A chemically-responsive bis-acridinium receptor

Article abstract of DOI:10.1039/c7nj03712k

A dicationic receptor based on two acridinium moieties linked by a triphenylene spacer was studied in solution and in the solid state. Recognition moieties, namely acridiniums, were exploited to evidence a host-guest response of the receptor with electron rich guests. Upon addition of methoxide anions, the formation of the bis-acridane form of the receptor was observed. The chemical responsiveness of the receptor to these anions inhibits its recognition properties towards π-donor guests. In addition, the reversibility of the chemical response was demonstrated under acidic conditions.

Full text of DOI:10.1039/c7nj03712k

View Article Online
View Journal
NJC
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: A. Gosset, Z. Xu, F.
Maurel, L. Chamoreau, S. Nowak, G. Vives, C. PERRUCHOT, V. Heitz and H. Jacquot de Rouville, New J.
Chem., 2018, DOI: 10.1039/C7NJ03712K.
This is an Accepted Manuscript, which has been through the
Volume 40 Number
1 January 2016 Pages 1–846
Royal Society of Chemistry peer review process and has been
accepted for publication.
NJC
Accepted Manuscripts are published online shortly after
New Journal of Chemistry
www.rsc.org/njc
A journal for new directions in chemistry
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 1144-0546
PAPER
Jason B. Benedict et al.
The role of atropisomers on the photo-reactivity and fatigue of
diarylethene-based metal–organic frameworks
rsc.li/njc

Please do not adjust margins
New Journal of Chemistry
Page 1 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
Journal Name
ARTICLE
A Chemically-Responsive bis-Acridinium Receptor
A. Gosset,a Z. Xu,a F. Maurel,*a L.-M. Chamoreau,b S. Nowak,a G. Vives,b C. Perruchot,a V. Heitz*c
and H.-P. Jacquot de Rouville*a,c
Received 00th January 20xx,
Accepted 00th January 20xx
A dicationic receptor based on two acridinium moieties linked by a triphenylene spacer has been studied in solution and in
the solid state. The recognition moieties, namely acridiniums, have been exploited to evidence a host-guest response of
the receptor with electron rich guests. Upon addition of methoxide anions, the formation of the bis-acridane form of the
receptor has been observed. The chemical responsiveness of the receptor to these anions inhibits its recognition
properties towards π-donor guests. In addition, the reversibility of the chemical response has been demonstrated under
DOI: 10.1039/x0xx00000x
www.rsc.org/
acidic
conditions.
numerous efforts to synthesize a number of systems in order
to understand and control these interactions.5,6,7 Among these
systems, molecular tweezers are an important class of
molecules8 wherein two recognition units are pre-organized to
interact with organic and inorganic polyaromatic guests.9
Since the pioneer work of Zimmerman and his co-workers,10 9-
phenyl-acridines11 and their positively charged counterparts,
namely 9-phenyl-N-acridiniums,12 have been used for the
recognition of electron rich aromatic guests. However, until
now the switching ability of the 9-phenyl-N-acridinium has
been scarcely exploited in the field of supramolecular
chemistry.13 The photo switching properties of the 9-phenyl-N-
acridiniums was used to trigger the motion of a crown ether
macrocycle in a family of rotaxanes.13a-c More recently, 9-
phenyl-N-acridiniums were incorporated into the structure of a
chemically-switchable polyaromatic macrocycle to reversibly
bind long hydrophilic molecules in water.13d The 9-phenyl-N-
acridinium building block show several mesomeric forms and
two of them exhibit i) a pyridinium central core and ii) a
triarylium motif (Scheme 1). Like triarylmethane dyes (e.g.
malachite green),14 they demonstrate chemically-responsive
behaviour.15 The positive charge of the 9-phenyl-N-acridiniums
can formally be seen as localized on the carbon at the 9-
position. Therefore, the addition of a hydroxide ion leads to
the formation of an acridane derivative, this reaction being
reversible under acidic conditions.
Introduction
Molecular switches are systems changing their chemical and
physico-chemical properties (colorimetric/fluorometric,
conductivity, etc.) as the result of external stimuli (light,
protons, metal cations, anions, temperature, etc.) The most
common switches incorporate photo- and/or electro-
responsive species such as dimethyldihydropyrene,1
spiropyran2 and diarylethene.3 These components form a
unique class of building blocks that hold promise for emerging
applications in molecular electronics and smart material
design.4 The logical evolution of these materials will be their
incorporation in supramolecular architectures in order to
favour (or disfavour) weak interactions between different
components thus paving the path to a new generation of
receptors.
Non-covalent and weak forces, such as
π-π stacking
interactions are fundamental interactions for biological
systems. For example, these interactions combined with
hydrogen bonds ensure the three-dimensional organization of
double-strand architectures whereas they can engender
diseases when polyaromatics intercalate in between two
nucleobases of DNA. As a result, chemists have devoted
HO-
OH
H+
N
N
N
Pyridinium
Triarylium
Acridane
Mesomeric Form
Mesomeric Form
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
New Journal of Chemistry
Page 2 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
ARTICLE
Journal Name
Scheme 1. Two possible mesomeric forms of the 9-phenyl-N-methyl acridinium
molecule showing the regioselective addition of HO– anion.
