Synthesis, characterization and properties of aryl-fused bis-BN dihydropyrenes

Article abstract of DOI:10.1039/c8cc01748d

A series of aryl-fused bis-BN dihydropyrenes were synthesized via amino-directed borylation reaction. The aryl-fused bis-BN dihydropyrenes showed blue emission, and their physical properties could be finely tuned through varying the fused aryl rings. In particular, their response towards fluoride anions was greatly dependent on the nature of the fused aryl rings.

Full text of DOI:10.1039/c8cc01748d

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: J. Zhang, F. Liu, Z.
Sun, C. Li, Q. Zhang, C. Zhang, Z. Liu and X. Liu, Chem. Commun., 2018, DOI: 10.1039/C8CC01748D.
This is an Accepted Manuscript, which has been through the
Volume 52 Number
1 4 January 2016 Pages 1–216
Royal Society of Chemistry peer review process and has been
accepted for publication.
ChemComm
Accepted Manuscripts are published online shortly after
Chemical Communications
www.rsc.org/chemcomm
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1359-7345
COMMUNICATION
Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc3N@C2n (2n 68 and 80). Synthesis of the
first methanofullerene derivatives of Sc N@D5h-C80
=
3
rsc.li/chemcomm

Please do not adjust margins
ChemComm
Page 1 of 5
View Article Online
DOI: 10.1039/C8CC01748D
Journal Name
COMMUNICATION
Synthesis, Characterization and Properties of Aryl-Fused Bis-BN
Dihydropyrenes
Received 00th January 20xx,
Accepted 00th January 20xx
Jinyun Zhang,a Fude Liu,a Zhe Sun,a Chenglong Li,a Qian Zhang,a Chen Zhang,a Zhiqiang Liu,c
Xuguang Liu*a,b
DOI: 10.1039/x0xx00000x
www.rsc.org/
A series of aryl-fused bis-BN dihydropyrenes were synthesized via found that their photophysical properties were greatly
amino-directed borylation reaction. The aryl-fused bis-BN dependent on the ring fused to the dihydropyrene. We also
dihydropyrenes showed blue emission, and their physical found significant variation in the response of these BN-
properties could be finely tuned through varying the fused aryl containing aromatics towards fluoride ions.
rings. In particular, their response towards fluoride anions was
greatly dependent on the nature of the fused aryl rings.
S
S
S
S
Ph
Ph
Ph
Ph
Ph
Heteroatom-doped polycyclic aromatic hydrocarbons (PAHs) are of
high importance in optoelectronic materials.1 In particular,
substitution of the C=C functionality with the isosteric and
isoelectronic B-N moiety has emerged as a powerful way to expand
the family of PAHs.2 When B-N functionality is incorporated into
aromatic hydrocarbons, usually some degree of aromaticity of the
sub-azaborine unit is retained despite changes to the overall
B
N
B
N
B
N
B
N
B
N
N
B
N
B
N
B
N
B
N
B
Ph
Ph
Ph
Ph
Ph
S
S
S
S
4a
4b
4c
4d
4e
electronic structure.3 BN-containing PAHs have been explored as Figure 1. Chemical structures of aryl-fused bis-BN dihydropyrenes.
