Revealing Topological Influence of Phenylenediamine Unit on Physicochemical Properties of Donor-Acceptor-Donor-Acceptor Thermally Activated Delayed Fluorescent Macrocycles

Article abstract of DOI:10.1002/asia.202001173

A new thermally activated delayed fluorescence (TADF)-displaying macrocyclic compound m-1 comprising of two electron-donors (N,N’-diphenyl-m-phenylenediamine) and two electron-acceptors (dibenzo[a,j]phenazine) has been synthesized. The macrocycle developed herein is regarded as a regioisomer of the previously reported TADF macrocycle p-1, which has two N,N’-diphenyl-p-phenylenediamines as the donors. To understand the influence of the topology of the phenylenediamine donors on physicochemical properties of TADF-active macrocycles, herein the molecular structure in the single crystals, photophysical properties, electrochemical behavior, and TADF properties of m-1 have been investigated compared with those of p-1. The substitution of p-phenylene donor with m-phenylene donor led to distinct positive solvatoluminochromism over the full visible-color range, unique oxidative electropolymerization, and slightly lower contribution of TADF, due to the lower CT character in the excited states.

Full text of DOI:10.1002/asia.202001173

CHEMISTRY
AN ASIAN JOURNAL
www.chemasianj.org
Accepted Article
Title: Revealing Topological Influence of Phenylenediamine Unit on
Physicochemical Properties of Donor–Acceptor–Donor–Acceptor
Thermally Activated Delayed Fluorescent Macrocycles
Authors: Saika Izumi, Aleksandra Nyga, Piotr de Silva, Norimitsu
Tohnai, Satoshi Minakata, Przemyslaw Data, and Youhei
Takeda
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Chem. Asian J. 10.1002/asia.202001173
Link to VoR: https://doi.org/10.1002/asia.202001173
A Journal of
A sister journal of Angewandte Chemie
and Chemistry – A European Journal

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
Revealing Topological Influence of Phenylenediamine Unit on
Physicochemical Properties of Donor–Acceptor–Donor–Acceptor
Thermally Activated Delayed Fluorescent Macrocycles
Saika Izumi,[a] Aleksandra Nyga,[b] Piotr de Silva,*[c] Norimitsu Tohnai,[a] Satoshi Minakata,*[a]
Przemyslaw Data,*[b,d] and Youhei Takeda*[a]
[a]
[b]
[c]
[d]
S. Izumi, Prof. Dr. N. Tohnai, Prof. Dr. S. Minakata, Prof. Dr. Y. Takeda
Department of Applied Chemistry
Graduate School of Engineering, Osaka University
Yamadaoka 2-1, Suita, Osaka 5650871 (Japan)
E-mail: minakata@chem.eng.osaka-u.ac.jp; takeda@chem.eng.osaka-u.ac.jp
A. Nyga, Prof. P. Data
Faculty of Chemistry
Silesian University of Technology
M. Strzody 9, 44-100 Gliwice (Poland)
E-mail: przemyslaw.data@polsl.pl
Prof. P. de Silva
Department of Energy Conversion and Storage
Technical University of Denmark
Anker Engelunds Vej 301, 2800 Kgs. Lyngby (Denmark)
E-mail: pdes@dtu.dk
Prof. P. Data
Centre of Polymer and Carbon Materials
Polish Academy of Science
M. Curie-Sklodowskiej 34, 41-819, Zabrze (Poland)
Supporting information for this article is given via a link at the end of the document.
Abstract: A new thermally activated delayed fluorescence (TADF)-
displaying macrocyclic compound m-1 comprising of two electron-
donors (N,N’-diphenyl-m-phenylenediamine) and two electron-
acceptors (dibenzo[a,j]phenazine) has been synthesized. The
macrocycle developed herein is regarded as a regioisomer of the
previously reported TADF macrocycle p-1, which has two N,N’-
diphenyl-p-phenylenes as the donors. To understand the influence of
the topology of the phenylenediamine donors on physicochemical
properties of TADF-active macrocycles, herein the molecular
structure in the single crystals, photophysical properties,
electrochemical behavior, and TADF properties of m-1 have been
investigated compared with those of p-1. The substitution of p-
phenylene donor with m-phenylene donor led to distinct positive
solvatoluminochromism over the full visible-color range, unique
oxidative electropolymerization, and slightly lower contribution of
TADF, due to the lower CT character in the excited states.
