Supersnowflakes: Stepwise Self-Assembly and Dynamic Exchange of Rhombus Star-Shaped Supramolecules

Article abstract of DOI:10.1021/jacs.7b01326

With the goal of increasing the complexity of metallo-supramolecules, two rhombus star-shaped supramolecular architectures, namely, supersnowflakes, were designed and assembled using multiple 2,2′:6′,2″-terpyridine (tpy) ligands in a stepwise manner. In the design of multicomponent self-assembly, ditopic and tritopic ligands were bridged through Ru(II) with strong coordination to form metal-organic ligands for the subsequent self-assembly with a hexatopic ligand and Zn(II). The combination of Ru(II)-organic ligands with high stability and Zn(II) ions with weak coordination played a key role in the self-assembly of giant heteroleptic supersnowflakes, which encompassed three types of tpy-based organic ligands and two metal ions. With such a stepwise strategy, the self-sorting of individual building blocks was prevented from forming the undesired assemblies, e.g., small macrocycles and coordination polymers. Furthermore, the intra- and intermolecular dynamic exchange study of two supersnowflakes by NMR and mass spectrometry revealed the remarkable stability of these giant supramolecular complexes.

Full text of DOI:10.1021/jacs.7b01326

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Article
Super Snowflakes: Step-Wise Self-Assembly and Dynamic
Exchange of Rhombus Star-Shaped Supramolecules
Zhe Zhang, Heng Wang, Xu Wang, Yiming Li, Bo Song, Olapeju Bolarinwa, R. Alexander Reese, Tong
Zhang, Xu-Qing Wang, Jianfeng Cai, Bingqian Xu, Ming Wang, Changlin Liu, Hai-Bo Yang, and Xiaopeng Li
J. Am. Chem. Soc., Just Accepted Manuscript • Publication Date (Web): 30 May 2017
Downloaded from http://pubs.acs.org on May 30, 2017
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Journal of the American Chemical Society
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Super Snowflakes: Step-Wise Self-Assembly and Dynamic Ex-
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Zhe Zhang,†,‡,§ Heng Wang, Xu Wang, Yiming Li, Bo Song, Olapeju Bolarinwa, R. Alexander
‡,§
┴
‡
‡
‡
#
‡
,
∥
,†
∇
∇
∇
Reese, Tong Zhang, Xu-Qing Wang, Jianfeng Cai, Bingqian Xu, Ming Wang,* Changlin Liu,*
#
,‡
Hai-Bo Yang, Xiaopeng Li*
†
Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, School of Chemistry, Central China Normal Uni-
versity, Wuhan, Hubei 430079, China
‡Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
┴
Department of Chemistry, Texas State University, San Marcos, Texas 78666, United States
#Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal Uni-
versity, Shanghai 200062, China
∥State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin
1
30012, China
∇
Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of
Georgia, Athens, Georgia 30602, United States
KEYWORDS Supramolecule, Terpyridine, Self-assembly, Ion mobility-mass spectrometry
ABSTRACT: With the goal of increasing the complexity of metallo-supramolecules, two rhombus star-shaped supramolecular ar-
chitectures, namely super snowflakes, were designed and assembled using multiple 2,2’:6’,2”-terpyridine (tpy) ligands in a step-wise
manner. In the design of multi-component self-assembly, ditopic and tritopic ligands were bridged through Ru(II) with strong coor-
dination to form metal-organic ligands for the subsequent self-assembly with a hexatopic ligand and Zn(II). The combination of
Ru(II)-organic ligands with high stability and Zn(II) ions with weak coordination played a key role in the self-assembly of giant
heteroleptic super snowflakes, which encompassed three types of tpy-based organic ligands and two metal ions. With such step-wise
strategy, the self-sorting of individual building blocks were prevented from forming the undesired assemblies, e.g., small macrocycles
and coordination polymers. Furthermore, the intra- and intermolecular dynamic exchange study of two super snowflakes by NMR
and mass spectrometry revealed the remarkable stability of these giant supramolecular complexes.
Introduction
To advance supramolecular chemistry into a new level of so-
phistication, efforts have been made to create more complex
metallo-supramolecular architectures and ultimately to achieve
new chemistry and functionality. To date, the following strate-
gies have been used to increase structural complexity and diver-
sity issues, including i) rational design of ligands with self-sort-
Self-assembly as a powerful bottom-up approach has been
extensively used by nature to create complex biological systems.
Synthetic supramolecular chemistry aims to use the principles
of biological self-assembly to construct artificial nanostructures
using molecular building blocks with desired functions and
2
7
ing ability for multicomponent self-assembly; ii) synthesis of
multi-armed building blocks for self-assembly of multi-layered
1
properties. Among this diverse research field, coordination-
2
−4
2
8
driven self-assembly, a burgeoning section of supramolecu-
lar chemistry, is flourishing for the construction of a vast variety
structures; iii) step-wise self-assembly of heteroleptic archi-
2
9
tectures using metal-organic ligands; iv) employing both co-
ordination and dynamic covalent chemistry for subcomponent
5
6
7−9
of structures, such as helicates, grids, polygons, polyhe-
10−12
13
14−17
18
19
1
2h,30
dra,
rotaxanes, catenanes,
knots, and links. On the
self-assembly;
v) introducing other types of weak interac-
basis of their precisely controlled shapes and sizes, these spec-
tacular metallo-supramolecules have found a wide array of ap-
tions for orthogonal self-assembly in addition to coordina-
24a,25b,31
tion.
1
6a,20
21
plications, including catalysis,
sensing, drug delivery and
2
,2’:6’,2”-terpyridine (tpy) ligands are widely used as build-
2
2
23
24,25
release, gas storage, smart materials,
and stabilization of
ing blocks in supramolecular and macromolecular chemis-
2
6
reactive substances. Most of these achievements, however,
were centered on highly symmetric metallo-supramolecules as-
sembled by single type of organic ligand and metal ion. The
corresponding abiological assemblies still suffered from a lack
of complexity and thus were unable to reach the high degrees
of functionality found in natural systems.
2a,32
try.
An extremely interesting aspect of this tridentate ligand
is the different binding strength of tpy and transition metal ions
with order as Ru(II)> Fe(II) > Ni(II) > Zn(II) > Cd(II) in the
2+ 33
2
complex of [M(tpy) ] . This main characteristic allows us to
harness strong and weak binding metal ions, e.g., Ru(II) with
Fe(II), Zn(II) or Cd(II) in a step-wise manner, in which stable
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Ru(II)-organic ligand was assembled or synthesized for the sub-
according to the characteristic resonance peaks of tpyH3’,5’. Af-
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sequent self-assembly with metal ions with low binding
strength and high reversibility to construct heteroleptic metallo-
ter complexation, S1 shows slightly broad NMR pattern in the
aromatic region with six types of tpy (A-F), due to the overlap
of the resonance signals ascribed to the protons in each ligand.
All the 3’, 5’ protons on the metal free tpy units of L3 and L5,
3
4
supramolecules with increasing complexity. With this step-
wise approach, most of the previous studies, however, was lim-
ited to the combination of two types of ligands and metal
3
’,5’
3’,5’
3’,5’
i.e., A(E) , D , and F , were significantly shifted to
downfield (~0.3 ppm) after coordinating with Zn(II) ion, owing
to the electron deficiency of these protons brought about by the
9
a,29b−d,35
ions.
Challenges still remain by using three or more
types of tpy-based organic ligands in the journey towards multi-
component self-assembly.
4
0
metal ions. By contrast, all the 6,6” protons of the above men-
tioned tpy groups were dramatically shifted towards upfield
Beyond those boundaries, we describe herein a step-wise
self-assembly of giant rigid two-dimensional (2D) rhombus
star-shaped supramolecules, namely super-snowflakes, which
encompass three types of tpy ligands and two metal ions, i.e.,
Ru(II) and Zn(II) in each individual structure. It is worthy to
4
0
(
~0.8 ppm), due to the electron shielding effect. The methoxyl
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groups of L5 showed distinguished NMR peaks because of their
various distance from the metal ion. While in the complex, the
corresponding signal was singlet and relatively sharp, suggest-
ing the combination of D-tpy group with Zn(II) to form a unique
structure. In the alkyl region, the overlapped signals of the ter-
minal methyl on the hexyloxyl chain of L5 were split into two
sets of triplet peaks with an integration ratio of 2:1 (Figure S42).
It was indicated the formation of the designed snowflake struc-
ture, in which two of the three long alkyl chains on each arm
were settled inside the snowflake structure, while the third one
stayed freely outside the structure. All the assignments shown
in Figure 1 are readily confirmed by the 2D-COSY, 2D-
NOESY and 2D-ROESY spectra (Figures S45-46, S47-48, and
S56-S57).
3
6
note that the pioneering snowflake-like structures by Stang
3
7
and Newkome were based on the exo-functionalization of su-
pramolecular hexagons using dendrimers. While our shape-per-
sistent snowflakes were constructed with all rigid backbones.
Considering that tpy-based building blocks have been intro-
38
duced into infinite 2D metal−organic monolayer sheets, our
discrete and shape-persistent 2D supramolecular architectures
may serve as a model system to investigate the self-assembly
behavior and physical property in order to generate defect-free
2D materials for molecular electronics, energy storage, imaging,
and sensing.
