Synthesis, Photophysical Properties and Two-Photon Absorption Study of Tetraazachrysene-based N-Heteroacenes

Article abstract of DOI:10.1002/asia.201801656

Three novel N-heteroacene molecules (SDNU-1, SDNU-2 and SDNU-3) based on tetraazachrysene units as cores have been designed, synthesized and fully characterized. Their photophysical, electrochemical and fluorescence properties were investigated, and they

Full text of DOI:10.1002/asia.201801656

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Accepted Article
Title: Synthesis, Photophysical Properties and Two Photon Absorption
Study of Tetraazachrysene-based N-heteroacenes
Authors: Qichun Zhang
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Synthesis, Photophysical Properties and Two Photon Absorption
Study of Tetraazachrysene-based N-heteroacenes
Gang Li‡a, Shuaihua Wang‡a, Shufan Yang ‡a, Guangfeng Liuc,d, Pin Haoa, Yusen Zhengb, Guankui
Longe, Dandan Lia, Yu Zhanga, Wenbin Yanga, Liang Xu*b, Weibo Gaoe, Qichun Zhang*c, Guanwei Cuia
and Bo Tang*a
Abstract: Three novel N-heteroacene molecules (SDNU-1,
SDNU-2 and SDNU-3) based on tetraazachrysene units as
cores have been designed, synthesized and fully characterized.
Their photophysical, electrochemical and fluorescence
properties were investigated, and they exhibited blue to green
emission in solid state. Interestingly, SDNU-2 exhibited high
solid photoluminescence quantum efficiencies (75.3%), which is
the highest value of N-heteroacenes derivatives to date. Two-
photon absorption studies have been conducted by using open
two photons with identical or different frequencies in order to
excite a molecule from one state (usually the ground state) to a
higher energy state.[1] Organic molecules with high two-photon
absorption properties have attracted many scientists’ attention
due to their potential applications in three-dimensional (3D)
fluorescence imaging, lasing up-conversion, optical power
limitation, photodynamic therapy and 3D optical data storage.[2-13]
Benefiting from their diverse advantages including well-defined
structural diversity, flexibility and functionality, fast response,
and variable bandgap, organic π-conjugated compounds have
been widely explored as NLO materials to enhance TPA
absorption cross-sections.[14-22] In particular, extended π-
conjugated systems with the symmetrical substitution of
electron-donating and electron-accepting units have been
regarded as efficient TPA molecules to exhibit larger TPA
absorption cross-sections compared to the corresponding
and close aperture Z-san technique. SDNU-3 showed
a
significant enhancement in the two-photon absorption cross-
section with magnitudes as high as ∼700 GM (1 GM = 1 × 10–50
cm4 s/photon) when excited with 800 nm light, which is the
largest value based on heteroacene system measured by Z-
scan experiment so far. We attribute the outcome to sufficient
electronic coupling between the strong charge transfer of
quadrupolar substituents and the trtraazachrysene core. Our
result would provide a new guideline to design novel efficient
two-photon materials based on N-heteroacene cores.
unsubstituted counterparts, indicating that the efficient
[23, 24]
intramolecular charge transfer (ICT),
caused by the
donating and withdrawing abilities of electron donor and
acceptor, plays an important role in increasing their TPA cross-
sections values.[25-27] Efforts to further increase the nonlinearity
are usually focused on enlarging the conjugation length or
increasing the strength of donors or acceptors or both.[28] As a
result, the nonlinearity properties of the whole chromophores
could be well tuned.
1. Introduction
Two photon (TPA) process is
a nonlinear optical (NLO)
phenomenon, and the efficiency of this process can be
evaluated by accessing TPA, where one molecule can absorb
In the past decades, heteroacenes, a type of acenes with one
or more heteroatomsto replace the CH units in their skeleton,
have attracted great attention due to their unique photophysical
and electronic properties as well as their highly-ordered
structures in the solid state, which endows them wide
applications in organic electronics such as photovoltaic effect,
energy transfer, organic light-emitting diodes, TPA absorption
and so on.[29-34] For example, the TPA cross-section of
fluorescein,[35] Rhodamine B,[36] and Rhodamine 6G [37]have
been reported to be 36, 150and 134 GM, respectively. Recently,
Yu group[38] reported that three donor-acceptor ladder-type
heteroacene molecules exhibited intense intramolecular charge-
transfer and displayed obvious two-photon absorption behaviors
with TPA cross-sections of 64, 72, and 83 GM (chloroform, 800
nm), respectively. In order to further increase the TPA cross-
[a] Prof. Dr. G. Li, S. Wang, S. Yang, P. Hao, D. Li, Y. Zhang, W. Yang,
Prof. Dr. G. Cui, Prof. Dr. B. Tang.
