J. M.; Kim, M. J.; Park, J. H.; Raza, F.; Han, J.; Lee, H. R.;
Kim, J. H. Modulating the Photocatalytic Activity of Graphene Quantum Dots via Atomic
Tailoring for Highly Enhanced Photocatalysis under Visible Light. Adv. Funct. Mater. 2016, 26,
8211–8219.
ACS Paragon Plus Environment
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