promising components for organic light-emitting diodes (OLEDs)4
The synthetic route to the target aryl-fused bis-BN
and organic field transistors.5
dihydropyrenes 4a
Dibromoquinoxaline
was synthesized according to the literature approach.8 Suzuki
cross-coupling of with a variety of aryl boronic acids
delivered the corresponding 5,8-diarylquionxalines 2a 2e in
good yields. However, there is no universal way to reduce 5,8-
diarylquionxalines to their reduced forms 5,8-diaryl-1,2,3,4-
tetrahydroquinoxalines . After many attempts, we found that
-
4e is shown in Scheme 1. 5,8-
Pyrenes, which have been widely investigated for their unique
properties, are a promising building block to develop new
extended π-systems for organic optoelectronics.6 However,
the reduced forms of pyrene, particularly dihydropyrene, are
not well documented. Herein, we describe the synthesis,
crystallographic, spectral and electrochemical properties of
1
was used as a universal precursor, and
1
-
2
novel BN-containing PAHs 4a-4e containing dihydropyrene as
3
the central core structure. Compounds 4a/4d and 4b
/
4e are
the 5,8-dithienoquinoxalines 2a and 2d could be reduced using
NaBH4 as reductant, while Pd/C and H2 was an efficient
catalytic system for the reduction of the 5,8-
dibenzothienoquinoxalines 2b and 2e. In the case of the 5,8-
diphenylquinoxaline 2c, LiAlH4 was the reductant of choice. It
should be noted that the reduced product 5,8-diaryl-1,2,3,4-
thieno-fused and benzothieno-fused bis-BN dihydropyrenes,
respectively, while 4c is a benzo-fused bis-BN dihydropyrene
(Figure 1). These structures can also be viewed as the B-N
bridged terphenyl and dithienylbenzene derivatives.7 We
a.Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion,
School of Chemistry and Chemical Engineering, Tianjin University of Technology,
Tianjin 300384, People’s Republic of China. Email: xuguangliu@tjut.edu.cn
b.Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional
Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences,
345 Lingling Road, Shanghai 200032, People’s Republic of China.
tetrahydroquinoxaline
and stored under nitrogen, as prolonged exposure to air leads
to oxidation back to . Finally, nitrogen-directed borylation of
the 5,8-diaryl-1,2,3,4-tetrahydroquinoxalines 3a 3e went
smoothly to furnish the aryl-fused bis-BN dihydropyrenes 4a
3 must be isolated and purified rapidly
2
-
c. State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100,
People’s Republic of China..
Electronic Supplementary Information (ESI) available: [Electronic Supplementary
Information (ESI) available: Full details for the synthesis of aryl-fused bis-BN
-
4e in high yields. It is worth noting that the borylation worked
well in the less electron-rich 5,8-dibenzyl-1,2,3,4-
dihydropyrenes, and copies of NMR spectra, UV-vis and PL data, and tetrahydroquinoxaline 2c, even though elevated temperature
and Lewis acid are usually needed for this type of substrate.4b,
electrochemical data. X-ray crystallographic data in CIF and theoretical
calculations.]. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 5
View Article Online
DOI: 10.1039/C8CC01748D
COMMUNICATION
Journal Name
4c, 9
We also attempted to dehydrogenate an analogue of 4a
with a long alkyl chain attached to the terminal thiophene
(4a΄); however, with limited success (Scheme S17 and S18).
Ar
Ar
Ar
S
S
S
S
Ar
S
S
Ph
Ph
OH
B
N
B
PhBCl2
Et3N
H
N
S
N
N
OH
A) NaBH4
B) Pd/C, H2
PhCl
Pd(PPh3)4
N
H
N
B
130 o
C
Ar
Ar
Ar
Figure 2. Solid state structures of bis-BN dihydropyrenes 4a, 4c and
4d with views parallel and perpendicular to the polycyclic planes.
Thermal ellipsoids are set at the 35% probability level. H-atoms
have been omitted for clarity.
2a, Ar = H, 75% 3a, Ar = H, (method A), 44% 4a, Ar = H, 85%
2b, Ar = Ph, 84% 3b, Ar = Ph, (method B), 99% 4b, Ar = Ph, 60%
OH
Ph
B
Br
Br
B
N
OH
H
N
PhBCl2
Et3N
N
N
N
N
Table 1. Selected bond lengths (Å) and dihedral angles of 4a, 4c and
4d.