College of Chemistry, Chemical Engineering and Materials Science,
Collaborative Innovation Center of Functionalized Probes for Chemical
Imaging in Universities of Shandong, Institute of Materials and Clean
Energy, Shandong Provincial Key Laboratory of Clean Production of
Fine Chemicals, Key Laboratory of Molecular and Nano Probes,
Ministry of Education, Shandong Normal University, Jinan, 250014,
P.R. China.E-mail: tangb@sdnu.edu.cn
[b] Prof. Dr. L. Xu, Y. Zheng.
Department of Chemistry and Key Laboratory for Preparation and
Application of Ordered Structural Materials of Guangdong Province,
Shantou
xuliang@stu.edu.cn
[c] Dr. G. Liu, Prof. Dr. Q. Zhang
University,
Shantou
515063,
P.R.
China.E-mail:
section value, Yu group prepared new ladder-type oligomers[39]
,
School of Materials Science and Engineering, Nanyang Technological
University, Singapore 639798. E-mail: qczhang@ntu.edu.sg
consisting of thienoacene derivatives as the donor and perylene
diimide (PDI)as the acceptor. They found that these compounds
could display the highest TPA cross-section value of 125 GM.
However, all currently-reported TPA cross-sections values
based on heteroacenes are relatively small compared with other
organic TPA materials such as triphenylamine derivatives (a
TPA cross-section of 790 GM)[40] and some other conjugated
compounds[41 ]excited with 800nm light. To further improve the
TPA cross-sections of heteroacenes molecules, structural
[d] Dr. G. Liu
Laboratoire de Chimie des Polymères, CP 206/01, Université Libre de
Bruxelles, Campus de la Plaine, 1050 Bruxelles, Belgique.
[e] Prof. Dr. W. Gao, Dr. G, Long
Division of Chemistry and Biological Chemistry, School of Physical and
Mathematical Sciences, Nanyang Technological University, Singapore
639798
Supporting information for this article is given via a link at the end of
the document.
‡G. Li, S. Wang and S. Yang contributed equally to the work.
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10.1002/asia.201801656
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adjustment of both backbones and branched chains for the
realization of more effective intramolecular charge transfer are
highly desirable.
2. Results and discussion
2.1. Synthesis and characterization
The synthetic procedures of SDNU-1, SDNU-2 and SDNU-3 are
shown in Scheme 1. The precursors 1, 2 and 3 were prepared
according to the previously-reported procedures with some
modification.[47-49] Compound 4 was prepared in 52% yield
through the palladium-catalyzed Stille-coupling reaction. All
three target products were obtained by condensing diketones
with diamines in pyridine solutions under reflux condition. The
1
as-synthesized materials were fully characterized by H and 13C
NMR, Fourier Transform infrared spectroscopy (FT-IR), and
matrix assisted laser desorption ionization time of flight mass
spectrometry (MALDI-TOF-MS). All the original data have been
provided in supporting information (SI). All final compounds have
shown good solubility in common organic solvents such as
chloroform, dichloromethane, and o-dichlorobenzene (O-DCB)
at room temperature. Also, all final molecules display excellent
thermal stability with the decomposition temperature (Td, 5%
weight loss) larger than 400 oC under nitrogen atmosphere. Note
that heating the solids of all three compounds in air at 200 oC for
two hours did not lead to detectable changes as indicated by 1H
NMR spectra.
Scheme 1. Synthetic procedures of SDNU-1, SDNU-2 and SDNU-3.
2.2. Crystal structure of SDNU-1
As one family member of heteroacenes, N-heteroacenes (or
azaacenes, nitrogen-contained analogues of acenes) have been
widely demonstrated as promising n-type semiconductors in
[29,30,42]
optoelectrical devices.
Especially, azaacenes-based
donor-acceptor molecules with various functions are very
promising[43] because their unique electronic/optical properties as
well as interesting intermolecular self-assembly motifs can show
the ideal TPA absorption ability. Especially, the high electron-
polarizability held by the large delocalized π-conjugated systems
can be further enhanced by the push–pull electronic
[44-46]
characteristics.
The combination of these factors are in
Figure 1. The crystal structure of SDNU-1.
favor of realizing a series of molecules with significant TPA
cross-section ability. Unfortunately, such NLO properties based
on azaacenes are scarcely available and rarely investigated.
Recently, our group synthesized novel TPA materials through
the combination of pyrazine species and triphenylamine unit[28]
and we demonstrated that the maximum TPA cross-section
value can reach 211 GM in dichloromethane solution with 800
nm excitation. These results convince us that azaacenes could
have great potential applications in highly efficient NLO
materials.
