Monolayer nanosheets formed by liquid exfoliation of charge-assisted hydrogen-bonded frameworks

Article abstract of DOI:10.1039/d0sc06906j

Hydrogen-bonded organic frameworks (HOFs) are a diverse and tunable class of materials, but their potential as free-standing two-dimensional nanomaterials has yet to be explored. Here we report the self-assembly of two layered hydrogen-bonded frameworks based on strong, charge-assisted hydrogen-bonding between carboxylate and amidinium groups. Ultrasound-assisted liquid exfoliation of both materials readily produces monolayer hydrogen-bonded organic nanosheets (HONs) with micron-sized lateral dimensions. The HONs show remarkable stability and maintain their extended crystallinity and monolayer structures even after being suspended in water at 80 °C for three days. These systems also exhibit efficient fluorescence quenching of an organic dye in organic solvents, superior to the quenching ability of the bulk frameworks. We anticipate that this approach will provide a route towards a diverse new family of molecular two-dimensional materials.

Full text of DOI:10.1039/d0sc06906j

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Monolayer nanosheets formed by liquid exfoliation
of charge-assisted hydrogen-bonded frameworks†
Cite this: Chem. Sci., 2021, 12, 3322
a
b
Nicholas G. White *b
All publication charges for this article Joshua Nicks, Stephanie A. Boer,
have been paid for by the Royal Society
of Chemistry
a
and Jonathan A. Foster
*
Hydrogen-bonded organic frameworks (HOFs) are a diverse and tunable class of materials, but their
potential as free-standing two-dimensional nanomaterials has yet to be explored. Here we report the
self-assembly of two layered hydrogen-bonded frameworks based on strong, charge-assisted hydrogen-
bonding between carboxylate and amidinium groups. Ultrasound-assisted liquid exfoliation of both
materials readily produces monolayer hydrogen-bonded organic nanosheets (HONs) with micron-sized
lateral dimensions. The HONs show remarkable stability and maintain their extended crystallinity and
Received 18th December 2020
Accepted 12th January 2021
ꢀ
monolayer structures even after being suspended in water at 80 C for three days. These systems also
exhibit efficient fluorescence quenching of an organic dye in organic solvents, superior to the quenching
ability of the bulk frameworks. We anticipate that this approach will provide a route towards a diverse
new family of molecular two-dimensional materials.
DOI: 10.1039/d0sc06906j
rsc.li/chemical-science
research into all these materials, the formation of monolayer
nanosheets with high aspect ratios in good yields remains
Introduction
Liquid exfoliation has been used to convert a diverse range of a challenge.
layered materials into two-dimensional nanosheets. This
Hydrogen-bonds can play a varied range of roles within two-
simple and scalable approach requires materials with strong in- dimensional materials. Most commonly, they are located
layer interactions but weak inter-layer interactions to create between layers providing relatively weak interactions that
free-standing single and few-layer nanosheets with high aspect interact strongly with polar solvents aiding their exfoliation and
ratios. Early studies focussed on two-dimensional materials dispersion. For example, interlayer hydrogen-bonding has been
1
9–21
formed using either covalent bonds, such as in graphene and used to improve the properties of 2D COFs.
More relevantly,
1,2
boron nitride, or ionic bonding such as in molybdenum a variety of nanosheets containing hydrogen-bonds within the
3,4
disulphide and layered double hydroxides. However, more layers have also been reported. For example, liquid–air inter-
recent examples have shown this approach can be adapted to faces have been used to direct the self-assembly of a number of
exfoliate supramolecular structures formed using dynamic carboxylic acid and amide functionalised molecules to create
covalent bonds, to form covalent organic framework nano- ultrathin nanosheets with high aspect ratios.
sheets (CONs), or coordination compounds, to form metal– have shown that naphthalene-diimide derivatives can self-
22–24
Other reports
5,6
7,8
organic framework nanosheets (MONs). The dynamic chem- assemble in solution to form nanosheets through face to face
25,26
istry of these materials allows them to be produced under stacking of the monomeric units.
A range of urea-based
milder conditions than inorganic two-dimensional materials gelators have also been shown to self-assemble into 2D nano-
27,28
and their molecular nature allows their structure and properties sheets rather than 1D tapes.
