Subphthalocyanine Triimides: Solution Processable Bowl-Shaped Acceptors for Bulk Heterojunction Solar Cells

Article abstract of DOI:10.1021/acs.orglett.9b01130

Ten subphthalocyanine triimides (SubPcTI) with different substituents at imide sites and B atoms were designed and synthesized. These compounds with low-lying lowest unoccupied molecular orbital energy levels (from -3.91 to -3.98 eV), strong absorption in

Full text of DOI:10.1021/acs.orglett.9b01130

Letter
Cite This: Org. Lett. XXXX, XXX, XXX−XXX
pubs.acs.org/OrgLett
Subphthalocyanine Triimides: Solution Processable Bowl-Shaped
Acceptors for Bulk Heterojunction Solar Cells
Xiaoshuai Huang, Ming Hu, Xiaohong Zhao, Chao Li, Zhongyi Yuan,* Xia Liu, Chunsheng Cai,†
†
†
†
,†,‡
†
,†
†
†
,‡
†
Youdi Zhang, Yu Hu, and Yiwang Chen*
†
‡
College of Chemistry and Institute of Polymers and Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang
30031, China
3
*
S Supporting Information
ABSTRACT: Ten subphthalocyanine triimides (SubPcTI) with
different substituents at imide sites and B atoms were designed
and synthesized. These compounds with low-lying lowest
unoccupied molecular orbital energy levels (from −3.91 to
−
3.98 eV), strong absorption in the range of 450−650 nm, and
adjustable solubility are expected to be excellent electron
acceptors. Non-fullerene bulk heterojunction organic solar cells
based on acceptor 8c showed power conversion efficiency of
4
.92%, which is the highest value among subphthalocyanine
derivatives.
ulk heterojunction organic solar cells (BHJOSCs) with
advantages of low-cost solution processing, light weight,
B
and charming flexibility have attracted great attention in the
1
past decade. Compared to their high efficiency and rich
organic donor counterparts, high-performance electron accept-
ors are scarce. Despite their weak visible absorption, high cost,
and difficult modification, fullerene derivatives such as
PC BM and PC BM are dominant electron acceptors for
7
1
61
2
long time.
Figure 1. Structures of SubPc, SubPcCl −Cl, and SubPcTI.
6
Non-fullerene acceptors rise rapidly in the past several years.
Small-molecule acceptors with well-defined structures, high
purity, and tunable absorption have displayed promising
unoccupied molecular orbital (LUMO) energy levels ca. −3.5
eV was usually used as donor in organic solar cells. In
addition, SubPcs without substituents show poor solubility,
3
8
performance in BHJOSCs. Many BHJOSCs with small-
molecule acceptors showed power conversion efficiency
4
(
PCE) higher than 10%. However, these excellent accept-
which makes synthesis and solution process difficult. Jones et
9
ors belong to either perylene diimides (PDI) family or 3,9-
bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-
al. demonstrated the single-heterojunction organic solar cells
with tetracene and SubPc, and a PCE of 2.9% was reached.
10
5
,5,11,11-tetrakris(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-
Paul et al. optimized the SubPc-based bilayer solar cells and
obtained a PCE of 4.69%; when fabricating a three-layer device
with SubPc, SubNc, and thiophene oligomer, a PCE of 8.4%
was got, which is a record efficiency for solar cells based on
SubPc derivatives. However, the purification of lightly soluble
SubPc is hard, and complicated vapor deposition under fine
vacuum and high temperature is necessary.
indaceno[1,2-b:5,6-b′]dithiophene (ITIC) derivatives (struc-
tures are in Figure S1). New acceptor chromophores with
5
excellent performance are desired badly in the field of organic
solar cells, because acceptors with different structures,
absorption, and crystallinity are required to match with diverse
donors, with which matched energy levels, complementary
absorption, and suitable phase separation can be coordinated
To transform SubPc into soluble acceptors, some efforts
1
1
6
have been done in the past several years. Paul et al. firstly
introduced F and Cl atoms to peripheral phenyl rings.
Halogenated SubPcs with enhanced solubility and lowered
LUMO energy levels could be used as solution processable
acceptors in BHJOSCs, and the highest PCE of 2.68% was
for high-performance devices.
