Chrysene-Based Blue Emitters

Article abstract of DOI:10.1002/chem.202001808

Chrysene and its bisbenzannulated homologue, naphtho[2,3-c]tetraphene, were synthesized through a PtCl₂-catalyzed cyclization of alkynes, which also furnished corresponding biaryls subsequent to a Glaser coupling reaction of the starting alkynes. The optoelectronic properties of 5,5′-bichrysenyl and 6,6′-binaphtho[2,3-c]tetraphene were compared to their chrysene-based “monomers”. Oxidative cyclodehydrogenations of bichrysenyl and its higher homologue towards large nanographenes were also investigated.

Full text of DOI:10.1002/chem.202001808

Accepted Article
Accepted Article
Title: Chrysene-Based blue Emitters
Authors: Marvin Nathusius, Barbara Ejlli, Frank Rominger, Jan
Freudenberg, Uwe H.F. Bunz, and Klaus Müllen
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. Eur. J. 10.1002/chem.202001808
Link to VoR: https://doi.org/10.1002/chem.202001808
01/2020

10.1002/chem.202001808
Chemistry - A European Journal
COMMUNICATION
Chrysene-Based blue Emitters
Marvin Nathusius,‡,[a], [b], [c], Barbara Ejlli,‡, [a], [b], [c], Frank Rominger,[b] Jan Freudenberg,[b], [c] Uwe H.F.
Bunz,[b] Klaus Müllen*,[a]
[a]
M. Nathusius, B. Ejlli, Prof. K. Müllen
Max Planck Institute for Polymer Research
Ackermannweg 10, 55128 Mainz, (Germany)
E-mail: muellen@mpip-mainz.mpg.de
[b]
[c]
[‡]
M. Nathusius, B. Ejlli, Dr. F. Rominger, Dr. J. Freudenberg, Prof. U. H. F. Bunz
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg
Im Neuenheimer Feld 270, 69120 Heidelberg (Germany)
M. Nathusius, B. Ejlli, Dr. J. Freudenberg
InnovationLab
Speyerer Str. 4, 69115 Heidelberg, (Germany)
M. Nathusius and B. Ejlli contributed equally.
Supporting information for this article is given via a link at the end of the document.
Abstract: Chrysene and its bisbenzannulated homologue,
naphtho[2,3-c]tetraphene, were synthesized via a PtCl2 catalyzed
cyclization of alkynes, which also furnished corresponding biaryls
subsequent to a Glaser coupling reaction of the starting alkynes. The
optoelectronic properties of 5,5’-bichrysenyl and 6,6’-binaphtho[2,3-
c]tetraphene were compared to their chrysene-based “monomers”.
Oxidative cyclodehydrogenations of bichrysenyl and its higher
homologue towards large nanographenes were also investigated.
Our synthetic access to chrysene and naphtho[2,3-
c]tetraphene as well as their homologues 5,5’-bichrysenyl and
6,6’-binaphtho[2,3-c]tetraphene is depicted in Scheme 1. Key
step in our synthesis was the Pt(II)-catalyzed cyclization reaction
of 1-alkynylbiphenyls, either employing a terminal alkyne or a
diyne to furnish π-extended phenanthrenes. Suzuki coupling of 2-
naphthaleneboronic
acid
with
((2-
bromophenyl)ethynyl)trimethylsilane yielded 1 (93%),[5a] from
which chrysene (3) was obtained in two steps via desilylation
(92%) and Pt(II)-mediated cyclization as a colorless solid (81%).
5,5’-Bichrysenyl (5) was obtained from TMS-protected 1 via
Glaser coupling yielding 4 (67%) followed by a selective twofold
cyclization as a pale yellow solid (30%).[10] Treatment of 4 with
trifluoromethanesulfonic acid in DCM[11] instead of PtCl2 resulted
in a partial rearrangement forming 6,6’-bichrysenyl (see SI, Figure
S45), inseparable from 5. The π-extended naphtho[2,3-
c]tetraphene and 6,6’-binaphtho[2,3-c]tetraphene were obtained
similarly: Sonogashira coupling of 1,2-bromoiodonaphthalene
(6)[12] with TMS-acetylene furnished bromonaphthalene 7, from
which 9 was obtained via Suzuki-reaction with anthracene-2-
boronic acid (8) (54%). Desilylation to alkyne 10 (67%) followed
by cyclization led to naphtho[2,3-c]tetraphene (11) as a pale
yellow solid in good yields of 80%. This simple access to 11
significantly improved the hitherto reported synthesis involving the
unstable 2-methyl-2H-isoindole.[9] 12 could not be obtained in a
Glaser coupling reaction directly from the TMS-protected alkyne
9 even at higher temperatures (up to 100 °C) and reaction times
of up to 14 days. Using the more reactive terminal alkyne 10,
bialkyne 12 was isolated in yields of 57% and subsequent PtCl2
induced cyclization led to 6,6’-binaphtho[2,3-c]tetraphene (13) as
a yellow solid (87%).
