Significantly improved performance of dye-sensitized solar cells by optimizing organic dyes with pyrrole as the isolation spacer and utilizing alkyl chain engineering

Article abstract of DOI:10.1039/C8TA06258G

The optimization of interfacial and intramolecular charge transfer of organic dyes is crucial to the photovoltaic performance of dye-sensitized solar cells. In this study, an efficient strategy was afforded by the introduction of alkylated pyrrole as the isolation spacer into organic dyes. The interfacial charge transfer can be organized by the tunable alkyl chains as a barrier layer to inhibit electron recombination, and the pull-push system can be strengthened by the incorporation of electron-withdrawing units (benzothiadiazole) and electron-rich moieties (pyrrole) into the conjugated bridge simultaneously, resulting in excellent light-harvesting capability. Therefore, the high conversion efficiency of 9.70% was achieved by LI-124 with suitable alkyl chains and device optimization.

Full text of DOI:10.1039/C8TA06258G

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Kun Chang, Zhaorong Chang et al.
Bubble-template-assisted synthesis of hollow fullerene-like
MoS2 nanocages as a lithium ion battery anode material
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DOI: 10.1039/C8TA06258G
Significantly Improved Performance of Dye-Sensitized Solar Cell by Optimizing
Organic Dyes with Pyrrole as the Isolation Spacer and Utilizing Alkyl Chain
Engineering
Jinfeng Wang,a Siwei Liu,a Zhaofei Chai,a Kai Chang,a Manman Fang,a Mengmeng Han,a Yi Yi Wang,a Sheng Li,b Hongwei
Han,b Qianqian Li,*a Zhen Lia
The conversion efficiencies of dye sensitized solar cells were largely enhanced by organic dyes bearing pyrrole as
the isolation spacer and alkyl chain engineering, which afforded an efficient strategy to suppress the charge
recombination together with the increased light-harvesting ability by the optimization of intramolecular and
interfacial charge transfer.

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Significantly Improved Performance of Dye-Sensitized Solar Cell
by Optimizing Organic Dyes with Pyrrole as the Isolation Spacer
and Utilizing Alkyl Chain Engineering
Received 00th January 20xx,
Accepted 00th January 20xx
Jinfeng Wang,a Siwei Liu,a Zhaofei Chai,a Kai Chang,a Manman Fang,a Mengmeng Han,a Yiyi Wang,a
Sheng Li,b Hongwei Han,b Qianqian Li,*a Zhen Lia
DOI: 10.1039/x0xx00000x
www.rsc.org/
The optimization of interfacial and intramolecular charge transfer of organic dyes is crucial to the photovoltaic
performance of dye-sensitized solar cells. In this text, the efficient strategy was afforded by the introduction of alkylated
pyrrole as isolation spacer into the organic dyes. The interfacial charge transfer can be organized by the tunable alkyl
chains as the barrier layer to inhibit the electron recombination, and the pull-push system can be strengthened by the
incorporation of electron-withdrawing unit (benzothiadiazole) and electron-rich moieties (pyrrole) into the conjugated
bridge simultaneously, resulting in the excellent light-harvesting capability. Therefore, the high conversion efficiency of
9.70%
was
achieved
by
LI-124
with
suitable
alkyl
chains
and
device
optimization.
cannot be well combined to generate the synergistic effect.
For instance, it is an efficient approach to broaden the
absorption spectra of organic dyes by the introduction of an
electron-withdrawing unit into the conjugated bridge as the
auxiliary acceptor (A’), but the A’ moieties can also act as the
Introduction
Converting sunlight into electrical energy is considered to be
the most effective way to solve the energy crisis and
environmental problems.1-4 Dye-sensitized solar cells (DSCs)
have attracted much attention in both academic and industrial
fields because of their low cost and simple construction. 5-10 In
the development of DSCs, the dye sensitizer engineering is
proved as an efficient approach to adjust the light-harvesting
ability and regulate the electron processes in devices, resulting
in the improved the photovoltaic performance. 11-14 Until now,
the conversion efficiency of 14.3% as a record was achieved by
an organic dye with electron donor-π-bridge-electron acceptor
(D-π-A) structure, 15which highlighted the superiority of these
pull-push systems with high polarities.
Generally, the optimization of D-π-A structures has focused
on the following two aspects: (1) the modulation of intrinsic
electron property to strengthen the intramolecular charge
transfer (CT), with the aim to harvest more sunlight as the
input energy; (2) the adjustment of molecular configurations
to optimize the interfacial charge transfer, including the
suppression of dye aggregation and electron recombination as
the energy loss. However, in most cases, the above two points
16-19
“electron trap” to aggravate the electron recombination.
Thus, with the aim to achieve the high conversion efficiencies,
the balance of these two effects should be controlled by the
well-designed molecular structures. Apart from the
modulation of electronic properties of A’ units by different
building blocks 20-22, in our previous study, the steric hindrance
effect was applied into the isolation spacers between
benzothiadiazole (A’) and cyanoacrylic acid (A), which was
conducted by the linkage of different substituents to β-
position of thiophene ring (Figure 1). With the increased sizes
of substituents, the involved dihedral angles were enlarged
with poorer conjugation effect, the electron back reaction can
be inhibited efficiently, as proved by the increased lifetimes of
electrons in TiO2 film. Accordingly, the conversion efficiencies
of corresponding DSCs increased from 3.44% to 6.48%,
affording an efficient way to suppress the electron
recombination by the partially twisted strategy. 23 However, on
the other hand, the absorption spectra became narrowed with
the onset wavelength blue-shifted from 693 to 626 nm (Chart
S1), leading to the lower light harvesting abilities. Thus, the
improvement of photovoltaic performance is limited by the
similar trends of input power and energy loss. Is it possible to
obtain the decreased charge recombination and the increased
light-harvesting ability simultaneously?
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and so on. In DSCs, the alkyl chains are mostly linked to the
electron donor moieties of organic dyes, which can act as the
first barrier layer to inhibit the dye aggregation and block the
electron recombination.34-40 Recently, the largely increased
conversion efficiency is achieved by cyclopentadithiophene-
based organic dyes from 4.74% to 9.07% (Chart S2),41 mainly
due to the dual protection of the two barrier layers from alkyl
chains in conjugated bridge. These indicated that the alkyl
chains as the side chains in organic dyes play the essential role
to the interfacial CT, which were varied with the different
linkage positions.