Cucurbituril-based nanosheets
to be more easily modied. The high surface area, aspect ratios, down to monolayer thickness have been reported which are
and nanoscopic dimensions of these nanosheets combined held together through a combination of p–p stacking, CH/p
29
with their diverse and tunable chemistry make them ideal for interactions and CH/C]O hydrogen-bonding. A bis-acylurea
9
,10
11–13
14,15
a wide range of sensing,
separation applications.
catalysis,
electronics,
and based organogelator was found to stack through hydrogen-
1
6–18
However, despite intensive bonds in two-dimensions to form nanosheets, rather than the
usual 1-dimensional structure. A range of self-assembled
peptides, and block-co-polymer-based nanosheets have also
a
Department of Chemistry, University of Sheffield, Sheffield, UK. E-mail: jona.foster@
sheffield.ac.uk
30–33
been reported.
All of these nanosheets are based on rela-
b
tively weak hydrogen-bonding interactions in combination with
hydrophobic aromatic or aliphatic groups which in most cases
Electronic supplementary information (ESI) available. CCDC 2047425–2047427. drive nanosheet formation through the hydrophobic effect.
Research School of Chemistry, The Australian National University, Canberra, ACT
2
600, Australia. E-mail: nicholas.white@anu.edu.au
34,35
†
For crystallographic data in CIF or other electronic format see DOI:
These nanosheets have also all been formed “bottom-up”
1
0.1039/d0sc06906j
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through dynamic self-assembly processes in solution. An array
of 2D hydrogen-bonded materials on surfaces have also been
demonstrated using a variety of building motifs, though these
Results and discussion
Synthesis of layered hydrogen-bonded frameworks
36,37
are not free-standing.
We are only aware of a few examples of Two hydrogen-bonded systems incorporating amidinium and
“top-down” formation of nanosheets containing hydrogen- carboxylate synthons either within a single mixed linker (1) or as
bonds within the layers, but in these examples hydrogen- a co-crystal (2$TP) were prepared using simple high yielding
bonds are only formed in one dimension and co-ordination syntheses, shown in Fig. 1. Commercially available 4-cyano-
38
39
40
H
bonds, covalent bonds, or pi-stacking, hold the nano- benzoic acid was converted to the amidinium compound 1 $Cl
sheets together in the other. To our knowledge there are no using excess lithium bis(trimethylsilyl)amide (LiHMDS) fol-
examples of nanosheets connected in two-dimensions exclu- lowed by acidic work-up. Crystals of the zwitterionic form of 4-
sively through strong hydrogen-bonding interactions.
amidiniumbenzoate (1) were obtained by heating in DMF/H O
2
ꢀ
Hydrogen-bonded organic frameworks (HOFs) are a class of at 120 C for two days. Co-crystals of 2$TP were obtained on
porous supramolecular materials assembled through intermo- a 300 mg scale by carefully layering an aqueous solution of
4
1,42
lecular hydrogen-bonding interactions.
Like MOFs and bis(amidinium) 2$Cl2 with an aqueous solution of sodium
53
COFs, in order to create porous structures these materials terephthalate (Na $TP).
2
typically rely on rigid aromatic linkers and strong directional
Single crystal X-ray diffraction studies show that the crystal
hydrogen-bonding groups. HOFs possess a distinct set of structures of both 1 and 2$TP are layered structures with strong
properties in comparison to most other framework materials, in-layer hydrogen-bonding and weak inter-layer interactions. As
including ease of synthesis, solution processability, and self- shown in Fig. 2, both HONs consist of 1D hydrogen bonded
43
healing. While many HOFs are constructed through hydrogen- chains, which propagate through short N–H/O hydrogen-
4
1,42
bonding between neutral self-complementary groups,
systems use charge-assisted hydrogen-bonds,
some bonds along the axis of the 1,4-disubstituted phenyl groups
44–47
which may [H/O ¼ 1.93, 1.94 ꢀA in 1 and 1.88, 1.89 ꢀA in 2$TP]. The 1D
lead to more robust materials. In particular, amidinium cations chains are linked together through additional N–H/O
and carboxylate anions are known to form strong charge- hydrogen bonds perpendicular to this, which are slightly longer
assisted hydrogen-bond donor–acceptor pairs, and we have [H/O ¼ 2.03, 2.06 ꢀA in 1, and 2.01, 2.07 ꢀA in 2$TP]. Overall, this
shown that 3D frameworks prepared from this pair show high assembles both structures into 2D hydrogen-bonded sheets.
stability, including to prolonged boiling in water, and heating
in polar solvents such as DMSO.