The development of new blue emitting materials based on
polycyclic aromatic hydrocarbons (PAHs) continues to be an
important challenge for organic chemistry and material science.[1]
During the last decades PAHs such as anthracene, phenanthrene,
pyrene and corresponding biaryls with blue emission have been
employed in optoelectronic devices such as OLEDs.[2] A major
advantage of PAH emitters is their increased stability.[3] Chrysene
is a well-known PAH with blue fluorescence but its derivatives are
sparsely employed as emitting material in optoelectronic devices
due to their low solubility.[4] One possibility to address this issue
is the substitution with solubility mediating groups such as aryl
and alkynyl as well as (electron-rich) amino substituents, reducing
π-π-stacking and aggregation.[5] Along this line, several chrysene
derivatives with high quantum yields were obtained.[5] However,
the HOMO-LUMO gap is affected by extension of the π-system
and/or by electron donating groups leading to red-shifted
emission bands. Similar to chrysene, dibenzochrysenes[6] have
attracted interest as they provide blue to blue-green emission with
remarkably high external efficiencies up to 2.0% in OLEDs.[7],[8]
However, among the different isomers, the synthesis of
naphtho[2,3-c]tetraphene is only reported in one article[9] and due
to its low solubility it remained poorly investigated. In this
contribution, we report a new synthetic access to chrysene and its
bisbenzannulated homologue as well as to their biaryl congeners
to investigate their optoelectronic properties in terms of their
applicability as blue emitters. Biaryl formation from strongly
twisted subunits holds promise to retain the optical gaps without
the use of functional groups. Further, the torsion between the two
naphtho[2,3-c]tetraphene or chrysene moieties increases
solubility of the compounds by reducing π-π-stacking.
1
This article is protected by copyright. All rights reserved.

10.1002/chem.202001808
Chemistry - A European Journal
COMMUNICATION
Scheme 1. Synthesis of compounds 3, 5 (top) and 11, 13 (bottom).
Single crystals of 5 and 11 suitable for structure analysis were
obtained after evaporation of a concentrated THF solution or slow
cooling of a hot toluene solution, respectively. 5,5’-Bichrysenyl (5)
did not form π-stacks – the chrysene moieties of neighboring
molecules were oriented perpendicular to each other in an edge-
to-face orientation. Due to intramolecular interactions, the
chrysenyls adopted a torsional angle of ~76° within the molecule
(Figure 1, top), responsible for the dramatic increase in solubility:
5 (>10 mg/mL in DCM) was more soluble than chrysene (3)
(4 mg/mL in DCM), which packs in a herringbone motif(see SI,
Figure S13).[13] Planar naphtho[2,3-c]tetraphene (11) also
crystallized in this motif (Figure 1, bottom).
Absorption n-Hexane
Emission n-Hexane
Emission Film
1.0
0.5
Emission Solid
3
0.0
1.0
0.5
5
0.0
1.0
0.5
a)
b)
11
13
0.0
1.0
0.5
0.0
c)
d)
300
400
500
600
700
Wavelength [nm]
Figure 1. Crystal structure and packing of 5 (a, b) and 11 (c, d).
Compared to its monomer 11 (3 mg/mL in THF), the solubility of
13 nearly doubled (5 mg/mL in THF), for which unfortunately only
amorphous solids were obtained after various crystallization
attempts. Thus, as expected, formal homocoupling resulted in a
remarkable solubility increase, even without the introduction of
solubility mediating groups, which was rationalized in terms of the
twisted nature of the biaryls.