Herein, continuing our research on functional azaacenes
compounds,[31] we report the synthesis and characterization of
three new N-heteroacene with tetraazachrysene units as their
backbone (SDNU-1, SDNU-2 and SDNU-3). Four spherical
triisopropylsilyl (TIPS) groups are attached onto the backbone,
which guarantees that the as-synthesized N-heteroacene is
stable and easily soluble in organic solvents by decreasing π-π
interactions via steric hindrance. Interestingly, we found that the
solid-state emission of all three compounds varied by changing
the linking substituents, and SDNU-2 exhibited an intriguing
intense solid-state fluorescence quantum yield (φ = 75.3%),
which is among the highest value reported for azaacene
materials so far. The investigation on the nonlinear optical (NLO)
properties revealed that SDNU-3 exhibited a TPA cross section
of 702 GM through open aperture z-scan measurement, which is
the largest value based on heteroacenes measured by Z-scan
experiment.
The crystals of SDNU-1 suitable for Single Crystal X-ray
crystallographic diffraction (SCXRD) was obtained by slow
diffusion of methanol into tetrahydrofuran (THF) solution. The
structure analysis of SDNU-1 (a = 11.67 Å, b = 19.34 Å, c =
14.37 Å, α= 90 oC, β= 107oC, γ= 90oC) crystallized in the
monoclinic space group P21/c with a big unit cell (V = 3102.56
(3) Å3; CCDC number: 1858979; details of the unit cell
parameters are provided in Table S1 and S2). As expected, the
configuration of the conjugated backbone is nearly planar (Fig.
1a), where the acetylene, the pyrazine ring and the naphthalene
group are in the same plane (Fig. 1b, 1c). As far as we know,
SDNU-1 is the first simplest ladder-type N-heteroacene, whose
structure has been confirmed by single crystal.[50] SDNU-1 forms
one-dimensional herringbone packing motif, but does not show
too much overlap of the backbone (plane distance of 5.27 Å)
due to the steric hindrance of TIPS substituents (Fig. S1).
2.3. Optical properties
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of SDNU-3 (7.45%). The introduction of four thienyl groups
resulted in a remarkable effect on the absorption and emission
spectra, which is probably due to the different structures
between in the excited state and in ground state.
Figure 2. The absorption spectra of SDNU-1, SDNU-2 and SDNU-3 in
dichloromethane solution. Inset were the corresponding photograph of SDNU-
1 (left), SDNU-2 (middle) and SDNU-3 (right).
Figure 4. Cyclic voltammograms of three compounds.
2.4. Cyclic voltammetry
The cyclic voltammetry (CV) is employed to investigate the
electrochemical properties of SDNU-1, SDNU-2 and SDNU-3 for
highest occupied molecular orbital (HOMO) and lowest
unoccupied molecular orbital (LUMO) energy levels. The as-
obtained CV curves are shown in Figure 4 and the resulting data
are summarized in Table S3. In the cathodic scan, the initial
onset oxidation potentials of the chromophores were found to
occur at − 1.11 V, − 1.18 V and − 1.22 V (vs Ag/AgCl), which
corresponded to LUMO levels of − 3.30 eV, − 3.23 eV and −
3.19 eV, respectively, according to the empirical equation ELUMO
= −[q(Ered–EFc/Fc+) + 4.8)].[51] The HOMO energy levels of three
compounds were calculated to be − 6.13eV, − 6.06 eV and −
5.67 eV, respectively, according to the equation EHOMO = −
(ELUMO + Egopt) eV.[17] Because SDNU-3 possesses the stronger
electron-donating effect from thienyl groups, it exhibited
relatively higher HOMO level in comparison with those of SDNU-
1 and SDNU-2 with ethynyl and phenyl unit as the peripheral
groups. All the electronic energy levels could be further
illustrated by the density functional theory (DFT) calculations
using B3LYP functional and 6-31G (d) basis set as discussed
below.
Figure 3. The fluorescence spectra of SDNU-1, SDNU-2 and SDNU-3 in
dichloromethane solution. Inset were the corresponding photograph of SDNU-
1 (left), SDNU-2 (middle) and SDNU-3 (right).
The normalized optical absorption spectra of three compounds
in dichloromethane (DCM) solutions are shown in Fig. 2 and the
corresponding data are summarized in Table S3. The UV-vis
absorption spectra of SDNU-1 and SDNU-2 exhibit an apparent
bathochromic shift and relatively lower molar extinction
coefficients relative to that of SDNU-3. The longest wavelength
absorption of SDNU-3 occurs at 468 nm (ε = 1.43× 105 cm2mol-
1), which is red-shifted by 40 nm and 50 nm relative to that of
SDNU-1 (428 nm, ε = 1.01 × 105 cm2mol-1) and SDNU-2 (418
nm, ε = 1.24 × 105 cm2mol-1). The red shift suggests a
considerable intramolecular charge-transfer transition absorption
of peripheral thiophene units to the tetraazachrysene core in
SDNU-3. Moreover, the absorption spectra of SDNU-1 and
SDNU-2 do not show any significant change by switching the
solvent from low polar solvent DCM to high polar solvent N,N-
dimethylformamide (DMF), suggesting the poor efficiency of
intramolecular charge-transfer in the ground state.
