A novel donor-π-acceptor halochromic 2,6-distyrylnaphthalene chromophore: synthesis, photophysical properties and DFT studies

Article abstract of DOI:10.1039/d0ra08508a

In this study a new 2,6-distyryl naphthalene [2-((4-((E)-2-(6-((E)-2,4-bis(methylsulfonyl)styryl)naphthalen-2-yl)vinyl)phenyl)(ethyl)amino)ethan-1-ol;ASDSN] was synthesized successfully using Heck chemistry as the main reaction. TheASDSNcompound is a dono

Full text of DOI:10.1039/d0ra08508a

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A novel donor–p–acceptor halochromic 2,6-
distyrylnaphthalene chromophore: synthesis,
Cite this: RSC Adv., 2021, 11, 168
photophysical properties and DFT studies†
a
Ali Mahmoodi,‡b Sajjad Ghodrati‡b and Fazlolah Eshghia
*
Farhad Panahi,
In this study a new 2,6-distyryl naphthalene [2-((4-((E)-2-(6-((E)-2,4-bis(methylsulfonyl)styryl)naphthalen-
2-yl)vinyl)phenyl)(ethyl)amino)ethan-1-ol; ASDSN] was synthesized successfully using Heck chemistry as
the main reaction. The ASDSN compound is a donor–pi–acceptor (D–p–A) conjugated system with
amino as electron donating and sulfonyl as electron withdrawing groups. The UV-vis absorption of
ASDSN was observed in the range of 403–417 nm with high molar extinction coefficients (3 ¼ 15 300–
56 200 Mꢀ1 cmꢀ1) in some different solvents. This new fluorescent 2,6-distyryl naphthalene compound
emits in the yellow region of the visible spectrum (557 nm) with Stokes shifts of 5930 cmꢀ1. ASDSN is
a pH-responsive fluorescence compound that shows yellow fluorescence in neutral form and blue
fluorescence in the protonated form. A white light emission (WLE) for the chromophore was observed at
pH ¼ 3.0. The ASDSN chromophore presented a satisfactory white light quantum yield (F) of 13% which
was desirable for producing white light emitting devices. Density functional theory (DFT) and time-
dependent (TD)-DFT were applied to study structural and electronic properties of the chromophore.
Received 6th October 2020
Accepted 9th December 2020
DOI: 10.1039/d0ra08508a
rsc.li/rsc-advances
synthesize these conjugated spacers, two important organic
transformations, namely Wittig and Heck reactions, are used.
Introduction
Depends on the availability of starting materials and the
strategy used to prepare the stilbene and distyrylbenzene
molecules, one of the aforementioned reactions is preferred to
be used. While sometimes, a combination of both reactions is
required to obtain desired stilbene and distyrylbenzene
compounds. Typically, feeding compounds participating in the
above mentioned reactions are already modied with electron
donating and electron withdrawing substitutes.
The emission of distyrylbenzenes highly depends on the
nature of electron donating and the electron-acceptor groups.
With increasing the strength of the donor and/or the acceptor
groups, frequently, a bathochromic shi is observable. So that,
by use of suitable electron-donating and the electron-acceptor
groups, the ICT band can even appear in the range of near
and far-infrared.14,15 Sulfone (–SO2R), is one of the most inter-
esting electron-acceptor groups that features remarkable
mobility of charge carriers which is an important photophysical
property in p-conjugated systems. In addition, hydrophobic
rigid backbone of sulfone group with excellent charge genera-
tion property can facilitate the electron migration in the struc-
ture of molecule, which is another essential character in
photonics.16 Amine functional groups are considered as
compelling candidates to be used as efficient electron-donating
moieties. The electron pair of amino groups can act as a ligand
or base to coordinate with metals and abstract protons,
respectively. Consequently, the amino-functionalized stilbene-
based uorescent materials are examined as potential sensors
The synthesis of uorophores incorporating distyrylbenzene p-
conjugated systems has attracted considerable attention
because of their high potential applications in optoelectronic
and sensory devices as well as uorescent probes in medical
utilization and in organic light-emitting diodes.1–6 On the other
hand, organic molecules that possess intramolecular charge
transfer (ICT) character are important in a large number of
areas, such as organic solar cells, polarity probes and nonlinear
optics.7,8
Donor–p–acceptor (D–p–A; where D is an electron-donating
group, A is an electron-accepting group, and p is a conjugating
moiety) systems with different congurations have been exten-
sively developed because their absorption spectra and energy
gaps can be readily tuned by controlling the ICT character using
different electron-donor and electron-acceptor groups. This
belonging plays an important role in the improvement of the
photophysical properties of photonic devices.9–11
Distyrylbenzenes are a well-known type of uorescent dyes
that possess high photochemical and thermal stability.12,13 To
aChemistry Department, College of Sciences, Shiraz University, Shiraz 71454, Iran.