Actually, this combine effect is hard to be realized by the
modification of thienyl unit as the common building block of
organic dyes for the steric hindrance effect. As a similar five-
membered ring to thiophene, pyrrole affords an additional
function site at the nitrogen atom, which can incorporate
various substituents with nearly no influence on the
Combined with the function of pyrrole and alkyl chains, a
series of organic dyes (LI-121-LI-125) with pyrrole as the
isolation spacer were designed and synthesized with the alkyl
chain engineering from methyl to dodecyl (Figure 1). Through
the replacement of thiophene in dye LI-80 with N-methyl
pyrrole moiety, the improved photovoltaic performance was
obvious with the increased conversion efficiency from 3.44%
to 4.27%. Furthermore, the highest conversion efficiency of
8.75% was achieved by LI-124 with N-decyl pyrrole as the
isolation spacer, which can further increase to 9.70% by device
optimization, indicating the great functionality of alkyl chains
engineering. These alkyl chains play the essential role to the
regulation of dye molecular arrangement and electron process
at the dye/TiO2/electrolyte interface, but have nearly no
adverse effect on the conjugated effect of molecular skeleton
for their perpendicular geometry to pyrrole ring, as proved by
the similar absorption spectra of these organic dyes. Thus, an
efficient method is afford to achieve the high conversion
efficiency by the suppression of electron recombination with
intramolecular CT effect of conjugated system, as proved by
our previous study.
24-28
Also, pyrrole with the electron-rich
property can act as the electron donor (D’) to the adjacent A’
unit, leading to the reversed charge transfer. It can relieve the
electron-trapping effect of A’ unit to some extent,29 indicating
the key role of pyrrole to the intramolecular CT effect of
organic dyes as the isolation spacer.
Besides, the interfacial CT in DSCs can be optimized by the
well-organized molecular arrangements of organic dyes on the
TiO2 surface, which can be conducted by the alkyl chain
engineering. It plays the key role to the molecular morphology
by the adjustable packing modes and intermolecular
interactions, and has been applied into many fields, including
organic field-effect transistors (OFETs),30 organic light-emitting
diodes (OLEDs)31 and organic photovoltaic devices (OPVs),32,33
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nm. The peak located at 380 nm is assigned to the π-π*
transitions of aromatics, while the other one located at 517
nm is attributed to the ICT through the whole molecule,
providing efficient charge-separation at the excited state. Once
these dyes were adsorbed onto the nanocrystalline TiO2 film,
the obvious red-shift of absorption spectra was observed in
comparison with those in solution, mainly attributing to the
interactions between TiO2 and organic dyes, together with
their intermolecular interactions in the aggregated state. With
the increased light-harvesting abilities, which can be applied to
various organic dyes to promote the development of DSCs.
Results and discussion
the increased thickness of TiO2 films (from 6 to 9 µm) , the
Synthesis of the Sensitizers
absorption spectra can be further extended (Figure S1). These
broader absorption regions are beneficial to the enhancement
of light-harvesting capability, leading to the improved
photovoltaic performance.
The alkyl chain engineering is the common strategy to tune
the molecular morphology in the aggregated state. In this text,
various alkyl moieties with different lengths were linked to the
nitrogen atom of pyrrole ring, which was located near the
cyanoacrylic acid moiety as the electron acceptor and
anchoring group. In this case, these flexible chains closed to
the TiO2 surface can act as the second barrier layer after the
first insulation effect by the alkyl chains linked to the electron
donor, with the aim to further inhibit the electron
recombination. Besides, the absorption behaviors of organic
molecules on TiO2 in the aggregated state can be adjustable by
different alkyl moieties as the side chains. Moreover, the
conjugated effect of the whole molecule has maintained in
spite of varied alkyl moieties, affording an efficient strategy to
reduce the energy loss in DSCs without any unfavorable effect
on the light-harvesting ability. It is mainly related to the
particular structure of pyrrole with the functional site on
nitrogen atom, which is hardly to be realized in the similar
moieties, including thiophene and furan. Thus, a series of
Electrochemical Properties
Regardless of the different lengths of alkyl chains substituted
to the nitrogen atom of pyrrole, the electrochemical
properties of these dyes were similar with each other (Figure
3). The reversible redox process were observed for these
organic dyes by cyclic voltammetry (Figure S2 and Table S1).
The first oxidation potentials (Eox) (0.8 V vs NHE), were
significantly more positive than that of the liquid electrolyte
−
I−/I3 redox potential (0.4 V vs NHE), indicating that the
oxidized dyes could be efficiently regenerated for the enough
driving force. The excited state oxidation potentials (Eox*) (-1.2
V vs NHE), estimated from Eox and zero-zero transition energy
(E0−0), were more negative than the conduction band-edge of
TiO2 (ECB) for thermodynamically favored electron injection.42
organic dyes (LI-121-LI-125) based on pyrrole with alkyl chain
Thus, dye LI-121-LI-125 can act as the efficient organic dyes for
modification have been synthesized (Scheme 1). After the
alkylation of pyrrole with different chains, the corresponding
heteroarylboronates were obtained by the followed C-H
activation, which can be linked to the main light-harvesting
moieties with bromine atoms (Ar-Br) by Suzuki coupling
reaction. Then, through the introduction of aldehyde group by
Vilsmeier-Haack reaction, the organic dyes were obtained by
the well-matched energy levels and chemical stability.
Theoretical Calculations
Through the incorporation of pyrrole moiety as the isolation
spacer into the organic dyes, the conjugated skeleton of dye
LI-121-LI-125 exhibited the almost planar geometry with the
the Knoevenagel condensation of compound 4a-e and small dihedral angle of 30.5o between benzothiadiazole and
1
cyanoacrylic acid, which were well characterized by H NMR,
13C NMR, ESI and EA.
pyrrole (Table S2), which is proved by the density functional
theory (DFT) calculation at B3LYP/6-31G* level.43 The efficient
charge transfer in the push-pull structure can be observed with
the almost separated HOMO and LUMO. Also, the extent of
charge separation upon excitation was estimated by natural
bond orbital analysis (Figure S3). These dyes were grouped
into four segments, including triarylamine-thiophene (TPA-Th),
benzothiadiazole (BT), isolation spacer (IS), and cyanoacrylic
Optical Properties
All of the organic dyes with the same conjugated skeleton
show the similar absorption spectra as single molecules (in
dilute solutions) and in the aggregated states (in TiO2 films)
(Figure 2), indicating that the alkyl chain engineering does not
affect ICT and molecular configuration of conjugated system.
There are two main absorption bands in the range of 350-700
acid (CAA). The charge differences (Δq, S0→S1) showed that
the prominent charge transfer occurred between TPA−Th and
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BT, acting as the main light-harvesting unit. Moreover, increased length of alkyl moieties as the side chains, the
compared to the analogue LI-80 with thiophene as the distances among the organic dyes can be enlarged,
isolation group, the electron-rich property of pyrrole in LI-121 accompanied with the decreased intermolecular interactions,
can promote ICT effect for the larger charge differences, which as demonstrated by the decreased dye- loading amount of LI-
was beneficial to the light harvesting.