The sheets stack with an interlayer distance of 3.77 and 3.72
ꢀA respectively and there are no contacts between sheets that are
48,49
Although a wide variety of layered HOFs have previously been shorter than the sum of the van der Waals radii (Fig. 2). The
50–52
reported,
to our knowledge there are currently no studies shortest centroid/centroid contacts between aromatic rings
investigating their exfoliation to form free-standing hydrogen- are >4.9 ꢀA in both 1 and 2$TP. Furthermore, the donor–acceptor
bonded framework nanosheets (HONs). This is perhaps pairs of the amidinium and carboxylate groups stack above/
because it is not necessarily obvious that materials formed below the phenyl rings of the adjacent layers, indicating an
using relatively weak intra-layer hydrogen-bonding interactions absence of substantial interlayer electrostatic interactions
would survive the high shear forces associated with liquid between the charged groups. This lack of any signicant inter-
exfoliation. In other examples of nanosheets that include layer hydrogen-bonding or electrostatic interactions combined
hydrogen-bonds within the layers, the hydrogen-bonds are with the non-interdigitated stacking mode of these hydrogen-
typically shielded from polar solvent by hydrophobic groups. bonded frameworks makes them ideal candidates for
However, the rigid structures of HONs mean that exfoliation to
form monolayer nanosheets would directly expose the
hydrogen-bonds, making them accessible to solvent molecules
and potentially leading to dissolution. HONs therefore currently
represent a new and unexplored class of two-dimensional
materials.
In this work, we report the formation of two layered
hydrogen-bonded frameworks connected in two-dimensions
through strong charge-assisted hydrogen-bonds between ami-
dinium and carboxylate groups. We hypothesized that the
strong in-layer interactions within these frameworks would
enable them to undergo ultrasonic exfoliation to produce
nanosheets. Remarkably, both materials were found to readily
exfoliate to form micron-sized single-layer HONs in good yields.
Furthermore, the nanosheets showed impressive stability in
water and the ability to quench uorescence of organic dyes
emphasising the potential of HONs as a distinct new class of 2D
materials.
Fig. 1 Scheme showing the synthesis of hydrogen-bonded frame-
works 1 and 2$TP and their exfoliation to form HON-1 and HON-2.
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Fig. 2 (a) and (b) Views of the X-ray crystal structures of 1 and 2$TP respectively, showing the 2D hydrogen bonded sheets (C–H hydrogen atoms
ꢀ
omitted for clarity). Portions of the structures are expanded in pink boxes, which highlight the H-bonding distances (in A). Views of the stacking of
the 2D hydrogen bonded layers in each structure, with interlayer distances, are shown adjacent (C–H hydrogen atoms omitted for clarity).
ultrasound-assisted liquid exfoliation. SEM imaging of the Preparation of HONs by liquid exfoliation
crystalline powders (Fig. 3a, b, S11 and S12†) indicates the
formation of rectangular prisms approximately 3–20 mm wide,
with evidence of layers stacking along the long direction of the
crystallites.
Exfoliation experiments were performed using a previously re-
ported bath sonicator setup which we have used to exfoliate
54,55
layered MOFs to form MONs.
80 kHz) ultrasound is used to minimise fragmentation and
samples are stirred in a temperature-controlled bath to mini-
Here, “soer” high frequency
(
54
mise hot-spots and ensure reproducibility. During ultra-
sonication, shear forces and cavitation exert force on the bulk
material and induce exfoliation, aer which the solvent–nano-
sheet interaction must overcome inter-sheet attraction to
prevent reaggregation. As such, a range of polar solvents
(acetone, acetonitrile, DMF, DMSO, and water) were initially
investigated for the exfoliation of both 1 and 2$TP, as it was
hypothesized that these would best penetrate between the layers
of each system, leading to enhanced exfoliation and colloidal
stabilization.