Suitable single crystals for X-ray diffraction were grown by
slow vapor diffusion of Et2O into a concentrated solution of
1.2PF6 in CH3CN.18 The receptor 1.2PF6 adopts a
U
-shaped
-shaped
In this report, we focused on understanding the different
physicochemical and supramolecular recognition properties of
a new molecular system incorporating two acridinium subunits
connected by a triphenylene spacer. By organizing the two
acridinium units, we expected to observe molecular
recognition properties and to modulate them by a chemical
stimulus thanks to the chemical responsiveness of the
acridinium moiety. Herein, we describe i) the synthesis of the
receptor 1.2PF6, ii) its solid state characterization, iii) its
response to a chemical stimulus and iv) its recognition
properties in solution towards π-donors and its potential as a
switchable receptor.
conformation in the solid state (Figure 1). This
U
–
conformation is favoured by the inclusion of a PF6 counter-
ion. In this conformation the acridinium subunits are
positioned in two quasi parallel planes (offset angle of 7.34°).
As a result of this organization, the C9-C9 and N-N distances
values within a molecule are close (7.804 Å and 8.127 Å
–
respectively). The included PF6 counter-ion interacts with
both acridiniums of 1.2PF6 through [C•••F] close contacts of
3.111 Å for the shortest distance. The induced-fit ability of the
receptor was rendered possible on account of the torsion
angle existing with the triphenyl spacer, 111.18° and 93.52°.
This observation is the result of the steric hindrance existing
between the protons at the 1- and 8- positions of the
acridinium units and the adjacent protons of the spacer. The
triphenyl spacer shows an out-of-plane distortion of its central
phenyl as the result of the steric hindrance existing between
the central C-H pointing towards the cavity and the two
corresponding C-H of the two external phenyls. The crystal
packing (see ESI, Fig. S7) shows that the molecules of 1.2PF6
are aligned in a top-to-tail arrangement along c axis and
according to a ladder type structure along the median of the a
and b axis. Noteworthy, the second PF6– counter-ion is located
in between two cavities of two acridiniums of two different
molecules of 1.2PF6 as the result of [CH•••F] close contacts of
2.406 Å thus providing additional interactions for the crystal
stabilization.
Results and discussion
Synthesis
The synthesis of the target molecule 1.2PF6 bearing two
acridinium units was performed in three synthetic steps as
shown in Scheme 2. First, the functionalization of 1,3-
dibromobenzene with bis(pinacolato)diboron was carried out
under Suzuki-Miyaura conditions using Pd(dppf)Cl2 as catalyst
and KOAc as base. After purification by column
chromatography,
1,3-bis(4,4,5,5-tetramethyl-1,3,2-
2
) was isolated in 89% yield.16
dioxaborolan-2-yl)benzene (
Compound
2 was then reacted with 1,3-dibromobenzene (3
eq.) in DMF under Suzuki cross-coupling conditions using
Pd(PPh3)4 as catalyst (20%) and K3PO4 (3 eq.) as base. The 3,3''-
dibromo-1,1':3',1''-terphenyl (
Finally, introduction of the acridinium units was performed by
metal-halogen exchange of using a 2.5M solution of n-BuLi in
3) was isolated in 59% yield.
3
hexanes, then followed by addition of 10-methyl-9(10H)-
acridone17 at –78°C (2 eq.). Acidification of the reaction
mixture with a 2N solution of HCl in H2O afforded the bis-
acridinium compound as chloride salt (1.2Cl) which was further
converted to the hexafluorophosphate salt by anion
metathesis using KPF6. After filtration, the receptor (1.2PF6
)
Figure 1. Solid state structure of the receptor 1.2PF6. a) Scheme of the 1.2PF6. b) Side
was obtained as a yellow solid in 87 % yield.
–
view of the receptor showing the U-shape conformation and the inclusion of a PF6
counter-ion inside the cavity formed by the two acridinium units. c) Top view of the
receptor showing the distortion of the triphenyl linker.
PF6
Br
Br
N
N
O
B
–
The calculated optimized geometry with two PF6 was also
O
O
Br
Br
iii)
ii)
i)
found to be the U
-shaped conformation with one PF6– included
between the two acridinium units (Figure 2). This observation
confirmed the stabilizing electrostatic interactions between
–
the PF6 anion and positively charged acridinium arms. As
B
O
PF6
1.2PF6
2
3
illustrated in Figure 2, the C9-C9 and N-N distances were
calculated to be 7.91 Å and 8.12 Å in 1.2PF6 and 7.98 Å and
8.57 Å in 12+. All these values are in excellent agreement with
the X-ray structure (7.804 Å and 8.127 Å, respectively).