124 (2.80×10-8 mol cm-2 m-1). Thus, the arrangement of
µ
organic dyes on the TiO2 surface could be regulated with the
almost homogeneous packing modes, which is beneficial to
Photovoltaic Performance
The current-voltage (J-V) curves of solar cells in conjunction the light-harvesting and the inhibition of electron
with an iodine electrolyte (0.05 M I2, 0.2 M LiI, 0.6 M DMPII, recombination, leading to the improved photovoltaic
0.1 M GuNCS and 0.5 M 4-TBP in acetonitrile) were measured performance. However, when the length of involved alkyl
under standard AM 1.5G conditions (100 mW cm−2) (Figure 4A chains increased to some extent, the ample sizes of organic
and Table S3). With the involved alkyl chains lengthened from molecules may largely decrease the amount of dyes on the
methyl to dodecyl, the open circuit voltages (Voc) of the TiO2 surface, leading to the lower light harvesting efficiencies.
corresponding DSCs firstly increased from 598 to 674 mV, then Also, the barrier effect for the suppression of electron
decreased to 618 mV. Also, their short-current densities (Jsc) recombination can be weakened with the decreased amount
exhibited the similar trend, and the highest conversion of alkyl chains. Thus, LI-125 bearing the longest alkyl chains
efficiency of 8.75% is achieved by DSC based on LI-124 with (dodecyl) exhibited the moderate conversion efficiency.
decyl modification. It is mainly related to the various Accordingly, decyl moiety is proved as the suitable side chain
aggregated states of organic dye on the TiO2 film, which can be to realize the increase of Jsc and Voc at the same time, resulting
partially demonstrated by the different dye-loading amounts in the best photovoltaic performance of LI-124. The density of
with alkyl chain engineering.
photogenerated electrons could also be analyzed from IPCE, as
The largest dye-loading amount of LI-121 (3.29×10-8 mol cm- shown in Figure 4B. The IPCE curves of these organic dyes
2
µ
m-1) with methyl modification meant the densely packed exhibited the similar shape with different IPCE values, which
molecules on the TiO2 surface. In this case, the severe dye was mainly related to the varied electron collection efficiencies
aggregates were usually formed for the strong intermolecular with different alkyl chains modification. Dye LI-123 and LI-124
interactions with the short contact of the adjacent molecules, bearing octyl and decyl moieties exhibited the higher values
resulting in the inhomogeneous distribution of organic dyes on for the well-organized molecular arrangement and dual
the TiO2 surface (Figure 5). Thus, the severe electron insulation effect by the alkyl chains in electron donor and
recombination may occur at the bare TiO2 surface, leading to isolation spacer together (Figure 5).
the lower Voc of LI-121. Also, the possible intermolecular
Besides, the energetic and dynamic origins of different Voc
energy transfer can be induced with the excited state
44,45
quenching, resulting in the photocurrent loss.
With the
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can be investigated and understood in detail by charge optimization.
extraction (CE) method and intensity-modulated photovoltage The storage stability of DSCs based on these dyes were
spectroscopy (IMVS). Since the related DSCs were fabricated investigated, and values for Jsc, Voc, FF and η were recorded
with the same electrolyte, Voc is mainly determined by the over a period of 500 h. Taking LI-124-sensitized solar cell with
electron quasi-Fermi-level (EF,n) of dye-loaded TiO2 film, which the best photovoltaic performance as the example, the overall
associated with conduction band (ECB) and the density of free efficiency remained 91% after 500 h of aging in the air (Figure
charge.46 As shown in Figure 6A, the shifts in ECB was much 8). Also, other dyes exhibited the excellent storage stabilities
different with the alkyl chain engineering of organic dyes. The (Figure S9 and S10), indicating organic dyes on the TiO2 surface
up-shift of conduction band to a greater extent was conducted remained intact after long time aging. Also, under continuous
by dye LI-121, which was related to their orientation and full sunlight irradiation at standard AM 1.5G conditions, the
arrangement on the TiO2 surface as mentioned above. dye-sensitized films almost keep intact for 15 h, as proved by
However, it did not result in the enhancement of Voc values, the similar absorption spectra and photographs (Figure S11-
mainly due to the shorter electron lifetime of LI-121-sensitized 13), further confirming their good photo-stabilities. Besides,
TiO2 film, as shown in Figure 6B. While DSCs based on dye LI- they possessed excellent thermal stability with the
123 and LI-124 exhibited the longer electron lifetime, meaning decomposition temperatures (the 5% of weight lost) higher
the lower electron recombination rate. Thus, the suitable alkyl than 220 oC (Figure S14).
chains closed to the TiO2 surface indeed can act as the efficient
Based on these excellent photovoltaic performance, some
barrier layer to further inhibit the contact of electrolyte with strategies can be proposed to optimize the molecular design of
electron in TiO2 film, which is beneficial to the suppression of organic dyes in DSCs (Figure 9). As discussed above, once the
charge
recombination.
Accordingly,
electrochemical A’ units were introduced into the conjugated bridges of
impedance spectroscopy (EIS), which was performed in the organic dyes with D-π-A structure to broaden the light harvest
dark under a forward bias of -0.69 V (Figure S4), showed the regions, it is essential to insert isolation spacers between the
similar trend with IMVS measurement, further confirming the A’ and A moieties to suppress the possible “electron trap”
important role of alkyl chains substituted to pyrrole moiety.
effect. In the previous study, some aromatic rings were
23
Thus, with different alkyl moieties applied into the organic employed, such as thienyl, phenyl, and so on.
However,
dyes as the side chains, the well-organized molecular when some alkyl chains were substituted to inhibit the charge
alignment can be achieved by the adjustable intermolecular recombination, the steric hindrance can result in the partially
interactions and dye-loaded amounts, which can be twisted configuration of organic dyes, leading to the decreased
considered as the chemical optimization of organic dyes. On light-harvesting capability. In this text, alkylated pyrrole was
the other hand, the physical doping can be conducted by the incorporated as the isolation spacers with the adjustable
introduction of chenodeoxycholic acid (CDCA), which is the lengths of alkyl chains, which can act as the second barrier
common coadsorbent to inhibit the dye aggregation on the layer closed to the TiO2 surface, after the first insulation by the
TiO2 surface. When it was applied into DSC based on dye LI- alkyl chains linked to electron donor part. Meanwhile, the light
124 with suitable alkyl chains, the high conversion efficiency of harvesting region was maintained, since nearly no steric
9.70% was achieved by the incorporation of CDCA with low hindrance would be caused by the alkyl chains linked to the
concentration (1 mM) (Figure 7 and S5-S8), which was mainly nitrogen atom of pyrrole. Thus, the intramolecular charge
attributed to the combine effect of chemical optimization and transfer of organic dyes can increase by the addition of
physical doping. Under the same conditions, the conversion electron-withdrawing unit and electron-rich ring to harvest
efficiency of N719 was 8.26% with Jsc of 16.76 mA cm-2, Voc of more sunlight, and the interfacial charge transfer can be
683 mV and FF of 0.72 (Table S3), meaning that the superiority
of organic dyes LI-124 with reasonable molecular structure and
the potential higher conversion efficiency by device
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45,47
optimized by the alkyl chain engineering closed to the TiO2 The DSC devices were fabricated according to literatures.