Subphthalocyanine (SubPc, Figure 1) derivatives with bowl-
shaped structures have drawn considerable attention in
photovoltaic area, due to their strong visible absorption and
7
high carrier mobility. Three-dimensional structure could
reduce serious aggregation in planar conjugated molecules
such as PDIs, which is favorable for proper morphology in
BHJOSCs. Unsubstituted SubPc with relatively high lowest
Received: March 31, 2019
©
XXXX American Chemical Society
A
DOI: 10.1021/acs.orglett.9b01130
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
1
2
obtained. Recently, Duan et al. optimized non-fullerene
Dehydration of 3 was performed in acetic anhydride in the
literature, while it was heating to 230 °C in this work, which is
much simpler for subsequent purification.
BHJOSCs based on SubPcCl −Cl and obtained a PCE of
.0%. SubPc was also used as a building block to construct
6
4
acceptors. For example, S-SubPc-PDI composed of a SubPc
Intermediates 4,5-dibromophthalic imides (5a−5e) with
different side chains were synthesized by condensation of 4
with corresponding amines in acetic acid in yield of 77−88%.
Compounds 5a−5e reacted with CuCN in the presence of KI
to afford 4,5-dicyanophthal imides (6a−6e) in yield of 63−
13
and three PDIs (Figure S2a) showed PCE of 4.53%; STIC
with SubPc and three 2-(3-oxo-2,3-dihydroinden-1-ylidene)-
malononitrile (IC) parts (Figure S2b) demonstrated PCE of
1
4
4
.69%.
Imide groups with strong electron-withdrawing property and
high stability have been proved to be excellent building blocks
70%, while a more complicated catalyst Pd(PPh
instead of KI for this kind of reaction in the literature.
Compounds 7a−7e were synthesized by cyclization reaction of
) was used
3 4
19
1
5
in semiconductors. Perylene diimides and naphthalene
2
0
diimides derivatives were representative star molecules and
6a−6e with BCl in refluxed p-xylene in yield of 46−55%.
3
16
Excess BCl and high concentrations of substrates are essential;
showed outstanding performance as photovoltaic materials.
3
otherwise, low yield and difficult purification will appear.
Herein, three imide groups were fused with SubPc core, and 10
related compounds (SubPcTI, Figure 1) with different
substituents at B atoms and imide sites were synthesized.
The LUMO energy level of SubPcTI was lowered by 0.35−
Compounds 8b−8e were obtained by substitution reaction of
2
1
7
b−7e with AgBF in toluene.
4
Substitution reaction of 7c with phenol in refluxed toluene
afforded 9 in yield of 47%. Pyridine is necessary. It could
complex with acid produced in the reaction, which facilitated
the substitution reaction.
0
.42 eV, and the solubility could be adjusted by alkyl groups at
N-terminals. Four of them with suitable solubility were used as
acceptors to fabricate BHJOSCs, and the maximum PCE was
up to 4.92%, which is the highest efficiency among SubPc-
based BHJOSCs.
All the new compounds 5a−5e, 6a−6e, 7a−7e, 8b−8e, and
1
13
9
were characterized clearly by H NMR, C NMR, and high-
resolution mass spectrometry (HRMS). Compounds 7c, 7d,
c, and 8d with n-butyl or 2-pentylhexyl side chains are well-
Since side chains have significant influence on the solubility,
17
8
mobility, and phase separation of organic acceptors, five
different groups at imide positions were adopted in this work.
F, Cl, and phenoxyl groups at B atom were used to study their
effect on absorption, energy levels, and photovoltaic perform-
ance.
soluble in solvents such as chlorobenzene, chloroform, and
toluene, with solubility higher than 20 mg/mL, which makes
them solution-processable. The rest of the compounds show
limited solubility in organic solvent; their solubility is less than
8
mg/mL in chlorobenzene.
The absorption profiles of these compounds in CH Cl and
As shown in Scheme 1, target compounds were synthesized
from commercially available o-xylene in six or seven steps.