Scheme 2. Synthesis of the bis(acridylium) receptor (1.2PF6) from 1,3-dibromobenzene
as starting material: (i) bis(pinacolato)diboron (2.5 eq.), Pd(dppf)Cl2 (10%), KOAc (3 eq.),
DMF, 80°C, 16 h (89%); (ii) 1,3-dibromobenzene (3 eq.), Pd(PPh3)4 (20%), K3PO4 (3 eq.),
DMF, 80°C, 16 h (59%); (iii) a) n-BuLi (2.1 eq.), THF, –78°C, 30 min, b) 10-methyl-9(10H)-
acridone (2.2 eq.), –78°C to RT, 16h, c) HCl (2N), H2O, 30 min, d) KPF6(s), H2O, RT (87%).
Solid State Structure
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
New Journal of Chemistry
Page 3 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
Journal Name
ARTICLE
geometry is less stable by 10.3 kJ.mol–1. This result is
consistent with general findings for aromatic-aromatic
interactions.19 Other conformations, namely
shaped, were obtained by varying the and
S
-shaped and
dihedral angles.
-shaped
W-
β
γ
Their energies were found to be similar to the
U
conformation suggesting that the interaction between both
acridiniums is negligible. These results are in agreement with
the low rotational barrier observed in the VT NMR studies.
Figure 2. Optimized U-shaped conformations of (a) 1.2PF6. and (b) bis-acridinium 12+
Solution Studies
The conformations of receptor 1.2PF6 were also studied in
solution by a combination of 1D (1H, 13C, 19F and 31P) and 2D
(namely COSY, HSQC and HMBC) NMR experiments. The 1H
NMR spectrum of 1.2PF6 in acetone-d6 reveals sharp signals in
the aromatic region in agreement with free rotations in 1.2PF6
thus witnessing the relatively low rotation barrier between the
different conformers of the molecule (fast exchange regime,
Figure 3a). Upon cooling, a broadening of all 1H signals are
observed on account of the slower rotations in both 9-phenyl-
N-acridinium moieties and the triphenyl linker which
corresponds to the intermediate exchange regime (Figure 3b
and ESI, Figure S3.23). At 193 K (lowest temperature reachable
in acetone-d6) no rotational freezing was observed at the NMR
timescale. In an attempt to reach the slow exchange regime,
increasing of the applied field from 400 to 600 MHz did not
Figure 4. Local minima of 1.2PF6 obtained by varying the dihedral angles (α, β, γ, δ);
DFT calculations (top) and their corresponding representative schemes (bottom).
Chemical Response
lead to
temperature (Figure S3.24). This observation suggests a low
rotational barrier between the different conformers of 1.2PF6
a simplification of the NMR spectrum at low
We were interested in probing the chemical responsive
.
properties of 1.2PF6
.
Upon addition of
hydroxide (TBAOH),
2
eq. of
tetrabutylammonium
immediate
bleaching of the yellowish solution of 1.2PF6 was observed
with the formation of a precipitate. The dihydroxylated
acridane was not soluble enough to allow its full
characterization by NMR spectroscopy in most common NMR
solvents. As a consequence, 1.2PF6 was converted into its
more soluble dimethoxylated derivative
was reacted in methanol with K2CO3 (3.3 eq) to afford the
desired bis-acridane as a white solid in quantitative yield (see
ESI). As expected, the H spectrum in DMSO-d6 of
4. The receptor 1.2PF6
4
1
4
shows a
dearomatization of the acridinium moieties compared to
1.2PF6 (Figure 5b). Large upfield shifts of the characteristic
signals of the acridinium subunits were monitored (ꢀH1/8 =
0.80 ppm, H2/7 = 0.62 ppm, H3/6 = 1.52 ppm and H4/5 = 1.60
ꢀ
ꢀ
ppm) reflecting the disappearance of their positive charges. An
ꢀ
analogous upfield shift was observed for the methyl protons
(ꢀMe = 1.43 ppm) which is consistent with the loss of
aromaticity of the acridinium cores. Additionally, a new singlet
Figure 3. Partial 1H NMR (400 MHz, Acetone-d6) spectra of 1.2PF6 at 298 K (top
spectrum) and 208 K (bottom spectrum). The red arrows indicate the fast free rotation
around the C-C bonds at 298K.
appears at 3.51 ppm assigned to the methoxy protons of the
newly formed acridane. Upon addition of
1
2 eq. of
trifluoroacetic acid (TFA), the original H NMR spectrum of 12+
The various conformations of the isolated bis-acridinium
compound 12+ were further investigated by DFT calculations
(Figure 4). As the result of the variation of the torsion angles
was restored. This observation can be rationalized by the
elimination of two methanol molecules (δ = 3.16 ppm, Figure
5c) leading to the re-aromatization of the acridinium cores.
(α
,
β
,
γ
, and
adopt several conformations. In its most stable conformation,
12+ shows a
-shaped geometry (edge to face interactions
δ
dihedral angles, Figure 4 and Table S6.1), 12+ can
T
between the two acridylium moieties) while the
U-shaped
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
New Journal of Chemistry
Page 4 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
ARTICLE
Journal Name
Figure 6. UV-Vis spectra of a solution (DMF, c = 4.10-5 mol.L–1, l = 1 cm) of 4 before (red)
and after addition of excess of TFA (blue) and a solution of 1.2PF6 (blue dashed line).