Figure 2. Top: Absorption (solution) and emission spectra (solution, film) of 3,
5, 11 and 13 in n-hexane. λex in solution: 3: 330 nm, 5, 11, 13: 345 nm, λex in
film: absorption maxima (see SI, Figure S7). Bottom: Photographs of solutions
of 3, 5, 11 and 13 in n-hexane (left) and crystalline 5 (right).
2
This article is protected by copyright. All rights reserved.

10.1002/chem.202001808
Chemistry - A European Journal
COMMUNICATION
We analyzed the absorption and photoluminescence of the target
compounds in n-hexane and in thin films (Figure 2). While the
normalized absorption spectra of chrysene and 5,5’-bichrysenyl
were nearly identical in solution with absorption of the latter tailing
into the visible region, the emission signal of 5,5’-bichrysenyl was
red-shifted by 58 nm compared to purple-blue emitting chrysene,
leading to a skyblue emission. A similar shift was observed for 11
and 13 - the emission maxima changed from 421 nm to 472 nm
furnishing a blue-greenish emission. The quantum yield QY in
solution (determined with an Ulbricht sphere) increased
noticeably between chrysene and naphtho[2,3-c]tetraphene from
11% to 46% and was slightly improved in the biaryls (16% for 5,5‘-
bichrysenyl and 49% for 6,6’-binaphtho[2,3-c]tetraphene).
Stability measurements involving 5 and 13 revealed no
change of absorption spectra over a period of 5 days under
continuous irradiation with a 365 nm hand-held UV lamp under
aerobic conditions in solution (see SI, Figures S9, S10),
underlining the high photostability of the compounds.
Table 1. Summary of the optoelectronic and quantum chemical characterization of compounds 3, 5, 11, 13.
[a]
[a], [b]
[c]
[c]
λabs
λem
λabs
λem
ε
QY solution/film
τf
[ns]
HOMO/LUMO[d]
[eV]
λonset.[f]/gap calc.[d]
[eV]
[nm]
269
271
306
308
[nm]
384
442
421
472
[nm]
278
278
274
270
[nm]
[L/mol*cm]
3
371
3.4*104
5.4*104
5.6*104
4.8*104
0.11/0.03
0.16/0.04
0.46/0.03
0.49/0.05
9.7
-5.71/-1.81
-5.56/-1.83
-5.19/-2.44
-5.13/-2.46
3.75/3.90
3.56/3.73
2.89/2.75
2.77/2.67
5
546(415)e
570
2.4, 9.6
8.6
11
13
593
2.7, 9.4
[a] All spectra were measured in n-hexane. [b] Excitation wavelength: 3: 330 nm, 5, 11, 13: 345 nm. [c] Thin films were spin-coated from THF, excitation wavelength:
absorption maxima. [d] Frontier molecular orbital energies were obtained from quantum-chemical calculations with Gaussian16 B3LYP/def2SVP//Gaussian16
B3LYP/def2TZVP. [e] Emission maximum of 5,5’-bichrysenyl in single crystals. [f] Absorption onset in n-hexane.
Emission of thin films of 5, 11 and 13, spincast from THF, was
dramatically red-shifted compared to that observed in solution:
5,5’-bichrysenyl (5) displayed a yellow photoluminescence with a
broad band around λmax,film = 546 nm, bathochromically shifted by
104 nm, and naphtho[2,3-c]tetraphene (11) and 6,6’-
binaphtho[2,3-c]tetraphene (13) were yellow-orange fluorescent
in films, with redshifted maxima by 149 nm and 121 nm,
respectively. Only the thin film emission spectrum of chrysene
itself resembled its solution spectrum, although a slight change in
the intensity distribution of its vibronic structure was observed.
The otherwise red-shifted emission bands indicated significant π-
π-interactions of the chromophores of 5, 11 and 13 in thin films.
Interestingly, crystalline 5,5’-bichrysenyl (5) (λmax,cryst = 415 nm)
was blue emissive (see Figure 2, bottom right), blue-shifted by
27 nm compared to emission in solution and by 131 nm compared
to films. In silico analysis of the rotamers of 5,5’-bichrysenyl by
stepwise changing the torsional angle (DFT, B3LYP/6-311++G**,
gas phase, see SI Figure S15) yields a potential with a minimum
at 78°, in accordance with the value obtained via X-ray structure
analysis. Between 30° and 150°, 5 rotates at room temperature
as the potential energies do not exceed 60 kJ/mol until the
emission of 5 in solution compared to its crystalline state as well
as the red-shifted emissions of biaryls 5 and 13 compared to their
monoaryls 3 and 11 in solution. To retain blue emission and to
reduce red-shifts of these biaryls, both in thin films and in solution,
partial planarization needs to be prohibited by steepening the
torsional potential curves. This could either be achieved via ortho-
functionalization, e.g. with methyl substituents, resulting in a
reduction of the bandwith of adoptable angles at room
temperature (50° to 130°) or by going to terchrysene-based
systems. Additionally, alternative ways of film formation, other
than spincoating, allowing for more time for the biaryl rotamers to
equilibrate and adopt their energetically preferred (twisted)
conformation should furnish blue emitting thin films for use in
OLEDs.