Three known compounds 4,5-dibromo-o-xylene (2), 4,5-
dibromo-o-phthalic acid (3), and 4,5-dibromophthalic anhy-
2
2
solid state were shown in Figure 2, and corresponding optical
18
dride (4) were obtained according to literature methods.
a
Scheme 1. Synthetic Route of 7a−7e, 8b−8e, and 9
−
5
Figure 2. Absorption of SubPcTIs in (a) CH Cl (1 × 10 M) and
2
2
(b) solid state.
data were summarized in Table 1. All of them with a similar
solution profile show strong absorption in the range of 450−
650 nm, which indicates that there is little electronic effect of
different substituents on the conjugated core. The maximum
absorption coefficient of 8d located at 588 nm is up to 148 000
−
1
−1
M
cm . Compounds 8b, 8c, and 8e with different side
chains show different maximum coefficients because of their
23
different aggregation in solution, as is confirmed in literature.
Absorptions of 7a−7e also have the similar phenomenon.
Compared to unsubstituted SubPc, introduction of three imide
groups causes the solution absorption to red-shift by 20−30
nm (Figure S3a), indicating effective electron communication
between imide and SubPc core. Solution absorption in toluene
and tetrahydrofuran (THF) were also measured, which
produced similar results as those in CH Cl (Figure S3b,c).
The maximum solid absorption red-shifts by 14−16 nm
compared with their corresponding solution results, and
absorption edge in solid state also red-shifts by 25−30 nm,
indicating strong intermolecular aggregation in solid state.
a
(
i) I , Br , 0 °C, 4 h, 77%; (ii) KMnO , H O, HCl, 140 °C, 7 h, 80%;
2 2 4 2
(
iii) 230 °C, 3 h, 97%; (iv) for 5a−5e, acetic acid, corresponding
2
2
amine, 130 °C, 6 h, 77−88%; (v) for 6a−6e, KI, CuCN,
dimethylformamide, 170 °C, 5 h, 63−70%; (vi) for 7a−7e, BCl , p-
3
xylene, 170 °C, 30 min, 46−55%; (vii) for 8b−8e, AgBF , toluene, 30
4
°C, 7 h, 68−76%; (viii) for 9, phenol, pyridine, toluene, 140 °C, 15 h,
4
7%.
B
DOI: 10.1021/acs.orglett.9b01130
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
Table 1. Optical and Electrochemical Data of All SubPcTIs
a
ε (1 ×10 M cm−1
3
−1
b
c
d
Egopt (eV)
e
f
λmax (nm)
)
λmax (nm)
Φf (%)
τ
(ns)
LUMO (eV)
7
7
7
7
7
8
8
8
8
9
a
b
c
d
e
b
c
590
590
590
590
592
588
588
588
592
592
102
113
108
143
121
129
131
148
118
604
604
602
600
602
602
604
602
602
14.3
15.4
13.8
14.3
15.0
10.5
10.1
9.1
3.29
1.94
1.94
1.94
1.94
1.93
1.93
1.93
1.92
1.93
1.92
−3.98
−3.93
−3.98
−3.95
−3.93
−3.93
−3.91
−3.94
−3.93
−3.96
3.31
3.38
3.40
3.36
2.34
2.34
2.35
2.34
3.07
d
e
10.2
11.8
105
604
c
a
b
Maximum absorption in CH Cl . Maximum absorption in film. Fluorescence quantum yield was determined with the standard N,N′-di(2,6-
2
2
2
2
d
e
isopropylphenyl)-perylene diimides (Φ = 1).
Fluorescence lifetime was measured in CH Cl . Estimated based on the film absorption onset.
2 2
f
f
Measured by cyclic voltammetry.
These compounds with optical band gaps in the range of
Figure S8. Photovoltaic results indicated that PM6 performed
best with these acceptors (Table S1).
1
.92−1.94 eV belong to moderate bandgap semiconductors.
Emission spectra of these compounds in CH Cl were
The optimized weight ratio of donor:acceptor was 1:1, as
shown in Table S2. Solvent additives 1,8-diiodooctane (DIO),
N-methyl pyrrolidone (NMP), 1-chloronaphthalene (CN),
and 1,2-diphenoxyethane (DPE) could improve device
performance, and addition of 0.5% DIO performed best
(Table S3). The optimized thickness of active layers was ∼90
nm, as determined by atomic force microscopy (AFM; Figure
4).
2
2
shown in Figure S4, and corresponding data were summarized
in Table 1. SubPcTI derivatives with quantum yield of 9.1−
7b,24
1
5.4% inherit fluorescence characters of SubPc family.