N
N
N
N
N
N
N
N
N
N
Results and Discussions
N
O
N
O
O
N
O
N
O
N
Synthesis, Self-Assembly and Characterization of Super
N
N
N
N N
N
N
N
Snowflake 1 (S1). Based on structural analysis, three tpy-based
N
N
39
organic ligands L1, L2, and L3 may assemble with metal ions
L1
L2
L4
O
N
with ratio 6:6:1:18 to generate a snowflake-like metallo-supra-
molecule (Scheme S1). All three ligands were prepared through
conventional Suzuki cross-coupling reactions. Direct self-as-
sembly was conducted by successively adding methanol solu-
O
N
O
N
O
N
N
N
N
N
Ru
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Ru
N
N
N
N
N
N
O
N
N
N
N
O
N
O
N
N
N
N
N
3
tion of Zn(NO ) (18 eq.) into chloroform solution of L1/L2/L3
N
(6:6:1) with shaking. Although the concentration of the ligands
and Zn(II) solution was low (1 mg/mL), precipitate was imme-
diately formed after the mixing. The predominant assemblies in
N
N
N
N
N
L5
L3
L6
the supernatant were identified as small triangles by ESI-MS
−
(
Figure S1, the counter ions were transformed to PF
6
) due to
the strong self-sorting ability of L1. We speculated that the pre-
6 x
6 x
cipitate was the 2D coordination polymers assembled by lig-
3
8
ands L2 and L3 with Zn(II). To block the self-sorting individ-
ual ligands, ruthenium chemistry was employed to prepare L5
by bridging L1 and L2 (Scheme S3.) in the first step. Briefly,
L5 was synthesized by Suzuki coupling reaction on a precursor
12 x
12 x
7
owing to the excellent chemical stability of tpy-Ru(II) com-
plexes during conventional coupling reaction and column sepa-
ration. Note that L5 was not able to be obtained by direct mixing
L1, L2 and Ru(II) because of self-sorting and separation chal-
lenges. In the second step, Ru(II)-organic ligand L5 were as-
sembled with a hexatopic ligand L3 and Zn(NO
3
)
2
in an exact
/MeOH at 50 C for 5 hours. The red
precipitate of S1 was obtained by adding excess amount of
NH PF into the assembly mixture, and purified by repeating
wash with DI water.
o
ratio of 6:1:12 in CHCl
3
4
6
1
Zn
Ru
Figure 1 shows the H NMR spectra of ligand L3, L5 and
their corresponding complex S1. Sharp and well-splitting sig-
nals can be figured out in the spectra of L3 and L5, which are
assigned to one and four sets of tpy-phenyl units, respectively,
S1
S2
Scheme 1. Self-assembly of snowflakes S1 and S2
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-
H
3
CO OCH
3
3
6PF6
1
2
3
4
5
6
7
8
9
N
N
N
N
N
N
N
Zn
N
N
N
N
N
N
N
N
Ru
N
N
N
13
1
3
H
m
H
6
6
H
3
CO
N
N
N
C6
H
13
O
OC
N
N
N
OCH
OCH
3
3
N
N
N
OCH
OC
f
3
H
3
CO
N
Ru
N
OC
6
H
13
C
6
H
13
O
N
Zn N D
N
D
C
N
OC
6
H
13
C H13O
N
Zn N D
N
D
C
OCH
6
3
C
n
e
OC H
6
13
N
N
N
N
N
N
N
N
N
N
N
C
N
Zn
N
N
Zn
N
Zn
N
N
Ru
N
N
N
N
N
B
13
H
N
N
N
N
6
B
OC
N
N
N
N
N
N
Zn
C
6
H
13
O
10
11
12
13
14
15
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60
C
H
O
N
Zn
N
F
F
N
N
A
A
OC
H
13
N
Zn
N
N
Ru
N
6
13
6
O C
OC
6
H
13
N
N
6
E
N
N
N
N
H
1
3
B
E
N
N
N
N
N
Zn
N
N
N
N
N
5 4
N
Ru
N
N
Zn
N
N
Zn
N
6
3
3'
B
N
N
N
N
N
N
N
N
C H13O
6
13
H
6
N
N
N
Zn
C
6
H
13
O
OC
N
N
N
F
F N Zn NA
A
OC
6
H
13
H
3
CO
CO
N
N
OC
6
H
13
C
H
O
N
Ru
N
OCH
5'
O C
6
13
3
N
N
j k
H
3
N
O
OC
H
13
N
OCH
E
6
3
13
6'' 3''
6
H
H
6
C
1 3
5
''4''
N
N
N
N
N
N
E
N
Ru
Zn
N
N
N
N
N
N
Zn
H
3
CO OCH
3
A(E)3’,5’
A(E)36
’,5’
,6’’
6,6’’
B5,5’’
B
A(E)5,5’’
D
4,4’’
C6,6’’
A(E)3,3’’
A(E)
4,4’’
j
A(E) C
C5,5’’
n
A(E)k
D4,4’’
4
,4’’
Dj
D5,5’’
m
D6
,6’’
,3’’
B
Bk
3
C3’,5’B3’,5’
D
k
Bj Cj
C
Dk
e f
C3,3’’ B3,3’’
L5
E3’,5’
nm
A3’,5’
Ej
5,5’’
4
,4’’
E
E
Aj
A5,5’’
A4,4’’
S1
L3
F6,6’’
F5,5’’
F3’,5’
F3,3’’
F4,4’’
7.8
Fj
Fk
9
.4
9.2
9.0
8.8
8.6
8.4
8.2
8.0
7.6
7.4
7.2
7.0
4.2
4.0
Chemical Shift (ppm)
1
Figure 1. H NMR spectra (500 MHz) of L5 and L3 in CDCl
3
and S1 in CD CN
3
.
The diffusion-ordered NMR spectroscopy (DOSY) provides
dimensional information of S1, as shown in Figure 2a (full
ranged spectra was shown in Figure S62). The spectrum showed
a narrow band of signal with a diffusion coefficient (D) around
1.70×10 m s . Using the modified Stocks-Einstein equation
based on oblate spheroid model (detailed calculation procedure
was summarized in SI), the experimental radius, i.e., the sem-
imajor axis radius, of S1 was 4.90 nm, which is comparable
with outer radii measured from the molecular modeling of S1
Multi-dimensional mass spectrometry, including elec-
trospray ionization-mass spectrometry (ESI-MS), traveling
wave ion mobility mass spectrometry (TWIM-MS), and gra-
dient tandem-mass spectrometry (gMS ), provide further evi-
dences for the formation of excepted discrete assembly. One
dominant set of peaks with continuous charge states from 12+
4
2
2
43
-
10
2 -1
4
1
to 25+ was observed in ESI-MS (Figure 3a), due to successive
−
loss of the counterions, PF
6
. After deconvolution of m/z, the
average measured molecular weight of the assembly is 20830
Da, which exactly agrees with the molecular composition of
(
~4.3 nm, Figure 3) with snowflake shape.
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S1[(C137
H
117
N
15
O
5
)
6
(C132
H
84
N
18)Zn12Ru
6
(PF AFM measurement, we observed individual dots with single
6
)36]. The experi-
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
mental isotope patterns of each charge state (Figure S2) are con-
sistent with the theoretical simulations based on the chemical
composition of S1. We also conducted self-assembly of L5 and
L3 with slightly different ratios of ligands and metals (Figures
S67). ESI-MS showed that S1 could be assembled even not in
the perfect stoichiometry. TWIM-MS results (Figure 3b) show
single set of signals with narrow distribution at each charge
state (m/z), which unambiguously addresses that no other iso-
mers or conformers of S1 existed. It is suggested that the snow-
flake is more rigid and shape-persistent compared to the previ-
molecular height, which is consistent with our molecular mod-
eling (Figure S75a-b). Note that the measured width of the mol-
ecule was much larger than the height measured by AFM and
molecular modeling because of an inevitable tip broadening ef-
2
8f
fect. In STM measurement (Figure S76a-b), the samples were
applied to highly oriented pyrolytic graphite (HOPG) by drop-
casting. Instead of observing individual supramolecules, STM
showed ribbon-like nanostructures with pores. We speculated
that formation of these nanoribbons were driven by the interac-
tion between metallo-supramolecules and HOPG surface along
with intermolecular interactions. This is consistent with our re-
cent study of hierarchical self-assembly of supramolecular
metal-organic nanoribbons by supramolecular concentric hexa-
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
3
6,37
ous dendron functionalized macrocycles.
(a)
(b)
28g
Log D
-11.5
gons.
17+
Theoretical
-
10.5
9.5
(a)
1081.2
1082.2
18+
17+
-
19+
0+
16+
1081.2
1082.2
S1
-8.5
ppm
2
15+
1081
1082 m/z
Experimental
21+
2+
14+
9
.2 8.8 8.4 8.0 7.6 7.4
9.2 8.8 8.4 8.0 7.6 7.4
2
3+
13+
2
Figure 2. 2D DOSY (500 MHz, CD
S1 and (b) S2.