A
surface, which can adjust the molecular arrangement of fluorine doped tin oxide (FTO) conducting glass (3.2 mm thickness,
organic dyes as the aggregated state and act as efficient 7-8 ohms/sq) which were cleaned with detergent, water, ethanol
contact inhibitor, to suppress the interfacial charge and acetone respectively and irradiated under O3 for 18 min, then
recombination. Therefore, the high conversion efficiency can immersed in TiCl4 solution (40 mM) for 30 min at 70 °C. After being
be gained by the increased input energy and reduced energy cooled to room temperature, they were washed with deionized
loss, which were conducted by the optimization of molecular water and ethanol three times respectively and dried. The
configuration and alignment, and pull-push electronic property photoanodes (16 ꢀm thickness), which consist of 12 μm layer of
of organic dyes. In the further research, more isolation spacers mesoporous TiO2 (18 NR-T, 18-20 nm, Dyesol) and 4 μm scatter
near the electron acceptor will be exploited to extend the layer (18 NR-AO, 20 - 450 nm, Dyesol), were prepared using the
conjugated system and organize the interfacial charge transfer screen printing technique and gradually heated under airflow at 325
o
o
o
together, with the aim to achieve the better photovoltaic oC for 5 min, 375 C for 5 min, 450 C for 15 min and 500 C for1 h.
performance.
After the film being cooled to room temperature, they were
o
immersed in TiCl4 solution (40 mM) for 30 min at 70 C once again,
o
then washed and annealed at 500 C for 30 min. After the TiO2 film
o
Conclusions
being cooled to 80 C, they were immersed in dye bath (0.3 mM) in
mixture solution (CH3CN/t-BuOH/CHCl3 = 2/2/1) for 18 h in dark
condition. Then, the sensitized electrodes were washed with
corresponding solvents and dried in air. Counter electrodes were
prepared by thermal deposition: FTO glass (2.2 mm thickness, 7-8
ohms/sq) with two small holes were cleaned as photocathodes, 10
ꢀL solution of H2PtCl6 (10 mM) in isopropyl alcohol were dispersed
on FTO glass and heated at 400 oC for 30 min. After then, dye
absorbed photoanodes and Pt-counter electrode were assembled
into a sandwich type cell and sealed with a hot-melt gasket (25 μm
thickness) made by the ionomer Surlyn 1702 (DuPont). The
electrolyte consisted of 0.05 M I2, 0.2 M LiI, 0.6 M DMPII, 0.1 M
GuNCS and 0.5 M 4-TBP in acetonitrile were injected into cells by
the two small holes after assembled. Lastly, the two holes were
sealed with a Surlyn sheet (50 μm thickness) and a thin ITO glass
covered by heating.
A series of organic dyes with alkylated pyrrole moieties as the
isolation spacers were designed and synthesized, with the
enhanced light-harvesting ability and inhibited charge
recombination in dye sensitized solar cells. With the
adjustment of alkyl chains closed to the TiO2 surface, the
interfacial charge transfer was optimized by the well-organized
molecular arrangement and formation of contact inhibitor.
Accordingly, the highest conversion efficiency can be achieved
as 9.70% for LI-124 with decyl-substituted pyrrole as the
isolation spacer. Also, with the investigation of relationship
between molecular structure and photovoltaic performance,
some strategies were proposed to promote the development
of DSCs by efficient organic dyes.
Photovoltaic measurement were conducted under AM 1.5 solar
simulator (Model 94023A equipped with a 450 W xenon arc lamp,
Newport Co). It was calibrated with a normal silicon solar cells
before measurement. Keithley model 2400 digital source meter
were connected with light source to get J-V curves when applying
an external bias to the cell. Incident photon-current conversion
efficiency (IPCE) was recorded on a DC Power Meter (Model 2931-C
equipped with a 300 W xenon arc lamp, Newport Co.) under
Experimental
Materials and Instrumentation:
Tetrahydrofuran (THF) was dried over and distilled from K-Na alloy
under an atmosphere of dry argon. All solvents were analytical
grade and used without further purification. Compound 1a (N-
methylpyrrole) was purchased without further purification.
Compound Ar-Br were synthesized according to our previous work.
23
1H and 13C spectra were obtained with a Bruker 300 MHz
irradiation with
a motorized monochromator (Oriel). Some
electrochemical properties were obtained by Modulab XM
PhotoEchem system such as IMVS (intensity modulated
photovoltage spectroscopy), CE (charge extraction), EIS
(electrochemical impedance spectroscopy). IMVS and CE were
measured under a white light emitting diode (LED) array. CE were
conducted in dark with different potential biases with a frequency
range from 1 Hz to 100 kHz.
spectrometer or Bruker Avance III HD 400 MHz using
tetramethylsilane (TMS; δ = 0 ppm) as internal standard. Elemental
analyses were performed by
a 73 CARLOERBA-1106 micro-
elemental analyzer. ESI-MS spectra were recorded with a Finnigan
LCQ advantage mass spectrometer. UV-visible spectra were
conducted on
a
Shimadzu UV-2550 spectrometer in
dichloromethane. Electrochemical cyclic voltammetry was
performed with a CHI 660 voltammetric analyzer with Pt disk, Pt
plate, and Ag/Ag+ electrode as working electrode, counter
electrode, and reference electrode, respectively, in nitrogen-purged
anhydrous CH2Cl2 with tetrabutylammonium hexafluorophosphate
(TBAPF6) as the supporting electrolyte (scanning rate: 100 mV/s).
The ferrocene/ferrocenium redox couple was used for potential
calibration.
The measurement of the dye loading amounts
The dye loading amounts (DLA) were measured by two steps, firstly,
the desorption of organic dyes from TiO2 films were conducted by
the immersion of dye-sensitized TiO2 films into the solution (3.0 mL)
of NaOH (0.1 M)/THF (v/v, 1/1). Then, the concentrations (c) of
these solutions were determined by standard curves of organic dyes
under the same conditions. Accordingly, DLA values were calculated
by a mathematical equation: DLA = (c×v)/(0.25 cm2×16 ꢀm), v was
DSC device fabrication and measurement
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the volume of desorption solution (3.0 mL), 0.25 cm2 was the area CH3).
ARTICLE
of TiO2 film, 16 ꢀm was the thickness of TiO2 film.