Their emission with peaks located around 610 nm are with
25
Stokes shifts nearby 20 nm. The fluorescence-decayed curves
were shown in Figure S5, and all the chlorinated compounds
7
a−7e with lifetimes of 3.29−3.40 ns are obviously higher than
those fluorinated compounds 8b−8e (2.34−2.35 ns), and the
The current density−voltage (J−V) curves of devices based
on PM6:SubPcTI were illustrated in Figure 3a. Their
7b
reason may be heavy-atom effect of Cl. The fluorescence
quantum yield of 7a−7e is in the small range of 13.8−15.4%,
because of their same parent chromophore, and the little
difference is derived from their different aggregation caused by
different side chains.
Cyclic voltammetry (CV) measurements (Figure S6) were
employed to study their electrochemical properties. All these
acceptors showed one semi-reversible reduction peak,
indicating their ability to accept at least one electron. Their
LUMO energy levels were calculated in the range from −3.91
to −3.98 eV (Table 1), based on the assumption that the
Figure 3. (a) J−V curves and (b) EQE spectra of solar cells based on
PM6:8c.
+
26
energy level of Fc/Fc is 4.8 eV relative to vacuum. Above
energy levels could match with many donors in BHJOSCs.
Compared to parent SubPc, introduction of imide groups
lowered LUMO energy levels by 0.35−0.42 eV, due to their
27
strong electron-withdrawing properties.
Table 2. Device Parameters of PM6:SubPcTI Solar Cells
Geometries of aromatic cores of these acceptors were
optimized with Gaussian 09 program, density functional theory
J
sc
2
a
cond
w/o
DIO
DIO/TA
DIO/TA
DIO/TA
DIO/TA
Voc (V)
(mA/cm )
FF (%)
PCE (%)
28
(
DFT) method, with basic set of B3LYP/6-311G (d, p).
8
c
0.88
0.84
0.84
0.82
0.89
0.96
7.00
9.23
9.69
7.19
6.4
52.96
52.36
59.92
53.09
46.26
47.12
(3.09 ± 0.15) 3.24
(3.96 ± 0.12) 4.08
(4.78 ± 0.14) 4.92
(2.98 ± 0.17) 3.15
(2.51 ± 0.16) 2.67
(3.18 ± 0.19) 3.37
Their absorption and band gaps were also calculated. As shown
in Figure S7, all these acceptors show bowl-shaped structures.
Unlike traditional planar conjugated molecules, rigid three-
dimensional structures could cause special molecular packing
and electron-transporting properties. Theoretical band gaps of
these compounds are 1.71 eV, close to experimental results of
7
7
8
c
d
d
7.44
a
The efficiency value was calculated from 10 devices.
1
.92−1.94 eV. Calculated maximum absorption located at
5
69−573 nm is also near experimental ones (588−592 nm).
The accordance of calculated and experimental results
confirms the reliability of theoretical method in this study.
An inverted device structure of indium tin oxide (ITO)/
corresponding parameters were summarized in Table 2.
Acceptor 8c gave the highest PCE of 4.92%, with V of 0.84
oc
−2
V, J of 9.69 mA cm , and the fill factor (FF) of 59.92%. The
sc
ZnO (30 nm)/donor:acceptor/MoO (7 nm)/Ag (100 nm)
addition of 0.5% DIO improved PCE from 3.24% to 4.08%.
After thermal annealing (TA) at 100 °C for 10 min, the PCE
raised to 4.92%.
The external quantum efficiency (EQE) spectra of solar cells
based on 8c was shown in Figure 3b. They exhibit broad
3
was used in BHJOSCs. Donor polymers PBDB-T-SF, PM6,
PM7, and PBDB-T-S with matched energy levels and
complementary absorption were selected to make solar cells;
their structures, energy levels, and absorption were shown in
C
DOI: 10.1021/acs.orglett.9b01130
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
photoresponse in the range from 300 to 700 nm, which is
contributed by both donor and acceptor. The maximal EQE is
AUTHOR INFORMATION
■
*
*
Corresponding Authors
5
7% with the spectra peak at 550 nm. The EQE spectra of the
E-mail: yuan@ncu.edu.cn. (Z.-y.Y.)