efficient thermally activated delayed fluorescence (TADF)
materials.[5]
TADF is a fundamental phenomenon that can harvest triplet
excitons to convert into the emissive singlet excitons via thermally
activated reverse intersystem crossing (RISC), yielding delayed
fluorescence in theoretically 100% internal quantum efficiency
(IQE). Due to the high utilization efficiency of triplet excitons,
purely organic TADF emitters can greatly improve external
quantum efficiency (EQE) of OLEDs, and very efficient
(EQE>20%) TADF-OLEDs have been already reported.[6] In
addition to optoelectronic applications, the potency of TADF
compounds as functional molecules has been also explored in the
fields of photocatalysis[7] and bio-imaging.[8] Since the RISC rate
(kRISC) increases as the inverse of an exponential function of the
energy splitting between the singlet (S1) and triplet (Tn) states
(DEST), a narrow DEST and a large spin-orbit coupling (SOC) for
S1–Tn transitions are the requisites for giving a large kRISC and
thereby efficient TADF. Since it has been believed that DEST is
just doublet electron exchange energy (2J) of the two unpaired
electrons in the excited states, the HOMO and LUMO should be
decoupled. However, recent theoretical results demonstrate that
the situation is more complicated, and different design strategies
should be pursued.[9] As earlier stated, a common molecular
design strategy for TADF materials is connecting a lone-pair-
containing D and an A units through a single s-bond with a large
twisting angle (ca. 90˚) to ensure a narrow DEST and a large SOC.
Over the last several years, many purely organic TADF materials
based on linearly or branchingly connected D–A molecular
architectures with a large twist angle have been developed.[5] In
contrast, macrocyclic TADF emitters comprising of D–A repeating
units have been scarcely explored, probably due to the synthetic
challenge for constructing such molecular scaffolds.[10,11] Due to
Introduction
Organic p-conjugated electron donor-acceptor (D–A) repeating
molecules, oligomers, and polymers have attracted much
attention as photo- and electroactive organic materials, as the
optical and electrochemical bandgaps, charge-carrier mobilities,
and luminescence properties are finely tunable through structural
modification. They find myriad applications in optoelectronic fields
such as organic field-effect transistors (OFETs),[1] organic
photovoltaics (OPVs),[2] organic light-emitting diodes (OLEDs),[3]
and some others.[4] Especially, over the last decade, the D–A p-
conjugated compounds with a large twisting angle around the D-
A-connecting bond have emerged as promising scaffolds for
1
This article is protected by copyright. All rights reserved.

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
the limited numbers of macrocyclic TADF compounds, little is
known for the structure-property relationship (SPR) of
macrocyclic TADF materials. Conversely, it would be rewarding
to investigate and reveal the SPR of macrocyclic TADF materials
to gain insights on the design strategy for efficient macrocyclic
TADF emitters.
Herein, we disclose the synthesis, structure, and
physicochemical properties of a new D–A–D–A macrocyclic
compound m-1 (Figure 1), which is a regioisomer of p-1. From the
comparison with p-1, the influence of the topology of the
phenylenediamine donor unit (meta versus para) on the molecular
conformation, electrochemical properties, and photophysical
properties including TADF functions has been revealed.
Recently, we have developed a thermally activated delayed
fluorescent electron-donor–acceptor–donor–acceptor (D–A–D–
A) type p-conjugated macrocycle p-1 (Figure 1),[11] comprising of
two U-shaped electron-acceptors, i.e., dibenzo[a,j]phenazine
(DBPHZ),[12] and two N,N’-diphenyl-p-phenylenediamine donors.
By taking advantage of the U-shaped structure of the acceptor
and proper-shaped triarylamine donor, the key macrocyclization
is rather high-yielding. Notably, this emitter represents the 1st
purely organic TADF macrocyclic emitting material that yields an
efficient OLED device with a high external quantum efficiency
(EQE), exceeding the theoretical EQE (ca 5%.) in the OLED
devices fabricated with a 1st generation fluorescent emitter.[13]
The comparison of the physicochemical properties of p-1 with its
linear analog (Linear) revealed the efficacy of cyclizing the D–A–
D–A structure for enhancing TADF contribution in emission. We
then became interested in the influence of the topology in the
phenylenediamine donor unit of p-1 on its properties including
TADF behavior. To date, topological influence of phenylene unit
(meta versus para) on the properties of phenylene-linked linear p-
Results and Discussion
Design and synthesis of macrocycle m-1.
To investigate the influence of topology in the phenylenediamine
donor, we designed D–A–D–A macrocycle m-1 (Figure 1), which
is regarded as the meta-variant of previously reported p-1.[11] The
synthetic route to macrocycle m-1 is illustrated in Scheme 1.
Unsymmetrical m-phenylene diamine donor 2 was efficiently
prepared, starting from 3-bromo-iodobenzene in 3 steps (Scheme
S1 in the SI). In a similar manner with the synthesis of macrocycle
p-1,[11] the donor
dibenzo[a,j]phenazine (2Br-DBPHZ)[12] through a Pd-catalyzed
double Buchwald–Hartwig amination to provide D–A–D
2
was coupled with 3,11-dibromo-
a
intermediate 3 in high yield (Scheme 1). The deprotection of the
N-Boc groups of 3 was conducted with an excess amount of
trifluoroacetic acid (TFA), giving rise to 4 in a quantitative manner.