LiAlH4
PhCl
N
H
N
B
Pd(PPh3)4
130 o
C
Ph
B1-N1
B2-N2
B-C
endo
B-C
exo
N-C
endo
dihedral
anglea
6.4o
1
2c, 83%
3c, 57%
4c, 85%
1.44(5)
4a 1.46(3)
1.64(4)
1.55(4)
1.58(4)
1.58(4)
1.39(3)
1.45(3)
S
4.8o
S
Ar
Ar
S
Ar
6.4o
Ph
Ph
1.409(12) 1.549(14) 1.593(14) 1.397(11)
1.422(13) 1.501(14) 1.569(15) 1.397(11)
1.427(11) 1.522(13) 1.559(13) 1.414(10)
B
N
H
N
PhBCl2
Et3N
6.6o
N
N
4c
Pd(PPh3)4
HO
A) NaBH4
4.5o
B) Pd/C, H2
PhCl
N
H
N
B
130 o
C
4d 1.423(10) 1.502(13) 1.581(13) 1.411(10)
5.7o
B
OH
a
Ar
Dihedral angles between the central benzene ring and the lateral
Ar
Ar
S
S
S
Ar
S
thiophene (4a, 4d)/benzene (4c) ring.
2d, Ar = H, 63%
2e, Ar = Ph, 59%
3d, Ar = H (method A), 55% 4d, Ar = H, 80%
3e, Ar = Ph (method B), 99% 4e, Ar = Ph, 83%
The nucleus-independent chemical shift (NICS) values are
important magnetic criteria of aromaticity.12 The NICS (1)
Scheme 1. Synthetic approaches to aryl-fused bis-BN
dihydropyrenes 4a-4e.
values of aryl-fused bis-BN dihydropyrenes 4a
shown in Figure 3. The relatively high values of NICS (1) of the
azaborine subunits in 4a 4c and 4d demonstrated their weak
, 4c and 4d are
All the new compounds were fully characterized except for
compound 4e. The low solubility of 4e in common solvents limited
its full characterization. The 11B NMR spectra of these compounds
displayed broad peaks at around 30–42 ppm, indicating the
presence of three coordinated boron atoms.
,
aromaticity. Remarkably, the NICS (1) values of the azaborine
subunits of 4a (-4.98 ppm) and 4d (-4.87 ppm) are smaller than
in the benzene-fused form 4c (-3.72 ppm), which
demonstrates the slightly stronger aromaticity of azaborines
fused to thiophene than those fused to benzene.13a, 13b
The structures of three representative aryl-fused bis-BN
dihydropyrenes 4a, 4c and 4d were further unambiguously
confirmed by X-ray analysis (Figure 2), and selected bond lengths
are shown in Table 1.10 The main scaffold of aryl-fused bis-BN 4,5-
dihydropyrenes 4a, 4c and 4d had a flat structure, which is again
demonstrated the B-N bond can plannarize the triaryls backbone.7
The dihedral angles between the terminal ring (thiophene ring in 4a
and 4d, benzene ring in 4c) and the central benzene ring in these
bis-BN dihydropyrenes were very small (4.5–6.6o, Table 1). The
substituted phenyl groups on boron were twisted and deviated
from the main backbones by approximately 54–86o, which limited
their conjugation with the main planes.
Figure 3. NICS (1) values of each ring in bis-BN dihydropyrenes 4a,
4c and 4d.
The B-N bond lengths (1.41–1.46 Å) are much shorter than a
typical B-N single bond (1.58 Å) and slightly longer than a
localized B=N double bond (1.403(2) Å), confirming their
essentially double-bond character. Furthermore, in bis-BN
The UV/Vis absorption spectra of 4a-4d in CH2Cl2 are illustrated in
Figure 4, and their absorption band maxima are presented in Table
2. The photophysical properties of 4e were not investigated
because of its limited solubility in common solvents. The absorption
spectra of 4a-4e featured vibronically split bands, indicating their
rigid conjugated structures. The absorption band below 400 nm
could be assigned to the π,π* transitions of the aromatic core,
which was also in line with their minor solvent effect (Figure S2).