The synthesis of large PAHs without solubility mediating
groups is a challenge for solution-based chemistry. Soluble
biaryls such as 5 and 13 may serve as precursors for large,
unsubstituted PAHs – this approach could thus complement the
hitherto explored one via exhaustive cyclodehydrogenations of
polyphenylene dendrimers which are planarized under Scholl
conditions[15]. With compounds 5 and 13 in hand we further
investigated the Scholl cyclodehydrogenations to obtain 14 and
15, respectively, which, as a member of the larger PAHs might be
utilized as IR emitters and/or be utilized for stimulated
emission.[16] Only one synthetic approach to 14 was reported so
far but separation from a naphtoindenozethrene[17] side product
was only achieved in minuscule amounts by HPLC due to the low
solubility, there for a selective access is of interest. Bichrysenyl
derivatives were employed by us to obtain several large PAH
aforementioned torsional angles are reached.[14] As
a
consequence, different conformations and morphologies in
kinetically trapped thin films compared to the single crystals are
expected even at ambient temperatures. The frontier molecular
orbitals were, even in the biaryl systems, located on the entire π-
system with a nodal plane on their single bonds. Biaryls 5 and 13
displayed only slightly increased gaps (Eg,calc = 3.73 eV/ 2.67 eV)
compared to that of 3 and 11 (Eg,calc = 3.90 eV/ 2.75 eV), which
are in good agreement with the optical gaps determined from their
absorption onsets (see Table 1), due to the twisted structures.
Cyclovoltammetry supports the calculated LUMO levels (SI, Table
S1). The dramatically redshifted photoluminescence in thin films
was thus explicable by the wide range of torsional angles of the
biaryl systems resulting in partial planarization and intermolecular
(π-π) interactions. This feature also explains the red-shifted
systems
such
as
graphene
nanoribbons
and
(dibenzo)ovalenes.[10a-c] Based on our experience with Scholl
reactions we tried three literature reported reaction conditions:
18]
DDQ/CF3SO3H, FeCl3 and DDQ/ScOTf3.[10c,
Only the
combination of DDQ with trifluoromethanesulfonic acid furnished
14 as a deep red double [4]helicene (Scheme 2) with a maximum
yield of 70%, identified by HR-MALDI (see SI, Figure S4). Its low
3
This article is protected by copyright. All rights reserved.

10.1002/chem.202001808
Chemistry - A European Journal
COMMUNICATION
solubility prohibited analysis via NMR, even at high temperature.
The planarization caused a redshift of both absorption (λabs = 495
nm) and emission (λem = 516 nm) maxima - 14 is yellow
fluorescent in n-hexane. The observed small Stokes shift
illustrated the rigidity of the compound. This is the first selective
access to 14 in reasonable yields.
polyphenylene dendrimers are conventionally employed as
precursors to large unsubstituted PAHs, as they planarize under
Scholl conditions, we explored
a
new strategy via
cyclodehydrogenation of (soluble) biaryl systems in this work,
which could furnish nanographenes with hitherto unexplored edge
type combinations. These types of sparsely investigated PAHs
are of interest for lasing applications[19] and NIR emission.[16] We
investigated oxidative Scholl coupling of 11 furnishing 14, but full
cyclodehydrogenation of its higher homologue 13 was only
observed in trace amounts: Most likely, solubility limits the full
conversion of the twofold cyclodehydrogenated intermediate,
which will be circumvented by utilizing surface-assisted fusion[20]
in the future.
Experimental Section
Crystallographic data
Scheme 2. Cyclodehydrogenation reaction to 14 and 15. Conditions: DDQ,
CF3SO3H, DCM, -78 °C-rt, 2 h.