3b: ArBr (200 mg, 0.27 mmol), compound 2b (374 mg, 1.35 mmol),
red solid (289 mg, 78%). 1H NMR (300 MHz, CDCl3) δ (ppm): 8.14-
8.09 (m, 2H, ArH), 7.66 (d, 1H, J = 7.2 Hz, ArH), 7.57 (d, 2H, J = 8.4
General synthesis of compound 1b-e
Under an atomsphere of nitrogen, a mixture of pyrrole (1.0 equiv) Hz, ArH), 7.49 (s, br, 1H, ArH), 7.05 (d, 5H, J = 6.6 Hz, ArH), 6.92 (d,
and RBr (1.5 equiv) in dry THF (30 mL) was placed in a 200 mL 4H, J = 8.7 Hz, ArH), 6.80 (d, 2H, J = 7.2 Hz, ArH), 6.41(s, br, 1H, ArH),
round-bottom and cooled to -20 °C. Then NaH (3.0 equiv) dissolved 6.20 (s, br, 1H, ArH), 3.94 (m, 6H, -OCH2-, -NCH2-), 1.70 (m, 6H, -CH2-
in THF (10 mL) was added slowly and the mixture was stirred at -20 ), 1.42-1.23 (m, 18H, -CH2-), 0.88 (s, br, 9H, -CH3).
°C for 1h, then 65 oC for 12h. The solid was filtered out, and the 3c: ArBr (224 mg, 0.30 mmol), compound 2c (458 mg, 1.5 mmol),
1
solvent was poured into water and extracted with chloroform for red solid (200 mg, 79.4%). H NMR (400 MHz, CDCl3) δ (ppm): 8.13
three times. The combined organic layers were dried with (d, 1H, J = 4.0 Hz, ArH), 7.89 (d, 1H, J = 8.0 Hz, ArH), 7.55-7.50 (m,
anhydrous sodium sulfate. After the solvent was evaporated, the 3H, ArH), 7.30 (d, 1H, J = 4.0 Hz, ArH), 7.09 (d, 4H, J = 8.0 Hz, ArH),
crude products were purified by flash column chromatography.
7.96-6.91 (m, 3H, ArH), 6.86 (d, 4H, J = 8.0 Hz, ArH), 6.50 (d, 1H, J =
1b: Pyrrole (670 mg, 10 mmol), C6H13Br (2.48 g, 15.0 mmol), NaH 4.0 Hz, ArH), 6.34 (t, 1H, J = 4.0 Hz, ArH), 3.98-3.94 (m, 6H, -OCH2-, -
(720 mg, 30.0 mmol). Brown oil (730 mg, 48.0%). 1H NMR (300 NCH2-), 1.80-1.77 (m, 4H, -CH2-), 1.62 (m, 2H, -CH2-), 1.49-1.33 (m,
MHz, CDCl3) δ (ppm): 6.66 (s, 2H, ArH), 6.15 (s, br, 2H, ArH), 3.87 (t, 12H, -CH2-), 1.21-1.10 (m, 10H, -CH2-), 0.93-0.80 (m, 9H, CH3).
J = 7.2 Hz, 2H, -NCH2-), 1.74 (m, 2H, -CH2-), 1.29 (m, 6H, -CH2-), 0.89 3d: ArBr (265 mg, 0. 35 mmol), compound 2d (583 mg, 1.75 mmol),
1
(s, br, 3H, -CH3).
red solid (207 mg, 68.1%). H NMR (400 MHz, CDCl3) δ (ppm): 8.12
1c: Pyrrole (720 mg, 10.7 mmol), C8H17Br (3.10 g, 16.0 mmol), NaH (d, 1H, J = 4.0 Hz, ArH), 7.87 (d, 1H, J = 8.0 Hz, ArH), 7.55-7.44 (m,
(770 mg, 32.1 mmol). Brown oil (832 mg, 43.4%). 1H NMR (300 3H, ArH), 7.28 (d, 1H, J = 4.0 Hz, ArH), 7.08 (d, 4H, J = 8.0 Hz, ArH),
MHz, CDCl3) δ (ppm): 6.63 (s, 2H, ArH), 6.14 (s, 2H, ArH), 3.78 (t, J = 6.98-6.88 (m, 3H, ArH), 6.84 (d, 4H, J = 8.0 Hz, ArH), 6.48 (d, 1H, J =
7.5 Hz, 2H, -NCH2-), 1.69 (m, 2H, -CH2-), 1.27 (m, 10H, -CH2-), 0.89 (s, 4.0 Hz, ArH), 6.35-6.29 (m, 1H, ArH), 4.05-3.84 (m, 6H, -OCH2-, -
br, 3H, -CH3).
NCH2-), 1.80-1.75 (m, 4H, -CH2-), 1.63-1.58 (m, 2H, -CH2-), 1.49-1.33
1d: Pyrrole (700 mg, 10.4 mmol), C10H21Br (3.45 g, 15.6 mmol), NaH (m, 12H, -CH2-), 1.21-1.10 (m, 14H, -CH2-), 0.93-0.83 (m, 9H, -CH3).
(749 mg, 31.2 mmol). Brown oil (679 mg, 31.5%). 1H NMR (300 MHz, 3e: ArBr (265 mg, 0. 35 mmol), compound 2e (632 mg, 1.75 mmol),
CDCl3) δ (ppm):6.65 (s, 2H, ArH), 6.14 (s, 2H, ArH), 3.77 (t, J = 7.2 Hz, red solid (178 mg, 56.9%), 1H NMR (400 MHz, CDCl3) δ (ppm): δ 8.04
2H, -NCH2-), 1.70 (m, 2H, -CH2), 1.27 (m, 14H, -CH2), 0.89 (s, br, 3H, - (d, 1H, J = 4.0 Hz, ArH), 7.82 (d, 1H, J = 8.0 Hz, ArH), 7.48-7.41 (m,
CH3).
3H, ArH), 7.23 (t, 1H, J = 4.0 Hz, ArH), 6.99 (d, 4H, J = 8.0 Hz ArH),
1e: Pyrrole (910 mg, 13.6 mmol), C12H25Br (5.08 g, 20.4 mmol), NaH 6.84-6.82 (m, 3H, ArH), 6.77 (d, 4H, J = 8.0 Hz, ArH), 6.33 (m, 1H,
(979 mg, 4.8 mmol). Brown oil (972 mg, 30.3%). 1H NMR (300 MHz, ArH), 6.19 (m, 1H, ArH), 3.85 (m, 6H, -OCH2-, -NCH2-), 172-1.65 (m,
CDCl3) δ (ppm): 6.67 (s, 2H, ArH), 6.14 (s, 2H, ArH), 3.77 (s, br, 2H, - 4H, -CH2-), 1.52-1.47 (m, 2H, -CH2-), 1.40-1.25 (m, 12H, -CH2-), 1.16-
NCH2-), 1.71 (m, 2H, -CH2), 1.27 (m, 18H, -CH2), 0.89 (s, br, 3H, -CH3). 1.00 (m, 18H, -CH2-), 0.85-0.75 (m, 9H, -CH3).