The bis-BN dihydropyrene 4b showed a slight bathochromic shift in
dihydropyrenes 4a, 4c and 4d, most of the bonds between B
and the C atom of the fused aryl ring (denoted B-C endo; 1.45–
1.54 Å) are shorter than a B-C single bond (1.58 Å), while the
N-C bonds are shorter (ca. 1.41 Å) than a regular N-C single
bond (1.48 Å), consistent with literature reports for other BN-
containing aromatics.4, 9, 11
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 3 of 5
View Article Online
DOI: 10.1039/C8CC01748D
Journal Name
COMMUNICATION
absorption onset (395 nm) relative to 4a (385 nm), which was in electrochemical behaviors with irreversible oxidation and reduction
line with its extended fused backbone. Interestingly, in the waves. The HOMO levels of 4a-4d calculated from the oxidation
absorption profile of bis-BN dihydropyrene 4d, the low-energy onset potential were comparable (4a, -5.52 eV; 4b, -5.62 eV; 4c, -
absorption maximum was at 341 nm, which is blue-shifted 5.51 eV and 4d, -5.56 eV). The low-lying HOMO energy levels
compared with its isomer 4a, which had a low-energy absorption suggest their potential usefulness as p-type semiconductors.14 The
maximum at 365 nm (Figure 4, Table 2). This blue-shift of the LUMO energy levels were calculated from the HOMO energy levels
absorption maximum of 4d compared with 4a (~24 nm) might be and the optical band gaps (4a, -2.30 eV; 4b, -2.49 eV; 4c, -2.18 eV
due to the relatively smaller conjugated system in 4d with only one and 4d, -2.18 eV) (Table 2 and Figure S6).
thiophene double bond strongly resonating with the central Furthermore, density functional theory calculations were
benzene ring, which was also in agreement with the shorter B-N performed. The plots of HOMO and LUMO for 4a-4d are
bonds in 4d observed by X-ray analysis (Table 1). Accordingly, the shown in Figure S1 and Table 2. Both HOMO and LUMO are
absorption onset of bis-BN dihydropyrene 4c was between that of mainly composed of the orbitals of the central, rigid, aryl-fused
4a and 4d. The band gaps estimated from the absorption onsets bis-BN dihydropyrene backbones, with negligible contributions
were found to be 3.22 eV, 3.14 eV, 3.33 eV and 3.38 eV for 4a, 4b, from the B-phenyl substituent. In 4a
, 4b and 4d, the HOMOs
4c and 4d respectively (Table 2). These numbers are qualitatively in are mostly located away from the nitrogen atom, while in
agreement with the calculated values (Table 2).
contrast, significant HOMO density is located on the nitrogen
The fluorescence properties of bis-BN dihydropyrenes 4a-4d atom in 4c. Conversely, there is no LUMO density on the boron
were also investigated (Figure 4). All of their emission bands atom in 4c, while considerable LUMO density can be seen on
were located in the blue region (350–475 nm). The emission the boron atoms in the other three bis-BN dihydropyrenes
energies of 4a
relatively lower-energy band (red-shifted). This is consistent qualitatively in agreement with the experimental values
with its larger -conjugation backbone. In addition, bis-BN determined by CV and UV/Vis spectroscopy (Table 2).
dihydropyrene 4a showed a more structured emission band
than its isomer 4d The vibronic spacing of 4a 4d is
, 4c and 4d were similar, while 4b showed a (Figure S1). The calculated HOMO and LUMO levels are
π
.
-
approximately 1100 cm-1, which corresponds to the aromatic
ring breathing mode. Furthermore, solvent polarity had little
influence on their emission energies (Figure S2). However, we
found large differences among the fluorescence quantum
yields of 4a-4d (Table 2). In particular, for the two isomers 4a
and 4d, the quantum yield of 4d (0.61) was three times that of
4a (0.21). These again demonstrated that isomerization
affected the photophysical properties of the BN-containing
aromatics.13 The small Stokes shifts of 4a
-4d (on the order of
Figure 5. Changes in emission spectra of 4a (λex = 345 nm) and 4d
(λex = 320 nm) in tetrahydrofuran upon addition of TBAF.