E-mail: Panahi@shirazu.ac.ir
bDepartment of Polymer Engineering and Color Technology, Amirkabir University of
Technology, Tehran, Iran
† Electronic supplementary information (ESI) available. See DOI:
10.1039/d0ra08508a
‡ These authors contributed equally.
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for detecting metal ions.17–19 Moreover, substantial shis in the the molecule in order to have a strong push–pull effect. We
absorption and emission of amino-functionalized stilbenes are showed that the ASDSN chromophore experience a hyp-
observed upon protonation, representing pH-sensory capability sochromic shi from yellow to blue with the variation of pH and
of these materials.20 In other words, they are halochromic emit white light at pH ¼ 3. The chromophore presents
chromophores with tunable uorescence through regulation of a remarkable quantum yield (F) with the maximum value of 13
pH. More interestingly, they can emit white uorescence at and 49% in its protonated and neutral state, respectively.
specic pH, because the emission of the neutral and protonated
forms of amino-functionalized stilbenes is different due to the
presence of different molecule forms simultaneously. There-
fore, the emission spectra cover the entire visible region ranging
Results and discussion
The Heck reaction using a palladium-catalyzed process was
employed as a main organic transformation for the synthesis of
the ASDSN chromophore (Scheme 1). The coupling partners in
the Heck reaction are aryl halides and alkenes.13 Therefore, aryl
halides A and B and also alkenes C and D were synthesized
using available starting materials using organic trans-
formations as shown in Scheme 1. To prepare the alkene
intermediate D a controlled Heck reaction between aryl
bromide A and alkene C was accomplished. Finally, the
coupling reaction of alkene D and aryl iodide B afforded
compound ASDSN with 87% isolated yield as a red solid.
from 400 nm to 700 nm leading to white light emission
(WLE).21–28 This exceptional feature enables white light emitter
chromophores to be utilized in single-component white organic
light-emitting diodes (WOLEDs).29
In this study, in continuation of our previous reports13,30–33
we synthesized a new D–p–A 2,6-distyryl naphthalene molecule
containing an amino group as electron-donating and sulfonyl
group as electron-withdrawing group in the terminals of the p-
conjugated system. Two sulfonyl groups were used in ortho and
para positions of the benzene ring in the acceptor terminal of
Scheme 1 Synthetic routes to prepare compound ASDSN. (i) K2CO3, Me–I, acetone, 50 ꢁC, 6 h. (ii) Bu4NBr (5 mol%), HNO3 (15% w/w),
dichloroethane, 20 ꢁC. (iii) AcOH, H2O2, CH2Cl2, 0 ꢁC-reflux, 2 h. (iv) I2, dioxane/pyridine, 0 ꢁC to rt, 3 h. (v) LiAlH4. (vi) PCC. (vii) Ph3PMeBr, KOtBu,
THF, rt, 18 h. (viii) Pd(OAc)2 (1.2–1.8 mol%), bis[(2-diphenylphosphino)phenyl] ether (DPEPhos) (2.5–3.6 mol%), K2CO3, DMF, 120 ꢁC, 6–12 h.