3
CN, 300 K) spectra of (a)
12+
24+
2
5+
600
800
1000
1200
1400
1600 m/z
TWIM-MS exhibits more information, i.e., collision cross
sections (CCSs), on the shape and size of the assemblies. CCSs
data of S1 on each charge state are summarized in Table 1, with
(b) m/z
14+
15+
2
an average value of 2959.1 Å . For comparison, the theoretical
1200
16+
CCSs of S1 were calculated based on the 70 candidate struc-
tures obtaining from each annealing cycle of energy minimized
molecular model of S1. The averaged result of the calculated
CCSs is 3054.6 Å (by trajectory method), which is in a good
agreement with the experimental one, further convinced the
17+
18+
1000
19+
2
44
20+
1+
2
22+
800 23+
2
snowflake shape of S1. gMS was also employed to measure the
stability of supramolecular complex. Figure 3c displays the
3
3.5
4
4.5
5
5.5
6
6.5
2
gMS results of the 17+ ions (m/z 1081.7) of S1 by applying a
Drift Time (ms)
graduate increase of collision energy from 4 V. No significant
fragment peaks were observed under 16 V. All the ions were
completely dissociated at 28 V, which gives a center-of-mass
collision energy as 0.06 eV, and is used for the comparison with
snowflake S2.
17+
1081.7
(c)
28V
26V
Transmission electron microscopy (TEM) was employed to
further confirm the shape and size of the snowflake S1 (Figure
4
c). High resolution TEM imaging clearly displayed star-
24V
shaped hollow structures for S1 with comparable size as the
modeling structures. Very interestingly, these supramolecules
may further self-assemble into 2D array with uniform pattern
on the lacey carbon coated Cu grid. The measured diameter of
these patterns from TEM (8.6 nm) was comparable with the mo-
lecular modeling diameter (8.5 nm) of S1. Furthermore, energy
dispersive X-ray spectra (EDXS) on the TEM patterns (Figure
S73) showed N, O, Ru, and Zn signals, confirming that the star-
shaped pattern observed in TEM was derived from metallo-su-
pramolecules. TEM imaging on regular carbon coated Cu grid
only showed individual dots without hollow pattern, perhaps
due to the background signals from the thick layer of carbon
20V
12V
4V
600
800
1000
1200 m/z
(
Figure S72). We also performed TEM for other negative con-
trols with non-ideal ratios of ligands and metals (Figures S69),
but did not observe any snowflake-like pattern.
Figure 3. (a) ESI-MS and (b) TWIM-MS plot (m/z vs. drift time)
2
of S1. (c) Gradient tandem-mass spectrometry (gMS ) of S1 at
We also performed atomic-force microscopy (AFM) and
scanning tunneling spectroscopy (STM) imaging for S1. In
m/z 1081.7 with different collision energy.
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Similar synthetic strategy as L5 was carried out to prepare
Synthesis, Self-Assembly and Characterization of Super
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
Snowflake 2 (S2). Encouraged by the success of S1, Ru(II)-
organic ligand L6 with similar geometry but slightly different
length was designed for the self-assembly of snowflake S2 with
L3. The major difference is the phenyl group in L5 was re-
placed by a triphenylamine moiety in L6. With such design, we
might be able to assemble a larger version of super snowflake
S2 with diameter around 9.4 nm according to molecular model-
ing (Figure 4b), in which no significant structural distortion was
observed. We expected that this robust snowflake system was
readily accommodate the variation of the ligand in the outer rim
but without losing the entire structural integrity benefitting from
the energy favorable features of the structure.
Ru(II)-organic ligand L6 by using tri(4-bromo-phenyl)amine as
starting material (Scheme S4). And the subsequent assembly of
S2 was performed by mixing L6, L3, and Zn(NO ) in the stoi-
3 2
chiometric ratio (6:1:12). The formation of the desired structure
1
was first characterized by H NMR (Figure 5), and the corre-
sponding 2D NMR results are summarized in supporting infor-
mation. The aromatic region in the spectrum of S2 is more com-
plicated than S1, because of the newly induction of three sets of
phenyl protons. Nevertheless, relative sharp peaks and charac-
3
’,5’
6,6’’
teristic shifts of tpyH (downfield), tpyH (upfield), meth-
oxyl protons (merged into one peak) after the assembly together
suggested the formation of unique structure via expected tpy-
Zn interaction.
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
(a)
(c)
(c)
(c)
S1
b)
(
d)
(d)
(
S2
Figure 4. (a and b) Representative energy-minimized structures from molecular modelling of S1 and S2. (c and d) TEM images of
S1 and S2.
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1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
H
3
CO OCH
3
-
36PF
6
N
N
N
N
N
N
N
Zn
N
N
N
Ru
N
N
m
H
3
CO
N
N
N
N
N
N
OCH
3
H
3
CO
N
Ru
N
N
N
N
Zn RN uD*2
D
C
OCH
3
N
N
N
k
D
OCH
3
j
f
N
N
N
N
Zn
C
N
N
Zn N D
N
OCH
3
n
e
N
N
N
N
N
N
Zn
N
N
N
N
Zn
N
N
N
N
N
Ru
N
N
C
k
j
N
N
N
N
Zn
N
N
B
N
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
C
B
E
N
N
N
N
N
N
N
F N Zn NA
N
B
E
N
Ru
N
N
Zn
N
F
A
A
N
N
N
N
N
N
N
Zn
N
N
N
B
N
N
N
Zn
N
N
N
N
E
N
N
N
N
N
N
Zn
N
N
N
N
Zn
N
Ru
N
N
N
N
5 4
N
B
E
N
N
N
6
3
N
N
3'
B
E
N
N
N
N
H
3
CO
N
Zn
N
N
N
N
Ru
N
OCH
OCH
3
F
F
N
Zn
N
A
A
A
c d
N
H
3
CO
N
N
N
3
5
'
a
b
N
6''
5
3''
''4''
N
N
N
N
N
N
Zn
N
Ru
N
N
N
N
N
E
N
N
N
Zn
H
3
CO OCH
3
3’,5’
A(E)
A(E)6
,6’’
’,5’
k
4,4’’
5,5’’
C
D
5,5’’
D
A(E)
B6,6’’
3
A(E)4,4’’
Bc
D
4,4’’
a
A(E)3,3’’
D6,6’’
C
A(E)
B4,4’’
k
D
A(E)c
n
m
C3’,5B’ 3’,5’
A(E) A(E) C6,6’’
b
d
5,5’’
B5,5’’ e f
C
D3,3’’
Cj
Dj
C3,3’’B3,3’’
Ba
B
d
Bb
L6
A4,4’’
A3
’,5’
n m
E3
’,5’
A3,3’’
E3,3’’
S2
L3
E4,4’’
F6,6’’
F5,5’’
F3’,5’
F3,3’’
Fk
F4,4’’
Fj
9
.2
9.0
8.8
8.6
8.4
8.2
8.0
7.8
7.6
7.4
7.2
7.0
4.1
1
3 3 .
Figure 5. H NMR spectra (500 MHz) of L6 and L3 in CDCl , and S2 in CD CN
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increment of CCS value of S2 from S1 comes from the elon-
1
7+
Theoretical
(
a)
17+
16+
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
1034.2
1035.2
gated outer rims of the snowflake as we anticipated in the de-
sign. Additionally, 2D DOSY of S2 shows a lower value of dif-
fusion efficiency (D) (Figure 2b, full ranged spectra was shown
in Figure S63) with higher conducted semimajor axle radius
(5.9 nm), and TEM imaging of S2 also displays clear images of
snowflake shaped patterns with narrow dispersity of diameter
around 9.5 nm. (Figure 4d). TEM was also conducted for nega-
tive controls with non-ideal ratios of ligands and metals (Figure
S70), but did not display any snowflake-like pattern. As S1,
similar AFM and STM results were obtained for S2 (Figure
S75c-d, S76c-d).
1
5+
14+
S2
1034.2
1035.2
18+
1
3+
1035 m/z
Experimental
1
034
12+
19+
20+
11+
1
0+
1800 m/z
15+
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
800
1000
1200
1400
1600
(
b)
m/z
Table 1. Experimental and Theoretical Collision Cross Sections
16+
(CCSs).