These observations can be best interpreted in terms of the
regeneration of 12+ as the result of the loss of two methanol
molecules leading to the rearomatization of the acridinium
cores. In conclusion, 1.2PF6 presents reversible chemiochromic
properties coming from the clean conversion between its
aromatic acridinium form (absorbing in the visible region) and
its non-aromatic acridane form (absorbing in the near UV
region).
Figure 5. Partial 1H NMR (400 MHz, DMSO-d6, 298 K) spectra of (a) 1.2PF6 (c = 5.10-3
mol.L–1) and 4 (c = 5.10–3 mol.L–1) before (b) and after (c) addition of 2 eq. of TFA.
The switching was also monitored by UV-Vis spectroscopy. The
optical spectrum of 1.2PF6 (Figure 6) shows five maxima at 337
(
ε
= 17000 L.mol–1.cm–1), 360 (31150), 397 (11200), 426
(12450) and 450 nm (8300) in DMF. These transitions were in
agreement with the reported wavelengths in litterature20 and
reflect a linear superposition of the absorption of two 9-
phenyl-N-acridinium subunits in 1.2PF6. In other words, no
additional transitions were detected compared to a 9-phenyl-
N-acridinium moiety thus demonstrating that no electronic
coupling occurs in these conditions between the two subunits.
Calculations carried out on 12+ using TD-DFT method were
performed to gain insight into the nature of the two first low-
energy bands (Table S6.2). The first dipole-allowed absorption
is predicted at 411 nm, a value in remarkable agreement with
experiments (ca. 425 nm). This transition is predicted to arise
from a mixing of one-electron excitations from HOMO–2 and
HOMO–3 to the LUMO and LUMO+1 (Figure S6.1). The quasi-
degenerated two HOMOs and two LUMOs are localized on a
different acridinium units. This transition is mainly due to
Host-Guest Response
As shown in the X-ray structure, the large distance between
the acridinium units allows the inclusion of a planar and π-
conjugated guest. Although the average distance (7.95 Å)
between the two acridinium subunits was found in solid state
(vide supra) to be above the optimum distance (7 Å) for
stacking interactions, we were interested in probing inclusion
complex formation in solution through stacking
π-π
π-π
interactions using two electron-rich guests, namely
tetrathiafulvalene (TTF) and pyrene. Shifts for all signals of
1.2PF6 were observed in 1H NMR upon addition of small
aliquots of a stock solution of the guests in CDCl3 to a solution
of 1.2PF6 (c = 10–2 mol.L–1) in CD3CN (Figure S4.1). As depicted
in Figure 6 using TTF as guest,
guest and the acridinium subunits is evidenced by the upfield
shift of the acridinium protons ( H1/8 = 0.12 ppm, H2/7 = 0.09
ppm, H3/6 = 0.11 ppm and H4/5 = 0.12 ppm respectively)
π-π interactions between the
localized π-π* electronic excitation on each aromatic unit. A
second transition is calculated at 364 nm very close to the
experimental value recorded at 360 nm. This transition is
assigned from a mixing of H–5→L and H–4→L+1 excitaꢀons
corresponding to a charge transfer from a phenylene unit of
the central bridge to the acridinium units.
ꢀ
ꢀ
ꢀ
ꢀ
upon addition of 7 eq. of TTF. The inclusion of TTF was
confirmed by the downfield shifts of the inner protons of the
triphenyl spacer (ꢀH = 0.04 and 0.02 ppm respectively).
In comparison, the UV–Vis spectrum of 4 shows an absorbance
Noteworthy, the TTF signal at 6.2 ppm is broadened as the
result of its dynamic complexation on the NMR timescale (see
ESI, Figure S4.3). In a similar manner, upfield shifts of the
only in the UV region at 275 (30300), 310 (9500) and 326 nm
(7600) as depicted in Figure 5. Upon addition of an excess of
TFA (40 eq.), full restoration of the optical spectrum of 12+ was
observed with the appearance of the maxima at 360, 397, 426
and 450 nm.
acridinium protons (
= 0.43 ppm and H4/5 = 0.29 ppm respectively) are observed
upon addition of 15 eq. of pyrene. The chemical shifts of the
pyrene protons are also shifted upfield ( H1/3/6/8 = 0.02, H2/7
= 0.02 and H4/5/9/10 = 0.01 ppm) as the result of the
interaction of pyrene with 1.2PF6
ꢀH1/8 = 0.31 ppm, ꢀH2/7 = 0.14 ppm, ꢀH3/6
ꢀ
ꢀ
ꢀ
ꢀ
.