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Fig. 1 UV-vis spectra (a) and emission spectra (b) of ASDSN chromophore at concentration of 10ꢀ5 M in different solvents. The photographs of
the chromophore in different solutions [from left to right, xylene, dichloromethane (DCM), ethyl acetate (ETA), ethanol, and dimethyl formamide
(DMF)] were taken under natural daylight simulator (D65) lamps (top image), and irradiation of A-Class UV lamps (bottom image) (c).
Table 1 Optical data of the ASDSN chromophore
solvent polarity that is related to the low dipole moment of the
ground state of ASDSN. ASDSN was found to be uorescence
lab
lem
Stockes shi
3
only in xylene with an emission band of 557 nm as well as an
excellent uorescence quantum yield (F) of 0.49. However, its
uorescence was quenched in more polar solvents. The
observed strong uorescence quenching in more polar solvents
may be attributed to the non-radiative relaxation process. In
other words, polar solvents can stabilize the excited state of the
chromophore, decrease the energy level between the ground
and excited state, and promote radiation less decay.34–36
The absorption and emission spectra of the compound in
xylene containing various amounts of triuoroacetic acid (TFA)
were recorded to investigate the effect of pH on its photo-
physical. The obtained results are shown in Fig. 2.
Solvent (nm) (nm) (cmꢀ1
)
(L Mꢀ1 cmꢀ1
)
Ea (eV) Fb
Xylene
ETA
DCM
417
407
414
557
—
—
—
—
5930
—
—
—
—
15 300
41 100
56 200
24 700
49 000
2.61
2.67
2.58
2.54
2.53
0.49
—
—
—
—
Ethanol 408
DMF
403
a
Calculated from the absorption spectra by using the empirical formula
b
of
E
(eV)
¼
hc/lonset
¼
1240 (eV nm)/lmax (nm).
9,10-
Diphenylanthracene was used as standard (F ¼ 0.90 in cyclohexane).
As shown in Fig. 2, with the decrease of pH from 7 to 4, no
signicant shi was observed for both absorption and emission
bands of the chromophore. Further decreasing of pH from 4 to
1 caused a signicant blue shi in the absorption and emission
bands of the ASDSN chromophore. The color of the solution
containing the ASDSN chromophore was changed from yellow
to colorless, and its uorescence color was changed from yellow
to blue. The blue shi values for the chromophore were found
to be 121 nm (from 405 to 284 nm) and 132 nm (from 554 to 422
nm) for the absorption and emission bands, respectively, when
pH was changed from 7 to 1. These results can be attributed to
Aer synthesis and characterization of the ASDSN molecule,
its photophysical properties were investigated. The absorption
and emission spectra of the chromophore in different solvents
from low to high polarity were obtained to study the effect of
solvent polarity on the photophysical behavior of the chromo-
phore. The obtained results are shown in Fig. 1 and Table 1.
The ASDSN chromophore showed a broad and structure-less
absorption band around 400 nm attributed to the ICT transition
arising from the push–pull effect of the donor (amine) and the
acceptor groups (sulfonyl). The absorption band of ASDSN
chromophore experienced a minor change with the variation of
Fig. 2 UV-vis spectra (a) and emission spectra (b) of the ASDSN chromophore in xylene at concentration of 10ꢀ5 M upon adjustment of pH from
1 to 7 by TFA. The photographs of the solutions (pH increases from left to right) were taken under natural daylight simulator (D65) lamps (top
image), and irradiation of A-Class UV lamps (bottom image) (c).
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the protonation of the chromophore by the addition of TFA, yield (F) of 0.13. This nding represented the great potential of
which decreases the ICT character of the chromophore (Fig. 3a). this chromophore for white lighting device fabrication.