General synthesis of compound 2a-e
Under an atomsphere of nitrogen, a mixture of 1a-e (1.0 equvi), Under an atomsphere of nitrogen, fresh distilled DMF (3.0 equvi)
4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) (1.2 and POCl3 (2.0 equvi) were added into round-bottom flask and
General synthesis of compound 4a-e
equvi), [Ir(COD)Cl]2 (0.05 equvi) and 4,4’-ditert-butyl-2,2’-dipyridyl stirred at 0 °C. After the resultant solution turn to glassy solid.
(0.05 equvi) in degassed cyhexane was (60 mL) stirred at 65 °C for compound 3 (1.0 equvi) dissolved in 1,2-dichloroethane (10 mL) was
14 h. The mixture were poured into water (100 mL) then extracted added dropwise. The solution was warmed to room temperature
with dichloromethane. The organic layers were collected and and sirred for 12 h. then poured into Na2CO3 solution (1 M, 50 mL),
evaporated under reduced pressure, and the crude products were and stirred for another 2 h. The mixture was extracted with
used directly without further purification.
chloroform for three times. The combined organic layers were dried
with anhydrous sodium sulfate. After the solvent was evaporated,
General synthesis of compound 3a-e
Under an atomsphere of nitrogen, a mixture of compound ArBr (1.0 the crude product was purified by column chromatography.
equvi), compound 2a-e (5.0 equvi), Pd(PPh3)4 (0.05 equiv) and K2CO3 4a: 3a (200 mg, 0.27 mmol), DMF (59 mg, 0.81 mmol), POCl3 (83
(5 equvi) in 30 mL solvent (THF/H2O = 5/1) was placed in 100 mL dry mg, 0.54 mmol), red solid (130 mg, 62.6%). 1H NMR (300 MHz,
Schlenk tube and refluxed for 12 hours. The mixture was poured CDCl3) δ (ppm): 9.66 (s, 1H, -CHO), 8.17 (d, 2H, J = 5.1 Hz, ArH), 7.92
into water and extracted with chloroform for three times. The (d, 1H, J = 7.2 Hz, ArH), 7.64 (d, 2H, J = 7.2 Hz, ArH), 7.50 (d, 2H, J =
combined organic layers were dried with anhydrous sodium sulfate. 8.8 Hz, ArH), 7.31(d, 2H, J = 3.9 Hz, ArH), 7.10 (d, 4H, J = 9.0 Hz,
After the solvent was evaporated, the crude products were purified ArH), 6.95 (d, 2H, J = 9.0 Hz, ArH), 6.85 (d, 4H, J = 8.7 Hz, ArH), 6.59
by column chromatography.
(d, 1H, J = 3.9 Hz, ArH), 3.95 (m, 6H, -NCH2- , -OCH2-), 1.80-1.76 (m,
3a: ArBr (225 mg, 0.30 mmol), compound 2a (310 mg, 1.50 mmol), 4H, -CH2-), 1.47-1.25 (m, 12H, -CH2-), 0.92 (s, br, 6H, -CH3).
red solid (200 mg, 90%). 1H NMR (300 MHz, CDCl3) δ (ppm): 8.15 (m, 4b: 3b (270 mg, 0.33 mmol), DMF (73 mg, 1.00 mmol), POCl3 (101
2H, ArH), 7.70 (d, 1H, J = 6.6 Hz, ArH ), 7.59 (d, 2H, J = 8.7 Hz, ArH), mg, 0.66 mmol), red oil (180 mg, 65.0%). 1H NMR (300 MHz, CDCl3)
7.49 (s, 1H, ArH), 7.06 (d, 5H, J = 8.4 Hz, ArH), 6.94 (d, 4H, J = 8.4 Hz, δ (ppm): 9.62 (s, 1H, -CHO), 8.21 (m, 2H, ArH), 7.83 (d, 1H, J = 8.0
ArH), 6.81 (d, 2H, J = 7.8 Hz, ArH), 6.41(s, 1H, ArH), 6.55 (m, 1H, Hz, ArH), 7.59 (d, 2H, J = 8.7 Hz, ArH), 7.51 (s, br, 1H, ArH), 7.25 (d,
ArH), 6.20 (s, br, 1H, ArH), 3.95 (m, 4H, -OCH2-), 3.69 (s, 3H, -NCH3), 1H, J = 8.4 Hz, ArH), 7.05 (d, 4H, J = 8.4 Hz, ArH), 6.80 (d, 2H, J = 7.8
1.72 (s, br, 4H, -CH2-), 1.43-1.32 (m, 12H, -CH2-), 0.89 (s, br, 6H, - Hz, ArH), 6.56 (d, 1H, J = 8.4 Hz, ArH), 4.30 (s, br, 2H, -NCH2-), 3.92
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Journal Name
(m, 4H, -OCH2-), 1.69 (m, 6H, -CH2-), 1.41-1.23 (m, 18H, -CH2-), 0.88 (ppm): 8.20 (m, 3H, ArH, -CH=), 7.81 (d, 1H, J = 8.1 Hz, ArH), 7.67 (d,
(m, 9H, -CH3). 1H, J = 8.7 Hz, ArH), 7.58 (d, 2H, J = 9.0 Hz, ArH), 7.52 (d, 1H, J = 8.4
4c: 3c (190 mg, 0.23 mmol), DMF (50 mg, 0.69 mmol), POCl3 (71 mg, Hz, ArH), 7.05 (d, 4H, J = 8.1 Hz, ArH), 6.92 (d, 4H, J = 8.4 Hz, ArH),
0.46 mmol), red oil (143 mg, 71.9%). 1H NMR (400 MHz, CDCl3) δ 6.80 (m, 3H, ArH), 4.18 (m, 2H, -NCH2-), 3.94 (m, 4H, -OCH2-), 1.69
(ppm): 9.63 (s, 1H, CHO), 8.19 (d, 1H, J = 3.9 Hz, ArH), 7.92 (d, 1H, J (m, 6H, -CH2-), 1.41-1.23 (m, 18H, -CH2-), 0.89 (m, 9H, -CH3). 13
C
= 7.4 Hz, ArH), 7.62 (d, 1H, J = 7.5 Hz, ArH), 7.57-7.46 (m, 2H, ArH), NMR (75 MHz, CDCl3 and DMSO-d6) δ (ppm): 165.57, 155.74,
7.31 (d, 1H, J = 4.0 Hz, ArH), 7.15-7.05 (m, 5H, ArH), 6.95 (d, 2H, J = 153.82, 151.98, 148.76, 146.72, 139.94, 139.45, 138.64, 136.29,
8.8 Hz, ArH), 6.85 (d, 4H, J = 8.0 Hz, ArH), 6.52 (d, 1H, J = 8.0 Hz, 130.80, 129.91, 128.21, 127.95, 126.89, 126.34, 125.25, 124.25,
ArH). 4.39-4.29 (m, 2H, -NCH2-), 3.95 (t, 4H, J = 6.5 Hz, -OCH2-), 1.78 122.67, 122.35, 119.71, 119.10, 117.75, 115.31, 94.36, 83.41, 68.10,
(m, 4H, -CH2-), 1.39 (m, 12H, -CH2-), 1.22 (m, 2H, -CH2-), 1.19-0.98 45.05, 31.58, 30.92, 29.65, 29.28, 26.03, 25.74, 25.05, 22.61, 14.16,
(m, 10H, -CH2-), 0.92 (t, 6H, J = 4.5 Hz, -CH3), 0.84 (m, 3H, -CH3).