The final and key macrocyclization of 4 with 2Br-DBPHZ was
completed through a Pd-catalyzed double Buchwald–Hartwig
amination (Scheme 1), although the chemical yield in the
macrocyclization step is much lower (10%) than that for p-1
(45%).[11] Since a significant amount of polymeric uncharacterized
residue was observed in the crude 1H NMR chart, this significant
lowering in macrocyclization efficiency might ascribe to competing
for intermolecular aminative oligomerization/polymerization
pathways over the desired intramolecular cyclization.
electron
conjugated
systems,
such
as
oligo(phenylenevinylene)s,[14] oligo(phenylene ethynylene)s,[15]
oligo(aniline)s,[16] phenylene-bridged bis(triarylamine)s[17] and
bis(ethynyltriarylamine)s,[18]
perylene diimide
dimers,[19]
phenylene-linked
N-annulated
and
aminostilbenes,[20]
bis(ethynylene)phenylene-linked donor (carbazole) and acceptor
(naphthalimides) compound,[21] has been moderately explored.
The topology in phenylene unit in these previously investigated p-
conjugated systems gives an impact on properties such as
HOMO–LUMO optical gap,[14] photoluminescence quantum yield
(PLQY),[15] spin localization of radical cation,[16,17] the rate of
charge separation,[19] for instance. Nevertheless, such topological
studies of p-conjugated macrocyclic compounds are quite limited
to cyclic oligo(phenylenediamine)s[22] and B-p-N ambipolar
macrocycles.[23] To the best of our knowledge, the influence of the
topology of the electron donors of the macrocyclic TADF
compound has never been investigated.[24]
Crystallographic
analysis
of
single
crystals
and
photoluminescence properties in the solid states.
Macrocycle m-1 is less soluble in organic solvents than p-1, and
the recrystallization leads to tiny microcrystals. After several
attempts of recrystallization, we were able to acquire yellow single
crystals from a mixed solution of 1,2-dichlorobenzene and n-
hexane solution of m-1 suitable for the X-ray diffraction
crystallographic analysis (for the detailed analytical data, see the
SI). In the crystal, the macrocycle m-1 similarly takes a saddle
conformation with p-1 (Figure 2a).[11] When compared with the
saddle conformer of p-1, the interplane angle of the two DBPHZ
panels is much smaller (91˚) than that of p-1 (148˚), due to the
closer distance of the two N atoms on the phenylene donor
(Figure 2b). The saddle-shaped macrocyclic molecules form a 1D
self-assembled structure, where intermolecular DBPHZ units
stack, with contact between adjacent molecules being 3.43 Å
(Figure 2c). Although p-1 exhibited two different polymorphs with
different conformers (helical and saddle conformers),[11] m-1
formed only one conformer.
Figure 1. Structures of D–A–D–A macrocycles p-1 and m-1.
2
This article is protected by copyright. All rights reserved.

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
N
N
N
N
Ph
Ph
2Br-DBPHZ (1 equiv)
Pd2(dba)3 (5.0 mol%)
QPhos (20 mol%)
H
N
N
N
Pd2(dba)3 (1 mol%)
QPhos (4 mol%)
Ph
Ph
Ph
Ph
CF3COOH (excess)
N
N
N
N
+
m-1
NaOt-Bu (2.2 equiv)
toluene
CH2Cl2
RT, 30 min.
K2CO3 (2.2 equiv)
1,4-dioxane
100 ºC, 24 h
Boc
N
Br
Br
Boc
H
Boc
H
60 ºC, 12 h
N
N
N
N
quant.
2Br-DBPHZ
2
93%
10%
Ph
Ph
Ph
Ph
(2.1 equiv)
3
4
Scheme 1. Synthetic route to macrocycle m-1.
