Synthesis and Optoelectronic Properties of Hexa-peri-hexabenzoborazinocoronene

Article abstract of DOI:10.1002/anie.201700907

The first rational synthesis of a BN-doped coronene derivative in which the central benzene ring has been replaced by a borazine core is described. This includes six C?C ring-closure steps that, through intramolecular Friedel–Crafts-type reactions, allow

Full text of DOI:10.1002/anie.201700907

Angewandte
Communications
Chemie
International Edition: DOI: 10.1002/anie.201700907
German Edition: DOI: 10.1002/ange.201700907
Supramolecular Chemistry
Synthesis and Optoelectronic Properties of Hexa-peri-
hexabenzoborazinocoronene
Jacopo Dosso, Jonathan Tasseroul, Francesco Fasano, Davide Marinelli, Nicolas Biot,
Andrea Fermi, and Davide Bonifazi*
Abstract: The first rational synthesis of a BN-doped coronene
derivative in which the central benzene ring has been replaced
À
by a borazine core is described. This includes six C C ring-
closure steps that, through intramolecular Friedel–Crafts-type
reactions, allow the stepwise planarization of the hexaarylbor-
azine precursor. UV/Vis absorption, emission, and electro-
chemical investigations show that the introduction of the
central BN core induces a dramatic widening of the HOMO–
LUMO gap and an enhancement of the blue-shifted emissive
properties with respect to its all-carbon congener.
G
raphene is one of the leading materials in todayꢀs
science,[1] but the lack of a band gap limits its application to
Figure 1. HBC and its borazino-doped analogue HBBNC.
replace semiconductors in optoelectronic devices.[2] To over-
=
come this limitation, the replacement of C C bonds by
obtained through bottom-up synthesis involving aniline-type
precursors[3] that undergo planarization through intramolec-
ular electrophilic aromatic substitution reactions, simultane-
[3]
=
isostructural and isoelectronic bonds such as polar B N is
emerging as an effective strategy to open a band gap in
monoatomic graphene layers.[4] To the best of our knowledge,
only one example of a BN-doped covalent network featuring
a regular doping pattern has been described so far through
surface-assisted reaction.[5] Otherwise, only sheets containing
B, N and C (h-BNC) over wide compositional ranges
randomly distributed in domains of h-BN and graphitic
phases have been prepared so far.[6] At the molecular level,
notable examples include BN-doped polycyclic aromatic
hydrocarbons.[7] Among those, the isolation of the first
hexa-peri-hexabenzoborazinocoronene (HBBNC)[8] from
pyrolysis of a borazino precursor by Bettinger and co-workers
is an important example in view of the creation of hybrid
graphenes featuring controlled BN-doping patterns
(Figure 1). However, the stunted solubility of this molecule
limited in-depth structural and physical studies.
À
À
ously forming C B and B N bonds in the presence of BCl3
and a Lewis acid. At the synthetic planning level, this
consideration guided us to contemplate at first a convergent
path relegating the formation of the HBBNC core to the last
step (Scheme 1, path A). However, the scarce yield for
preparing the triamino-spherand precursor forced us to defer
this synthetic path and to anticipate the B3N3 formation in an
earlier step.
Herein we describe the first rational synthesis of B3N3-
doped benzocoronene 1 that, being soluble in common
organic solvents, allowed a direct comparison of optoelec-
tronic properties with those of its full-carbon congener.
Generally, controlled BN-doping patterns in PAHs are
[*] J. Dosso, F. Fasano, D. Marinelli, N. Biot, Dr. A. Fermi,
Prof. Dr. D. Bonifazi
School of Chemistry, Cardiff University, Main Building
Park Place, Cardiff CF10 3AT (UK)
E-mail: bonifazid@cardiff.ac.uk
Dr. J. Tasseroul, Prof. Dr. D. Bonifazi
Department of Chemistry, University of Namur (UNamur)
Rue de Bruxelles 61, Namur 5000 (Belgium)
Supporting information and the ORCID identification number(s) for
the author(s) of this article can be found under:
http://dx.doi.org/10.1002/anie.201700907.
Scheme 1. Retrosynthetic strategies toward HBBNC.
Angew. Chem. Int. Ed. 2017, 56, 1 – 6
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
These are not the final page numbers!

Angewandte
Communications
Chemie
This would lead to the HBBNC core through two, three or
six ring-closure reactions involving the aryl substituents
(Scheme 1, paths B, C, and D). As we have predicted
a potential instability of the strained borazine precursors[9]
of paths B and C, a decision was made to undertake plan D.