Samples (5 mg) of 1 and 2$TP were each suspended in 6 mL
of solvent in a sealed vial, and subject to ultrasonication at 80
ꢀ
kHz for 12 hours at temperatures below 18 C. The samples were
then centrifuged at 1500 rpm for 1 hour to remove unexfoliated
material and isolate nanosheets in suspension (illustrated in
Fig. S13†). Tyndall scattering observations provided qualitative
evidence indicating that DMF and acetone were optimal
solvents for the exfoliation of 1 and 2$TP into HON-1 and HON-
2
respectively, with each exhibiting strong scattering effects
(Fig. S14†). The other solvents showed weaker Tyndall scat-
tering, indicating nanoparticle formation but with signicantly
reduced yields and thus were not further investigated.
Sample suspensions were drop-cast onto hot mica plates for
topographical AFM imaging (Fig. 3c and d, S15 and S16†). Size
Fig. 3 (a) and (b) SEM images of bulk 1 and 2$TP respectively. Scale distribution analysis of the recorded images indicated consis-
bars represent 10 mm. (c) and (d) selected AFM topographical images of tently ultrathin thicknesses of approximately 0.8 nm for both
the nanosheets formed from exfoliation of 1 and 2$TP respectively. (e)
and (f) height profiles of the nanosheets shown in (c) and (d) (repre-
approximately 0.35 nm from the single crystal data. Graphene
sented by white bars).
systems. The expected thickness of a monolayer is calculated as
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ꢀ
has a nominal thickness of 0.34 nm but AFM imaging typically 2, 2]), compared to the in-layer planes (24 , [1, ꢁ1, ꢁ1]). Line
shows thickness of 0.4–1.7 nm which is typically attributed to broadening of this type is caused by the nite number of unit
tip surface interactions, image feedback settings and surface cells as crystal dimensions become severely reduced, as
56
chemistry. Whilst it is possible that bi- or tri-layer nanosheets described by the Scherrer equation. AFM shows that both
2–3 layers) have been consistently formed, the uniform thick- systems form monolayer nanosheets so we would expect not to
ness and lack of step edges is better explained by monolayer see the out of plane reections at all. However, as seen with
(
11,59
formation.
related MON systems,
some degree of restacking occurs
Analysis of the lateral dimensions of the imaged nanosheets when samples are dried for analysis. The differences in line
indicated lengths between 0.3–1.5 mm for HON-1, and 0.9–3.4 broadening therefore most likely reect different degrees of
mm for HON-2. As such, the as prepared HONs possess restacking during sample preparation. It is interesting to note
remarkably large aspect ratios and exposed surface areas as that despite the strong hydrogen-bond donor capabilities of
a result. The nanosheets have a consistently at morphology, both acetone and DMF, the extended crystallinity is still main-
with no wrinkling or rolling observed via AFM. The smaller tained throughout treatment.
HONs are observed to be rounded in shape, whereas the larger
>
800 nm wide sheets have more irregular shapes. Dynamic light
scattering measurements of the nanosheets in colloidal
suspension corroborate these size distribution observations Encouraged by the formation of HONs in highly competitive
Water stability and uorescence quenching activity
(
Fig. S17†).
solvents such as DMF, we decided to test the stability of HONs
The as-prepared HON suspensions were colloidally stable for in water. Samples of each HON were heated for 3 days at 80 C
ꢀ
approximately two days before precipitation was observed. The then re-investigated. Powder X-ray diffractometry of both
nanosheets were removed from suspension by centrifugation at hydrogen-bonded nanosheet systems indicates that the HONs
1
0 000 rpm for 1 hour. Yields of 10 and 12% were obtained for maintain their extended crystallinity (Fig. 4a). This is further
HON-1 and HON-2 respectively. Ultrasonic liquid exfoliation of supported by the presence of Tyndall scattering in the aqueous
other supramolecular nanosheets such as MONs and CONs suspensions post-treatment (Fig. S18†). AFM imaging of the
typically produce nanosheets with a range of thicknesses and aqueous suspensions drop-cast onto hot mica shows that the
sub-micron lateral dimensions. Only a few reports of monolayer nanosheets maintain their monolayer nature (Fig. S19 and 20†).
nanosheets with micron-sized lateral dimensions have been It is remarkable that atomically thin nanosheets with a supra-
57,58
reported,
and these are typically formed in much lower molecular structure connected only through hydrogen-bonds
overall yields. The improved yields and aspect ratios of HONs and without any shielding hydrophobic groups should prove
relative to other MON and CON systems emphasizes the novelty so stable under these conditions. This is particularly notable
of these new materials and may be related to the more reversible given that all starting materials dissolve readily in water. This
bonds that assemble them.