2.5. Molecular simulations
To get further insight into geometrical configurations and
electronic structures of SDNU-1, SDNU-2 and SDNU-3, TD-DFT
calculations at the B3LYP/ 6-31G(d)[52] level were performed.
The results are illustrated in Fig. S2 and Table S4. From the
optimized ground-state geometries (Fig. S2), their HOMO
electron densities mainly distribute on the aza-chrysene cores
as well as substituted moieties, while the LUMO ones are mainly
located on the tetraazachrysene cores. The DFT calculated
LUMO levels for SDNU-1, SDNU-2 and SDNU-3 are − 2.99, −
2.87 and − 2.97 eV, and HOMO levels are − 6.10, − 5.82 and −
5.57 eV (Table S4), which are consistent with the experimental
data. Moreover, the HOMO–LUMO energy gaps (Egcal) of SDNU-
1, SDNU-2 and SDNU-3 range from 2.60 to 3.11 eV (Table S4),
which are consistent with their optical bandgap results.
The fluorescence quantum yields (Φl) of all three compounds in
DCM solution were measured with quinine bisulfate (Φl = 55% in
0.1 M H2SO4) as a standard and are summarized in Table S3.
Upon irradiation with UV light, the solutions of SDNU-1 and
SDNU-2 in DCM exhibited a moderate blue fluorescence while
the solution of SDNU-3 in DCM showed
a weak green
fluorescence (Fig. 3). The quantum yields of SDNU-1 (36.3%)
and SDNU-2(22.8%) were found to be obviously higher than that
2.6. Solid-state fluorescence study
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As shown in Fig. S3, SDNU-1 exhibits solid-state fluorescence
emission at 456 nm along with a shoulder peak at 487 nm, while
SDNU-2/SDNU-3 emits a strong peak at 481/559 nm. The solid
fluorescence quantum yields (Φs) of SDNU-1, SDNU-2 and
SDNU-3 are 8.75%, 75.3% and 6.09%, respectively (Table 1).
To the best of our knowledge, 75.3% is the highest value of
solid-state fluorescence quantum yields in azaacenes
derivatives. Furthermore, time-resolved fluorescence spectra
(Figure S31-33) reveal that the fluorescence decay times (τ) of
SDNU-1, SDNU-2 and SDNU-3 (Table 1) are 0.90, 3.00 and
0.91 ns, respectively. We also estimated the radiative and
nonradiative decay rates of SDNU-1, SDNU-2 and SDNU-3, and
found that the radiative decay rate decreases with the trend of
SDNU-2 (9.72 ×107 s-1), SDNU-1 (25.11 ×107 s-1), SDNU-3 (6.65
×107 s-1); while the nonradiative decay rate increases with the
order of SDNU-2 (1.01 ×107 s-1), SDNU-1(0.08 ×107 s-1), SDNU-
3 (1.03 ×107 s-1), which is consistent with their solid-state
fluorescence quantum yields.
Molecular simulation was conducted to analyze the dihedral
angle between the tetraazachrysene cores and peripheral
substituents for SDNU-1, SDNU-2 and SDNU-3. The as-
obtained results (Fig. S5) indicates that there is a tilt angle of
1.15o for SDNU-1, 40.1o for SDNU-2 and 29.6o for SDNU-3,
suggesting that the trend of increasing steric hindrance is
SDNU-1, SDNU-3, and SDNU-2. Generally, molecules with
higher stereo-hindrance effect will be beneficial for their
fluorescence efficiency because of the relatively loose solid-
state stacking pattern.[53]
2.7. Two-Photon Absorption Investigation
Figure 6. Opened and closed Z-scan curves of SDNU-3.
The third-order nonlinear optical properties of SDNU-1, SDNU-2
and SDNU-3, were studied using opened and closed aperture Z-
san technique excited with 800 nm light and a repetition rate of 1
kHz. The resulting curves are shown in Fig. 5 and 6. The
experimental data of nonlinear refractive index (n2), TPA
max
coefficient (β) and TPA cross-section value (δ2
) are
summarized in Table 2. All three compounds were measured at
dichloromethane solution (5
10-3 M). Note that
×
dichloromethane does not show any two-photon absorption
activity under the experimental conditions. Due to the weak
electron-donating ability of (triisopropylsilyl)acetylene segment,
SDNU-1 exhibited negligible third-order nonlinear optical
properties. Fig. 5a and 6a showed the opened Z-scan curves of
SDNU-2 and SDNU-3, and their nonlinear absorption coefficient
(β) are 0.43 × 10-12 and 0.51 × 10-12 cmW-1, respectively. Fig. 5b
and 6b showed the closed Z-scan curves and their nonlinear
refractive coefficient (n2) of SDNU-2 and SDNU-3 are 0.13 × 10-
16 and 0.12 × 10-16 cmW-1, respectively. Therefore, the calculated
TPA cross-sections (δ2max) of SDNU-2 and SDNU-3 are 592 and
702 GM, respectively. SDNU-3 shows the highest TPA cross-
section bahavior among all azaacene derivatives. The TPA
cross-section is strongly associated with the charge transfer
character of the material. The relative electron-rich thienyl group
of SDNU-3 demonstrated the enhanced intramolecular charge-
transfer (ICT) states. So we attribute the outcome to sufficient
electronic coupling between the strong charge transfer of
quadrupolar substituents and the tetraazachrysene core. The
results indicate that the ladder-type azaacene derivatives can
enhance the TPA cross-section.