E-mail: ywchen@ncu.edu.cn. (Y.-w.C.)
other acceptors were shown in Figure S10.
The charge mobility of the pure acceptor and SubPcTI:PM6
blend films was evaluated by space-charge limited current
ORCID
2
9
(
SCLC) method. As shown in Table S5 and Figure S11, the
Zhongyi Yuan: 0000-0002-8796-4106
Yiwang Chen: 0000-0003-4709-7623
Notes
electron mobility (μ ) of the pure films was calculated to be on
e
−
5
2
−1 −1
the magnitude order of 1 × 10 cm V s ; the blended
films showed similar μ , while their hole mobility (μ ) was ∼1
10 cm V s . Blend films have relatively balanced carrier
mobility with μ /μ of 9.91−19.72. These results demonstrate
the four acceptors have good charge-transporting properties for
photovoltaic applications.
e
h
−
4
2
−1 −1
×
The authors declare no competing financial interest.
h
e
ACKNOWLEDGMENTS
■
AFM and transmission electron microscopy (TEM) were
employed to investigate the morphology of active layers. As
shown in Figure 4, PM6:7c and PM6:8c blend films show
The work was supported by grants from the National Natural
Science Foundation of China (Nos. 21562031, 51863012,
51833004, and 51425304) and from the Natural Science
Foundation of Jiangxi Province in China (Nos.
20171ACB21012 and 2018ACB21022)
REFERENCES
■
(
1) (a) Zhang, G.; Zhao, J.; Chow, P. C. Y.; Jiang, K.; Zhang, J.; Zhu,
Z.; Zhang, J.; Huang, F.; Yan, H. Chem. Rev. 2018, 118, 3447−3507.
b) Collins, S. D.; Ran, N. A.; Heiber, M. C.; Nguyen, T.-Q. Adv.
(
Energy Mater. 2017, 7, 1602242. (c) Liu, F.; Zhou, Z.; Zhang, C.;
Vergote, T.; Fan, H.; Liu, F.; Zhu, X. J. Am. Chem. Soc. 2016, 138,
1
5523−15526. (d) Li, S.; Liu, W.; Shi, M.; Mai, J.; Lau, T.-K.; Wan,
J.; Lu, X.; Li, C.-Z.; Chen, H. Energy Environ. Sci. 2016, 9, 604−610.
2) (a) Cai, C.; Wan, J.; Zhang, Y.; Yuan, Z.; Huang, Q.; Xu, G.; Hu,
Y.; Zhao, X.; Chen, Y. J. Polym. Sci., Part A: Polym. Chem. 2018, 56,
(
Figure 4. (a−d) AFM height and (e−h) phase images (scale bar: 1.0
μm) of optimum blend films.
1
16−124. (b) Yuan, Z.; Li, J.; Xiao, Y.; Li, Z.; Qian, X. J. Org. Chem.
2
010, 75, 3007−3016. (c) Kan, B.; Feng, H.; Wan, X.; Liu, F.; Ke, X.;
Wang, Y.; Wang, Y.; Zhang, H.; Li, C.; Hou, J.; Chen, Y. J. Am. Chem.
Soc. 2017, 139, 4929−4934.
small root-mean-square (RMS) roughness of 1.61 and 1.77
nm, indicating their good compatibility with the donor, which
led to the higher FF in BHJOSCs. Combining with TEM
images (Figure S12), the blend film of PM6:8c showed
appropriate domain sizes in nanoscale phase separation. Proper
phase separation and domain size were beneficial for exciton
separation and charge transport, which contributes to the high
Jsc, FF, and PCE.
(
3) (a) Lin, K.; Xie, B.; Wang, Z.; Xie, R.; Huang, Y.; Duan, C.;
Huang, F.; Cao, Y. Org. Electron. 2018, 52, 42−50. (b) Anthony, J. E.;
Facchetti, A.; Heeney, M.; Marder, S. R.; Zhan, X. Adv. Mater. 2010,
22, 3876−3892.