highlights the potential of these materials and of HOFs more
Powder X-ray diffractometry of the bulk crystalline powder, generally as stable materials with potential for real-world
unexfoliated material, and isolated nanosheets indicates that applications.
the extended supramolecular structure is maintained post-
To demonstrate the potential for HONs in sensing applica-
exfoliation (Fig. 4a). In particular, for the HON-2 system there tions, we investigated the quenching of a uorescent dye in
is a noticeable reduction in the intensity of peaks correspond- suspension and compared it to that of the bulk layered frame-
ꢀ
ing to through-layer planes for the as synthesised HOF (28 , [1, work. Addition of HON-1 or HON-2 to a dilute solution of
Rhodamine B in acetone resulted in 93 and 95% quenching of
Fig. 4 (a) Powder X-ray diffractometry patterns for both the one (blue) and two (pink) component systems, of: the calculated and as synthesised
frameworks, nanosheets, and water treated nanosheets. (b) The quenching efficiencies of hydrogen-bonded framework nanosheets and bulk
frameworks towards Rhodamine B fluorescence (lex ¼ 556, lem ¼ 577 nm). Emission titration spectra can be seen in Fig. S21–S24.†
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the emission respectively (Fig. 4b, S21–S24†). Furthermore, J. A. F. All authors have given approval to the nal version of the
addition of the same mass of respective bulk materials resulted manuscript.
in signicantly less effective quenching of the emission, which
is attributed to the much higher accessible surface area of the
HONs. The nanosheets exhibit no absorption in the UV-visible
Conflicts of interest
region beyond 330 nm (acetone's cut-off). This indicates that There are no conicts to declare.
quenching by the HONs, rather than competitive absorbance of
the light, is responsible for the reduction in intensity. This
quenching mechanism is widely employed by other nanosheet
Acknowledgements
systems in a variety of biological and environmental sensing Part of this work was conducted using the MX1 beamline at the
65
applications, particularly by quenching of dye-labelled single- Australian Synchrotron. Thanks to Michael Harris, Chris Hill
60–63
stranded DNA for biomolecular detection.
and the University of Sheffield BioMedical Sciences EM unit for
SEM analysis.
Conclusions
References
We have demonstrated a simple process for the top-down
exfoliation of layered hydrogen-bonded frameworks into ultra-
thin, high aspect ratio nanosheets with remarkable stability in
water and sensing capabilities. Two frameworks incorporating
amidinium and carboxylate synthons, either within a single
mixed linker or as a co-crystal, were prepared using simple high-
yielding syntheses. Single-crystal analysis show both systems
formed layered materials held together in two-dimensions by
strong, charge assisted hydrogen-bonding interactions, with
only weak van der-Waal interlayer interactions. The systems
underwent a “so” liquid-phase ultrasonic exfoliation proce-
dure to produce HONs with a thickness of 0.8 nm and micron
sized lateral dimensions. The HONs exhibit remarkable stability
in a range of highly competitive solvents, including maintaining
1 M. J. Allen, V. C. Tung and R. B. Kaner, Chem. Rev., 2010, 110,
132–145.
2 L. H. Li and Y. Chen, Adv. Funct. Mater., 2016, 26, 2594–2608.
3 X. Huang, Z. Zeng and H. Zhang, Chem. Soc. Rev., 2013, 42,
1934–1946.
4 Q. Wang and D. O'Hare, Chem. Rev., 2012, 112, 4124–4155.
5 D. Rodr ´ı guez-San-Miguel, C. Montoro and F. Zamora, Chem.
Soc. Rev., 2020, 49, 2291–2302.
6 W. Wang, W. Zhao, H. Xu, S. Liu, W. Huang and Q. Zhao,
Coord. Chem. Rev., 2020, 213616.
7 D. J. Ashworth and J. A. Foster, J. Mater. Chem. A, 2018, 6,
16292–16307.
8 M. Zhao, Y. Huang, Y. Peng, Z. Huang and Q. Ma, Chem. Soc.
Rev., 2018, 47, 6267–6295.