Drift times
[ms]
CCS
[Å ]
CCS
CCS
1
7+
2
Average
(calcd. avg)
1
000
18+
2
2
[Å ]
[Å ]
19+
S1
6.50 (+14)
2929.5
2917.3
2933.9
2918.5
2912.9
2928.3
2976.5
3010.5
3029.7
3033.6
3047.1
3043.4
3041.8
3047.7
3077.3
3085.2
3070.7
2959.1±48.9
3054.6±64.2
20+
5
.73 (+15)
5.18 (+16)
.63 (+17)
4.19 (+18)
2
1+
800
4
4
4.5
5
5.5
6
6.5
2
1+
Drift Time (ms)
3
3
3
.86 (+19)
.64 (+20)
.42 (+21)
(c)
17+
1
034.7
24V
3.20 (+22)
.98 (+23)
6.17 (+15)
2
22V
S2
3059.0±18.2
3176.5±57.1
5
4
4
4
3
3
.51 (+16)
.96 (+17)
.52 (+18)
.19 (+19)
.86 (+20)
.53 (+21)
20V
16V
Further characterization of S2 on its stability was performed
by gMS , shown in Figure 6c. The 17+ ions (m/z = 1034.7) com-
12V
2
pletely disappeared under 24 V, which was 4 V lower than the
same situation of S1. This suggested the lower stability of S2
than that of S1. The lower stability of S2 was determined by its
4
V
2
8c,45
larger size, and lower density of coordination sites (DOCS)
,
6
00
800
1000
1200
m/z
accordingly. DOCS provides quantitative relationship between
stability and coordination site number/size (theoretical CCSs)
of assemblies. With the same coordination site number, larger
size brings about lower DOCS, and thus, lower stability of as-
Figure 6. (a) ESI-MS and (b) TWIM-MS plot of S2. (c) gMS2
of 17+ ions of S2 at m/z 1034.7 with different collision energy.
2
sembly structure. DOCS value of S1 is 0.0118 site/Å , which is
ESI-MS result of S2 (Figure 6a) displays a series of peaks
with continuous charge states from 10+ to 20+. And each
charge state displays well-resolved isotope patterns, which is
consistent with the theoretical ones (Figure S3). The averaged
measured mass of S2 was 20030 Da, supporting its composition
2
5
% larger than that of S2’s value (0.0113 site/Å ).
Intramolecular Dynamic Exchange within S1 and S2. In
both snowflakes S1 and S2, there are two sets of tpy, i.e., A and
E from ligands L5 and L6. In the scaffolds of snowflakes, a
slow intramolecular dynamic exchange between A- and E-tpy
may occur in S1 and S2 alone. Therefore, we performed de-
tailed ROESY NMR study with a variety of mixing time to ad-
dress the possible intramolecular exchange. As shown in Fig-
ures S60-S61, the cross-exchange signals of A- and E-tpy can
be observed at mixing time over 200 ms, which indicated a very
slow-exchange process at 300 K compared to other reported
[
(C131
H
90
N
16
O
2
)
6
(C132
H
84
N
18)Zn12Ru
6
(PF )36]. Narrowly dis-
6
tributed signals of each charge state are also exhibited on
TWIM-MS, indicating its exceptional rigidity and shape persis-
tence. However, S2 was not observed in ESI-MS for self-as-
sembly of L6 and L3 with slightly different ratios of ligands
and metals (Figure S68).
Experimental CCSs obtained from TWIM-MS results of S2
2
46
were summarized in Table 1. The averaged CCS is 3059 Å ,
consistent with the averaged theoretical result (3176 Å ). The
compounds with mixing time less than 100 ms.
2
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(
a)
16+
(
b)
m/z
1
7+
7+
S1
S2
S1
S2
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
16+
14+
14+
1
1
5+
1
5+
15+
1
8+
1
8+
1200
16+
1
4+
14+
15+
17+
17+
1
6+
1
9+
19+
20+
20+
18+
1
3+
1
000
19+
1
3+
18+
12+
20+
1
9+
1
2+
21+
3.5
1
1+
20+
4
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
800
2
1+
8
00
1000
1200
15+
1400
1600
m/z
4.5
5
5.5
Drift Time (ms)
6
6.5
7
1
6+
(c)
(d)
m/z
1
7+
16+
1
4+
1
200
1000
800
1
8+
1
3+
12+
1
9+
11+
2
0+
800
1000
1200
1400
1600
Zn L5 L6 L3
m/z
3.5
4
4.5
5
5.5
6
6.5
7
Drift Time (ms)
(e)
12
2
4
Zn L5 L6 L3
12
3
3
Zn L5 L6 L3
12 4 2
S216+
Zn L5 L6 L3
12 1 5
Zn L5 L6 L3
12
5
1
S116+
5
3
d
d
2
1
d
d
5
h
3
0 min
0
min
S216+
S116+
1
110
1120
1130
1140
1150
m/z
Figure 7. Dynamic exchange of preassembled S1 and S2. (a) ESI-MS and (b) TWIM-MS plot of preassembled S1 and S2 at 0 min.
c) ESI-MS and (d) TWIM-MS plot of preassembled S1 and S2 at 5 d. (e) Time–dependent spectra of dynamic exchange of S1 and
S2 at 0 min, 30 min, 5 h, 1 d, 2 d, 3 d, 5 d for expanded region of 16+ signals.
(
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1
(a)
(
b)
Variable temperature H NMR was also carried out to inves-
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
tigate the dynamic exchange. As shown in Figure S65, the sig-
nals of 3’,5’-proton of A and E-tpy group of S1 were well-split-
ted at 300 K with 0.034 ppm distance, which was gradually
shrunk to 0.027 ppm by increasing the operating temperature to
40 K (65 C). It indicates that the dynamic exchange of A and
1.0
0.8
0.6
S1
S2
S1
S2
1
0
0
0
.0
.8
.6
.4
0
.4
0.2
.0
o
3
0.2
0.0
4
7
E-tpy can be enhanced by increasing temperature. Similar
0
emerging signals of A3’,5’ and E3’,5’ of S2 were also recorded
300
600
400
500
600 630 660 690 720
Wavelength (nm)
1
Wavelength (nm)
by variable temperature H NMR spectra (Figure S66).
-6
Figure 8. UV-Vis ((a), 10 M in CH
3
CN, RT) and emission
Intermolecular Dynamic Exchange between S1 and S2. In
spite of the difference of ligand L5 and L6 in the outer rim, both
S1 and S2 could be assembled with similar structures. If preas-
sembled S1 and S2 were mixed in solution, the following three
circumstances might occur, i.e., coexistence of two discrete su-
per snowflakes without communication, collapse and formation
of unidentified complexes, or generation of hybrid snowflakes
through ligand exchange. To answer the above question, preas-
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
-6
(
(b), 10 M in CH CN, 73 K) of complexes of S1 and S2.
3
The electrochemical properties of these two complexes in
DMF were studied, and the results are shown in Figure 9. Both
S1 and S2 exhibit three tpy-ligand-centered redox couples be-
tween -2.0 V to -0.5 V. Between 1.0 V to 1.5 V, S2 showed two
irreversible oxidization peaks, corresponding to the oxidization
of triphenylamine moiety and Ru(II) atoms; while S1 displayed
only one oxidization peak of Ru(II). In addition, under the ef-
fect of triphenylamine group, although the peak-to-peak poten-
tial difference for each redox couple was still very similar be-
tween two complexes, potentials of each single peak of S2 were
moved to more positive value than those of S1.
3
sembled S1 and S2 (CH CN, 1 mg/mL) solutions were mixed
with 1:1 ratio at room temperature for dynamic behavior study.
All the process was monitored by ESI-MS and TWIM-MS (Fig-
ure 7).
At 0 min after mixing, ESI-MS displayed two series of peaks
corresponding to S1 and S2, respectively. Remarkably, 2D sep-
aration by TWIM-MS clearly showed two sets of signals with-
out any superimposition (Figures 7a and 7b). The slow dynamic
ligand exchange started around 5 h after the mixing, indicating
the great stability of each snowflake. In addition to the original
x10-5
S1
S2
4.0
1
6+
16+
peaks of S1 and S2, for instance S1 and S2 , five new peaks
appeared, corresponding to all the statistical hybrid snowflakes.
After 5 d, no significant change was detected by mass spectrom-
etry. In the 2D spectrum of TWIM-MS (Figure 7d), all the hy-
brid signals drifted out with very similar times, suggesting they
should possess the similar snowflake architectures as S1 and
S2. We speculated that the dynamic exchange reached equilib-
rium around 5 d with partial S1 and S2 left. To validate this
assumption, a control study was performed by mixing equal
molar amounts of L5 and L6 with L3 and Zn(II) at 3:3:1:12
2.0
0
-2.0
-2.0 -1.5 -1.0 -0.5
0.0
0.5
1.0
1.5
Potential (V)
o
ratio. After heating at 50 C for 15 hours, the mass spectrometry
exhibited almost identical result as the one of 5 d dynamic ex-
change (Figure S7). Finally, we performed DOSY-NMR for the
mixtures of snowflakes with high number of possible structures
and isomers after complete intermolecular dynamic exchange.
The measured D of mixture was obtained between that of S1
and S2 (Figure S64), indicating that those hybrid supramolecu-
lar snowflakes have the intermediate size between S1 and S2.
Figure 9. Cyclic voltammograms (CV) of solutions of S1 and
4 4
S2 (performed in 0.1 M n-Bu NBF in DMF at 298 K).
Conclusions
By utilizing the diverse coordination ability of tpy with transi-
tion metal, we have designed and assembled two snowflake su-
pramolecules using the combination of Ru(II) and Zn(II). In-
stead of using direct self-assembly, such giant metallo-supra-
molecules were approached through step-wise synthesis strat-
egy, which successfully prevented the formation of undesired
assemblies by the self-sorting of individual ligand. For the first
time, in tpy-based supramolecular field, we were able to con-
struct complex supramolecular architectures with three types of
organic ligand. Additionally, dynamic ligand exchange of two
preassembled indicated that this versatile system was capable
to accommodate the variation of the outer rims to form a series
of hybrid snowflakes but without the entire structural integrity.