13.93. MS (ESI, m/z): calcd for C54H59N5O4S2, 905.4; Found, 905.4.
4d: 3d (200 mg, 0.23 mmol), DMF (50 mg, 0.69 mmol), POCl3 (71 Anal. Calcd for C54H59N5O4S2: C, 71.57; H, 6.56; N, 7.73; S, 7.08;
mg, 0.46 mmol), red oil (156 mg,75.7%). 1H NMR (400 MHz, CDCl3) δ Found: C, 71.43; H, 6.85; N, 7.65; S, 7.11.
(ppm):9.63 (s, 1H, -CHO), 8.19 (d, 1H, J = 4.0 Hz, ArH), 7.92 (d, 1H, J LI-123: 4c (140 mg, 0.16 mmol), cyanoacrylic acid (40 mg, 0.48
1
= 8.0 Hz, ArH), 7.62 (d, 1H, J = 8.0 Hz, ArH), 7.54-7.47 (m, 2H, ArH), mmol). Black solid (97 mg, 65.1%). H NMR (400 MHz, DMSO-d6) δ
7.31 (d, 1H, J = 4.0 Hz, ArH), 7.14-7.03 (m, 5H, ArH), 6.95 (d, 2H, J = (ppm): 8.16 (m, 2H, ArH, -CH=), 8.07 (s, 1H, ArH), 7.78 (d, 1H, J = 7.2
8.8 Hz, ArH), 6.85 (m, 4H, ArH), 6.52 (d, 1H, J = 8.0 Hz, ArH), 4.41- Hz, ArH), 7.58 (d, 2H, J = 8.4 Hz, ArH), 7.50(s, br, 1H, ArH), 7.45 (s, br,
4.25 (m, 2H, -NCH2-), 3.95 (t, 4H, J = 6.5 Hz, -OCH2-), 1.79 (m, 4H, - 1H, ArH), 7.05 (d, 4H, J = 8.7 Hz, ArH), 6.92 (d, 4H, J = 8.4 Hz, ArH),
CH2-), 1.58-1.33 (m, 12H, -CH2-), 1.20 (m, 2H, -CH2-), 1.20-0.97 (m, 6.80 (d, 2H, J =8.7 Hz, ArH), 6.64 (d, 1H, J = 3.9 Hz, ArH), 4.06 (s, br,
14H, -CH2-), 0.97-0.78 (m, 9H, -CH3).
2H, -NCH2-), 3.94 (t, 3H, J = 6.0 Hz, -OCH2-), 1.73-1.68 (m, 5H, -CH2-,
4e: 3e (170 mg, 0.19 mmol), DMF (42 mg, 0.57 mmol), POCl3 (58 -CH-), 1.41-1.30 (m, 16H, -CH2-), 0.88 (m, 16H, -CH2-, -CH3). 13C NMR
mg, 0.38 mmol), red oil (123 mg,70.3%). 1H NMR (400 MHz, CDCl3) δ (100 MHz, THF- d8) δ (ppm): 165.21, 156.72, 154.66, 152.74, 149.61,
(ppm): 9.63 (s, 1H, CHO), 8.19 (d, 1H, J = 4.0 Hz, ArH), 7.92 (d, 1H, J 147.34, 140.87, 139.43, 138.86, 137.24, 131.43, 130.29, 129.18,
= 8.0 Hz, ArH), 7.62 (d, 1H, J = 8.0 Hz, ArH), 7.50 (d, J = 8.0, 2H, ArH), 128.42, 127.37, 126.80, 126.39, 124.78, 123.66, 123.21, 120.52,
7.31 (d, 1H, J = 4.0 Hz, ArH), 7.12-7.07 (m, 5H, ArH), 6.95 (d, 2H, J = 118.89, 117.72, 117.55, 115.75, 95.84, 68.45, 45.38, 39.85, 32.45,
8.8 Hz, ArH), 6.85 (d, 4H, J = 8.0 Hz, ArH), 6.52 (d, 1H, J = 8.0 Hz, 32.36, 32.30, 30.02, 29.66, 29.51, 26.94, 26.46, 23.26, 23.16, 14.13.
ArH), 4.34 (t, 2H, J = 8.0 Hz, -NCH2-), 3.95 (t, 4H, J = 8.0 Hz, -OCH2-), MS (ESI, m/z): calcd for C56H63N5O4S2, 933.4; Found, 933.4. Anal.
1.82-1.75 (m, 4H, -CH2-), 1.49-1.34 (m, 12H, -CH2-), 1.17 (m, 2H, - Calcd for C56H63N5O4S2: C, 71.99; H, 6.80; N, 7.50; S, 6.86; Found: C,
CH2-), 1.15-1.01 (m, 18H, -CH2-), 0.93-0.83(m, 9H, -CH3).
72.16; H, 6.61; N, 7.26; S, 6.61.
LI-124: 4d (150 mg, 0.17 mmol), cyanoacrylic acid (43 mg, 0.51
mmol). Black solid (102 mg, 62.6%). 1H NMR (400 MHz, DMSO-d6) δ
General synthesis of sensitizers
A mixture of compound 4a-e (1.0 equiv), cyanoacrylic acid (3.0 (ppm): 8.21-8.15 (m, 3H, ArH, -CH=), 7.81 (d, 1H, J = 7.5 Hz, ArH),
equiv) and catalytic amount of piperidine in 10 mL solvent 7.67 (d, 1H, J = 4.3 Hz, ArH), 7.58 (d, 2H, J = 8.7 Hz, ArH), 7.51 (d, 1H,
(MeCN/THF = 4/1) were placed in a 50 mL dry round-bottom with a J = 3.9 Hz, ArH), 7.05 (d, 4H, J = 8.9 Hz, ArH), 6.92 (d, 4H, J = 9.0 Hz,
condensation tube. The mixture was refluxed for 16 h, then pour ArH), 6.80 (d, 2H, J = 8.8 Hz, ArH), 6.76 (d, 1H, J = 4.3 Hz, ArH), 4.19
into hydrochloric acid solution (50 mL, 2 M). The crude product was (s, br, 2H, -NCH2-), 3.94 (t, 4H, J = 6.4 Hz, -OCH2-), 1.75-1.66 (m, 4H, -
extracted with chloroform for three times, and the combined CH2-), 1.51-0.95 (m, 28H, -CH2-), 0.90-0.74 (m, 9H, -CH3). 13C NMR
organic layer were dried with anhydrous sodium sulfate. After the (100 MHz, THF-d8) δ (ppm): 164.87, 156.73, 154.65, 152.74, 149.63,
solvent was evaporated, the crude product was purified by column 147.42, 140.88, 139.72, 139.23, 137.22, 131.49, 130.31, 129.10,
chromatography.