To investigate the fundamental photophysical properties of m-1,
the steady-state UV-vis absorption and photoluminescence (PL)
spectra of the diluted solutions (c 10–5 M) of m-1 were acquired
(Figure 4a and Table 1). The solubility of macrocycle m-1 toward
cyclohexane is very low, and due to this, it was not possible to
obtain well-resolved UV-vis spectra. In other solvents such as
toluene, THF, CH2Cl2, CHCl3, and DMF, m-1 displayed similar
UV-vis absorptions comprising of intramolecular charge-transfer
(ICT) transition at around labs 470 nm, which is mainly ascribed
to the HOMO→LUMO transition (for the details of theoretical
calculations, see the SI), and p–p* transitions at around labs 315
nm (Figure 3a, dotted lines). The simulated absorption spectra
of m-1 in toluene, using the conformation found in the single
crystal (saddle shape), nicely agreed with the experimental one
(Figure S11). Also, according to the conformational search, the
saddle shape is the most stable conformer (ca. 4 kcal/mol more
stable than the secondarily stable conformer). Taken together,
we can conclude that almost all the m-1 molecules take saddle
conformer in solutions, as is the case with p-1.[11] The absorption
onset in the lower energy region (l 500–550 nm) slightly red-
shifts as the solvent polarity increases (Figure 4a), indicating the
absorption peaked at around labs 470 nm is ascribed to a hybrid
type CT. This characteristic is very similar to that of p-1.[11] When
the absorption spectra of m-1 are compared with those of p-1,[10]
one would notice that as a whole the spectra shapes are very
similar to each other but different in absorption peaks. Both of
the ICT and p–p* bands of m-1 locales in the bluer region than
p-1 by ca. 10 nm, due to shorter effective conjugation length of
the phenylenediamine unit of m-1 than p-1. The experimental
absorption spectra for m-1 and p-1 qualitatively agree with the
calculated ones (Figure S11), which were calculated by the TD-
DFT method using an optimally tuned range separated hybrid
functional (wPBE) and a state-specific non-equilibrium PCM
solvation model. The macrocycle m-1 nicely displayed positive
solvatoluminochromism as a function of solvent polarity (Figure
4a). Given the UV-vis absorption spectra are less affected by
solvent polarity than PL spectra, macrocycle m-1 has a much
larger charge transfer nature in the excited states rather than in
the ground states, as is the case with p-1.[11] A large difference
in PL behavior of m-1 and p-1 is the degree of solvatochromism,
which indicates a much larger CT character of p-1 in the excited
states. It would be interesting to note that the solvatochromic
behavior of m-1 is very similar with that of 3,11-bis(N,N-
diphenylamino)-substituted DBPHZ,[25] suggesting that the
topology of the phenylene unit in the D–A–D–A macrocycles
strongly affects the CT nature in the excited states, probably due
to the difference in effective p-conjugation length through the
molecule.
Figure 2. a) Molecular structure of m-1 (hydrogen atoms and solvent
molecules are omitted for clarity); b) a side view of m-1 (hydrogen atoms, the
N-Ph groups and solvent molecules are omitted for clarity); c) packing structure
of m-1.
Upon the irradiation of a UV light, the solids of m-1
displayed orange photoluminescence (lem 636 nm) with a low
PLQY (FPL 0.04) (Figure 3). When compared with the solid-state
PL of the saddle conformer polymorphs of p-1 (saddle: lem 654
nm, FPL 0.01),[11] the emission wavelength of the solids of m-1
appeared in a slightly blue-shifted region. This suggests that m-
1 has a weaker charge-transfer character in the excited states
than p-1, which is seen by the solvatochromic behavior of m-1 in
organic solvents (vide infra).
Figure 3. PL spectrum of m-1 in the solid states. The inset photograph shows
the image of emission under a UV lamp (lex 365 nm).
Steady-state photophysical properties of diluted solutions
of m-1.
3
This article is protected by copyright. All rights reserved.

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
Since TADF is irradiated via RISC from the triplet excited
states, TADF emission is sensitive toward the presence of
oxygen gas, which promptly quenches the long-lived triplet
excited states through energy transfer or electron transfer
mechanisms. In fact, the PL intensity of the TADF-active p-1
compound in degassed toluene drastically decreased upon the
injection of oxygen gas.[11] The PL intensity of the degassed
dichloromethane and THF solutions of m-1 dropped after the
saturation with oxygen gas by about 10% (Figure 4b and c),
indicating the involvement of triplet states character in the PL. It
is noted that the decline rate of m-1 is much smaller than that of
p-1 (ca. 60%), which indicates less TADF contribution in PL of
solutions of m-1 than those of p-1. The TADF contribution is
much smaller in the toluene solvent (3%, Figure S8), which
suggests that the decrease of the RISC component is mostly due
to the ΔEST gap.
Electrochemistry.
The electrochemical behavior of m-1 was investigated with the
cyclic voltammetry (CV) method. The cyclic voltammogram
displayed one reversible reduction at
red
E
1/2
–1.93 V and one
ox
irreversible oxidation at
E
1/2
0.41 V (Figure 5a). According to
the oxidation and reduction potentials, the HOMO and LUMO
energy levels of m-1 are calculated as –5.51 eV and –3.17 eV,
respectively. These values are close to the HOMO of the donor
unit N,N,N‘,N‘-tetraphenyl-m-phenylenediamine (–5.52 eV)[26]
and the LUMO of the acceptor unit DBPHZ (–3.22 eV),[12]
respectively. This suggests that the HOMO and LUMO are
localized on the donor and acceptor units, respectively, and
which is favorable for achieving small DEST. It is noted that m-1
showed significantly different electrochemical behavior when
compared to p-1. The macrocycle m-1 displayed only one
irreversible oxidation peak at the potential 0.46 V (Figure 5a).