We anticipate that these discrete and shape-persistent supramo-
lecular architectures may serve as a model system for further
study of the self-assembly behavior and physical property of 2D
materials.
Physical Properties. Considering the tpy and triphenylamine
have been widely used in optoelectronics in both photoreceptor
4
8
devices and organic light-emitting diodes, we performed the
following photo- and electrochemical properties study. In the
absorption spectra (Figure 8a), both S1 and S2 show character-
istic absorption bands peaked at 495 nm, corresponding to al-
4
9
lowed metal-to-ligand charge transfer (MLCT) transitions. S2
also exhibits a unique broad absorption band located around
4
00 nm, which comes from intramolecular charge transfer
(
ICT) transition from the triphenylamine moiety to the tpy-M
4
9
complex moieties. The emissions of S1 and S2 were detected
in CH CN solution under 73 K (Figure 8b), showing peaks at
40 nm (S1) and 650 nm (S2), respectively.
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667; (d) Manna, J.; Whiteford, J. A.; Stang, P. J.; Muddiman, D. C.;
ASSOCIATED CONTENT
Supporting Information. Synthetic details, molecular modeling,
ligand and complex characterization, including H NMR,
NMR, 2D COSY, 2D NOESY, 2D ROESY, ESI-MS, TWIM-MS
and MALDI-TOF are included in supporting information. This ma-
terial is available free of charge via the Internet at
http://pubs.acs.org.
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Smith, R. D., J. Am. Chem. Soc. 1996, 118, 8731; (e) Stang, P. J.;
Persky, N. E.; Manna, J., J. Am. Chem. Soc. 1997, 119, 4777; (f) Ghosh,
K.; Yang, H.-B.; Northrop, B. H.; Lyndon, M. M.; Zheng, Y.-R.;
Muddiman, D. C.; Stang, P. J., J. Am. Chem. Soc. 2008, 130, 5320; (g)
Chakrabarty, R.; Stang, P. J., J. Am. Chem. Soc. 2012, 134, 14738.
1
13
C
9
. (a) Chan, Y.-T.; Li, X.; Yu, J.; Carri, G. A.; Moorefield, C. N.;
Newkome, G. R.; Wesdemiotis, C., J. Am. Chem. Soc. 2011, 133,
1967; (b) Sautter, A.; Schmid, D. G.; Jung, G.; Würthner, F., J. Am.
1
AUTHOR INFORMATION
Corresponding Author
Chem. Soc. 2001, 123, 5424; (c) Sautter, A.; Kaletaş, B. K.; Schmid,
D. G.; Dobrawa, R.; Zimine, M.; Jung, G.; van Stokkum, I. H.; De Cola,
L.; Williams, R. M.; Würthner, F., J. Am. Chem. Soc. 2005, 127, 6719;
(d) You, C.-C.; Würthner, F., J. Am. Chem. Soc. 2003, 125, 9716; (e)
Jeong, K. S.; Kim, S. Y.; Shin, U.-S.; Kogej, M.; Hai, N. T.;
Broekmann, P.; Jeong, N.; Kirchner, B.; Reiher, M.; Schalley, C. A., J.
Am. Chem. Soc. 2005, 127, 17672; (f) Safarowsky, C.; Merz, L.; Rang,
A.; Broekmann, P.; Hermann, B.; Schalley, C. A., Angew. Chem. Int.
Ed. 2004, 43, 1291; (g) Campos-Fernández, C. S.; Clérac, R.; Koomen,
J. M.; Russell, D. H.; Dunbar, K. R., J. Am. Chem. Soc. 2001, 123, 773;
(h) Campos-Fernández, C. S.; Schottel, B. L.; Chifotides, H. T.; Bera,
J. K.; Bacsa, J.; Koomen, J. M.; Russell, D. H.; Dunbar, K. R., J. Am.
Chem. Soc. 2005, 127, 12909; (i) Chifotides, H. T.; Giles, I. D.;
Dunbar, K. R., J. Am. Chem. Soc. 2013, 135, 3039.
10. (a) Sun, Q.-F.; Iwasa, J.; Ogawa, D.; Ishido, Y.; Sato, S.; Ozeki, T.;
Sei, Y.; Yamaguchi, K.; Fujita, M., Science 2010, 328, 1144; (b) Fujita,
D.; Ueda, Y.; Sato, S.; Yokoyama, H.; Mizuno, N.; Kumasaka, T.;
Fujita, M., Chem 2016, 1, 91; (c) Tominaga, M.; Suzuki, K.; Kawano,
M.; Kusukawa, T.; Ozeki, T.; Sakamoto, S.; Yamaguchi, K.; Fujita, M.,
Angew. Chem. Int. Ed. 2004, 43, 5621
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xiaopengli1@usf.edu; mingwang358@jlu.edu.cn;
liuchl@mail.ccnu.edu.cn.
Author Contributions
§
These authors contributed equally.
ACKNOWLEDGMENT
The authors gratefully acknowledge the support from NSF (CHE-
1
506722 and DMR-1205670 for X.L.; ECCS-1609788 for B.X.),
Research Corporation for Science Advancement (23224 for X.L.),
and ACS Petroleum Research Fund (55013-UNI3 for X.L.). Z.Z.
thanks China Scholarship Council for graduate assistantship. The
support of Program of Introducing Talents of Discipline to Univer-
sities of China (111 Program, B17019) is also appreciated.
1
1. (a) Yan, X.; Cook, T. R.; Wang, P.; Huang, F.; Stang, P. J., Nat.
REFERENCES
Chem. 2015, 7, 342; (b) Olenyuk, B.; Whiteford, J. A.; Fechtenkotter,
A.; Stang, P. J., Nature 1999, 398, 796; (c) Kuehl, C. J.; Kryschenko,
Y. K.; Radhakrishnan, U.; Seidel, S. R.; Huang, S. D.; Stang, P. J.,
Proc. Nat. Acad. Sci. U.S.A 2002, 99, 4932; (d) Leininger, S.; Fan, J.;
Schmitz, M.; Stang, P. J., Proc. Nat. Acad. Sci. U.S.A 1999, 97, 1380;
1
. (a) Cram, D. J., Angew. Chem. Int. Ed. Engl. 1988, 27, 1009; (b)
Lehn, J.-M., Angew. Chem. Int. Ed. Engl. 1988, 27, 89; (c) Lehn, J.-
M., Science 2002, 295, 2400; (d) Pedersen, C. J., Angew. Chem. Int.
Ed. Engl. 1988, 27, 1021.
(
e) Olenyuk, B.; Levin, M. D.; Whiteford, J. A.; Shield, J. E.; Stang, P.
2
. (a) Sauvage, J.-P.; Collin, J.-P.; Chambron, J.-C.; Guillerez, S.;
J., J. Am. Chem. Soc. 1999, 121, 10434.
12. (a) Wang, M.; Wang, C.; Hao, X.-Q.; Li, X.; Vaughn, T. J.; Zhang,
Y.-Y.; Yu, Y.; Li, Z.-Y.; Song, M.-P.; Yang, H.-B., J. Am. Chem. Soc.
Coudret, C.; Balzani, V.; Barigelletti, F.; De Cola, L.; Flamigni, L.,
Chem. Rev. 1994, 94, 993; (b) Holliday, B. J.; Mirkin, C. A., Angew.
Chem. Int. Ed. 2001, 40, 2022; (c) Davis, A. V.; Yeh, R. M.; Raymond,
K. N., Proc. Nat. Acad. Sci. U.S.A 2002, 99, 4793; (d) Dalgarno, S. J.;
Power, N. P.; Atwood, J. L., Coord. Chem. Rev. 2008, 252, 825; (e)
Smulders, M. M.; Riddell, I. A.; Browne, C.; Nitschke, J. R., Chem.
Soc. Rev. 2013, 42, 1728; (f) Ward, M. D.; Raithby, P. R., Chem. Soc.
Rev. 2013, 42, 1619; (g) Saha, M. L.; De, S.; Pramanik, S.; Schmittel,
M., Chem. Soc. Rev. 2013, 42, 6860; (h) Han, M.; Engelhard, D. M.;
Clever, G. H., Chem. Soc. Rev. 2014, 43, 1848.
2
014, 136, 10499; (b) Xie, T.-Z.; Liao, S.-Y.; Guo, K.; Lu, X.; Dong,
X.; Huang, M.; Moorefield, C. N.; Cheng, S. Z.; Liu, X.; Wesdemiotis,
C., J. Am. Chem. Soc. 2014, 136, 8165; (c) Xie, T. Z.; Guo, K.; Guo,
Z.; Gao, W. Y.; Wojtas, L.; Ning, G. H.; Huang, M.; Lu, X.; Li, J. Y.;
Liao, S. Y., Angew. Chem. Int. Ed. 2015, 127, 9356; (d) Hiraoka, S.;
Harano, K.; Shiro, M.; Ozawa, Y.; Yasuda, N.; Toriumi, K.; Shionoya,
M., Angew. Chem. Int. Ed. 2006, 118, 6638; (e) Clever, G. H.; Tashiro,
S.; Shionoya, M., J. Am. Chem. Soc. 2010, 132, 9973; (f) Bar, A. K.;
Chakrabarty, R.; Mostafa, G.; Mukherjee, P. S., Angew. Chem. Int. Ed.