In general, amine groups, as a strong electron donor in the
A DFT study was accomplished to have the frontier molec-
push–pull uorescent molecule, are protonated in the presence ular orbitals of ASDSN and H-ASDSN [the highest occupied
of acids and converted to an electron acceptor (quaternary molecular orbital (HOMO) and lowest unoccupied molecular
ammonium salt; H-ASDSN). Consequently, the lack of electron- orbital (LUMO) orbitals] (Fig. 3b). The shape of orbitals shows
donating ability in the structure of the molecule interrupts the that the HOMO and LUMO of ASDSN are both more centralized
push–pull effect of the chromophores and decreases its ICT on donor (amino) and acceptor (sulfone) groups, respectively.
character.37–41 The most striking result to emerge from the data While, H-ASDSN HOMO and LUMO orbitals are mostly
shown in Fig. 2 was the broad emission for the chromophore at centralized on p-conjugated system. The optimized geometry
pH ¼ 3, which resulted in almost pure white uorescence with structure of both ASDSN and H-ASDSN are shown in Fig. 3d and
the commission international de l'eclairage (CIE 1931) color e, respectively. It seems that the geometry of ASDSN molecule
coordinates of (0.33, 0.32). This observation indicated that at aer protonation (in the form of H-ASDSN) not changed
specic pH, neutral and protonated form of the chromophore remarkably.
whose emission bands are complementary with a broad distri-
The interaction between ASDSN and solvents cause changing
bution could simultaneously exist in the solution and cause in energy levels and re-distribution of electrons, excited state,
white light emission.42–45 Another surprising outcome that dipole moment of the uorophore, and substantial Stocks
emerged from the data was a noticeable white light quantum shi.42,43 These issues describe by Lippert–Mataga (LM)
equation:
Fig. 3 Protonation of ASDSN and formation of H-ASDSN form and their equilibrium in acidic environment (a). The HOMO–LUMO shapes of
ASDSN and H-ASDSN and calculated energy gaps using DFT (b and c). Optimized structures of ASDSN (d) and H-ASDSN (e) using PBE/6-311++g
(d, p) level of theory.
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Table 2 Calculated stocks shift (cmꢀ1) and re-orientation of solvent
molecules (Df) in different solvents
lighting devices. Theoretical study showed that the sol-
vatochromic effect caused the changing of internal charge
transfer (ICT) and dipole moment. Also, the protonation of
luminophore mainly resulted in planarity and affected on the
ASDSN properties.
a
a
Solvents
nA
nE
Dn
3
n
Df
para-Xylene
ETA
DCM
Ethanol
DMF
19 263
19 415
19 924
20 741
20 113
16 418
16 356
16 552
17 016
16 569
2845
3059
3372
3725
3544
2.2705
2.3832
8.9300
24.8520
37.2190
1.4958
1.4960
1.4244
1.3617
1.4305
0.0033
0.0138
0.2170
0.2890
0.2747
Experimental section
General
a
Wave number of absorption and emission ðvA; vEÞ.
Chemicals were purchased from Merck and Aldrich chemical
companies. All the chemicals and solvents were used as received
without further purication. For known products the spectral
data were compared with those previously reported. For
recording 1H NMR and 13C NMR spectra we used a Bruker (250
MHz) Avance DRX and samples were dissolved in pure deuter-
ated CDCl3 with tetramethylsilane (TMS) as an internal stan-
dard.
FT-IR
spectroscopy
(Shimadzu
FT-IR
8300
spectrophotometer) was employed for characterization of the
products. Melting points were determined in open capillary
tubes in a Barnstead electro-thermal 9100 BZ circulating oil
melting point apparatus. The reaction monitoring was accom-
plished by TLC on silica gel PolyGram SILG/UV254 plates.
Column chromatography was carried out on columns of silica
gel 60 (70–230 mesh).
Fig. 4 Lippert–Mataga plot for protic and aprotic solvents at selected
level of theory.