Commonly, the planarization of covalently preorganized aryl
moieties into PAHs is obtained through Scholl-type oxidative
ring-closure reactions.[2b,10] However, the vulnerability of the
borazine ring under oxidative conditions[11,3d] directed us to
consider a Friedel–Crafts-type substitution as the planariza-
tion reaction. This line of thought led us back to hypothetical
borazine precursors bearing appropriate leaving groups (LG)
at the ortho positions of the B-aryl substituents (path D) that,
triggered under given conditions, can yield reactive arylium
species. It is hard to not notice that the presence of ortho LG
additionally exerts protection to the B-atom centers, making
the borazine precursor enough stable to be handled. Embrac-
ing this synthetic strategy, we prepared a borazine precursor
bearing Fand peripheral xylyl moieties as LGs and solubilizing
groups, respectively.
obtained by vapor diffusion of MeOH to a CH2Cl2 solution of
5 (Figure 2). The quasi-orthogonal arrangement of the aryl
moieties forces the F substituents to nest atop the B atoms
(B···F = 2.922 ꢁ), negatively shielding the electrophilic
center. Capitalizing on the Friedel–Crafts ring-closure reac-
tion of fluoroarenes developed by Siegel and co-workers,[14]
borazine 5 could be planarized into HBBNC 1 (5% yield,
À
61% per C C bond formation) in the presence of
[iPr3Si···CB11H6Cl6] and Me2SiMes2 at 1108C in PhCl operat-
ing in a Schlenk line. Together with HBBNC 1, partially fused
BN-derivative 7 was obtained as major product (17% yield),
suggesting that the ring closure proceeds stepwise with the
last aryl fusion likely being the rate-determining step. All-
carbon congener HBC 2 (Scheme 2) was also prepared for
comparison
purposes
(Supporting
Information,
Scheme S1).[13]
Molecule 1 was characterized using NMR, UV/Vis, and
IR spectroscopy and HR-MALDI spectrometry. At first,
HBBNC 1 was unambiguously identified by HR-MALDI
through the detection of the peak corresponding to the
Following previous procedures,[12] hexafluoro borazine 5
was thus obtained after reaction of 4-xylyl aniline 3 with BCl3
upon subsequent addition of difluoro-ArLi 4 (Scheme 2). A
crystal of borazine 5, suitable for X-ray diffraction, was
molecular ion at m/z 837.3652 (C60H42B3N3 , calc.: 837.3658).
+
1
Solution H-NMR spectra further confirmed the structure of
HBBNC 1 (Figure 3B). Specifically, coupled Ha and Hb
Figure 3. Exerts of the 1H-NMR spectra (400 MHz, CDCl3) in the
aromatic region for HBBNC 1 (bottom) and HBC 2 (above).
Scheme 2. Synthetic path for preparing xylyl-substituted HBBNC 1;
full-carbon congener 2.[13]
.
protons appear as triplet (8.05 ppm) and doublet
(8.55 ppm), respectively, whereas one singlet (8.58 ppm) is
observed for Hc proton. An analogous resonance pattern
(Figure 3A) is also observed for reference 2. Notably, the
presence of the inner B3N3 cycle in 1 induces a high-field shift
of the proton resonances with respect to those of 2, suggesting
a significant decrease of the magnetic anisotropic properties
of the B3N3-doped derivative. Analogously, a remarkable
high-field shift was also observed for the boron resonance (at
30.59 ppm) in the 11B-NMR spectrum (Supporting Informa-
tion, Figure S24) of 1 when compared to that of precursor 5
(at 34.9 ppm).
To further corroborate the chemical structure of 1, crystals
suitable for X-ray diffraction analysis were obtained by
vapour diffusion of iPrOH to a C6H6 solution of 1 (Figure 4A).
Figure 2. X-ray structure and ESP mapped on the vdW surface up to
an electron density of 0.001 electronbohrÀ3 for 5. B pink, N blue,
[19]
À
F green, C gray; space group: P21/c. B N distances in ꢀ are shown.
2
www.angewandte.org
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2017, 56, 1 – 6
These are not the final page numbers!