4 | 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
New Journal of Chemistry
Page 5 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
Journal Name
ARTICLE
The more pronounced shifts of the acridinium protons
compared to the triphenyl spacer protons can be explained by
the closer proximity of the guest to the charged moieties on
account of π-π interactions. These effects were confirmed by
DFT calculations indicating an intercalation of the TTF guest
between two acridinium units (Figure 7). The optimized
geometry of the inclusion complex TTF 12+ reveals that the
receptor 12+ adapts to the guest. The noticeable feature is a
shortening of the characteristic N-N and C9-C9 distances (from
8.57 to 7.10 Å and from 7.98 to 7.34 Å, respectively) when
compared to its isolated counterpart reflecting the interaction
between 12+ and TTF. The electrostatic potential of 12+ exhibits
a strong negative potential in the vicinity of acridinium units
and a more positive potential on the central phenylene of the
bridge (Figure 7b). The TTF shows positive potential consistent
with its electron rich character. As a consequence, the overlap
between the positive potential of TTF with the negative
potential of the two acridiniums units is responsible for the
electrostatic stabilization upon complexation (Figure 7c). The
interaction of TTF with 12+ is also confirmed by i) the analysis
of non-covalent interactions showing large attractive area
between planar aromatic rings (Figure S6.2) and ii) by the total
interaction energy calculated to be –123.3 kJ.mol–1. The
association constants with TTF and pyrene, fitted to a 1:1
binding model by NMR,21 were found to be similar (Ka ≈ 10 M–
1) for both guests. This rather low binding constant can be
rationalized by i) the acridinium-acridinium distance found to
Figure 7. Electrostatic potential surface of a) the isolated TTF, b) the receptor 12+ and c)
the TTF 12+ inclusion complex. d) Optimized geometry of the TTF 12+ inclusion
complex (ωB97xD/6-31G(d) calculations).
We were interested in probing the recognition properties of 4.
1H NMR titration experiments were performed in CDCl3 using
both guests. As expected, no binding was observed with bis-
acridane
4 derivative as host as the result of the
be slightly above the optimum distance for π-π stacking in the
dearomatization of the acridinium core. This observation is a
proof of concept of a modulation of the binding of this bis-
acridinium receptor by a chemical stimulus.
solid state structure of 1.2PF6 (7.95 Å), ii) the relative flexibility
of the triphenyl spacer and iii) the low energy barrier between
conformers leading to very different relative orientations of
both acridiniums in solution. Moreover, larger binding
constants could be expected by increasing the
π overlap
Conclusions
between the host and the guest such as in the case of
porphyrin tweezers.8e,23 As control experiments, titrations
have been carried out using 9-phenyl-N-acridinium monomer
as host. As expected, no binding affinity was observed for
either the TTF or pyrene guests thus suggesting a cooperative
assistance between the two acridinium moieties in 1.2PF6 even
if the binding constant are rather low. This cooperative effect
can also be confirmed by the color change observation upon
addition of guests to a solution of 1.2PF6 (see ESI, Figures S5.3
and S5.5, from yellowish to greenish solution for TTF 12+ and
to orange solution for Pyrene 12+). These colour changes are
the result of the appearance of new absorption bands in the
visible region of the spectra. These bands are absent in the
absorption spectra of the sum of the equimolar mixture of
host and guest. As a consequence, they can be attributed to a
charge transfer from the electron rich guest to the electron
poor receptor. The Ka values were found to be similar to the
Ka values found by NMR titrations for both guests, fitted to a
1:1 binding model.
The synthesis of a molecular receptor bearing two acridiniums
connected to a triphenyl spacer has been described. It exhibits
recognition properties in the solid state as well as in solution.
In the solid state, the receptor adopts a U-shaped structure on
account of the formation of an inclusion complex with one
hexafluorophosphate counter-ion. NMR titrations have
revealed the recognition properties of 1.2PF6 in solution with
electron donor guests (perylene, TTF) through
π-π stacking.
The receptor has also shown its ability to reversibly respond to
a chemical stimulus and to modify its structure upon addition
of nucleophiles (HO–, CH3O–) leading to its bis-acridane form.
In this form, the receptor does not exhibit any recognition
properties. Moreover, the chemical response can be best
interpreted in terms of chemiochromic response as
demonstrated by the changes in the optical spectra. Finally,
DFT calculations shed light on the electronic states of our
receptor. Work is underway to design and synthesize a new
receptor incorporating two acridiniums with enhanced
switchable receptor properties.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
New Journal of Chemistry
Page 6 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
ARTICLE
Journal Name
benchmark calculations for the 12+ in an water environment
and the calculated absorption energies are summarized in
Table S6.2 of the ESI. As can be seen from Table S6.2 (ESI), the
M06 method gives the absorption energies in excellent
agreement with experiment. Hence, the MO6 functional was
used to calculate the lowest singlet transitions from the
Experimental Section
Materials, syntheses and general procedures of the target
molecule 1.2PF6, including 10-methyl-9(10H)-acridone17 and
1,3-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) benzene
(2
),16 are provided in the ESI. All compounds were synthesized
optimized geometry calculated with
compounds
ωB97XD for all the studied
using Schlenk technics and were fully characterized by 1D (1H,
13C{1H}, 31P{1H} and 19F{1H}) and 2D (COSY, HSQC and HMBC)
NMR experiments and by mass spectrometry experiments.
NMR experiments were monitored at 400 MHz, on a Bruker
Advance III 400 at 298 K unless specified by other means. Mass
spectra (MS) were obtained using gas chromatography
(Finnigan Trace GC Ultra, Thermo Electron) coupled to a mass
spectrometer (Finnigan Trace DSQ, Thermo Electron) (GC–MS).