(4) (a) Fei, Z.; Eisner, F. D.; Jiao, X.; Azzouzi, M.; Rohr, J. A.; Han,
Y.; Shahid, M.; Chesman, A. S. R.; Easton, C. D.; McNeill, C. R.;
Anthopoulos, T. D.; Nelson, J.; Heeney, M. Adv. Mater. 2018, 30,
1
705209. (b) Zhang, H.; Yao, H.; Hou, J.; Zhu, J.; Zhang, J.; Li, W.;
Yu, R.; Gao, B.; Zhang, S.; Hou, J. Adv. Mater. 2018, 30, 1800613.
5) (a) Lu, Z.; Jiang, B.; Zhang, X.; Tang, A.; Chen, L.; Zhan, C.;
In summary, introduction of imide groups to SubPc was
proved to be an effective strategy to construct organic
semiconductors. SubPcTI with LUMO energy levels ca.
(
Yao, J. Chem. Mater. 2014, 26, 2907−2914. (b) Wang, J.; Wang, W.;
Wang, X.; Wu, Y.; Zhang, Q.; Yan, C.; Ma, W.; You, W.; Zhan, X. Adv.
Mater. 2017, 29, 1702125.
−3.95 eV, adjustable solubility, and strong visible absorption
is an excellent chromophore for electron acceptors. Different
substituents at imide sites or B atoms showed significant
influence on the solubility, mobility, and photovoltaic perform-
ance of these acceptors. More functional derivatives deriving
from this interesting chromophore deserve intensive inves-
tigation, to improve their promising applications in organic
solar cells.
(6) Chen, W.; Zhang, Q. J. Mater. Chem. C 2017, 5, 1275−1302.
(7) (a) Jin, F.; Chu, B.; Li, W.; Su, Z.; Yan, X.; Wang, J.; Li, R.;
Zhao, B.; Zhang, T.; Gao, Y.; Lee, C. S.; Wu, H.; Hou, F.; Lin, T.;
Song, Q. Org. Electron. 2014, 15, 3756−3760. (b) Claessens, C. G.;
Gonzalez-Rodriguez, D.; Rodriguez-Morgade, M. S.; Medina, A.;
Torres, T. Chem. Rev. 2014, 114, 2192−2277. (c) Beaumont, N.;
Castrucci, J. S.; Sullivan, P.; Morse, G. E.; Paton, A. S.; Lu, Z.-H.;
Bender, T. P.; Jones, T. S. J. Phys. Chem. C 2014, 118, 14813−14823.
(8) (a) Lin, C.-F.; Nichols, V. M.; Cheng, Y.-C.; Bardeen, C. J.; Wei,
ASSOCIATED CONTENT
M.-K.; Liu, S.-W.; Lee, C.-C.; Su, W.-C.; Chiu, T.-L.; Han, H.-C.;
Chen, L.-C.; Chen, C.-T.; Lee, J.-H. Sol. Energy Mater. Sol. Cells 2014,
■
*
S
Supporting Information
1
22, 264−270. (b) Mutolo, K. L.; Mayo, E. I.; Rand, B. P.; Forrest, S.
R.; Thompson, M. E. J. Am. Chem. Soc. 2006, 128, 8108−8109.
9) Beaumont, N.; Cho, S. W.; Sullivan, P.; Newby, D.; Smith, K. E.;
Jones, T. S. Adv. Funct. Mater. 2012, 22, 561−566.
10) Cnops, K.; Rand, B. P.; Cheyns, D.; Verreet, B.; Empl, M. A.;
Heremans, P. Nat. Commun. 2014, 5, 3406.
11) Sullivan, P.; Duraud, A.; Hancox, l.; Beaumont, N.; Mirri, G.;
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.or-
glett.9b01130.
(
(
Synthesis and characterization, UV−vis and fluorescence
absorption spectra, DFT calculations, cyclic voltamme-
try, optimization of photovoltaic applications, TEM
images, and NMR spectra (PDF)
(
Tucker, J. H. R.; Hatton, R. A.; Shipman, M.; Jones, T. S. Adv. Energy
Mater. 2011, 1, 352−355.
D
DOI: 10.1021/acs.orglett.9b01130
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
(
12) Duan, C.; Zango, G.; Garcia Iglesias, M.; Colberts, F. J.; Wienk,
M. M.; Martinez-Diaz, M. V.; Janssen, R. A.; Torres, T. Angew. Chem.,
Int. Ed. 2017, 56, 148−152.