ꢀ
structures aer suspension in water at 80 C for three days. This
stability is particularly remarkable given that both components
are highly water soluble and the nanosheets are only held
together by strong hydrogen-bonds. The HONs also demon-
9 Y. Peng, Y. Huang, Y. Zhu, B. Chen, L. Wang, Z. Lai, Z. Zhang,
M. Zhao, C. Tan, N. Yang, F. Shao, Y. Han and H. Zhang, J.
Am. Chem. Soc., 2017, 139, 8698–8704.
strate the potential for use in sensing applications showing 10 G. Lan, K. Ni, E. You, M. Wang, A. Culbert, X. Jiang and
strong quenching of uorescent dyes. W. Lin, J. Am. Chem. Soc., 2019, 141, 18964–18969.
HOFs are a diverse class of materials with a variety of useful 11 J. Nicks, J. Zhang and J. A. Foster, Chem. Commun., 2019, 55,
properties and promising applications. Exfoliation dramatically 8788–8791.
increases a materials surface area, exposes active sites, and aids 12 C. Tan, K. Yang, J. Dong, Y. Liu, Y. Liu, J. Jiang and Y. Cui, J.
incorporation within membranes and thin lms unlocking Am. Chem. Soc., 2019, 141, 17685–17695.
distinct new opportunities for HONs. A wide range of extended 13 H. J. Zhu, M. Lu, Y. R. Wang, S. J. Yao, M. Zhang, Y. H. Kan,
and functionalised derivatives of HON-1 and HON-2 can readily
be envisaged which could enable their use in a wide range of
J. Liu, Y. Chen, S. L. Li and Y. Q. Lan, Nat. Commun., 2020, 11,
1–10.
sensing, catalysis, separation, and electronics applications. We 14 K. Sasitharan, D. G. Bossanyi, N. Vaenas, A. J. Parnell,
anticipate that this simple and scalable approach will be
broadly applicable to a wide range of other layered HOFs,
J. Clark, A. Iraqi, D. G. Lidzey and J. A. Foster, J. Mater.
Chem. A, 2020, 8, 6067–6075.
particularly those based on other strong hydrogen-bond donor– 15 H. Chen, H. Tu, C. Hu, Y. Liu, D. Dong, Y. Sun, Y. Dai,
4
5,64
acceptor pairs.
The remarkable stability of these hydrogen-
S. Wang, H. Qian, Z. Lin and L. Chen, J. Am. Chem. Soc.,
2018, 140, 896–899.
16 T. Rodenas, I. Luz, G. Prieto, B. Seoane, H. Miro, A. Corma,
F. Kapteijn, F. X. Llabr ´e s i Xamena and J. Gascon, Nat.
Mater., 2014, 14, 48–55.
7 Y. Ying, M. Tong, S. Ning, S. K. Ravi, S. B. Peh, S. C. Tan,
S. J. Pennycook and D. Zhao, J. Am. Chem. Soc., 2020, 142,
4472–4480.
bond based materials also has broad implications for the
design of a wide range of other supramolecular materials.
Author contributions
1
S. A. B. synthesized and characterized 1. N. G. W. synthesized
and characterized 2$TP. J. N. performed exfoliation studies,
nanosheet characterization, water stability tests, and quenching 18 H. Yang, L. Yang, H. Wang, Z. Xu, Y. Zhao, Y. Luo, N. Nasir,
experiments. The project was conceived by N. G. W. and J. A. F.
The manuscript was written by J. N. with editing by N. G. W. and
Y. Song, H. Wu, F. Pan and Z. Jiang, Nat. Commun., 2019, 10,
1–10.
3326 | Chem. Sci., 2021, 12, 3322–3327
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View Article Online
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1
2
9 S. B. Alahakoon, S. D. Diwakara, C. M. Thompson and 43 J. Luo, J. Wang, J. Zhang, S. Lai and D. Zhong,
R. A. Smaldone, Chem. Soc. Rev., 2020, 49, 1344–1356. CrystEngComm, 2018, 20, 5884–5898.
0 S. B. Alahakoon, K. Tan, H. Pandey, S. D. Diwakara, 44 V. A. Russell, C. C. Evans, W. Li and M. D. Ward, Science,
G. T. McCandless, D. I. Grinffiel, A. Durand-Silva, 1997, 276, 575–579.
T. Thonhauser and R. A. Smaldone, J. Am. Chem. Soc., 45 T. Adachi and M. D. Ward, Acc. Chem. Res., 2016, 49, 2669–
020, 142, 12987–12994. 2679.