Figure 5. Opened and closed Z-scan curves of SDNU-2.
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The TPA cross-section value of SDNU-3 is parallel to those of
donor-π-acceptor (D-π-A) type compounds excited with 800 nm
light.40 However, their TPA cross-sections are relatively small
compared with those of other organic TPA materials, such as
porphyrin derivatives41, which showed a TPA cross-section of
3500 GM excited with 800 nm light. Thus, reasonable molecular
design of both the backbones and branched chains based on
azaacenes may be required to obtain the enhanced two-photon
absorption cross-sections.
This work was supported by the National Natural Science
Foundation of China (NSFC) (No. 21535004, 91753111,
21390411, 21702132), the Key Research and Development
Program of Shandong Province (No. 2018YFJH0502),
Shandong Province Natural Science Foundation (No.
ZR2016BM24) and STU Scientific Research Foundation for
Talents (NTF15005). Q.Z acknowledges financial support from
AcRF Tier 1 (RG 111/17, RG 2/17, RG 114/16, RG 8/16) and
Tier
2 (MOE 2017-T2-1-021 and MOE 2018-T2-1-070),
Singapore. G. L thanks the European Union’s Horizon 2020
research and innovation programme under the Marie
Sklodowska-Curie grant agreement (No. 791207).
T
able 1. Optical properties of three compounds.
Φs
knr(107
s-1)
a
Samples
λem (nm)
τ (ns)
kr(107 s-1)c
(%)b
8.75
75.3
6.09
Keywords: Azaacenes •Two Photon Absorption • Fluorescence
SDNU-1
SDNU-2
SDNU-3
456
481
559
0.90
3.00
0.91
9.72
25.11
6.65
1.01
0.08
1.03
quantum yields • Synthesis
[1]
[2]
P. Miłosz, C. H. A., D. R. G., A. H. L., Angew. Chem. Int. Ed. 2009, 48,
3244-3266.
M. Rumi, J. E. Ehrlich, A. A. Heikal, J. W. Perry, S. Barlow, Z. Hu, D.
McCord-Maughon, T. C. Parker, H. Röckel, S. Thayumanavan, S. R.
Marder, D. Beljonne, J.-L. Brédas, J. Am. Chem. Soc. 2000, 122, 9500-
9510.
b
c
aThe solid emission.
absolute fluorescence quantum yield
Rate
constants for radiative (kr) and nonradiative decay (knr) were calculated
from the Φs and τ, kr =Φs/τ and knr = (1 -Φs)/ τ.
[3]
[4]
C. C. C., H. Z.-L., B. K. D, Adv. Mater. 2006, 18, 2910-2914.
J. E. Raymond, A. Bhaskar, T. Goodson, N. Makiuchi, K. Ogawa, Y.
Kobuke, J. Am. Chem. Soc. 2008, 130, 17212-17213.
M. Williams-Harry, A. Bhaskar, G. Ramakrishna, T. Goodson, M.
Imamura, A. Mawatari, K. Nakao, H. Enozawa, T. Nishinaga, M. Iyoda,
J. Am. Chem. Soc. 2008, 130, 3252-3253.
Table 2. The calculated nonlinear refractive index, nonlinear coefficient
and TPA cross-section for SDNU-2 and SDNU-3.
[5]
max
n2
β
δ2
Samples
(cm2W-1, 10-16
)
(cmW-1 10-12
)
(GM)
[6]
[7]
[8]
[9]
A. Bhaskar, R. Guda, M. M. Haley, Goodson, J. Am. Chem. Soc. 2006,
128, 13972-13973.
SDNU-2
SDNU-3
0.13
0.12
0.43
0.51
592
702
B. Liu, H.-L. Zhang, J. Liu, Y.-D. Zhao, Q.-M. Luo, Z.-L. Huang, J. Mater.
Chem. 2007, 17, 2921-2929.
L. C. N., F. J. T., B. Tommaso, F. R. A., Angew. Chem. Int. Ed. 2007,
46, 6238-6258.