When the cycle was repeated, the peak current was increased
(Figure 5b), indicating the oxidative polymerization of m-1 on the
electrode. The polymerization started at around 0.30 V, and the
onset potential gradually shifted to the lower regime in every
scan (Figure 5b). Since the macrocycle p-1 shows distinct
electrochemically and chemically reversible 2 step oxidation at a
similar potential,[11] the polymerization of m-1 should be ascribed
to the difference in phenylene topology. This significant
difference in the electrochemical behavior would be rationalized
by the spin density distribution of diradical dication generated by
the 1st oxidation step (Figure 5c and Figure S14). In both cases,
the spin densities are largely localized on the phenylene donor
units, but m-1••+2 has a larger density at the o-positions of the
amino units (Figure 5c) when compared with p-1••+2 (Figure 5c),
probably due to the decoupling of conjugation in the phenylene
unit. In addition to the difference in the spin density, the o-
positions of the amino units in m-1••+2 are sterically much less
congested than p-1••+2 (Figure 5c). Taken together, we suppose
that m-1 more easily undergoes oxidative polymerization at the
o-position of the amino units than p-1. Since within the EL
devices organic emitters are electrically excited, this unstable
electrochemical behavior of m-1 might not be suitable for the
application of m-1 as an emitter for OLEDs. Instead, such an
electropolymerization behavior of m-1 might find alternative
electroactive material applications such as electrochromic
devices (Figure S7) or semiconducting polymeric materials.
Figure 4. a) UV-vis absorption and PL spectra of solutions of m-1 in various
solvents (c~10–5 M); b) PL spectra of m-1 (10 µM) in b) dichloromethane and
c) THF with aerated (purple lines) and degassed (green lines).
Table 1. Summary of steady-state photophysical data of solutions of m-1.
[b]
Solvent[a]
Cyclohexane[c]
Toluene
THF
l
abs [nm]
—
l
em [nm]
481
FPL
0.30
0.39
0.46
0.43
0.35
0.07
285, 316, 466
275, 313, 467
277, 315, 469
277, 316, 470
277, 310, 470
509
554
CH2Cl2
591
CHCl3
564
DMF
629
[a] Concentration: 10–5 M. [b] Determined with an integrated sphere. [c]
Saturated solution (concentration < 10–6 M) was used, due to the low solubility
in cyclohexane.
4
This article is protected by copyright. All rights reserved.

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
Figure 5. a) Cyclic voltammogram of m-1, b) sweep-repeated cyclic
voltammograms of m-1 in the positive potential regime; c) spin density of
diradical dications of m-1 and p-1 calculated at the PBE0/aug-cc-pVDZ level.
CV experiments were conducted with 0.5 mM CH2Cl2 solution of m-1
containing 0.1 M (n-Bu)4NBF4 supporting electrolyte using Pt disc as a working
electrode, Pt wire as a counter electrode, and Ag wire as the reference
electrode. The potential was scanned at the rate of 50 mV s–1
.
Time-Resolved Spectroscopic Analysis.
To investigate the detailed photophysics of m-1, time-resolved
spectroscopic analysis of a blending film (1wt% m-1 in Zeonex®,
and 10wt% m-1 in CBP) was conducted (Figure 6). Prompt
emission (time delay: 5 ns) at 80 K and 300 K from the film
displayed Gaussian-type spectra centered at around 520 nm
(blue and black lines, Figure 6a, respectively). It should be noted
that at a delayed emission observed at 100 µs at ambient
temperature (300 K) nicely matched with the prompt emission
(red line, Figure 6a), indicating the delayed emission is radiated
from the singlet excited state (S1). The slope of the plot of the
integral of the delayed emission intensity against the laser pulse
energy is 1.00 (Figure S9), confirming the delayed emission of
m-1 in the film is TADF. The phosphorescence spectra (green,
Figure 6a) displayed one similar to DBPHZ (3LEA),[12] which is
characteristic to DBPHZ-cored D–A–D compounds[5j] and
macrocycle p-1.[11] The triplet energy (ET1) calculated from the
phosphorescence spectra is 2.39 eV, which is a little bit higher
than that of p-1 (ET1 = 2.19 eV in Zeonex®)[11] but almost the
same as those of DBPHZ-cored twisted D–A–D TADF
emitters.[5j] This significant increase in the T1 energy when
compared to p-1 should be derived from the break in the p-
conjugation by the meta substitution pattern. The singlet excited
state (1CT) of m-1 is also destabilized when compared to that of
p-1, giving higher singlet energy (ES1 = 2.70 eV), which is also
higher than those of previously reported D–A–D TADF
compounds by about 0.3 eV. As a result, DEST of m-1 in Zeonex®
is 0.31 eV, which is a little bit wider than that of p-1 (0.24 eV).[11]
This was qualitatively reproduced by the theoretical calculations:
calcDEST for m-1 is 0.37 eV (Table S2) and calcDEST for p-1 is 0.30
eV.[11] What is also important in comparison with p-1, meta-type
macrocycle m-1 in CBP does not present TADF emission, or the
TADF emission component is very weak. The time-resolver
analysis in the CBP matrix did not reveal a delay component, and
even at low temperatures, the phosphorescence was not
observed (Figure 6b and d). Such behavior excludes this
compound as an efficient OLED emitter. Taken together with the
electrochemical instability of m-1, the analysis of m-1 in an
OLED device was not performed.