UV-Vis. Spectra were recorded on a Cary 500 spectrometer
and on a Perkin Elmer Lambda 1050 equipped with a 3D WB
detector module in the range 250-800 nm. A single crystal of
the compound was selected, mounted onto a cryoloop, and
transferred in a cold nitrogen gas stream. Intensity data were
collected with a BRUKER Kappa-APEXII diffractometer with
.
Acknowledgements
This work was supported by the CNRS, the Université Paris
Diderot, the Université Pierre and Marie Curie and the
Université of Strasbourg. AG thanks the ANR (E-storic project,
call 2014) and ZX thanks the French Ministry of National
Education for PhD Fellowships. Dr A. N. Basuray is thanked for
fruitful discussions.
Notes and references
graphite-monochromated Mo-K
α radiation (λ = 0.71073 Å).
1
a) S. Muratsugu, S. Kume, H. Nishihara, J. Am. Chem. Soc.,
2008, 130, 7204–7205; b) R. H. Mitchell, Eur. J. Org. Chem.,
1999, 2695–2703; c) D. Roldan, V. Kaliginedi, S. Cobo, V.
Kolivoska, C. Bucher, W. Hong, G. Royal, T. Wandlowskib, J.
Am. Chem. Soc., 2013, 135, 5974−5977.
Data collection were performed with APEX2 suite (BRUKER).
Unit-cell parameters refinement, integration and data
reduction were carried out with SAINT program (BRUKER).
SADABS (BRUKER) was used for scaling and multi-scan
absorption corrections. In the WinGX suite of programs,24 the
structure was solved with ShelxT25 program and refined by full-
matrix least-squares methods using SHELXL-14.26 All non-
hydrogen atoms were refined anisotropically. Hydrogen atoms
were placed at calculated positions and refined with a riding
2
3
4
a) G. Berkovic, V. Krongauz, V. Weiss, Chem. Rev., 2000, 100,
1741–1753; b) V. I. Minkin, Chem. Rev., 2004, 104, 2751–
2776; c) R. Klajn, Chem. Soc. Rev., 2014, 43, 148–184.
a) M. Irie, Chem. Rev., 2000, 100, 1685−1716. b) S. L. Gilat, S.
H. Kawai, J.-M. Lehn, Chem. Eur. J., 1995, 1, 275−284. c) A.
–
Peters, N. R. Branda, Chem. Commun., 2003, 954−955.
a) B. L. Feringa, W. R. Browne, (Eds. Molecular Switches, 2nd
ed.) Wiley-VCH, Weinheim, Germany, 2011; b) S. J. van der
model. A model of disorder was introduced for a PF6 anion
and for an acetonitrile molecule. The inability of DFT method
to correctly account for dispersive interactions is well known.
This problem is due to the fact that dispersion forces result
from long-range correlations between electrons, whereas
some of the current exchange-correlation potentials model
only local correlation effects. Several improvements to correct
the drawbacks of first functionals have been proposed. We
Molen, P. J. Liljeroth, Phys.: Condens. Matter, 2010, 22
133001; c) N. Darwish, A. C. Aragonès, T. Darwish, S. Ciampi,
,
I. Díez-Pérez, Nano Lett., 2014, 14, 7064−7070; d) S.-Z. Pu, Q.
Sun, C.-B. Fan, R.-J. Wang, G. Liu, J. Mater. Chem. C, 2016, 4,
3075–3093; e) B. Doistau, L. Benda, J.-L. Cantin, L.-M.
Chamoreau, E. Ruiz, V. Marvaud, B. Hasenknopf, G. Vives, J.
Am. Chem. Soc., 2017, 139, 9213–9220; f) M. Barboiu, A.-M.
Stadler, J.-M. Lehn, Angew. Chem. Int. Ed., 2016, 55, 4130–
4154.
used in this paper the long range corrected ωB97XD functional
that allow an accurate description of systems involving
noncovalent interactions with strong dispersion effects with a
moderate computational cost. All ab initio simulations have
been achieved with the GAUSSIAN09 program,27 applying
default procedures, integration grids, algorithms and
parameters, except when noted. The geometries of the
5
a) P. R. Ashton, B. Odell, M. V. Reddington, A. M. Z. Slawin, J.
F. Stoddart, D. J. Williams, Angew. Chem. Int. Ed. Engl., 1988,
27, 1550–1553, b) D. B. Amabilino, J. F. Stoddart, Chem. Soc.
Rev. 1995, 95, 2725–2828; c) J. F. Stoddart, Chem. Soc. Rev.,
2009, 38, 1521–1529 and 1802–1820; d) R. S. Forgan, J.-P.