W. Denk, J. Strickler, W. Webb, Science. 1990, 248, 73-76.
[10] A. R. Guzman, M. R. Harpham, Ö. Süzer, M. M. Haley, T. G. Goodson,
J. Am. Chem. Soc. 2010, 132, 7840-7841.
3. Conclusion
[11] B. H. Cumpston, S. P. Ananthavel, S. Barlow, D. L. Dyer, J. E. Ehrlich,
L. L. Erskine, A. A. Heikal, S. M. Kuebler, I. Y. S. Lee, D. McCord-
Maughon, J. Qin, H. Röckel, M. Rumi, X.-L. Wu, S. R. Marder, J. W.
Perry, Nature.1999, 398, 51.
In conclusion, we have designed and synthesized three new
3,6,9,12-tetrasubstituted tetraazachrysene derivatives with
various alkynyl and aryl groups. The HOMOs and LUMOs of all
as-prepared tetraazachrysene derivatives are easily affected by
the different substituents because significant orbital coefficients
are located on the tetraazachrysenes attached by these
substituents. Their photophysical, electrochemistry and
fluorescence properties were fully investigated, and these
materials exhibited blue to green emission in solution and
obviously enhanced emission in the solid state. Interestingly,
SDNU-2 displayed a high fluorescence quantum efficiency of
75.3%, which is the highest value of azaacene derivatives to
date. The Z-scan method is employed to characterize the two-
photon absorption (TPA) properties of tetraazachrysene
derivatives, elucidating a TPA δ maximum of ∼700 GM in
dichloromethane solution, which is the largest value among all
heteroacenes, measured by Z-scan experiment at present.
Currently, the devices based on SDNU-2 and SDNU-3 are under
investigation in our lab.
[12] C. Y.-S., T. A., T. D. B., K. S. M., Adv. Func. Mater. 2006, 16, 1739-
1744.
[13] V. Marappan, S. Jiun-Yi, L. J. T., L. Yi-Chih, H. Cheng-Chih, L. Chin-
Hung, L. Chih-Wei, H. Mei-Lin, C. Yu-Chun, C. Pi-Tai, H. Jong-Kai, Adv.
Func. Mater. 2009, 19, 2388-2397.
[14] X. Liang, Z. Qichun, Sci. China. Mater. 2017, 60, 1093.
[15] S. Alías, R. Andreu, M. J. Blesa, S. Franco, J. Garín, A. Gragera, J.
Orduna, P. Romero, B. Villacampa, M. Allain, J. Org. Chem. 2007, 72,
6440-6446.
[16] B. J. Coe, J. Fielden, S. P. Foxon, J. A. Harris, M. Helliwell, B. S.
Brunschwig, I. Asselberghs, K. Clays, J. Garín, J. Orduna, J. Am. Chem.
Soc. 2010, 132, 10498-10512.
[17] Q. Li, J. Huang, A. Zhong, C. Zhong, M. Peng, J. Liu, Z. Pei, Z. Huang,
J. Qin, Z. Li, J. Phys. Chem.B. 2011, 115, 4279-4285.
[18] B. Sadowski, H. Kita, M. Grzybowski, K. Kamada, D. T. Gryko, J. Org.
Chem. 2017, 82, 7254-7264.
[19] H. M. Kim, Y. O. Lee, C. S. Lim, J. S. Kim and B. R. Cho, J. Org. Chem.
2008, 73, 5127-5130.
[20] M. Drobizhev, Y. Stepanenko, Y. Dzenis, A. Karotki, A. Rebane, P. N.
Taylor, H. L. Anderson, J. Am. Chem. Soc. 2004, 126, 15352-15353.
[21] T. V. Esipova, H. J. Rivera-Jacquez, B. Weber, A. E. Masunov, S. A.
Vinogradov, J. Am. Chem. Soc. 2016, 138, 15648-15662.
[22] S. Julie, H. Valérie, S. Angélique, B. Frédéric, F. Hussein, N. Jean-
Francois, F. Lucia, V. Barbara, Angew. Chem., Int. Ed. 2015, 54, 169-
173.
Conflict of interest
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Acknowledgements
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[23] C.-L. Sun, Q. Liao, T. Li, J. Li, J.-Q. Jiang, Z.-Z. Xu, X.-D. Wang, R.
Shen, D.-C. Bai, Q. Wang, S.-X. Zhang, H.-B. Fu, H.-L. Zhang, Chem.
Sci. 2015, 6, 761-769.
[48] H. Cao, S. G. Van Ornum, J. Deschamps, J. Flippen-Anderson, F. Laib,
J. M. Cook, J. Am. Chem. Soc. 2005, 127, 933-943.
[49] M. Frank, R. Erik, M. Klaus, Angew. Chem. Int. Ed. 1997, 36, 631-634.
[50] S. Hahn, S. Koser, M. Hodecker, O. Tverskoy, F. Rominger, A. Dreuw,
U. H. F. Bunz, Chem.-Eur. J. 2017, 23, 8148-8151.
[24] C.-L. Sun, S.-K. Lv, Y.-P. Liu, Q. Liao, H.-L. Zhang, H. Fu, J. Yao, J.