Figure 6. Prompt fluorescence, delayed fluorescence, and phosphorescence
spectra of (a) 1% m-1 in Zeonex, (b) 10% m-1 in CBP (w/w) thin films.
Photoluminescence decay of (c) 1% m-1 in Zeonex, (d) 10% m-1 in CBP (w/w)
thin films.
Conclusion
In summary, we have successfully synthesized and
characterized a new donor–acceptor-repeating p-conjugated
macrocycle m-1. In the single crystals, m-1 takes a saddle
conformer with a larger bending angle than that of p-1, due to
the shorter distance between two amino unit. The absorption and
photoluminescence spectra of solutions along with theoretical
calculations revealed the shorter effective length and weaker
charge-transfer character in the excited states of m-1 than those
of p-1, which allowed distinct solvatoluminochromism of m-1
over the full range of visible-light regime. The topology of the
phenylenediamine donors significantly gives impacts on the
distribution of the spin-density on the donor units and thereby
results in unique oxidative electropolymerization. Time-resolved
spectroscopy revealed that the DEST of m-1 is slightly larger than
that of p-1, leading to weaker TADF character. Although m-1
would be less promising as TADF-OLED emitting materials, yet,
the compound m-1 represents a rare example of a TADF
macrocyclic compound and could find other applications by
taking advantages of distinct solvatoluminochromism and
electropolymerization.
Acknowledgments
P.D and A.N. acknowledge the support received from the First
Team program of the Foundation for Polish Science co-financed
by the European Union under the European Regional
Development Fund (project number: POIR.04.04.00-00-
4668/17-00). Y.T. and P.D. acknowledge the EU’s Horizon 2020
for funding the OCTA project under grant agreement No. 778158.
Y.T. acknowledges a Grant-in-Aid for Scientific Research on
5
This article is protected by copyright. All rights reserved.

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
Chem. 2020, 132, 17166–17173; Angew. Chem., Int. Ed. 2020, 59,
17018–17025.
Innovative Area “Aquatic Functional Materials: Creation of New
Materials Science for Environment-Friendly and Active
Functions” (JSPS KAKENHI Grant Number JP19H05716) from
the MEXT (Ministry of Education, Culture, Science and
Technology, Japan), and the Continuation Grants for Young
Researchers from the Asahi Glass Foundation. We acknowledge
Prof. Seihou Jinnai and Yutaka Ie at Osaka University for the
kind assistance of the purification of materials by sublimation.
[9]
a) P. de Silva, C. A. Kim, T. Zhu, T. Van Voorhis, Chem. Mater. 2019,
31, 6995–7006; b) P. de Silva, J. Phys. Chem. Lett. 2019, 10, 5674–
5679.
[10] a) N. Uchida, T. Sato, J. Kuwabara, Y. Nishimura, T. Kanbara, Chem.
Lett. 2014, 43, 459–461; b) Y. Hu, Z. Wang, X. Jiang, X. Cai, S.-J. Su,
F. Huang, Y. Cao, Chem. Commun. 2018, 54, 7850–7853; c) Y. Hu, J.
Yao, Z. Xu, Z. Wang, L. Li, S.-J. Su, D. Ma, F. Huang, Sci. China Chem.
2020, 63, 897–903.
[11] S. Izumi, H. F. Higginbotham, A. Nyga, P. Stachelek, N. Tohnai, P. de
Silva, P. Data, Y. Takeda, S. Minakata, J. Am. Chem. Soc. 2020, 142,
1482–1491.
Keywords: macrocycles• thermally activated delayed
fluorescence • organic light-emitting diodes • donor-acceptor •
charge transfer
[12] Y. Takeda, M. Okazaki, S. Minakata, Chem. Commun. 2014, 50,
10291–10294.
[13] C. Adachi, M. A. Baldo, M. E. Thompson, S. R. Forrest, J. Appl. Phys.
2001, 90, 5048–5051.
[1]
a) M. Li, C. An, W. Pisula, K. Müllen, Acc. Chem. Res. 2018, 51, 1196–
1205; b) J. D. Yuen, F. Wudl, Energy Environ. Sci. 2013, 6, 392–406.