CCDC 1996744, 1996745, 1996746, 1996747, 1996748,
1996749 contain the supplementary crystallographic data for this
paper. These data are provided free of charge by The Cambridge
Crystallographic Data Centre.
Cyclodehydrogenation of 6,6’-binaphtho[2,3-c]tetraphene (13)
under similar conditions only lead to an insoluble and inseparable
mixture of twofold cyclodehydrogenated product of unknown
identity and, in traces, to fully oxidized 15 (see SI Figure S5 for
mass spectra). Higher temperatures and prolonged reaction times
up to 7 d did not drive the reaction to completion. While the
solubility of 11 as well as that of its monocyclodehydrogenated
reaction intermediate is sufficiently high for a complete fusion to
yield 14, the limit of this approach is quickly met in terms of
solubility of the reaction intermediates when attempting to
synthesize 15. As such, cyclodehydrogenation cannot compete
with oligophenylene planarization in terms of PAH size,[15a, 15b] but
offers an access to smaller derivatives with cove edges
inaccessible via the latter strategy. Whether 11 really poses the
limit to PAH structures via the biaryl approach in terms of size or
Syntheses
General procedure for the synthesis of acenes
General procedure (GP): In a flame dried Schlenk flask, the starting
material (1.00 eq.) and PtCl2 (0.25 eq.) were dried for 1 h under vacuum.
Dry toluene was added and the reaction was stirred at 80 °C for 3 d. The
reaction mixture was allowed to cool to room temperature and purified. The
crude product was further purified by flash chromatography (SiO2, PE/EA
10:1) to obtain the compound.
5,5'-Bichrysenyl (5)
only
bisbenzannelated
derivative,
e.g.
13,13'-
According to GP, 4 (600 mg, 1.32 mmol, 1.00 eq.) and PtCl2 (87.7 mg, 329
µmol, 0.25 eq.) were dried for 1 h under vacuum. 20 mL of dry toluene
(freeze pumped three times) were added and the reaction was stirred at
80 °C for 3 d. The mixture was allowed to cool to room temperature before
the solvent was removed under reduced pressure. The crude product was
purified by flash chromatography (SiO2, PE/EA 10:1) to obtain 5 as a pale
yellow solid (180 mg, 1.32 mmol, 30%). Rf = 0.29 (SiO2, petroleum ether,
bibenzo[c]tetraphene, may also be fully dehydrogenated, remains
to be investigated.
In conclusion, we reported a simple PtCl2-mediated synthetic
strategy towards chrysene (3), 5,5‘-bichrysenyl (5), naphtho[2,3-
c]tetraphene (11) and 6,6’-binaphtho[2,3-c]tetraphene (13) via 6-
endo-dig cyclizations of 1-alkynylbiaryls and their Glaser coupled
bialkynes. Although biaryl formation does only slightly influence
the calculated frontier molecular orbital energy levels, it results in
an increased solubility without additional solubility-mediating
groups. The shallow torsional potential, not greatly hindering
rotation about the connecting single bond, leads to a pronounced
red-shift in the thin film emission due to partial planarization and
intermolecular interactions. In the crystalline state, however, blue
emission is retained due to the herringbone motif of the twisted
biaryls. Key to soluble, all sp2 hybridized blue fluorescent
derivatives for OLED applications is thus to rigidify the system
even further, e.g. as in 5,11-polychrysenylene, which also served
as a graphene nanoribbon precursor[10a] A new approach via
polymerization of dihalogenated bialkyne 4 has the potential to
exceed the previously reported oligomers in size due to reduced
steric hindrance upon C-C bond formation. Whereas
1
ethyl acetate 10:1, v/v), M.p.: > 300 °C, H NMR (600 MHz, CD2Cl2, 295
K): δ [ppm] = 8.98 (d, J=9.16 Hz, 2H), 8.94 (d, J=8.88 Hz, 2H), 8.28 (d,
J=9.09 Hz, 2H), 8.16 (d, J=9.13 Hz, 2H), 7.98 (d, J=8.01 Hz, 2H), 7.80 -
7.74 (m, 4H), 7.66 (s, 2H), 7.62 (td, J=7.43, 0.92 Hz, 2H), 7.37 (td, J=7.40,
0.99 Hz, 2H), 6.88 (td, J=7.85, 1.51 Hz, 2H), 13C{1H} NMR (151 MHz,
CD2Cl2, 303 K): δ [ppm] = 141.6, 134.1, 132.3, 131.2, 130.8, 130.6, 129.0,
128.8, 128.3, 127.5, 127.4, 126.5, 125.9, 123.9, 122.2, IR: 휈̅
[cm-1] = 3054,
3018, 2961, 2922, 2872, 2853, 1592, 857, 797, 757, HRMS (MALDI+) m/z:
[M+H]+: calc. for [C36H22]+: 454.1720, found 454.1659, correct isotope
distribution.