Mater. Chem. C. 2017, 5, 1224-1230.
[25] L. Porrès, O. Mongin, C. Katan, M. Charlot, T. Pons, J. Mertz, M.
Blanchard-Desce, Org. Lett. 2004, 6, 47-50.
[51] J. Zhang, Y. Li, J. Huang, H. Hu, G. Zhang, T. Ma, P. C. Y. Chow, H.
Ade, D. Pan, H. Yan, J. Am. Chem. Soc. 2017, 139, 16092-16095.
[52] M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb,
J. R. Cheeseman, G. Scalmani, V. Barone, G. A. Petersson, H.
Nakatsuji, X. Li, M. Caricato, A. Marenich, J. Bloino, B. G. Janesko, R.
Gomperts, B. Mennucci, H. P. Hratchian, J. V. Ortiz, A. F. Izmaylov, J.
L. Sonnenberg, D. Williams-Young, F. Ding, F. Lipparini, F. Egidi, J.
Goings, B. Peng, A. Petrone, T. Henderson, D. Ranasinghe, V. G.
Zakrzewski, J. Gao, N. Rega, G. Zheng, W. Liang, M. Hada, M. Ehara,
K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda,
O. Kitao, H. Nakai, T. Vreven, K. Throssell, J. A. Montgomery, Jr., J. E.
Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V.
N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A.
Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, J. M. Millam,
M. Klene, C. Adamo, R. Cammi, J. W. Ochterski, R. L. Martin, K.
Morokuma, O. Farkas, J. B. Foresman, D. J. Fox, Gaussian 09, revision
A.1; Gaussian, Inc.: Wallingford, CT, 2009.
[26] W.-H. Lee, H. Lee, J.-A. Kim, J.-H. Choi, M. Cho, S.-J. Jeon, B. R. Cho,
J. Am. Chem. Soc.2001, 123, 10658-10667.
[27] G. S. He, J. Swiatkiewicz, Y. Jiang, P. N. Prasad, B. A. Reinhardt, L.-S.
Tan, R. Kannan, J. Phys. Chem. A. 2000, 104, 4805-4810.
[28] L. Xu, H. Zhu, G. Long, J. Zhao, D. Li, R. Ganguly, Y. Li, Q.-H. Xu, Q.
Zhang, J. Mater. Chem. C.2015, 3, 9191-9196.
[29] U. H. F. Bunz, Accounts. Chem. Res. 2015, 48, 1676-1686.
[30] Q. Miao, Adv. Mater. 2014, 26, 5541-5549.
[31]
(a) C. Wang, J. Zhang, G. Long, N. Aratani, H. Yamada, Y. Zhao, Q.
Zhang, Angew. Chem. Int. Ed. 2015, 54, 6292-6296; (b) J. Li, S. Chen,
Z. Wang, Q. Zhang, Chem. Rec. 2016, 16, 1518-1530; (c) Q. Zhang, J.
Xiao, Z. Y. Yin, H. M. Duong, F. Qiao, F. Boey, X. Hu, H. Zhang, F.
Wudl, Chem. Asian. J. 2011, 6, 856-862; (d) G. Li, H. M. Duong, Z.
Zhang, J. Xiao, L. Liu, Y. Zhao, H. Zhang, F. Huo, S. Li, J. Ma, F. Wudl,
Q. Zhang, Chem. Comm. 2012, 48, 5974–5976; (e) P.-Y. Gu, Y. Zhao,
J.-H. He, J. Zhang, C. Wang, Q.-F. Xu, J.-M. Lu, X. W. Sun, Q. Zhang,
J. Org. Chem. 2015, 80, 3030-3035; (f) P. Gu, Z. Wang and Q. Zhang,
J. Mater. Chem. B. 2016, 4, 7060 – 7074; (g) P. Gu, Z. Wang, G. Liu,
H. Yao, Z. Wang, Y. Li, J. Zhu, S. Li, Q. Zhang, Chem. Mater. 2017, 29,
4172-4175; (h) P. Gu, N. Wang, C. Wang, Y. Zhou, G. Long, M. Tian,
W. Chen, X. Sun, M. G. Kanatzidis, Q. Zhang, J. Mater. Chem. A., 2017,
5, 7339 – 7344; (i) N. Wang, K. Zhao, T. Ding, W. Liu, A. S. Ahmed, Z.
Wang, M. Tian, X. W. Sun, Q. Zhang, Adv. Energy Mater., 2017, 7,
1700522; (j) Z. Wang, P. Gu, G. Liu, H. Yao, Y. Wu, Y. Li, G. Rakesh, J.