J. Roncali, I. Grosu, Adv. Sci. 2019, 6, 1801026/1–27.
[14] L. Pascal, J. J. V. Eynde, V. Van Haverbeke, P. Dubois, A. Michel, U.
Rant, E. Zojer, G. Leising, L. O. Van Dorn, N. E. Gruhn, J. Cornil, J. L.
Brédas, J. Phys. Chem. B 2002, 106, 6442–6450.
[2]
[3]
[4]
[5]
L. Duan, J. Qiao, Y. Sun, Y. Qiu, Adv. Mater. 2011, 23, 1137–1144.
L Beverina, G. A. Pagani, Acc. Chem. Res. 2013, 47, 319–329.
a) Y. Tao, K. Yuan, T. Chen, P. Xu, H. Li, R. Chen, C. Zheng, L. Zhang,
W. Huang, Adv. Mater. 2014, 26, 7931–7958; b) R. Czerwieniec, M. J.
Leitl, H. H. H. Homeier, H. Yersin, Coord. Chem. Rev. 2016, 325, 2–28;
c) F. B. Dias, T. J. Penfold, A. P. Monkman, Methods Appl. Fluoresc.
2017, 5, 012001; d) Z. Yang, Z. Mao, Z. Xie,Y. Zhang, S. Liu, J. Zhao,
J. Xu, Z. Chi, M. P. Aldred, Chem. Soc. Rev. 2017, 46, 915–1016; e) M.
Y. Wong, E. Zysman-Colman, Adv. Mater. 2017, 29, 1605444; f) M.
Sarma, K.-T. Wong, ACS Appl. Mater. Interfaces 2018, 10, 19279–
19304; g) X.-K. Chen, D. Kim, J.-L. Brédas, Acc. Chem. Res. 2018, 51,
2215–2224; h) Y. Liu, C. Li, Z. Ren, S. Yan, M. R. Bryce, Nat. Rev.
Mater. 2018, 3, 18020; i) P. Data, Y. Takeda, Chem. Asian J. 2019, 14,
1613–1636; j) Y. Takeda, P. Data, S. Minakata, Chem. Commun. 2020,
56, 8884–8894.
[15] Y. Yamaguchi, S. Kobayashi, T. Wakamiya, Y. Matsubara, Z.-i. Yoshida,
Angew. Chem. 2005, 117, 7202–7206; Angew. Chem. Int. Ed. 2005, 44,
7040–7044.
[16] M. M. Wienk, R. A. J. Janssen, J. Am. Chem. Soc. 1997, 119, 4492–
4501.
[17] M. Uebe, A. Ito, Chem. Asian J. 2019, 14, 1692–1696.
[18] J. Schäfer, M. Holzapfel, B. Mladenova, D. Kattnig, I. Krummenacher,
H. Braunschweig, G. Grampp, C. Lambert, J. Am. Chem. Soc. 2017,
139, 6200–6209.
[19] Y. Guo, Z. Ma, X. Niu, W. Zhang, M. Tao, Q. Guo, Z. Wang, A. Xia, J.
Am. Chem. Soc. 2019, 141, 12789–12796.
[20] J.-S. Yang, K.-L. Liau, C.-Y. Li, M.-Y. Chen, J. Am. Chem. Soc. 2007,
129, 13183–13192.
[21] A. L. Thompson, T.-S. Ahn, K. R. J. Thomas, S. Thayumanavan, T. J.
Martínez, C. J. Bardeen, J. Am. Chem. Soc. 2005, 127, 16348–16349.
[22] M. Uebe, A. Ito, Chem. Asian J. 2019, 14, 1692–1696.
[23] A. Ito, M. Uebe, R. Kurata, S. Yano, H. Fueno, T. Matsumoto, Chem.
Asian J. 2018, 13, 754–760.
[6]
a) H. Kaji, H. Suzuki, T. Fukushima, K. Shizu, K. Suzuki, S. Kubo, T.
Komino, H. Oiwa, F. Suzuki, A. Wakamiya, Y. Murata, C. Adachi, Nat.
Commun. 2015, 6, 8476/1–8; b) J. W. Sun, J. Y. Baek, K.-H. Kim, C.-K.
Monn, J.-H. Lee, S.-K. Kwon, Y.-H. Kim, J.-J. Kim, Chem. Mater. 2015,
27, 6675–6681; c) L.-S. Cui, J. U. Kim, H. Nomura, H. Nakanotani, C.
Adachi, Angew. Chem. 2016, 128, 6978–6982; Angew. Chem. Int. Ed.
2016, 55, 6864–6868; d) S. Y. Lee, C. Adachi, T. Yasuda, Adv. Mater.