Naphtho[2,3-c]tetraphene (11)
According to GP, 10 (200 mg, 609 µmol, 1.00 eq.) and PtCl2 (40.5 mg,
329 µmol, 0.25 eq.) were dried for 1 h under vacuum. 50 mL of dry toluene
(freeze pumped three times) were added and the reaction was stirred at
80 °C for 3 d. The mixture was allowed to cool to room temperature before
4
This article is protected by copyright. All rights reserved.

10.1002/chem.202001808
Chemistry - A European Journal
COMMUNICATION
the organic phase was washed several times with 1 N aqueous HCl. The
precipitated solid was filtered and washed with 1 N HCl, EtOAc, H2O and
ethanol. The crude product was purified by flash chromatography (SiO2,
PE/EA 10:1) to obtain 11 as a pale yellow solid (160 mg, 487 µmol, 80%).
Rf = 0.25 (SiO2, petroleum ether, ethyl acetate 10:1, v/v), M.p.: > 300 °C,
1H NMR (600 MHz, THF-d8, 323 K): δ [ppm] = 9.42 (s, 2H), 8.94 (d,
J=9.11 Hz, 2H), 8.58 (s, 2H), 8.23 - 8.21 (m, 4H), 8.12 - 8.08 (m, 2H), 7.57
- 7.52 (m, 4H), 13C{1H} NMR (151 MHz, THF-d8, 323 K): δ [ppm] = 133.4,
133.1, 132.1, 130.4, 129.5, 128.8, 128.6, 127.6, 126.6, 126.5, 123.3, 122.4,
[4]
[5]
A. S. Ionkin, W. J. Marshall, B. M. Fish, L. M. Bryman, Y. Wang, Chem.
Commun. 2008, 2319-2321.
a) T.-L. Wu, H.-H. Chou, P.-Y. Huang, C.-H. Cheng, R.-S. Liu, J. Org.
Chem. 2014, 79, 267-274; b) H. Shin, H. Jung, B. Kim, J. Lee, J. Moon,
J. Kim, J. Park, J. Mater. Chem. C 2016, 4, 3833-3842; c) H. Lee, H.
Jung, S. Kang, J. H. Heo, S. H. Im, J. Park, J. Org. Chem. 2018, 83,
2640-2646.
[6]
a) C.-W. Li, C.-I. Wang, H.-Y. Liao, R. Chaudhuri, R.-S. Liu, J. Org. Chem.
2007, 72, 9203-9207; b) L. Ahrens, S. Hahn, F. Rominger, J.
Freudenberg, U. H. F. Bunz, Chem. Eur. J. 2019, 25, 14522-14526.
S. Tokito, K. Noda, H. Fujikawa, Y. Taga, M. Kimura, K. Shimada, Y.
Sawaki, Appl. Phys. Lett. 2000, 77, 160-162.
IR: 휈̅
[cm-1] = 3046, 2961, 1467, 1354, 1260, 1088, 1074, 1053, 1017, 1005,
957, 895, 879, 841, 811, HRMS (MALDI+) m/z: [M+H]+: calc. for [C26H16]+:
328.1252, found 328.1249, correct isotope distribution.
[7]
[8]
a) S. Yamaguchi, T. M. Swager, J. Am. Chem. Soc. 2001, 123, 12087-
12088; b) S. Jeong, S. H. Kim, D. Y. Kim, C. Kim, H. W. Lee, S. E. Lee,
Y. K. Kim, S. S. Yoon, Thin Solid Films 2017, 636, 8-14.
6,6'-Binaphtho[2,3-c]tetraphene (13)
[9]
C. S. LeHoullier, G. W. Gribble, J. Org. Chem. 1983, 48, 1682-1685.
According to GP, 12 (120 mg, 183 µmol, 1.00 eq.) and PtCl2 (14.6 mg,
55.0 µmol, 0.25 eq.) were dried for 1 h under vacuum. Dry toluene (20 mL,
freeze pumped three times) were added and the reaction was stirred at
80 °C for 3 d. The mixture was allowed to cool to room temperature before
the organic phase was washed several times with 1 N HCl solution. The
precipitated solid was filtered and washed with 1 N HCl, EtOAc, H2O and
ethanol. The crude product was purified by flash chromatography (SiO2,
PE/EA 10:1) to obtain 13 as a pale yellow solid (105 mg, 160 µmol, 87%).