Sauvage, J. F. Stoddart, Chem. Rev., 2011, 111, 5434–5464. e)
J. C. Barnes, M. Juríček, N. L. Strutt, M. Frasconi, S. Sampath,
M. A. Giesener, P. L. McGrier, C. J. Bruns, C. L. Stern, A. A.
Sarjeant, J. F. Stoddart, J. Am. Chem. Soc., 2013, 135, 183–
192.
studied compounds were optimized using both the
ω
B97XD28
hybrid exchange correlation functional and the standard 6-
31G* basis set.29 We have systematically computed the
vibrational spectrum on the minimized structures to check that
there is no imaginary vibrational mode. The complexation
energies between 1 and TTF have been estimated by energy
difference between the complex and the sum of the isolated
constituents. The complexation energy was corrected from the
basis set superposition errors (BSSE) using the standard
counterpoise (CP) approach. The modelling of bulk solvent
effects (here acetonitrile, as in the experiments) is included
through the Polarizable Continuum Model (PCM). The accuracy
of the different DFT functionals (such as PBE0, BLYP, CAM-
6
a) E. Breinlinger, A. Niemz, V. M. Rotello, J. Am. Chem. Soc.,
1995, 117, 5379–5380; b) E. C. Breinlinger, V. M. Rotello, J.
Am. Chem. Soc., 1997, 119, 1165–1166. c) A. Niemz, V. M.
Rotello, Acc. Chem. Res., 1999, 32, 44–52; d) G. Cooke, V. M.
Rotello, Chem. Soc. Rev., 2002, 31, 275–286.
7
8
a) J. Jazwinskia, A. J. Blacker, J.-M. Lehn, M. Cesario, J.
Guilhem, C. Pascard, Tetrahedron Lett., 1987, 28, 6057–
6060; b) S. Ulrich, J.-M. Lehn, Chem. Eur. J., 2009, 15, 5640–
5645.
a) C.-W. Chen, H. W. Jr. Whitlock, J. Am. Chem. Soc., 1978,
100, 4921–4922; b) M. Hardouin–Lerouge, P. Hudhomme, M.
Sallé, Chem. Soc. Rev., 2011, 40, 30–43; c) J. Leblond, A.
B3LYP, HSEH1PBE, LC-ωPBE, ωB97XD, M06 and M062X) for the
optical properties have been explored by performing
6 | 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
New Journal of Chemistry
Page 7 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
Journal Name
ARTICLE
Petitjean, ChemPhysChem, 2011, 12, 1043–1051; d) S. Asif
Ikbal, A. Dhamija, S. P. Rath, Chem. Commun., 2015, 51,
14107–14110; e) M. Tanaka, K. Ohkubo, C. P. Gros, R. Guilard
for the structures reported in this communication have been
deposited with the Cambridge Crystallographic Data Center
as supplementary publication no. CCDC–1560847.
S. Fukuzumi, J. Am. Chem. Soc., 2006, 128, 14625–14633; f) 19 C. R. Martinez, B. L. Iverson, Chem. Sci. 2012,
M. Linke-Schaetzel, C. E. Anson, A. K. Powell, G. Buth, E. 20 S. A. Jonker, F. Ariese, J. W. Verhoeven, Recl. Trav. Chim.
Palomares, J. D. Durrant, T. S. Balaban, J.-M. Lehn Chem. Eur. Pays-Bas 1989, 108, 109–115.
J., 2006, 12, 1931–1940; g) F.-G. Klärner, B. Kahlert Acc. 21 P. Thordarson, Chem. Soc. Rev., 2011, 40, 1305–1323.
Chem. Res. 2003, 36, 919−932. 22 L. J. Farrugia, J. Appl. Cryst., 1999, 32, 837–838.
3, 2191–2201.
9
a) A. J. Goshe, I. M. Steele, B. Bosnich, J. Am. Chem. Soc., 23 A. Chaudhary, S. P. Rath, Chem. Eur. J., 2012, 18, 7404–7417.
2003, 125, 444–451; b) Y. Tanaka, K. M.-C. Wong, V. W.-W. 24 G. M. Sheldrick, Acta Cryst., Section A, 2015, 71, 3–8.
Yam, Chem. Sci., 2012,
Wong, V. W.-W. Yam, Angew. Chem. Int. Ed., 2013, 52
14117–14120; d) Y. Tanaka, K. M.-C. Wong, V. W.-W. Yam,
3, 1185–1191; c) Y. Tanaka, K. M.-C. 25 G. M. Sheldrick, Acta Cryst., Section C, 2015, 71, 3–8.
,
26 M.J. Frisch, et al., GAUSSIAN 09 Revision A.02, Gaussian Inc.,
Wallingford CT, 2009.
Chem. Eur. J., 2013, 19, 390–399; e) B. Doistau, C. Rossi- 27 a) J. D. Chai, M. Head-Gordon, J. Chem. Phys., 2008, 128
,
Gendron, A. Tron, N. D. McClenaghan, L.-M. Chamoreau, B. 084106; b) J. D. Chai, M. Head-Gordon, Phys. Chem. Chem.
Hasenknopf, G. Vives, Dalton Trans., 2015, 44, 8543–8551; Phys., 2008, 10, 6615–6620.
f) B. Doistau, A. Tron, S. A. Denisov, G. Jonusauskas, N. D. 28 V. A. Rassolov, M. A. Ratner, J. A. Pople, P. C. Redfern, L. A.