Angewandte
Communications
Chemie
Figure 4. A) Horizontal (top) and side (bottom) view of the X-ray
À
crystal structures of HBBNC (with the B N distances in ꢀ) 1 (right)
and HBC 2 (left). B pink, N blue, C gray; space groups: I2/a and P1,
¯
respectively. B) ESP mapped on the vdW surface up to an electron
density of 0.001 electronbohrÀ3 [19]
.
The X-ray analysis confirms the nearly flat shape of the BNC
framework, displaying a similar structure to that of all-carbon
Figure 5. Absorption (black) and normalized fluorescence (blue) spec-
tra of 1 (B, lex =315 nm) and 2 (A, lex =355 nm) in air equilibrated
CH2Cl2 at RT; fluorescence (blue dotted) and phosphorescence (red)
spectra at 77 K in a CH2Cl2:CH3OH (1:1, v/v) rigid matrix.
À
congener 2, with shorter B N lengths (1.433–1.442 ꢁ, Fig-
ure 4A) than those measured in hexagonal boron nitride (h-
BN, 1.446 ꢁ). To appraise the effect of the BN doping on the
aromatic p-surface, we further determined the charge distri-
bution of the crystal structure of 1 in the form of ESP
(Figure 4B) calculated with Gaussian 09 at B3LYP/6-31G-
(d,p) level of theory (Supporting Information).
this finding suggests that the B3N3-doping widens the
molecular optical band gap (DEopt = 0.53 eV). Furthermore,
the absorption bands of 1 show noticeable vibrational
substructures evidencing a high degree of rigidity of the
molecular skeleton.[16]
As expected, the p-surface of 2 is negatively charged
showing the presence of a homogenous p-cloud above and
below the HBC skeleton. On the
Table 1: Photophysical data for 1 and 2 in solution and at the solid state.
other hand,
1 displays a great
charge polarization of the p-sur-
face, with the N and B atoms
negatively and positively charged,
respectively, and the outer hexa-
phenylene rim negatively charged.
These results are consistent with the
expected ambipolar character of the
molecule.[15] UV/Vis absorption and
emission properties in CH2Cl2 of
molecules 1 and 2 are displayed in
Figure 5 and Table 1. The lowest-
energy electronic transition of
1 appears in the near-UV (375 nm)
at significantly higher energy with
respect to that of 2 (446 nm). In line
Absorption
Emission
F
fl
[a]
[c]
Molecule
l [nm] (e, LmolÀ1 cmÀ1
)
lmax,fl Eopt,fl tfl
lmax,PH [nm][d] tph [s][d]
[nm] [eV][b] [ns]
2 (CH2Cl2) 446 (1000)
388 (53800)
485[a] 2.76 16.4[a]
27.9[f]
0.03[a] 570
0.05[f]
0.8
358 (159100)
–
2 (solid)
487
–
3.7 (64%)
–
–
–
12.1 (36%)[e]
1 (CH2Cl2) 375 (24000)
404[a] 3.29 8.2[a]
10.9[f]
0.43[a] 492
0.77[f]
4.0
–
314 (31200)
–
1 (solid)
426
–
1.5 (43%)
–
–
8.0 (57%)[e]
[a] Recorded in air-equilibrated CH2Cl2 at RT. [b] Calculated from the higher-energy maxima of the
emission spectra in air-equilibrated CH2Cl2 at RT (Eopt =1240/lfl). [c] Quinine sulfate in 0.5m H2SO4 was
used as the standard (FQS =0.546). [d] Recorded in a 1:1 CH2Cl2:CH3OH v/v rigid matrixes at 77 K
(Supporting Information, Figure S31). [e] Fitting of the emission decays. Vaues in [%] indicate the weight
with theoretical predictions,[4a,b,11] of each exponential component in the biexponential fitting. [f] Calculated for O2-free solutions.
Angew. Chem. Int. Ed. 2017, 56, 1 – 6
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3
These are not the final page numbers!