Rf = 0.24 (SiO2, petroleum ether, ethyl acetate 10:1, v/v), M.p.: > 300 °C,
1H NMR (600 MHz, THF-d8, 323 K): δ [ppm] = 9.66 (s, 1H), 9.18 (d,
J=9.35 Hz, 2H), 8.77 (s, 2H), 8.51 (s, 2H), 8.35 (s, 2H), 8.32 (d, J=8.53 Hz,
2H), 8.27 (s, 2H), 8.22 (d, J=9.38 Hz, 2H), 8.04 (d, J=8.25 Hz, 2H), 7.79
(d, J=8.53 Hz, 2H), 7.58 (t, J=7.25 Hz, 3H), 7.52 (t, J=7.87 Hz, 2H), 7.19
(t, J=7.41 Hz, 2H), 6.92 (t, J=7.95 Hz, 2H), 6.69 (d, J=8.25 Hz, 2H),
13C{1H} NMR (151 MHz, THF-d8, 323 K): δ [ppm] = δ 142.5, 133.7, 133.5,
132.9, 132.0, 131.7, 131.5, 130.1, 130.0, 130.0, 129.8, 129.5, 129.0, 128.7,
[10] a) J. Liu, B.-W. Li, Y.-Z. Tan, A. Giannakopoulos, C. Sanchez-Sanchez,
D. Beljonne, P. Ruffieux, R. Fasel, X. Feng, K. Müllen, J. Am. Chem. Soc.
2015, 137, 6097-6103; b) Q. Chen, S. Thoms, S. Stöttinger, D.
Schollmeyer, K. Müllen, A. Narita, T. Basché, J. Am. Chem. Soc. 2019,
141, 16439-16449; c) G. M. Paternò, Q. Chen, X.-Y. Wang, J. Liu, S. G.
Motti, A. Petrozza, X. Feng, G. Lanzani, K. Müllen, A. Narita, F.
Scotognella, Angew. Chem. Int. Ed. 2017, 56, 6753-6757; d) J. Ma, J.
Liu, M. Baumgarten, Y. Fu, Y.-Z. Tan, K. S. Schellhammer, F. Ortmann,
G. Cuniberti, H. Komber, R. Berger, K. Müllen, X. Feng, Angew. Chem.
Int. Ed. 2017, 56, 3280-3284.
[11] R. Bam, W. Yang, G. Longhi, S. Abbate, A. Lucotti, M. Tommasini, R.
Franzini, C. Villani, V. J. Catalano, M. M. Olmstead, W. A. Chalifoux, Org.
Lett. 2019, 21, 8652-8656.
[12] F. Cottet, E. Castagnetti, M. Schlosser, Synth. 2005, 2005, 798-803.
[13] CCDC. 1483901.
[14] G. Roos, C. Roos, in Organic Chemistry Concepts (Eds.: G. Roos, C.
Roos), Academic Press, Boston, 2015, pp. 43-54.
128.5, 127.7, 127.6, 127.0, 126.8, 126.5, 126.5, 125.7, 123.6, 122.7, IR: 휈
̅
[cm-1] = 048, 2957, 1672, 1600, 1587, 1474, 1282, 1258, 1071, 1006, 953,
905, 885, 861, 803, HRMS (MALDI+) m/z: [M+H]+: calc. for [C52H30]+:
654.2348, found 654.2448, correct isotope distribution.
[15] a) C. D. Simpson, J. D. Brand, A. J. Berresheim, L. Przybilla, H. J. Räder,
K. Müllen, Chem. Eur. J. 2002, 8, 1424-1429; b) C. D. Simpson, G.
Mattersteig, K. Martin, L. Gherghel, R. E. Bauer, H. J. Räder, K. Müllen,
J. Am. Chem. Soc. 2004, 126, 3139-3147; c) V. S. Iyer, M. Wehmeier, J.
D. Brand, M. A. Keegstra, K. Müllen, Angew. Chem. Int. Ed. 1997, 36,
1604-1607; d) M. D. Watson, A. Fechtenkötter, K. Müllen, Chem. Rev.