2016, 28, 4626–4631; e) D. Chen, K. Liu, L. Gan, M. Liu, K. Gao, G. Xie,
Y. Ma, Y. Cao, S.-J. Su, Adv. Mater. 2016, 28, 6758–6765; f) I. S. Park,
H. Komiyama, T. Yasuda, Chem. Sci. 2017, 8, 953–960; g) Y. H. Lee,
S. Park, J. Oh, J. W. Shin, J. Jung, S. Yoo, M. H. Lee, ACS Appl. Mater.
Interfaces 2017, 9, 24035–24042; h) Y. Liu, L. Hua, S. Yan, Z. Ren,
Nano Energy 2020, 73, 104800/1–8.
[24] a) N. A. Kukhta, T. Matulaitis, D. Volyniuk, K. Ivaniuk, P. Turyk, P.
Stakhira, J. V. Grazulevicius, A. P. Monkman, J. Phys. Chem. Lett. 2017,
8, 6199–6205; b) T. Zhang, X. Wang, Z. An, Z. Fang, Y. Zhang, W. Z.
Yuan, ChemPhysChem 2018, 19, 2389–2396.
[25] M. Okazaki, Y. Takeda, P. Data, P. Pander, H. Higginbotham, A. P.
Monkman, S. Minakata, Chem. Sci. 2017, 8, 2677–2686.
[26] A. Ito, H. Ino, K. Tanaka, K. Kanemoto, T. Kato, J. Org. Chem. 2002,
67, 491–498.
[7]
[8]
a) J. Luo, J. Zhang, ACS Catal. 2016, 6, 873–877; b) A. A. Mousawi, D.
M. Lara, G. Noirbent, F. Dummur, J. Toufaily, T. Hamieh, T.-T. Bui, F.
Goubard, B. Graff, D. Gimes, J. P. Fouassier, J. Lalevée,
Macromolecules 2017, 50, 4913–4926; c) E. Speckmeier, T. G. Fischer,
K. Zeitler, J. Am. Chem. Soc. 2018, 140, 15353–15365.
a) X. Xiong, F. Song, J. Wang, Y. Zhang, Y. Xue, L. Sun, N. Jiang, P.
Gao, L. Tian, X. Peng, J. Am. Chem. Soc. 2014, 136, 9590–9597; b) T.
Li, D. Yang, L. Zhai, S. Wang, B. Zhao, N. Fu, L. Wang, Y. Tao, W.
Huang, Adv. Sci. 2017, 4, 1600166/1–11; c) Z. Zhu, D. Tian, P. Gao, K.
Wang, Y. Li, X. Shu, J. Zhu, Q. Zhao, J. Am. Chem. Soc. 2018, 140,
17484–17491; d) F. Ni, Z. Zhu, X. Tong, M. Xie, Q. Zhao, C. Zhong, Y.
Zou, C. Yang, Chem. Sci. 2018, 9, 6150–6155; e) S. Kumar, S. M. Pegu,
S. K. Behera, S. K. Narra, P. Thilagar, Chem. Asian. J. 2019, 14, 4588–
4593; f) F. Ni, Z. Zhu, X. Tong, W. Zeng, K. An, D. Wei, S. Gong, Q.
Zhao, X. Zhou, C. Yang, Adv. Sci. 2019, 6, 1801729/1–10; g) X. Li, G.
Baryshnikov, C. Deng, X. Bao, B. Wu, Y. Zhou, H. Ågren, L. Zhu, Nat.
Commun. 2019, 10, 731/1–9; h) Q. Zhang, S. Xu, M. Li, Y. Wang, N.
Zhang, Y. Guan, M. Chen, C.-F. Chen, H.-Y. Hu, Chem. Commun. 2019,
55, 5639–5642; i) C. J. Christopherson, D. M. Mayder, J. Poisson, N. R.
Paisley, C. M. Tonge, Z. M. Hudson, ACS Appl. Mater. Interfaces 2020,
12, 20000–20011; j) M Luo, X. Li, L. Ding, G. Baryshnikov, S. Shen, M.
Zhu, L. Zhou, M. Zhang, J. Lu, H. Ågren, X.-D. Wang, L. Zhu, Angew.
6
This article is protected by copyright. All rights reserved.

10.1002/asia.202001173
Chemistry - An Asian Journal
FULL PAPER
A new donor–acceptor–donor–acceptor macrocyclic p-conjugated compound comprising of two electron-donors (N,N’-diphenyl-m-
phenylenediamine) and two electron-acceptors (dibenzo[a,j]phenazine) has been synthesized, and its structure and physicochemical
properties have been investigated. In comparison with para-linked macrocyclic analogue, the influence of topology of the
phenylenediamine donors on properties has been revealed.
Institute and/or researcher Twitter usernames: @Piotr_deSilva, @MinakataLab, @Takephos
7
This article is protected by copyright. All rights reserved.