Angewandte
Communications
Chemie
Consistently, the emission spectra (Figure 5) in solution at
room temperature reflect the same trend, with the intense
emission peak of 1 (lmax = 404 nm, Ffl = 0.43) significantly
blue-shifted with respect to that of 2 (lmax = 485 nm). Notably,
the Ffl value significantly increases to 0.77 in O2-free
solutions. Phosphorescence spectra at low temperature
(Figure 5) showed long-lasting emission profiles (tPhos = 4 s)
In conclusion, we have described the first synthetic
methodology to prepare a soluble HBBNC molecule follow-
ing a planarization strategy based on a Friedel–Crafts
À
reaction. This involves the simultaneous formation of six C
C bonds starting from a hexafluoroborazine precursor. First,
X-ray diffraction confirmed the presence of the inner B3N3
À
cycle, with short B N bond lengths. The remarkable UV
with
1
providing the highest-energy triplet emission
absorption, strong blue–violet singlet emission, and green
phosphorescence of this class of hybrid B3N3-doped molecules
are in line with the theoretical predictions. Given the
importance and ubiquity of graphene in scientific research,
the development of novel synthetic strategies leading to
hybrid graphene derivatives featuring precise doping patterns
will undoubtedly lead to new discoveries and applications in
materials science. In this respect, the synthesis and photo-
physical study of this long-awaited compound marks an
important milestone toward the understanding of the opto-
electronic properties of doped molecular graphenes.
(lmax,Phos = 492 and 570 nm for 1 and 2, respectively).[17]
Furthermore, 1 displays appreciable solid-state fluorescence
emission in the violet–blue region (lmax = 426 nm vs. lmax
=
487 nm for 2) at room temperature (Supporting Information,
Figure S32).
Cyclic voltammetry (CV) measurements showed a quasi-
reversible first oxidation wave at approximately 1.46 V vs.
SCE in CH2Cl2 for HBBNC 1 (Figure 6; Supporting Infor-
Acknowledgements
D.B. gratefully acknowledges the EU through the ERC
Starting Grant “COLORLANDS” project. J.T. thanks the
FRS-FNRS for his FRIA doctoral fellowship. The authors
also acknowledge the use of the Advanced Computing
@Cardiff (ARCCA) at Cardiff University, and associated
support services.
Conflict of interest
The authors declare no conflict of interest.
Figure 6. Left: Frontier orbital energies estimated from the CV and
photophysical data for 1 and 2. Reduction potentials of the triplet
excited states are evidenced by the narrower optical energy gaps
(ET*=E1/2oxÀEoptT). Fc+/Fc=0.46 V vs. SCE; À4.8 eV vs. vacuum.
Right: HOMO and LUMO profiles for 1 and 2 at B3LYP/6-31G(d,p)
level of theory (GAUSSIAN09).
Keywords: borazine · boron nitrides · heteroatom doping ·
hexabenzocoronenes · polycyclic aromatic hydrocarbons
mation, Figure S34), which is considerably higher in energy
with respect to that of its carbon congener (E1/2ox = 1.27 V vs.
SCE).[18] On the other hand, no relevant reduction waves were
detected at any scan rates under the same experimental
conditions for both molecules. Taken together, these data
allowed us to estimate the energies of the HOMO and LUMO
orbitals, resulting to be À5.80 (HOMO) and À2.51 eV
(LUMO) for 1 and À5.61 (HOMO) and À2.85 eV (LUMO)
for 2 (Figure 6; Supporting Information, Table S4). To shed
further light on the structure-property relation, we calculated
the HOMO and LUMO orbitals for 1 and 2 (Figure 6;
Supporting Information, Figure S35). As observed by oth-
ers,[4a,b,11] it transpires that both orbitals are homogenously
distributed on the p-surface of 2, whereas the LUMO for 1 is
only located on the hexaphenylene rim. This suggests that the
one-electron reduction of 1 is likely to be confined on the
hexaphenylene periphery excluding the B3N3 ring, whereas
that of 2 is localized on the entire carbon p-surface.
[1] a) S. Park, R. S. Ruoff, Nat. Nanotechnol. 2009, 4, 217 – 224; b) F.
Schwierz, Nat. Nanotechnol. 2010, 5, 487 – 496.
[2] a) J. Wu, W. Pisula, K. Mꢂllen, Chem. Rev. 2007, 107, 718 – 747;
b) A. Narita, X. Wang, X. Feng, K. Mꢂllen, Chem. Soc. Rev.
2015, 44, 6616 – 6643.
[3] a) Z. Liu, T. B. Marder, Angew. Chem. Int. Ed. 2008, 47, 242 –
244; Angew. Chem. 2008, 120, 248 – 250; b) P. G. Campbell,
A. J. V. Marwitz, S.-Y. Lui, Angew. Chem. Int. Ed. 2012, 51,
6074 – 6092; Angew. Chem. 2012, 124, 6178 – 6197; c) X. Wang, J.