2001, 101, 1267-1300.
Acknowledgement
[16] a) L. J. Allamandola, A. G. G. M. Tielens, J. R. Barker, Astrophys. J. 1985,
290, 25-28; b) A. Leger, L. D'Hendecourt, D. Defourneau, Astron.
Astrophys. 1989, 216, 148; c) S. A. Sandford, M. P. Bernstein, C. K.
Materese, Astrophys. J. Suppl. S. 2013, 205, 8.
We thank S. Maier for support with TD-DFT calculations and L.
Ahrens for support with cyclic voltammetry measurements.
[17] Y.-C. Hsieh, T.-C. Wu, J.-Y. Li, Y.-T. Chen, M.-Y. Kuo, P.-T. Chou, Y.-T.
Wu, Org. Lett. 2016, 18, 1868-1871.
Conflict of interest
[18] a) J. Wu, Ž. Tomović, V. Enkelmann, K. Müllen, J. Org. Chem. 2004, 69,
5179-5186; b) M. Grzybowski, B. Sadowski, H. Butenschön, D. T. Gryko,
Angew. Chem. Int. Ed. 2020, 59, 2998-3027.
The authors declare no conflict of interest.
[19] A. J. C. Kuehne, M. C. Gather, Chem. Rev. 2016, 116, 12823-12864.
[20] a) Q. Zhong, Y. Hu, K. Niu, H. Zhang, B. Yang, D. Ebeling, J. Tschakert,
T. Cheng, A. Schirmeisen, A. Narita, K. Müllen, L. Chi, J. Am. Chem. Soc.
2019, 141, 7399-7406; b) C. Rogers, C. Chen, Z. Pedramrazi, A. A.
Omrani, H.-Z. Tsai, H. S. Jung, S. Lin, M. F. Crommie, F. R. Fischer,
Angew. Chem. Int. Ed. 2015, 54, 15143-15146.
Keywords: 2D acenes • twisted biaryls• solubility increase • blue
emission • polyaromatic hydrocarbons •
[1]
a) A. John, M. Bolte, H.-W. Lerner, G. Meng, S. Wang, T. Peng, M.
Wagner, J. Mater. Chem. C 2018, 6, 10881-10887; b) T. M. Figueira-
Duarte, K. Müllen, Chem. Rev. 2011, 111, 7260-7314; c) X. Feng, J.-Y.
Hu, F. Iwanaga, N. Seto, C. Redshaw, M. R. J. Elsegood, T. Yamato,
Org. Lett. 2013, 15, 1318-1321.
[2]
a) J.-H. Lee, C.-H. Chen, P.-H. Lee, H.-Y. Lin, M.-k. Leung, T.-L. Chiu,
C.-F. Lin, J. Mater. Chem. C 2019, 7, 5874-5888; b) X. Yang, X. Xu, G.
Zhou, J. Mater. Chem. C 2015, 3, 913-944; c) C.-H. Chien, C.-K. Chen,
F.-M. Hsu, C.-F. Shu, P.-T. Chou, C.-H. Lai, Adv. Funct. Mater. 2009, 19,
560-566; d) K. Danel, T.-H. Huang, J. T. Lin, Y.-T. Tao, C.-H. Chuen,
Chem. Mater. 2002, 14, 3860-3865.
[3]
T. Watanabe, H. Sasabe, T. Owada, T. Maruyama, Y. Watanabe, H.
Katagiri, J. Kido, Chem. Lett. 2019, 48, 457-460.
5
This article is protected by copyright. All rights reserved.

10.1002/chem.202001808
Chemistry - A European Journal
COMMUNICATION
Entry for the Table of Contents
We report a synthesis of new blue, soluble and stable emitting materials based on chrysene. Chrysene and its bisbenzannulated
homologue, naphtho[2,3-c]tetraphene were synthesized via a PtCl2 catalyzed cyclization of alkynes followed by the synthesis of the
corresponding soluble biaryls. We further synthesized PAHs starting from the biaryls leading to PAHs with unknown edge type structure.
6
This article is protected by copyright. All rights reserved.