McClenaghan, G. Gontard, V. Marvaud, B. Hasenknopf, G.
Vives, Chem. Eur. J., 2014, 20, 15799–15807.
Curtiss, J. Comput. Chem., 2001, 22, 976–984.
29 J. Tomasi, B. Mennucci, R. Cammi, Chem. Rev., 2005, 105
2999–3094.
,
10 a) S. C. Zimmerman, Z. Zeng, W. Wu, D. E. Reichert, J. Am.
Chem. Soc., 1991, 113, 183–196; b) S. C. Zimmerman, K. W.
Saionz, J. Am. Chem. Soc., 1995, 117, 1175–117; c) S. C.
Zimmerman, K. W. Saionz, Z. Zeng, Proc. Nat. Acad. Sci. USA,
1993, 90, 1190–1193; d) S. C. Zimmerman, C. M. VanZyl, G. S.
Hamilton, J. Am. Chem. Soc., 1989, 111, 1373–1381; e) S. C.
Zimmerman, C. M. VanZyl, J. Am. Chem. Soc., 1987, 109
,
7894–7896; f) S. C. Zimmerman, W. Wu, J. Am. Chem. Soc.,
1989, 111, 8054–8055; g) S. C. Zimmerman, M. Mrksich, M.
Baloga, J. Am. Chem. Soc., 1989, 111, 8528–8530.
11 a) P. Cudic, J.-P. Vigneron, J.-M. Lehn, M. Cesario, T. Prangé,
Eur. J. Org. Chem., 1999, 2479–2484; b) S. Claude, J.-M. Lehn,
J.-P. Vigneron, Tetrahedron Lett., 1989, 30, 941–944.
12 a) A. Petitjean, R. G. Khoury, N. Kyritsakas, J.-M. Lehn, J. Am.
Chem. Soc., 2004, 126, 6637–6647; b) S. Claude, J.-M. Lehn,
F. Schmidt, J.-P. Vigneron, J. Chem. Soc., Chem. Commun.,
1991, 1182–1185.
13 a) A. Vetter, W. Abraham, Org. Biomol. Chem., 2010,
4666–4681; b) W. Abraham, A. Wlosnewski, K. Buck, S.
Jacob, Org. Biomol. Chem., 2009, , 142–154; c) W. Abraham,
8,
7
K. Buck, M. Orda-Zgadzaj, S. Schmidt-Schäffer, U.-W.
Grummt, Chem. Commun., 2007, 3094–3096. d) K. Kurihara,
K. Yazaki, M. Akita, M. Yoshizawa, Angew. Chem. Int. Ed.
Engl., 2017, 56,11360 –11364.
14 a) M. Irie, J. Am. Chem. Soc., 1983, 105, 2079–2080; b) M.
Irie, D. Kunwatchakun, Macromolecules, 1986, 19, 2480–
2484; c) K. Kimura, R. Mizutani, M. Yokoyama, R. Arakawa, G.
Matsubayashi, M. Okamoto, H. Doe, J. Am. Chem. Soc., 1997,
119, 2062–2063; d) K. Kimura, M. Kaneshige, M. Yokoyama,
J. Chem. Soc. Chem. Commun., 1994, 1103–1104; e) K.
Kimura, M. Kaneshige, M. Yokoyama, Chem. Mater., 1996, 7,
945–950.
15 a) A. J. Ackmann, J. M. J. Frechet, Chem. Commun., 1996,
605–606; b) D. Zhou, R. Khatmullin, J. Walpita, N. A. Miller,
H. L. Luk, S. Vyas, C. M. Hadad, K. D. Glusac, J. Am. Chem.
Soc., 2012, 134, 11301–11303; c) A. Raskosova, R. Stößer, W.
Abraham, Chem. Commun., 2013, 49, 3964–3966.
16 F. S. Han, M. Higuchi, D. G. Kurth, Org. Lett., 2007, 9, 559–
562.
17 L. A. Andronico, A. Quintavalla, M. Lombardo, M. Mirasoli,
M. Guardigli, C. Trombini, A. Roda, Chem. Eur. J., 2016, 22
18156–18168.
,
18 Crystal data for 1.2PF6: C46H34N2,2(PF6),2(C2H3N), yellow
needle, crystal size 0.25 x 0.12 x 0.11 mm3, triclinic, space
group P–1, a = 7.9128(6) Å; b = 16.8566(1) Å; c = 17.3103(1)
Å;
α
= 88.592(2)°;
ρ
β
= 88.414(2)°;
γ
calcd = 1.432 , T = 200(2) K, R1(F2 > 2
= 82.929(2)
°
; V = 2289.94
Å3, Z = 2,
wR2 = 0.1289. Out of 78626 reflection a total of 13455 were
unique. Crystallographic data (excluding structure factors)
σF2) = 0.0470,
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

New Journal of Chemistry
Page 8 of 8
View Article Online
DOI: 10.1039/C7NJ03712K
The recognition and the chemical-response properties of a bis-acridinium triphenylene receptor have
been investigated.