1-Bromo-2,4-bis(methylsulfonyl)benzene (A)
2
2 ꢂ ðDmÞ
Dv ¼
Df þ constant
(1)
hca3
In order to synthesis compound A, benzene-1,3-dithiol was used
as available starting material. A 100 mL canonical ask was
charged with benzene-1,3-dithiol (10 mmol, 1.42 g), K2CO3
(25 mmol, 3.45 g) and acetone (50 mL) at 0 ꢁC. Then methyl
iodide (22 mmol, 3.1 g) was added drop wise to the reaction
where Dn, Dm, h, c, a and Df are Stocks shi, difference of dipole
moments, Planks constant, speed of light, radius of cavity, and
solvent properties (below equation), respectively.
ꢀ
ꢁ
ꢀ
ꢁ
n2 ꢀ 1
ꢁ
3 ꢀ 1
mixture for 1 h. The reaction mixture was reuxed at 50 C for
Df ¼
ꢀ
(2)
23 þ 1
2n2 þ 1
12 h. Aer completion of the reaction, the temperature was cool
down to rt and the solvent was removed. The dense liquid was
extracted with diethyl ether and the pure product was obtained
by distillation (88%). 1H-NMR (250 MHz, DMSO-d6/TMS)
d (ppm): 2.41 (s, 6H), 7.52–7.96 (m, 3H). The spectral data was
correspond to the previously reported method.46
For the bromination step, a 100 mL canonical ask was
charged with KBr (20 mmol, 2.4 g), nitric acid (21% w/w, 40
mmol), dichloroethane (DCM, 20 mL), 1,3-bis(methylthio)
benzene (10 mmol, 1.7 g), and tetrabutylammonium chloride
(3 mol%, 0.9 g) and stirred at room temperature for 24 h. Aer
the completion of the reaction, it was diluted with water (50 mL)
and DCM (50 mL). The organic layer was separated from the
aqueous layer and it was washed with saturated NaHCO3 and
This equation shows the re-orientation of solvent molecules
with dielectric constant (3) and refractive index (n). The used
solvents as different environments mainly result in change of
dipole moment of these p-conjugated molecules (Table 2).
In order to have Lippert–Mataga plot, the Stocks shi vs.
environmental polarity was plotted (Fig. 4). High R2 index (0.93)
in the Lippert–Mataga plot mainly conrms enhancing of
dipole moment of excited state with increasing solvent polarity.
Conclusion
In conclusion,
a novel stilbene-based chromophore was saturated NaCl. The organic layer was separated and dried over
synthesized through the Heck reaction. The compound showed MgSO4. Aer concentration of organic layer under reduced
a substantial hypsochromic shi from its neutral form with pressure, the product was obtained as yellow oil (85%) which
yellow uorescence to its protonated form with blue emission. was used for next step without further purication.47
The chromophore displayed WLE at pH ¼ 3 due to the simul-
The obtained sulde from previous step (2.0 g, 8 mmol) was
taneous presence of its neutral and protonated forms repre- dissolved in 15 mL of glacial acetic acid at 0 ꢁC. Aerward, 30%
senting pH-responsive uorescence. Remarkable white light hydrogen peroxide (6 mL) was added and it was reuxed for 2 h
quantum yields of this uorescent molecule either in its neutral and then poured on crushed ice. Crud product was ltered,
or its protonated forms implied high potential application of dried and puried by column chromatography using petroleum
this chromophore in the preparation of high-performance ether and ethyl acetate elunt to obtain pure product (A) as
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a white solid (2.0 g, 81%).46 1H-NMR (250 MHz, CDCl3/TMS) 13.0 mg) and it was evacuated and backlled with argon. Then
d (ppm): 3.65 (s, 6H), 7.48–7.95 (m, 3H). 13C-NMR (62.5 MHz, 5 mL of dry DMF was added to the reaction mixture under fellow
CDCl3/TMS) d (ppm): 47.9, 48.1, 126.8, 127.2, 135.1, 135.3, of argon and tube was sealed with a screw-cap and the resulting
140.8, 143.9. Anal. cal. C8H9BrO4S2 (313.18): C, 30.68; H, 2.90; S, mixture was heated in an oil bath at 120 ꢁC for 6 h. The reaction
20.47; found: C, 30.56; H, 2.81 0; S, 20.41.