3. (a) Chakrabarty, R.; Mukherjee, P. S.; Stang, P. J., Chem. Rev. 2011,
1
(
4
11, 6810; (b) Cook, T. R.; Stang, P. J., Chem. Rev. 2015, 115, 7001;
c) Leininger, S.; Olenyuk, B.; Stang, P. J., Chem. Rev. 2000, 100, 853.
. (a) Yoshizawa, M.; Klosterman, J. K.; Fujita, M., Angew. Chem. Int.
2
008, 47, 8455; (g) Han, M.; Luo, Y.; Damaschke, B.; Gómez, L.;
Ribas, X.; Jose, A.; Peretzki, P.; Seibt, M.; Clever, G. H., Angew.
Chem. Int. Ed. 2016, 55, 445; (h) Riddell, I. A.; Smulders, M. M.;
Clegg, J. K.; Hristova, Y. R.; Breiner, B.; Thoburn, J. D.; Nitschke, J.
R., Nat. Chem. 2012, 4, 751; (i) Zhang, H.; Lee, J.; Lammer, A. D.;
Chi, X.; Brewster, J. T.; Lynch, V. M.; Li, H.; Zhang, Z.; Sessler, J. L.,
J. Am. Chem. Soc. 2016, 138, 4573.
Ed. 2009, 48, 3418; (b) Harris, K.; Fujita, D.; Fujita, M., Chem.
Commun. 2013, 49, 6703.
5. (a) Hasenknopf, B.; Lehn, J.-M.; Boumediene, N.; Leize, E.; Van
Dorsselaer, A., Angew. Chem. Int. Ed. 1998, 37, 3265; (b) Hasenknopf,
B.; Lehn, J.-M.; Kneisel, B. O.; Baum, G.; Fenske, D., Angew. Chem.
Int. Ed. Engl. 1996, 35, 1838; (c) Hasenknopf, B.; Lehn, J.-M.;
Boumediene, N.; Dupont-Gervais, A.; Van Dorsselaer, A.; Kneisel, B.;
Fenske, D., J. Am. Chem. Soc. 1997, 119, 10956; (d) Ayme, J.-F.;
Beves, J. E.; Campbell, C. J.; Leigh, D. A., Angew. Chem. Int. Ed 2014,
1
3. (a) Kraus, T.; Buděšínský, M.; Cvačka, J.; Sauvage, J. P., Angew.
Chem. Int. Ed. 2005, 45, 258; (b) Beyler, M.; Heitz, V.; Sauvage, J.-P.,
J. Am. Chem. Soc. 2010, 132, 4409; (c) Joosten, A.; Trolez, Y.; Collin,
J.-P.; Heitz, V. r.; Sauvage, J.-P., J. Am. Chem. Soc. 2012, 134, 1802;
(
d) Yang, Y.-D.; Fan, C.-C.; Rambo, B. M.; Gong, H.-Y.; Xu, L.-J.;
Xiang, J.-F.; Sessler, J. L., J. Am. Chem. Soc. 2015, 137, 12966.
4. (a) Dietrich-Buchecker, C. O.; Sauvage, J. P.; Kern, J. M., J. Am.
5
3, 7823; (e) Sørensen, A.; Castilla, A. M.; Ronson, T. K.; Pittelkow,
M.; Nitschke, J. R., Angew. Chem. Int. Ed. 2013, 52, 11273.
. (a) Bassani, D. M.; Lehn, J.-M.; Fromm, K.; Fenske, D., Angew.
1
6
Chem. Soc. 1984, 106, 3043; (b) Dietrich-Buchecker, C. O.; Sauvage,
J.; Kintzinger, J., Tetrahedron letters 1983, 24, 5095.
Chem. Int. Ed. 1998, 37, 2364; (b) Barboiu, M.; Vaughan, G.; Graff,
R.; Lehn, J.-M., J. Am. Chem. Soc. 2003, 125, 10257; (c) Toyota, S.;
Woods, C. R.; Benaglia, M.; Haldimann, R.; Wärnmark, K.;
Hardcastle, K.; Siegel, J. S., Angew. Chem. Int. Ed. 2001, 40, 751.
1
7
1
5. Fujita, M.; Ibukuro, F.; Hagihara, H.; Ogura, K., Nature 1994, 367,
20.
6. (a) Schulze, M.; Kunz, V.; Frischmann, P. D.; Würthner, F., Nat.
7
5
. (a) Fujita, M.; Yazaki, J.; Ogura, K., J. Am. Chem. Soc. 1990, 112,
645; (b) Fujita, M.; Nagao, S.; Iida, M.; Ogata, K.; Ogura, K., J. Am.
Chem. 2016, 8, 576; (b) Zhu, R.; Lübben, J.; Dittrich, B.; Clever, G.
H., Angew. Chem. Int. Ed. 2015, 54, 2796; (c) Freye, S.; Michel, R.;
Stalke, D.; Pawliczek, M.; Frauendorf, H.; Clever, G. H., J. Am. Chem.
Soc. 2013, 135, 8476; (d) Frank, M.; Hey, J.; Balcioglu, I.; Chen, Y.
S.; Stalke, D.; Suenobu, T.; Fukuzumi, S.; Frauendorf, H.; Clever, G.
Chem. Soc. 1993, 115, 1574.
. (a) Stang, P. J.; Cao, D. H., J. Am. Chem. Soc. 1994, 116, 4981; (b)
Stang, P. J.; Cao, D. H.; Saito, S.; Arif, A. M., J. Am. Chem. Soc. 1995,
17, 6273; (c) Stang, P. J.; Chen, K., J. Am. Chem. Soc. 1995, 117,
8
1
ACS Paragon Plus Environment

Page 11 of 13
Journal of the American Chemical Society
H., Angew. Chem. Int. Ed. 2013, 52, 10102; (e) Freye, S.; Hey, J.;
Am. Chem. Soc. 2015, 137, 9497; (c) Wang, M.; Wang, C.; Hao, X.-
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
Torras‐Galán, A.; Stalke, D.; Herbst‐ Irmer, R.; John, M.; Clever, G.
H., Angew. Chem. Int. Ed. 2012, 51, 2191.
Q.; Liu, J.; Li, X.; Xu, C.; Lopez, A.; Sun, L.; Song, M.-P.; Yang, H.-
B., J. Am. Chem. Soc. 2014, 136, 6664; (d) Wang, S.-Y.; Fu, J.-H.;
Liang, Y.-P.; He, Y.-J.; Chen, Y.-S.; Chan, Y.-T., J. Am. Chem. Soc
2016, 138, 3651; (e) Fu, J.-H.; Lee, Y. H.; He, Y. J.; Chan, Y. T.,
Angew. Chem. Int. Ed. 2015, 54, 6231; (f) Song, B.; Zhang, Z.; Wang,
K.; Hsu, C.-H.; Bolarinwa, O.; Wang, J.; Li, Y.; Yin, G.-Q.; Rivera, E.;
Yang, H.-B.; Liu, C.; Xu, B.; Li, X., Angew. Chem. Int. Ed. 2017, 56,
5258; (g) Wang, M.; Wang, K.; Wang, C.; Huang, M.; Hao, X.-Q.;
Shen, M.-Z.; Shi, G.-Q.; Zhang, Z.; Song, B.; Cisneros, A.; Song, M.-
P.; Xu, B.; Li, X., J. Am. Chem. Soc. 2016, 138, 9258.
29. (a) Sepehrpour, H.; Saha, M. L.; Stang, P. J., J. Am. Chem. Soc.
2017, 139, 2553; (b) Li, K.; Zhang, L.-Y.; Yan, C.; Wei, S.-C.; Pan,
M.; Zhang, L.; Su, C.-Y., J. Am. Chem. Soc. 2014, 136, 4456; (c)
Newkome, G. R.; Wang, P.; Moorefield, C. N.; Cho, T. J.; Mohapatra,
P. P.; Li, S.; Hwang, S.-H.; Lukoyanova, O.; Echegoyen, L.; Palagallo,
J. A., Science 2006, 312, 1782; (d) Lu, X.; Li, X.; Guo, K.; Xie, T.-Z.;
Moorefield, C. N.; Wesdemiotis, C.; Newkome, G. R., J. Am. Chem.
Soc. 2014, 136, 18149; (e) Li, Y.; Jiang, Z.; Wang, M.; Yuan, J.; Liu,
D.; Yang, X.; Chen, M.; Yan, J.; Li, X.; Wang, P., J. Am. Chem. Soc.
2016, 138, 10041. (f) Ramsay, W. J.; Rizzuto, F. J.; Ronson, T. K.;
Caprice, K.; Nitschke, J. R., J. Am. Chem. Soc. 2016, 138, 7264;
30. (a) Granzhan, A.; Schouwey, C.; Riis-Johannessen, T.; Scopelliti,
R.; Severin, K., J. Am. Chem. Soc. 2011, 133, 7106; (b) Mal, P.;
Schultz, D.; Beyeh, K.; Rissanen, K.; Nitschke, J. R., Angew. Chem.