Zhu, H. Fu, Q. Zhang, Chem Commun., 2017, 53, 7772-7775; (k) G. Li,
W. Xiong, P. Gu, J. Cao, J Zhu, R. Ganguly, Y. Li, A. C. Grimsdale, Q.
Zhang, Org. Lett., 2015, 17, 560–563; (l) P. Gu, N. Wang, A. Wu, Z.
Wang, M. Tian, Z. Fu, X. Sun, Q. Zhang, Chem. Asian J., 2016, 11,
2135–2138; (m) C. Wang, B. Hu, J. Wang, J. Gao, G. Li, W. Xiong, B.
Zou, M. Suzuki, N. Aratani, H. Yamada, F. Huo, P. S. Lee, Q. Zhang,
Chem. Asian J. 2015, 10, 116-119.
[53] P.-Y. Gu, G. Liu, J. Zhao, N. Aratani, X. Ye, Y. Liu, H. Yamada, L. Nie,
H. Zhang, J. Zhu, D.-S. Li, Q. Zhang, J. Mater. Chem. C. 2017, 5, 8869-
8874.
[32]
(a) J. E. Anthony, Angew. Chem. Int. Ed. 2008, 47, 452-483; (b) C.
Wang, P. Gu, B. Hu, Q. Zhang, J. Mater. Chem. C. 2015, 3, 10055–
10065.
[33] R. M. Metzger, Chem. Rev. 2015, 115, 5056-5115.
[34] T. J. Sisto, Y. Zhong, B. Zhang, M. T. Trinh, K. Miyata, X. Zhong, X. Y.
Zhu, M. L. Steigerwald, F. Ng, C. Nuckolls, J. Am. Chem. Soc. 2017,
139, 5648-5651.
[35] C. Xu, W. W. Webb, J. Opt. Soc. Am. B. 1996, 13, 481-491.
[36] D. Oulianov, I. Tomov, A. Dvornikov, P. Rentzepis, Opt.Commun. 2001,
191, 235-243.
[37] J. Yoo, S. K. Yang, M.-Y. Jeong, H. C. Ahn, S.-J. Jeon, B. R. Cho, Org.
Lett. 2003, 5, 645-648.
[38] T. Zheng, Z. Cai, R. Ho-Wu, S. H. Yau, V. Shaparov, T. Goodson, L. Yu,
J. Am. Chem. Soc. 2016, 138, 868-875.
[39] Z. Cai, R. J. Vázquez, D. Zhao, L. Li, W.-y. Lo, N. Zhang, Q. Wu, B.
Keller, A. Eshun, N. Abeyasinghe, H. Banaszak-Holl, T. Goodson, L. Yu,
Chem. Mater. 2017, 29, 6726-6732.
[40] W. J. Yang, D. Y. Kim, C. H. Kim, M.-Y. Jeong, S. K. Lee, S.-J. Jeon, B.
R. Cho, Org. Lett., 2004, 6, 1389-1392.
[41] T. K. Ahn, K. S. Kim, D. Y. Kim, S. B. Noh, N. Aratani, C.Ikeda, A.
Osuka, D. Kim, J. Am. Chem. Soc. 2006, 128, 1700-1704.
[42] M. Stępień, E. Gońka, M. Żyła, N. Sprutta, Chem. Rev. 2017, 117,
3479-3716.
[43] J. Li and Q. Zhang, ACS Appl. Mater. Interfaces.2015, 7, 28049-28062.
[44] P. Singh, A. Baheti, K. R. J. Thomas, J. Org. Chem. 2011, 76, 6134-
6145.
[45] X. Liu, T. Liu, C. Duan, J. Wang, S. Pang, W. Xiong, Y. Sun, F. Huang,
Y. Cao, J. Mater. Chem. A. 2017, 5, 1713-1723.
[46] P.-Y. Gu, Z. Wang, G. Liu, H. Yao, Z. Wang, Y. Li, J. Zhu, S. Li, Q.
Zhang, Chem. Mater. 2017, 29, 4172-4175.
[47] K. Kawashima, I. Osaka, K. Takimiya, Chem. Mater. 2015, 27, 6558-
6570.
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Through the condensation reaction
Gang Li, Shuaihua Wang, ShufanYang ,
Guangfeng Liu, Pin Hao, Yusen Zheng,
Guankui Long, Dandan Li, Yu Zhang,
Wenbin Yang, Liang Xu*,Weibo Gao,
Qichun Zhang*, Guanwei Cui and Bo
Tang*
between
naphthalenetetraamine
1,2,5,6-
and
triisopropylsilyl (TIPS) substituted
diketones, three novel azaacenes
coded as SDNU-1, SDNU-2 and
SDNU-3, have been designed and
Page No. – Page No.
synthesized.
compounds
nonlinear optical properties.
The
exhibited
as-prepared
distinctive
Syntheses, Photophysical Properties
and Two Photon Absorption Study of
Tetraazachrysene-based N-
heteroacenes
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