1 A. Halder, S. Karak, M. Addicoat, S. Bera, A. Chakraborty, 46 G. Xing, T. Yan, S. Das, T. Ben and S. Qiu, Angew. Chem., Int.
2
2
S. H. Kunjattu, P. Pachfule, T. Heine and R. Banerjee,
Angew. Chem., Int. Ed., 2018, 57, 5797–5802.
2 X. Hou, M. Schober and Q. Chu, Cryst. Growth Des., 2012, 12,
Ed., 2018, 57, 5345–5349.
47 G. Xing, I. Bassanetti, S. Bracco, M. Negroni,
C. Bezuidenhout, T. Ben, P. Sozzani and A. Comotti, Chem.
Sci., 2019, 10, 730–736.
2
5159–5163.
23 R. Makiura, K. Tsuchiyama, E. Pohl, K. Prassides, O. Sakata, 48 S. A. Boer, M. Morshedi, A. Tarzia, C. J. Doonan and
H. Tajiri and O. Konovalov, ACS Nano, 2017, 11, 10875–
0882.
4 M. Vybornyi, Y. B. Hechevarria, M. Glauser, A. V Rudnev and
N. G. White, Chem.–Eur. J., 2019, 25, 10006–10012.
49 W. Liang, F. Carraro, M. B. Solomon, S. G. Bell,
H. Amenitsch, C. J. Sumby, N. G. White, P. Falcaro and
C. J. Doonan, J. Am. Chem. Soc., 2019, 141, 14298–14305.
50 Q. Huang, W. Li, Z. Mao, L. Qu, Y. Li, H. Zhang, T. Yu,
Z. Yang, J. Zhao, Y. Zhang, M. P. Aldred and Z. Chi, Nat.
Commun., 2019, 10, 1–8.
1
2
R. Ha, Chem. Commun., 2015, 51, 16191–16193.
2
2
5 D. S. Pal and S. Ghosh, Chem.–Eur. J., 2018, 24, 8519–8523.
6 Y. Sun, C. He, K. Sun, Y. Li, H. Dong, Z. Wang and Z. Li,
Langmuir, 2011, 27, 11364–11371.
2
2
2
7 W. Bai, Z. Jiang, A. E. Ribbe and S. Thayumanavan, Angew. 51 I. Hisaki, Y. Suzuki, E. Gomez, Q. Ji, N. Tohnai, T. Nakamura
Chem., Int. Ed., 2016, 55, 10707–10711. and A. Douhal, J. Am. Chem. Soc., 2019, 141, 2111–2121.
8 R. Davis, R. Berger and R. Zentel, Adv. Mater., 2007, 19, 3878– 52 K. Ma, P. Li, H. John, R. R. Maldonado, R. Q. Snurr,
3881.
O. K. Farha, K. Ma, P. Li, J. H. Xin, Y. Chen, Z. Chen and
9 Q. An, Q. Chen, W. Zhu, Y. Li, C. A. Tao, H. Yang, Z. Li,
S. Goswami, Cell Reports Phys. Sci., 2020, 1, 100024.
L. Wan, H. Tian and G. Li, Chem. Commun., 2010, 46, 725– 53 M. Thomas, T. Anglim Lagones, M. Judd, M. Morshedi,
7
27.
M. L. O'Mara and N. G. White, Chem.–Asian J., 2017, 12,
1587–1597.
3
3
3
0 I. W. Hamley, A. Dehsorkhi and V. Castelletto, Chem.
Commun., 2013, 49, 1850–1852.
1 J. P. Joseph, A. Singh, D. Gupta, C. Miglani and A. Pal, ACS
Appl. Mater. Interfaces, 2019, 11, 28213–28220.
54 D. J. Ashworth, A. Cooper, M. Trueman, R. W. M. Al-Saedi,
S. D. Liam, A. J. Meijer and J. A. Foster, Chem.–Eur. J.,
2018, 24, 17986–17996.