Int. Ed. 2008, 47, 8297; (c) Meng, W.; Breiner, B.; Rissanen, K.;
Thoburn, J. D.; Clegg, J. K.; Nitschke, J. R., Angew. Chem. Int. Ed.
2011, 50, 3479; (d) Bilbeisi, R. A.; Clegg, J. K.; Elgrishi, N.; Hatten,
X. d.; Devillard, M.; Breiner, B.; Mal, P.; Nitschke, J. R., J. Am. Chem.
Soc. 2012, 134, 5110; (e) Bilbeisi, R. A.; Ronson, T. K.; Nitschke, J.
R., Angew. Chem. Int. Ed. 2013, 52, 9027.
31. (a) Black, S. P.; Stefankiewicz, A. R.; Smulders, M. M.; Sattler, D.;
Schalley, C. A.; Nitschke, J. R.; Sanders, J. K., Angew. Chem. Int. Ed.
2013, 52, 5749; (b) Li, S.; Huang, J.; Zhou, F.; Cook, T. R.; Yan, X.;
Ye, Y.; Zhu, B.; Zheng, B.; Stang, P. J., J. Am. Chem. Soc. 2014, 136,
5908; (c) Park, K.-M.; Kim, S.-Y.; Heo, J.; Whang, D.; Sakamoto, S.;
Yamaguchi, K.; Kim, K., J. Am. Chem. Soc. 2002, 124, 2140; (d)
Zhukhovitskiy, A. V.; Zhong, M.; Keeler, E. G.; Michaelis, V. K.; Sun,
J. E.; Hore, M. J.; Pochan, D. J.; Griffin, R. G.; Willard, A. P.; Johnson,
J. A., Nat. Chem. 2016, 8, 33.
32. (a) Eryazici, I.; Moorefield, C. N.; Newkome, G. R., Chem. Rev
2008, 108, 1834; (b) Constable, E. C., Chem. Soc. Rev. 2007, 36, 246;
(c) Hofmeier, H.; Schubert, U. S., Chem. Soc. Rev. 2004, 33, 373; (d)
Wild, A.; Winter, A.; Schlütter, F.; Schubert, U. S., Chem. Soc. Rev.
2011, 40, 1459.
1
7. (a) Padilla-Tosta, M. E.; Fox, O. D.; Drew, M. G.; Beer, P. D.,
Angew. Chem. Int. Ed. 2001, 40, 4235; (b) Samanta, D.; Mukherjee, P.
S., J. Am. Chem. Soc. 2014, 136, 17006; (c) Wood, C. S.; Ronson, T.
K.; Belenguer, A. M.; Holstein, J. J.; Nitschke, J. R., Nat. Chem. 2015,
7, 354.
1
8. (a) Ayme, J.-F.; Beves, J. E.; Leigh, D. A.; McBurney, R. T.;
Rissanen, K.; Schultz, D., J. Am. Chem. Soc. 2012, 134, 9488; (b)
Ayme, J.-F.; Beves, J. E.; Leigh, D. A.; McBurney, R. T.; Rissanen,
K.; Schultz, D., Nat. Chem. 2012, 4, 15; (c) Leigh, D. A.; Pritchard, R.
G.; Stephens, A. J., Nat. Chem. 2014, 6, 978; (d) Guo, J.; Mayers, P.
C.; Breault, G. A.; Hunter, C. A., Nat. Chem. 2010, 2, 218; (e) Barran,
P. E.; Cole, H. L.; Goldup, S. M.; Leigh, D. A.; McGonigal, P. R.;
Symes, M. D.; Wu, J.; Zengerle, M., Angew. Chem. Int. Ed. 2011, 50,
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
1
2280.
9. (a) Beves, J. E.; Campbell, C. J.; Leigh, D. A.; Pritchard, R. G.,
Angew. Chem. Int. Ed. 2013, 52, 6464; (b) Schouwey, C.; Holstein, J.
J.; Scopelliti, R.; Zhurov, K. O.; Nagornov, K. O.; Tsybin, Y. O.;
Smart, O. S.; Bricogne, G.; Severin, K., Angew. Chem. Int. Ed. 2014,
5
3, 11261; (c) Chichak, K. S.; Cantrill, S. J.; Pease, A. R.; Chiu, S.-H.;
Cave, G. W.; Atwood, J. L.; Stoddart, J. F., Science 2004, 304, 1308.
0. (a) Yoshizawa, M.; Tamura, M.; Fujita, M., Science 2006, 312, 251;
b) Nishioka, Y.; Yamaguchi, T.; Kawano, M.; Fujita, M., J. Am.
2
(
Chem. Soc. 2008, 130, 8160; (c) Howlader, P.; Das, P.; Zangrando, E.;
Mukherjee, P. S., J. Am. Chem. Soc. 2016, 138, 1668; (d) Wang, Q.-
Q.; Gonell, S.; Leenders, S. H.; Dürr, M.; Ivanović-Burmazović, I.;
Reek, J. N., Nat. Chem. 2016, 8, 225; (e) Cullen, W.; Misuraca, M. C.;
Hunter, C. A.; Williams, N. H.; Ward, M. D., Nat Chem. 2016, 8, 231;
(
f) Marcos, V.; Stephens, A. J.; Jaramillo-Garcia, J.; Nussbaumer, A.
L.; Woltering, S. L.; Valero, A.; Lemonnier, J.-F.; Vitorica-Yrezabal,
I. J.; Leigh, D. A., Science 2016, 352, 1555; (g) Wang, Z. J.; Clary, K.
N.; Bergman, R. G.; Raymond, K. N.; Toste, F. D., Nat. Chem. 2013,
5
2
2
, 100; (h) Pluth, M. D.; Bergman, R. G.; Raymond, K. N., Science
007, 316, 85.
1. (a) Masar, M. S.; Gianneschi, N. C.; Oliveri, C. G.; Stern, C. L.;
Nguyen, S. T.; Mirkin, C. A., J. Am. Chem. Soc. 2007, 129, 10149; (b)
Roy, B.; Ghosh, A. K.; Srivastava, S.; D'Silva, P.; Mukherjee, P. S., J.
Am. Chem. Soc. 2015, 137, 11916; (c) Chen, L.-J.; Ren, Y.-Y.; Wu, N.-
W.; Sun, B.; Ma, J.-Q.; Zhang, L.; Tan, H.; Liu, M.; Li, X.; Yang, H.-
B., J. Am. Chem. Soc. 2015, 137, 11725.
2
2. (a) Samanta, S. K.; Moncelet, D.; Briken, V.; Isaacs, L., J. Am.
Chem. Soc. 2016, 138, 14488; (b) Zheng, Y.-R.; Suntharalingam, K.;
Johnstone, T. C.; Lippard, S. J., Chem. Sci. 2015, 6, 1189.
2
2
3. Schwamborn, K.; Caprioli, R. M., Nat. Rev. Cancer 2010, 10, 639.
4. (a) Li, Z.-Y.; Zhang, Y.; Zhang, C.-W.; Chen, L.-J.; Wang, C.; Tan,
33. Meier, M. A.; Lohmeijer, B. G.; Schubert, U. S., J. Mass. Spectrom.
2003, 38, 510.
34. Newkome, G. R.; Moorefield, C. N., Chem. Soc. Rev. 2015, 44,
3954.
H.; Yu, Y.; Li, X.; Yang, H.-B., J. Am. Chem. Soc. 2014, 136, 8577;
b) Shi, Y.; Wang, M.; Ma, C.; Wang, Y.; Li, X.; Yu, G., Nano letters
015, 15, 6276.
(
2
35. (a) Chan, Y. T.; Li, X.; Moorefield, C. N.; Wesdemiotis, C.;
Newkome, G. R., Chem. Eur. J. 2011, 17, 7750; (b) Schultz, A.; Li, X.;
McCusker, C. E.; Moorefield, C. N.; Castellano, F. N.; Wesdemiotis,
C.; Newkome, G. R., Chem. Eur. J. 2012, 18, 11569; (c) Schultz, A.;
Li, X.; Barkakaty, B.; Moorefield, C. N.; Wesdemiotis, C.; Newkome,
G. R., J. Am. Chem. Soc. 2012, 134, 7672; (d) Liu, D.; Jiang, Z.; Wang,
M.; Yang, X.; Liu, H.; Chen, M.; Moorefield, C. N.; Newkome, G. R.;
Li, X.; Wang, P., Chem. Commun. 2016, 52, 9773.
36. Yang, H.-B.; Hawkridge, A. M.; Huang, S. D.; Das, N.; Bunge, S.
D.; Muddiman, D. C.; Stang, P. J., J. Am. Chem. Soc. 2007, 129, 2120.
37. Wang, J.-L.; Li, X.; Lu, X.; Chan, Y.-T.; Moorefield, C. N.;
Wesdemiotis, C.; Newkome, G. R., Chem. Eur. J. 2011, 17, 4830.