Wang, J. Pei, Chem. Eur. J. 2015, 21, 3528 – 3539; d) D. Bonifazi,
F. Fasano, M. M. Lorenzo-Garcia, D. Marinelli, H. Oubaha, J.
Tasseroul, Chem. Commun. 2015, 51, 15222 – 15236; e) H.
Helten, Chem. Eur. J. 2016, 22, 12972 – 12982.
[4] a) W. Xie, T. Yanase, T. Nagahama, T. Shimada, C 2016, 2, 2;
b) N. Otero, K. E. El-kelany, C. Pouchan, M. Rꢃrat, P. Karama-
nis, Phys. Chem. Chem. Phys. 2016, 18, 25315 – 25328; c) N.
Otero, P. Karamanis, K. E. El-Kelany, M. Rꢃrat, L. Maschio, B.
Civalleri, B. Kirtman, J. Phys. Chem. C 2017, 121, 709 – 722.
[5] C. Sꢄnchez-Sꢄnchez, S. Brꢂller, H. Sachdev, K. Mꢂllen, M. Krieg,
H. F. Bettinger, A. Nicolaꢅ, V. Meunier, L. Talirz, R. Fasel, P.
Ruffieux, ACS Nano 2015, 9, 9228 – 9235.
4
www.angewandte.org
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2017, 56, 1 – 6
These are not the final page numbers!

Angewandte
Communications
Chemie
[6] a) L. Ci, L. Song, C. Jin, D. Jariwala, D. Wu, Y. Li, A. Srivastava,
[9] S. Biswas, M. Mꢂller, C. Tçnshoff, K. Eichele, C. Maichle-
Nat. Mater. 2010, 9, 430 – 435; b) C. Huang, C. Chen, M. Zhang,
L. Lin, X. Ye, S. Lin, M. Antonietti, X. Wang, Nat. Commun.
2015, 6, 7698 – 7704.
Mçssmer, A. Ruff, B. Speiser, H. F. Bettinger, Eur. J. Org. Chem.
2012, 4634 – 4639.
[10] M. D. Watson, A. Fechtenkçtter, K. Mꢂllen, Chem. Rev. 2001,
101, 1267 – 1300.
[7] Selected examples: a) G. C. Culling, M. J. S. Dewar, P. A. Marr,
J. Am. Chem. Soc. 1964, 86, 1125 – 1127; b) D. J. H. Emslie, W. E.
Piers, M. Parvez, Angew. Chem. Int. Ed. 2003, 42, 1096 – 1109;
Angew. Chem. 2003, 115, 1290 – 1293; c) C. A. Jaska, D. J.
Emslie, M. J. Bosdet, W. E. Piers, J. Am. Chem. Soc. 2006, 128,
10885 – 10896; d) M. J. D. Bosdet, C. A. Jaska, W. E. Piers, T. S.
Sorensen, Org. Lett. 2007, 9, 1395 – 1398; e) M. J. D. Bosdet,
W. E. Piers, T. S. Sorensen, M. Parvez, Angew. Chem. Int. Ed.
2007, 46, 4940 – 4943; Angew. Chem. 2007, 119, 5028 – 5031;
f) A. J. V. Marwitz, M. H. Matus, L. N. Zakharov, D. A. Dixon,
S.-Y. Liu, Angew. Chem. Int. Ed. 2009, 48, 973 – 977; Angew.
Chem. 2009, 121, 991 – 995; g) T. Hakateyama, S. Hashimoto, S.
Seki, M. Nakamura, J. Am. Chem. Soc. 2011, 133, 18614 – 18617;
h) J. S. A. Ishibashi, J. L. Marshall, A. Mazie, G. J. Lovinger, B.
Li, L. N. Zakharov, A. Dargelos, A. Gracia, A. Chrostowska, S.
Liu, J. Am. Chem. Soc. 2014, 136, 15414 – 15421; i) G. A.
Molander, S. R. Wisniewski, J. Org. Chem. 2014, 79, 6663 –
6678; j) H. Braunschweig, M. A. Celik, F. Hupp, I. Krumme-
nacher, L. Mailꢆnder, Angew. Chem. Int. Ed. 2015, 54, 6347 –
6351; Angew. Chem. 2015, 127, 6445 – 6449; k) X. Wang, F.
Zhang, K. S. Schellhammer, P. Machata, F. Ortmann, G.
Cuniberti, Y. Fu, J. Hunger, R. Tang, A. A. Popov, R. Berger,
K. Mꢂllen, X. Feng, J. Am. Chem. Soc. 2016, 138, 11606 – 11615;
l) M. Numano, N. Nagami, S. Nakatsuka, T. Katayama, K.