(
13) Hang, H.; Zhang, Z.; Wu, X.; Chen, Y.; Li, H.; Wang, W.;
Tong, H.; Wang, L. J. Mater. Chem. C 2018, 6, 7141−7148.
14) Hang, H.; Wu, X.; Xu, Q.; Chen, Y.; Li, H.; Wang, W.; Tong,
H.; Wang, L. Dyes Pigm. 2019, 160, 243−251.
15) Wu, Q.; Zhao, D.; Schneider, A. M.; Chen, W.; Yu, L. J. Am.
Chem. Soc. 2016, 138, 7248−7251.
16) (a) Zhong, Y.; Trinh, M. T.; Chen, R.; Purdum, G. E.;
(
(
(
Khlyabich, P. P.; Sezen, M.; Oh, S.; Zhu, H.; Fowler, B.; Zhang, B.;
Wang, W.; Nam, C. Y.; Sfeir, M. Y.; Black, C. T.; Steigerwald, M. L.;
Loo, Y. L.; Ng, F.; Zhu, X. Y.; Nuckolls, C. Nat. Commun. 2015, 6,
8
242. (b) Yi, J.; Wang, Y.; Luo, Q.; Lin, Y.; Tan, H.; Wang, H.; Ma, C.
Q. Chem. Commun. 2016, 52, 1649−1652.
17) Lian, X.; Zhang, L.; Hu, Y.; Zhang, Y.; Yuan, Z.; Zhou, W.;
Zhao, X.; Chen, Y. Org. Electron. 2017, 47, 72−78.
18) (a) He, N.; Chen, Y.; Doyle, J.; Liu, Y.; Blau, W. J. Dyes Pigm.
008, 76, 569−573. (b) Wang, X.; Zhang, Y.; Sun, X.; Bian, Y.; Ma,
C.; Jiang, J. Inorg. Chem. 2007, 46, 7136−7141.
19) Gonidec, M.; Amabilino, D. B.; et al. Dalton Trans 2012, 41,
3632−13639.
20) Giribabu, L.; Vijay Kumar, C.; Surendar, A.; Gopal Reddy, V.;
Chandrasekharam, M.; Yella Reddy, P. Synth. Commun. 2007, 37,
141−4147.
21) Guilleme, J.; Gonzalez-Rodriguez, D.; Torres, T. Angew. Chem.
(
(
2
(
1
(
4
(
2
(
(
011, 123, 3568−3571.
22) Wurthner, F. Chem. Commun. 2004, 1564−1579.
23) Li, Y.; Gao, J.; Di Motta, S.; Negri, F.; Wang, Z. J. Am. Chem.
Soc. 2010, 132, 4208−4213.
24) Shimizu, S.; Miura, A.; Khene, S.; Nyokong, T.; Kobayashi, N.
J. Am. Chem. Soc. 2011, 133, 17322−17328.
25) Turrisi, R.; Sanguineti, A.; Sassi, M.; Savoie, B.; Takai, A.;
(
(
Patriarca, G. E.; Salamone, M. M.; Ruffo, R.; Vaccaro, G.; Meinardi,
F.; Marks, T. J.; Facchetti, A.; Beverina, L. J. Mater. Chem. A 2015, 3,
8
(
045−8054.
26) Xia, D.; Wu, Y.; Wang, Q.; Zhang, A.; Li, C.; Lin, Y.; Colberts,
F. J. M.; van Franeker, J. J.; Janssen, R. A. J.; Zhan, X.; Hu, W.; Tang,
Z.; Ma, W.; Li, W. Macromolecules 2016, 49, 6445−6454.
(
27) Zhu, G.; Zhang, Y.; Hu, Y.; Zhao, X.; Yuan, Z.; Chen, Y. J.
Polym. Sci., Part A: Polym. Chem. 2018, 56, 276−281.
28) Zhao, X.; Xiong, Y.; Ma, J.; Yuan, Z. J. Phys. Chem. A 2016, 120,
554−7560.
29) Zhang, Y.; Guo, X.; Su, W.; Guo, B.; Xu, Z.; Zhang, M.; Li, Y.
Org. Electron. 2017, 41, 49−55.
(
7
(
E
DOI: 10.1021/acs.orglett.9b01130
Org. Lett. XXXX, XXX, XXX−XXX