128.53, 127.36, 126.79, 126.38, 124.74, 123.59, 123.19, 120.52,
LI-121: 4a (165 mg, 0.21 mmol), cyanoacrylic acid (53 mg, 0.63 119.07, 117.37, 115.73, 115.67, 95.08, 68.43, 45.37, 32.51, 32.45,
mmol). Black solid (110 mg, 62.8%). 1H NMR (300 MHz, DMSO-d6) δ 32.29, 30.10, 30.01, 29.97, 29.90, 29.52, 26.91, 26.45, 23.24, 23.21,
(ppm): 8.17 (m, 2H, ArH, -CH=), 8.05 (s, 1H, ArH), 7.78 (d, 1H, J = 7.2 14.13, 14.09. MS (ESI, m/z): calcd for C58H67N5O4S2, 961.5; Found,
Hz, ArH), 7.58 (d, 2H, J = 8.4 Hz, ArH), 7.51 (s, br, 1H, ArH), 7.43 (s, 961.5.Anal. Calcd for C58H67N5O4S2, C, 72.39; H, 7.02; N, 7.28; S,
br, 1H, ArH), 7.05 (d, 4H, J = 8.4 Hz, ArH), 6.93 (d, 4H, J = 8.4 Hz, 6.66; Found: C, 72.05; H, 7.15; N, 7.55; S, 6.45.
ArH), 6.80 (d, 2H, J = 9.0 Hz, ArH), 6.72 (s, 1H, ArH), 3.94 (m, 4H, - LI-125: 4e (120 mg, 0.13 mmol), cyanoacrylic acid (33 mg, 0.39
1
OCH2-), 3.66 (s, 3H, -NCH3), 1.70 (m, 4H, -CH2-), 1.41-1.23 (m, 12H, - mmol). Black solid (80 mg, 62.0%). H NMR (400 MHz, DMSO-d6) δ
CH2-), 0.88 (m, 6H, -CH3). 13C NMR (100 MHz, THF-d8) δ (ppm): (ppm): 8.23-8.14 (m, 3H, ArH, -CH=), 7.79 (d, J = 7.5 Hz, 1H, ArH),
165.21, 157.11, 155.01, 153.14, 149.99, 147.77, 141.26, 140.04, 7.68 (d, J = 4.4 Hz, 1H, ArH), 7.55 (d, J = 8.6 Hz, 2H, ArH), 7.48 (d, J =
139.94, 137.65, 131.69, 130.80, 130.72, 128.80, 127.76, 127.19, 3.8 Hz, 1H, ArH), 7.03 (d, J = 8.8 Hz, 4H, ArH), 6.91 (d, J = 8.9 Hz, 4H,
126.76, 125.12, 123.60, 123.43, 120.88, 119.12, 117.81, 116.13, ArH), 6.79-6.75 (m, 3H, ArH), 4.19 (s, br, 2H, -NCH2-), 3.93 (t, J = 6.3
115.86, 95.32, 68.84, 33.21, 32.68, 30.39, 26.84, 23.63, 14.50. MS Hz, 4H, -OCH2-), 1.68 (m, 4H, -CH2-), 1.44-1.08(m, 32H, -CH2-), 0.89-
(ESI, m/z): calcd for C49H49N5O4S2, 835.3; Found, 835.3; Anal. Calcd 0.74 (m, 9H, -CH3). 13C NMR (100 MHz, CDCl3 and DMSO-d6) δ
for C49H49N5O4S2: C, 70.39; H, 5.91; N, 8.38; S, 7.67; Found: C, 69.93; (ppm): 167.67, 155.71, 153.88, 151.97, 148.69, 146.48, 139.99,
H, 5.78; N, 8.71; S, 7.58.
136.77, 136.71, 136.38, 130.48, 129.59, 128.61, 127.47, 126.81,
LI-122: 4b (160 mg, 0.19 mmol), cyanoacrylic acid (48 mg, 0.57 126.31, 125.40, 124.23, 123.07, 122.60, 119.79, 116.98, 115.34,
mmol). Black solid (127 mg, 73.8%). 1H NMR (300 MHz, DMSO-d6) δ 114.53, 68.14, 44.60, 31.81, 31.68, 31.50, 29.53, 29.43, 29.22,
8 | J. Name., 2012, 00, 1-3
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ARTICLE
23 Z. Chai, M. Wu, M. Fang, S. Wan, T. Xu, R. Tang, Y. Xie, A.
Mei, H. Han, Q. Li and Z. Li, Adv. Energy Mater., 2015, 5,
28.77, 26.14, 25.66, 22.57, 22.52, 18.49, 14.13, 14.07. MS (ESI, m/z):
calcd for C60H71N5O4S2, 990.5; Found, 990.6. Anal. Calcd for
C60H71N5O4S2, C, 72.77; H, 7.23; N, 7.07; S, 6.47; Found: C, 72.89; H,
7.33; N, 6.90; S, 6.67.
1500846.
24 M. Fang, H. Li, Q. Li and Z. Li, RSC Adv., 2016,
6, 40750.
25 H. Li, Y. Hou, Y. Yang, R. Tang, J. Chen, H. Wang, H. Han, T.
Peng, Q. Li and Z. Li, ACS Appl. Mater. Interfaces, 2013, 5,
12469.
26 H. Li, L. Yang, R. Tang, Y. Hou, Y. Yang, H. Wang, H. Han, J.
Qin, Q. Li and Z. Li, Dyes Pigm., 2013, 99, 863.
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Conflicts of interest
There are no conflicts to declare.
28 Q. Li, J. Shi, H. Li, S. Li, C. Zhong, F. Guo, M. Peng, J. Hua, J.
Qin and Z. Li, J. Mater. Chem., 2012, 22, 6689.
29 H. Li, M. Fang, Y. Hou, R. Tang, Y. Yang, C. Zhong, Q. Li and Z.
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30 X. Zhan, J. Zhang, Y. Gong, S. Tang, J. Tu, Y. Xie, Q. Peng, G.
Yu and Z. Li, Mater. Chem. Front., 2017, , 2341.
31 G. Qian, B. Dai, M. Luo, D. Yu, J. Zhan, Z. Zhang, M. Dongge
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32 N. Liang, W. Jiang, J. Hou and Z. Wang, Mater. Chem. Front.,
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We are grateful to the National Science Foundation of China
(51673151), Hubei Province (2017CFA002), and the
Fundamental Research Funds for the Central Universities
(2042017kf0247 and 2042018kf0014) for financial support.
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