2 M. Tsuksamoto, K. Ebata, H. Sakiyama, S. Yamamoto, 55 J. A. Foster, S. Henke, A. Schneemann, R. A. Fischer and
M. Mitsuishi, T. Miyashita and J. Matsui, Langmuir, 2019,
5, 3302–3307.
3 T. Sato, M. Tsukamoto, S. Yamamoto, M. Mitsuishi,
A. K. Cheetham, Chem. Commun., 2016, 52, 10474–10477.
56 C. J. Shearer, A. D. Slattery, A. J. Stapleton, J. G. Shapter and
C. T. Gibson, Nanotechnology, 2016, 27, 125705.
3
3
T. Miyashita, S. Nagano and J. Matsui, Langmuir, 2017, 33, 57 Y. Peng, Y. Li, Y. Ban, H. Jin, W. Jiao, X. Liu and W. Yang,
2897–12902. Science, 2014, 346, 1356–1359.
4 T. Govindaraju and M. B. Avinash, Nanoscale, 2012, 4, 6102– 58 Y. Zhao, J. Wang and R. Pei, J. Am. Chem. Soc., 2020, 142,
117. 10331–10336.
5 L. Z. Jin, S. S. Wang, L. H. Xie and W. Huang, Chin. J. Chem., 59 Z.-R. Tao, J.-X. Wu, Y.-J. Zhao, M. Xu, W.-Q. Tang,
1
3
3
3
3
6
2
019, 37, 405–416.
Q.-H. Zhang, L. Gu, D.-H. Liu and Z.-Y. Gu, Nat. Commun.,
2019, 10, 2911.
6 A. G. Slater, L. M. A. Perdig ˜a o, P. H. Beton and
N. R. Champness, Acc. Chem. Res., 2014, 47, 3417–3427.
7 D. P. Goronzy, M. Ebrahimi, F. Rosei, Arramel, Y. Fang, S. De
60 B. J. C ´o rdova Wong, D. M. Xu, S. S. Bao, L. M. Zheng and
J. Lei, ACS Appl. Mater. Interfaces, 2019, 11, 12986–12992.
Feyter, S. L. Tait, C. Wang, P. H. Beton, A. T. S. Wee, 61 M. Zhao, Y. Wang, Q. Ma, Y. Huang, X. Zhang, J. Ping,
P. S. Weiss and D. F. Perepichka, ACS Nano, 2018, 12,
445–7481.
Z. Zhang, Q. Lu, Y. Yu, H. Xu, Y. Zhao and H. Zhang, Adv.
Mater., 2015, 27, 7372–7378.
7
38 F. Moghzi and J. Soleimannejad, Nanotechnology, 2020, 31, 62 H. Q. Zhao, G. H. Qiu, Z. Liang, M. M. Li, B. Sun, L. Qin,
2
45706.
S. P. Yang, W. H. Chen and J. X. Chen, Anal. Chim. Acta,
2016, 922, 55–63.
3
9 M. Li, M. Song, G. Wu, Z. Tang, Y. Sun, Y. He, J. Li, L. Li,
H. Gu, X. Liu, C. Ma, Z. Peng, Z. Ai and D. J. Lewis, Small, 63 Q. Wang, W. Wang, J. Lei, N. Xu, F. Gao and H. Ju, Anal.
017, 13, 1–7. Chem., 2013, 85, 12182–12188.
0 L. Xu, Y. Huang, J. Li, D. Wang, M. Chen, J. Tao, K. Cui, 64 V. A. Russell, M. C. Etter and M. D. Ward, J. Am. Chem. Soc.,
G. Pan, N. Huang and L. Li, Langmuir, 2013, 29, 3813–3820. 1994, 116, 1941–1952.
1 R. B. Lin, Y. He, P. Li, H. Wang, W. Zhou and B. Chen, Chem. 65 N. P. Cowieson, D. Aragao, M. Cli, D. J. Ericsson, C. Gee,
2
4
4
4
Soc. Rev., 2019, 48, 1362–1389.
S. J. Harrop, N. Mudie, S. Panjikar, J. R. Price, A. Riboldi-
tunnicliffe, R. Williamson and T. Caradoc-davies, J.
Synchrotron Radiat., 2015, 187–190.
2 J. Yang, J. Wang, B. Hou, X. Huang, T. Wang and Y. Bao,
Chem. Eng. J., 2020, 399, 125873.
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