103 cm-1, Table 2) indicated that the extent of structural
relaxation was fairly small, presumably because of the
structural rigidities of triaryls backbone plannarized by the B-N
bond. These planarization might also be the reason of the red-
Organoboron compounds are widely used as sensors for
environmentally harmful fluoride ions.15 We found that addition of
tetrabutylammonium fluoride (TBAF) to the solution of 4a leads to
generate a long-wavelength band around 425 nm while its original
absorption band was diminished (Figure S3). The binding constant
log Ka ≈ 5.6 ± 0.2 was obtained (in THF). The fluoride addition to 4a
leads to appearance a long wavelength emission band around 525
nm and extenuates its original emission band (Figure 5). In contrast,
upon addition of TBAF to the solution of 4d, although its
absorbance spectrum was likewise slightly red-shifted and
diminished in intensity, its emission band was suppressed without
generation of a new band (Figure 5), only very weak long-
wavelength band was observed up to 2.0 equivalent of TBAF was
added (Figure S3). We also monitored the fluoride addition of 4a by
11B NMR and found that 11B NMR signal change from 38 ppm to
around 4 ppm, which is the typical signal of tetracoordination boron.
The other compounds showed similar phenomena (Figure S4). It
should be noted that the only difference in structure between 4a
and 4d is the position of the fused thiophene, which again
shift of the absorption and emission spectra of 4a
compared to the para-terphenyls derivatives.3c In addition, we
found 4a 4e showed blue emission in solid state as well
-4d
-
(Figure S5 and Table S14).
Figure 4. The normalized absorption (left) and emission spectra
(right) of 4a-4d in CH2Cl2 at a concentration of 10-5 M.
The electrochemical properties of the bis-BN dihydropyrenes 4a-4d demonstrates the marked difference in behavior caused by
were investigated using cyclic voltammetry (CV) (Figure S6 and positional isomerization of the BN-containing aromatics.3a, 13c The
Table 2). Bis-BN dihydropyrenes 4a-4d all exhibited similar bis-BN dihydropyrene 4c showed a similar response to TBAF as that
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 5
View Article Online
DOI: 10.1039/C8CC01748D
COMMUNICATION
Journal Name
Table 2. Photophysical properties of 4a-4d in CH2Cl2.
opt
EG
Eox
EHOMO (eV),
ELUMO (eV),
exp.e /DFT
Comp λabs
λonset
nm
λex
λem
Φpl
Stokes shift
(103 cm-1)a
exp.d /DFT
(eV)b
(eV)c
ound
4a
nm
nm
345
349
329
320
nm
365, 346, 330
377, 356, 339
363, 348, 329
341, 328, 315
385
395
372
367
375, 392, 412
404, 428, 455
374, 389, 410
382, 395
0.21 1.88
0.11 1.78
0.37 1.84
0.61 3.15
3.22
3.14
3.33
3.38
0.72
0.82
0.71
0.76
-5.52/-5.49
-5.62/-5.57
-5.51/-5.60
-5.56/-5.63
-2.30/-1.47
-2.49/-1.67
-2.18/-1.16
-2.18/-1.23
4b
4c
4d
aStokes shift = 1/λabs-1/λem; bOptical band gap EGopt = 1240/λonset; cRelative to Fc+/Fc recorded in CH2Cl2 with [Bu4N][PF6] as the electrolyte.;
dEstimated from the first oxidation potential onset, EHOMO = 4.8 eV-Eox; eELUMO = EHOMO + EG
opt
;
(k) Z. X. Giustra and S.-Y. Liu, J. Am. Chem. Soc., 2018, 140
1184..