Nakajima, S. Tatsumi, N. Yasuda, T. Hatakeyama, Chem. Eur. J.
2016, 22, 11574 – 11577.
[11] C. Tçnshoff, M. Mꢂller, T. Kar, F. Latteyer, T. Chassꢃ, K.
Eichele, H. F. Bettinger, ChemPhysChem 2012, 13, 1173 – 1181.
[12] a) S. J. Groszos, S. F. Stafiej, J. Am. Chem. Soc. 1958, 80, 1357 –
1360; b) A. Wakamiya, T. Ide, S. Yamaguchi, J. Am. Chem. Soc.
2005, 127, 14859 – 14866; c) S. Kervyn, O. Fenwick, F. Di Stasio,
Y. Sig Shin, J. Wouters, G. Accorsi, S. Osella, D. Beljonne, D.
Bonifazi, Chem. Eur. J. 2013, 19, 7771 – 7779; d) S. Kervyn, N.
Kalashnyk, M. Riello, B. Moreton, J. Tasseroul, J. Wouters, T. S.
Jones, A. De Vita, G. Costantini, D. Bonifazi, Angew. Chem. Int.
Ed. 2013, 52, 7410 – 7414; Angew. Chem. 2013, 125, 7558 – 7562.
[13] R. Yamaguchi, S. Hiroto, H. Shinokubo, Org. Lett. 2012, 14,
2472 – 2475.
[14] O. Allemann, S. Duttwyler, P. Romanato, K. K. Baldridge, J. S.
Siegel, Science 2011, 332, 574 – 577.
[15] E. Vessally, S. Soleimani-Amiri, A. Hosseinian, L. Edjlali, A.
Bekhradnia, Appl. Surf. Sci. 2017, 396, 740 – 745.
[16] X. Wang, F. Zhuang, R. Wang, X. Wang, X. Cao, J. Wang, J. Pei,
J. Am. Chem. Soc. 2014, 136, 3764 – 3767.
[17] S. Hashimoto, T. Ikuta, K. Shiren, S. Nakatsuka, J. Ni, M.
Nakamura, T. Hatakeyama, Chem. Mater. 2014, 26, 6265 – 6271.
[18] a) A. Stabel, P. Herwig, K. Mꢂllen, J. P. Rabe, Angew. Chem. Int.
Ed. Engl. 1995, 34, 1609 – 1611; Angew. Chem. 1995, 107, 1768 –
1770; b) R. Rathore, C. L. Burns, J. Org. Chem. 2003, 68, 4071 –
4074.
[19] CCDC 1523993 (1), 1523994 (2), and 1523995 (5) contain the
supplementary crystallographic data for this paper. These data
are provided free of charge by The Cambridge Crystallographic
Data Centre.
[8] a) M. Krieg, F. Reicherter, P. Haiss, M. Strçbele, K. Eichele, J.
Treanor, R. Schaub, H. F. Bettinger, Angew. Chem. Int. Ed. 2015,
54, 8284 – 8286; Angew. Chem. 2015, 127, 8402 – 8404; b) F.
ˇ
Ciccullo, A. Calzolari, I. Pꢇs, S. A. Savu, M. Krieg, H. F.
Bettinger, E. Magnano, T. Chassꢃ, M. B. Casu, J. Phys. Chem.
C 2016, 120, 17645 – 17651.
Manuscript received: January 25, 2017
Final Article published: && &&, &&&&
Angew. Chem. Int. Ed. 2017, 56, 1 – 6
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5
These are not the final page numbers!

Angewandte
Communications
Chemie
Communications
Supramolecular Chemistry
A BN-doped coronene derivative in which
the central benzene ring has been
J. Dosso, J. Tasseroul, F. Fasano,
D. Marinelli, N. Biot, A. Fermi,
replaced by a borazine core is described.
UV/Vis absorption, emission, and elec-
trochemical investigations show that the
introduction of the central BN core
induces a dramatic widening of the
HOMO–LUMO gap and an enhancement
of the blue-shifted emissive properties
with respect to its all-carbon congener.
D. Bonifazi*
&&&& — &&&&
Synthesis and Optoelectronic Properties
of Hexa-peri-hexabenzoborazinocoronene
6
www.angewandte.org
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2017, 56, 1 – 6
These are not the final page numbers!