38. (a) Fermi, A.; Bergamini, G.; Roy, M.; Gingras, M.; Ceroni, P., J.
Am. Chem. Soc. 2014, 136, 6395; (b) Bauer, T.; Zheng, Z.; Renn, A.;
Enning, R.; Stemmer, A.; Sakamoto, J.; Schlüter, A. D., Angew. Chem.
Int. Ed. 2011, 50, 7879; (c) Zheng, Z.; Opilik, L.; Schiffmann, F.; Liu,
W.; Bergamini, G.; Ceroni, P.; Lee, L.-T.; Schütz, A.; Sakamoto, J.;
Zenobi, R., J. Am. Chem. Soc. 2014, 136, 6103; (d) Takada, K.;
Sakamoto, R.; Yi, S.-T.; Katagiri, S.; Kambe, T.; Nishihara, H., J. Am.
Chem. Soc. 2015, 137, 4681.
25. (a) Yan, X.; Xu, J.-F.; Cook, T. R.; Huang, F.; Yang, Q.-Z.; Tung,
C.-H.; Stang, P. J., Proc. Nat. Acad. Sci. U.S.A 2014, 111, 8717; (b)
Yan, X.; Cook, T. R.; Pollock, J. B.; Wei, P.; Zhang, Y.; Yu, Y.; Huang,
F.; Stang, P. J., J. Am. Chem. Soc. 2014, 136, 4460; (c) Yan, X.; Li, S.;
Cook, T. R.; Ji, X.; Yao, Y.; Pollock, J. B.; Shi, Y.; Yu, G.; Li, J.;
Huang, F., J. Am. Chem. Soc. 2013, 135, 14036.
26. (a) Mal, P.; Breiner, B.; Rissanen, K.; Nitschke, J. R., Science 2009,
3
24, 1697; (b) Fiedler, D.; Bergman, R. G.; Raymond, K. N., Angew.
Chem. Int. Ed. 2006, 45, 745; (c) Sawada, T.; Yoshizawa, M.; Sato, S.;
Fujita, M., Nat. Chem. 2009, 1, 53.
2
2
7. (a) Samanta, S. K.; Rana, A.; Schmittel, M., Angew. Chem. Int. Ed.
016, 55, 2267; (b) Saha, M. L.; Schmittel, M., J. Am. Chem. Soc. 2013,
135, 17743; (c) Mahata, K.; Schmittel, M., J. Am. Chem. Soc. 2009,
131, 16544; (d) Mahata, K.; Saha, M. L.; Schmittel, M., J. Am. Chem.
Soc. 2010, 132, 15933; (e) Ronson, T. K.; Roberts, D. A.; Black, S. P.;
Nitschke, J. R., J. Am. Chem. Soc 2015, 137, 14502; (f) Smulders, M.
M.; Jiménez, A.; Nitschke, J. R., Angew. Chem. Int. Ed. 2012, 51, 6681;
(
g) Ramsay, W. J.; Szczypiński, F. T.; Weissman, H.; Ronson, T. K.;
Smulders, M. M. J.; Rybtchinski, B.; Nitschke, J. R., Angew. Chem.
Int. Ed 2015, 54, 5636.
39. (a) Bauer, T.; Schlüter, A. D.; Sakamoto, J., Synlett 2010, 2010,
877; (b) Wang, J.-L.; Li, X.; Lu, X.; Hsieh, I.-F.; Cao, Y.; Moorefield,
2
8. (a) Sun, Q.-F.; Murase, T.; Sato, S.; Fujita, M., Angew. Chem. Int.
Ed. 2011, 50, 10318; (b) Bhat, I. A.; Samanta, D.; Mukherjee, P. S., J.
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Journal of the American Chemical Society
Page 12 of 13
C. N.; Wesdemiotis, C.; Cheng, S. Z.; Newkome, G. R., J. Am. Chem.
Soc. 2011, 133, 11450.
0. (a) Wang, J.-L.; Li, X.; Lu, X.; Hsieh, I. F.; Cao, Y.; Moorefield,
C. N.; Wesdemiotis, C.; Cheng, S. Z. D.; Newkome, G. R., J. Am.
Chem. Soc. 2011, 133, 11450; (b) Lu, X.; Li, X.; Cao, Y.; Schultz, A.;
Wang, J.-L.; Moorefield, C. N.; Wesdemiotis, C.; Cheng, S. Z. D.;
Newkome, G. R., Angew. Chem. Int. Ed. 2013, 52, 7728.
41. (a) Giuseppone, N.; Schmitt, J.-L.; Allouche, L.; Lehn, J.-M.,
Angew. Chem. Int. Ed. 2008, 47, 2235; (b) Schulze, B. M.; Watkins, D.
L.; Zhang, J.; Ghiviriga, I.; Castellano, R. K., Organic & Biomolecular
Chemistry 2014, 12, 7932.
Shvartsburg, A. A.; Liu, B.; Siu, K. M.; Ho, K.-M., J. Phys. Chem. A.
2000, 104, 6152.
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
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3
3
3
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3
3
3
3
3
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4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
4
45. (a) Sun, B.; Wang, M.; Lou, Z.; Huang, M.; Xu, C.; Li, X.; Chen,
L.-J.; Yu, Y.; Davis, G. L.; Xu, B., J. Am. Chem. Soc. 2015, 137, 1556;
(b) Wang, M.; Wang, K.; Wang, C.; Huang, M.; Hao, X.-Q.; Shen, M.-
Z.; Shi, G.-Q.; Zhang, Z.; Song, B.; Cisneros, A.; Song, M.-P.; Xu, B.;
Li, X., J. Am. Chem. Soc. 2016, 138, 9258.
46. (a) Shukla, R. B., J. Mag. Reson., A 1995, 113, 196.; (b)
Shokhireva, T. K.; Nesset, M. J. M.; Ann Walker, F., Inorg. Chim.
Acta. 1998, 272, 204.
47. Zheng, J.-Y.; Tashiro, K.; Hirabayashi, Y.; Kinbara, K.; Saigo, K.;
Aida, T.; Sakamoto, S.; Yamaguchi, K., Angew. Chem. Int. Ed. 2001,
40, 1857.
4
2. (a) Brocker, E. R.; Anderson, S. E.; Northrop, B. H.; Stang, P. J.;
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
Bowers, M. T., J. Am. Chem. Soc. 2010, 132, 13486; (b) Chan, Y.-T.;
Li, X.; Soler, M.; Wang, J.-L.; Wesdemiotis, C.; Newkome, G. R., J.
Am. Chem. Soc. 2009, 131, 16395; (c) Thiel, J.; Yang, D.; Rosnes, M.
H.; Liu, X.; Yvon, C.; Kelly, S. E.; Song, Y. F.; Long, D. L.; Cronin,
L., Angew. Chem. Int. Ed. 2011, 50, 8871; (d) Ujma, J.; De Cecco, M.;
Chepelin, O.; Levene, H.; Moffat, C.; Pike, S. J.; Lusby, P. J.; Barran,
P. E., Chem. Commun. 2012, 48, 4423.
43. (a) Li, X.; Chan, Y.-T.; Newkome, G. R.; Wesdemiotis, C., Anal.
Chem. 2011, 83, 1284; (b) Perera, S.; Li, X.; Soler, M.; Schultz, A.;
Wesdemiotis, C.; Moorefield, C. N.; Newkome, G. R., Angew. Chem.
Int. Ed. 2010, 49, 6539.
48. (a) Nazeeruddin, M. K.; Péchy, P.; Renouard, T.; Zakeeruddin, S.
M.; Humphry-Baker, R.; Comte, P.; Liska, P.; Cevey, L.; Costa, E.;
Shklover, V.; Spiccia, L.; Deacon, G. B.; Bignozzi, C. A.; Grätzel, M.,
J. Am. Chem. Soc. 2001, 123, 1613; (b) Satoh, N.; Cho, J.-S.; Higuchi,
M.; Yamamoto, K., J. Am. Chem. Soc. 2003, 125, 8104; (c) Wang, Q.;
Zakeeruddin, S. M.; Cremer, J.; Bäuerle, P.; Humphry-Baker, R.;
Grätzel, M., J. Am. Chem. Soc. 2005, 127, 5706; (d) Liu, C.-L.; Zheng,
C.-J.; Liu, X.-K.; Chen, Z.; Yang, J.-P.; Li, F.; Ou, X.-M.; Zhang, X.-
H., J. Mater. Chem. C. 2015, 3, 1068; (e) Watanabe, Y.; Yoshioka, R.;
Sasabe, H.; Kamata, T.; Katagiri, H.; Yokoyama, D.; Kido, J., J. Mater.
Chem. C. 2016, 4, 8980.
4
8
4. (a) Shvartsburg, A. A.; Jarrold, M. F., Chem. Phys. Lett. 1996, 261,
6; (b) Jarrold, M. F., Ann. Rev. Phys. Chem. 2000, 51, 179; (c)
49. Robson, K. C. D.; Koivisto, B. D.; Gordon, T. J.; Baumgartner, T.;
Berlinguette, C. P., Inorg. Chem. 2010, 49, 5335.
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