was followed by TLC. Aer completion of the reaction, the
mixture was cooled down to room temperature and ltered and
the remaining solid was washed with dichloromethane (3 ꢂ 5
mL) in order to separate the catalyst. Aer the extraction of
dichloromethane from water, the organic extract was dried over
Na2SO4. The products were puried by column chromatography
(hexane/ethyl acetate: 10/1) to obtain the pure product (0.31 g,
75%). Yellow solid; mp 213–215 ꢁC. IR (KBr): 3749, 3441, 1851.5,
1419, 1304, 1165, 1134, 1103, 964, 818, 763, 509 cmꢀ1. 1H-NMR
(250 MHz, CDCl3/TMS) d (ppm): 2.47 (s, 3H), 2.48 (s, 3H), 5.38
(d, J ¼ 11.0 Hz, 1H), 6.01 (d, J ¼ 17.5 Hz, 1H), 6.89 (dd, J ¼ 17.6,
10.7 Hz, 1H), 7.68 (s, 1H), 7.75–7.85 (m, 3H), 7.92–8.01 (m, 4H),
8.08 (d, J ¼ 3.2 Hz, 1H), 8.28–8.32 (m, 1H), 8.41 (d, J ¼ 1.7 Hz,
1H). 13C-NMR (62.5 MHz, CDCl3/TMS) d (ppm): 41.2, 42.0, 113.3,
128.5, 128.9, 129.0, 131.0, 131.6, 132.2, 132.3, 133.8, 134.0,
134.5, 135.6, 135.8, 139.2, 139.3. Anal. cal. C22H20O4S2 (412.5):
C, 64.05; H, 4.89; O, 15.51; S, 15.55; found: C, 64.11; H, 4.93.
2-(Ethyl(4-iodophenyl)amino)ethan-1-ol (B)
This compound was synthesized as a white solid based on
a known procedure in the literature.48 1H-NMR (250 MHz,
CDCl3/TMS) d (ppm): 1.16 (t, J ¼ 7.0 Hz, 3H), 1.61 (brs, 1H),
3.35–3.43 (m, 4H), 3.75 (t, J ¼ 5.5 Hz, 2H), 6.50 (d, J ¼ 8.5 Hz,
2H), 7.42 (d, J ¼ 8.5 Hz, 2H). 13C-NMR (62.5 MHz, CDCl3/TMS)
d (ppm): 11.7, 45.5, 52.4, 60.0, 114.9, 123.8, 137.7, 147.6. Anal.
cal. C10H14INO (291.13): C, 41.26; H, 4.85; N, 4.81; found: C,
41.17; H, 4.78; N, 4.75.
2,6-Divinylnaphthalene (C)
This material was prepared in three steps using known proce-
dures in the literature starting from naphthalene-2,6-
dicarboxylic acid as commercially available chemical. First,
naphthalene-2,6-dicarboxylic acid was converted to 2,6-bis(hy-
droxymethyl)naphthalene.49 A white solid was obtained which
its spectral data completely matched to the previously reported
2-2-2-{[4-(2-{6-[2-(2,4-Bis-methanesulfonyl-phenyl)-vinyl]-
naphthalen-2-yl}-vinyl)-phenyl]-ethyl-amino}-ethanol (ASDSN)
1
one. H-NMR (250 MHz, CDCl3/TMS) d (ppm): 4.11 (brs, 2H),
4.71 (d, J ¼ 5.8 Hz, 2H) 7.47–7.50 (m, 2H), 7.79 (s, 2H), 7.81–7.84
(m, 2H). Anal. cal. C12H12O2 (188.23): C, 76.57; H, 6.43; found: C,
76.51; H, 6.34.