,
of 4d (Figure S3). It should be noted that organoboron compounds
usually undergo blue-shifting of the absorbance and quenching of
the fluorescence upon addition of fluoride ions,16 although
relatively fewer examples of spectral red-shifting have been
documented.17
3
4
(a) M. J. D. Bosdet, C. A. Jaska, W. E. Piers, T. S. Sorensen and
M. Parvez, Org. Chem., 2007, , 1395; (b) S. Xu, L. N.
9
Zakharov and S.-Y. Liu, J. Am. Chem. Soc., 2011, 133, 20152;
(c) X. Liu, Y. Zhang, B. Li, L. N. Zakharov, M. Vasiliu, D. A.
Dixon and S.-Y. Liu, Angew. Chem., 2016, 128, 8437; Angew.
Chem., Int. Ed., 2016, 55, 8333.
(a) X. Wang, F. Zhang, J. Liu, R. Tang, Y. Fu, D. Wu, Q. Xu, X.
Zhuang, G. He and X. Feng, Org. Lett., 2013, 15, 5714; (b) G.
Li, Y. Zhao, J. Li, J. Cao, J. Zhu, X. W. Sun and Q. Zhang, J. Org.
Chem., 2015, 80, 196; (c) W. Zhang, F. Zhang, R. Tang, Y. Fu, X.
In conclusion, we have synthesized a series of aryl-fused bis-BN
dihydropyrenes through amino-directed borylation reaction. X-ray
crystallographic analysis demonstrated B-N units can planarize the
triaryl backbone. In addition, the aryl-fused bis-BN dihydropyrenes
showed blue emission and their photophysical properties could be
finely tuned by modifying the aryl moiety fused to the central bis-
BN dihydropyrene core. Moreover, we found that their response to
fluoride ion addition was greatly dependent on the nature of the
fused aryls, as well as the position of fusion. In view of their rich
photophysical properties, bis-BN dihydropyrenes show promise for
further investigations in optoelectronics.
Wang, X. Zhuang, G. He and X. Feng, Org. Lett., 2016, 18
,
3618; (d) S. Wang, D. Yang, J. Lu, H. Shimogawa, S. Gong, X.
Wang, S. K. Mellerup, A. Wakamiya, Y. Chang, C. Yang and Z.
Lu, Angew. Chem., Int. Ed., 2015, 54, 15074.
(a) X. Wang, H. Lin, T. Lei, D. Yang, F. Zhuang, J. Wang, S.
Yuan and J. Pei, Angew. Chem., Int. Ed., 2013, 52, 3117; (b) X.
Wang, F. Zhuang, R. Wang, X. Wang, X. Cao, J. Wang and J.
Pei, J. Am. Chem. Soc., 2014, 136, 3764.
5
6
7
8
9
T. M. Figueria-Duarte and K. Müllen, Chem. Rev., 2011, 111
7260.
C. Zhao, Y. Zhao, H. Pan, G. Fu, Chem. Commun. 2011, 47
5518
A. Durmus, G. E. Gunbas and L. Toppare, Chem. Mater., 2007,
19, 6247.
(a) G. Li, W. W. Xiong, P. Y. Gu, J. Cao, J. Zhu, R. Ganguly, Y. Li,
A. C. Grimsdale and Q. Zhang, Org. Lett., 2015, 17, 560; (b) X.
Y. Wang, F. D. Zhuang, X. C. Wang, X. Y. Cao, J. Y. Wang and J.
Pei, Chem. Commun., 2015, 51, 4368.
,
We gratefully acknowledge the financial support from the
Natural Science Foundation of Tianjin (17JCZDJC37700),
National Natural Science Foundation of China (21502140,
21672130), Tianjin University of Technology and Shanghai
Institute of Organic Chemistry (K2015-10). We also thank the
Training Project of Innovation Team of Colleges and
Universities in Tianjin (TD13-5020).
,
10 CCDC 1823245-1823247 contains the supplementary
crystallographic data for this paper. These data are provided
free of charge by the Cambridge Crystallographic Data
Centre.
11 (a) M. J. D. Bosdet, W. E. Piers, T. S. Sorensen and M. Parvez,
Angew. Chem., Int. Ed., 2007, 46, 4940; (b) E. R. Abbey, L. N.
Zakharov and S.-Y. Liu, J. Am. Chem. Soc., 2008, 130, 7250.
12 P. R. Schleyer, C. Maerker, A. Dransfeld, H. Jiao and N. J. R. E.
Hommes, J. Am. Chem. Soc., 1996, 118, 6317.
Conflicts of interest
There are no conflicts to declare
Notes and references
13 (a) D. R. Levine, M. A. Siegler and J. D. Tovar, J. Am. Chem.
Soc., 2014, 136, 7132; (b) Y. Yan, Z. Sun, C. Li, J. Zhang, L. Lv,
X. Liu and X. Liu, Asian J. Org. Chem., 2017, 6, 496; (c) X.
1
(a) M. Stępień, E. Gońka, M. Żyła and N. Sprutta, Chem. Rev.,
2017, 117, 3479; (b) A. Narita, X. Wang, X. Feng and K.
Müllen, Chem. Soc. Rev., 2015, 44, 6616.
Wang, F. Zhang, J. Gao, Y. Fu, W. Zhao, R. Tang, W. Zhang, X.
Zhuang and X. Feng, J. Org. Chem., 2015, 80, 10127.
14 J. H. Gao, J. R. Li, I. Q. Li, Q. Meng, H. Jiang, H. X. Li and W. P.
Hu, Adv. Mater., 2007, 19, 3008.
15 (a) F. Jäkle, Coord. Chem. Rev., 2006, 250, 1107; (b) C. R.
Wade, A. E. J. Broomsgrove, S. Aldridge and F. P. Gabbaï,
Chem. Rev., 2010, 110, 3958.
2
(a) Z. Liu and T. B. Marder, Angew. Chem., 2008, 120, 248;
Angew. Chem., Int. Ed., 2008, 47, 242; (b) M. J. D. Bosdet and
W. E. Piers, Can. J. Chem., 2009, 87, 8; (c) P. G. Campbell, A.
J. V. Marwitz and S.-Y. Liu, Angew. Chem., 2012, 124, 6178;
Angew. Chem., Int. Ed., 2012, 51, 6074; (d) E. R. Abbey and
S.-Y. Liu, Org. Biomol. Chem., 2013, 11, 2060; (e) A. J. Ashe,
III, Organometallics, 2009, 28, 4236; (f) X. Wang, J. Wang and
J. Pei, Chem. Eur. J., 2015, 21, 3528; (g) M. M. Morgan and W.
E. Piers, Dalton Trans., 2016, 45, 5920; (h) H. Helten, Chem.
Eur. J., 2016, 22, 12972; (i) J. Y. Wang and J. Pei, Chin. Chem.
16 S. Yamaguchi and A. Wakamiya, Pure Appl. Chem., 2006, 78
1413.
,
17 M. Lepeltier, O. Lukoyanova, A. Jacobson, S. Jeeva and D. F.
Perepichka, Chem. Commun., 2010, 46, 7007.
Lett., 2016, 27, 1139; (j) G. Bélanger-Chabot, H.
Braunschweig and D. K. Roy, Eur. J. Inorg. Chem., 2017, 4533;
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 5
ChemComm
View Article Online
DOI: 10.1039/C8CC01748D
S
Ar =
S
Ar
Ar
Ar
Ar
Ph
Ph
B
N
H
N
N
H
N
B
A series of aryl-fused bis-BN dihydropyrenes are synthesized, their photophysical properties are
fully investigated by experimental and theoretical calculations.