Next, 2,6-bis(hydroxymethyl)naphthalene was converted to
naphthalene-2,6-dicarbaldehyde using an oxidation process by
use of a known procedure.50 1H-NMR (250 MHz, CDCl3/TMS)
d (ppm): 8.03–8.08 (m, 2H), 8.09–8.13 (m, 2H), 8.41 (s, 2H), 10.19
(s, 2H). Anal. cal. C12H8O2 (184.19): C, 78.25; H, 4.38; found: C,
78.18; H, 4.31.
Finally, naphthalene-2,6-dicarbaldehyde was transferred to
2,6-divinylnaphthalene (C) using a known procedure.51 A reac-
tion vessel was charged with naphthalene-2,6-dicarbaldehyde
(0.92 g, 5 mmol), KOtBu (1.7 g, 15 mmol) and methyl-
triphenylphosphonium bromide (4.3 g, 12 mmol) and it was
degassed and lled with argon. The reaction temperature kept
at 0–5 ꢁC and then dry THF (30 mL) was added and it was stirred
for 1 h at this temperature. Aerward, the reaction mixture was
allowed to stir at room temperature for another 6 h. Aer
completion of the reaction it was concentrated, extracted (with
ether and water) and dried over Na2SO4. The obtained organic
layer was concentrated and puried by column chromatography
(n-pentane) (72%, 0.65 g). 1H-NMR (250 MHz, CDCl3/TMS)
d (ppm): 5.25 (d, J ¼ 10.9 Hz, 2H), 5.81 (d, J ¼ 17.5 Hz, 2H), 6.81
(dd, J ¼ 17.5, 10.6 Hz, 2H), 7.52–7.77 (m, 6H). Anal. cal. C14H12
(180.25): C, 93.29; H, 6.71; found: C, 93.21; H, 6.65.
A sealed Schlenk tube was charged with compound D
(0.5 mmol, 0.2 g), 2-[ethyl-(4-iodo-phenyl)-amino]-ethanol (B;
0.5 mmol, 0.14 g), and K2CO3 (2.0 mmol, 0.28 g), Pd(OAc)2
(1.2 mol%, 1.4 mg), DPEPhos ligand (2.4 mol%, 7.0 mg) and it
was evacuated and backlled with argon. Then 5 mL of dry
DMF was added to the reaction mixture under fellow of argon
and tube was sealed with a screw-cap and the resulting mixture
was heated in an oil bath at 120 ꢁC for 12 h. Aer completion of
the reaction, the mixture was ltered (in hot form) and the
remaining solid was washed with DMF (2 mL) in order to
separate the catalyst. Aerward, water (10 mL) was added to
the solution in order to precipitate product. The obtained solid
was puried by column chromatography (hexane/ethyl acetate:
10/2) to obtain the pure product (0.25 g, 87%). Red solid; mp
289–291 ꢁC. IR (KBr): 3441, 2924, 1589, 1520, 1304, 1165, 1142,
957, 802, 764, 656, 509 cmꢀ1 1H-NMR (250 MHz, DMSO-d6/
.
TMS) d (ppm): 1.10 (t, J ¼ 4.5 Hz, 3H), 2.50 (t, J ¼ 1.2 Hz, 2H),
1.10 (t, J ¼ 4.5 Hz, 3H), 3.35 (s, 2H), 3.54–3.58 (m, 2H), 4.80 (t, J
¼ 3.2 Hz, 1H), 6.70 (d, J ¼ 5.5 Hz, 2H), 7.22 (dd, J ¼ 49.5,
10.2 Hz, 2H), 7.46 (d, J ¼ 5.5 Hz, 1H), 7.74 (d, J ¼ 10.0 Hz, 1H),
7.82–7.87 (m, 2H), 7.92–7.95 (m, 3H), 8.03–8.08 (m, 2H), 8.23
(dd, J ¼ 5.2, 1.2 Hz, 1H), 8.36 (d, J ¼ 5.2 Hz, 1H), 8.43 (d, J ¼
1.2 Hz, 1H). 13C-NMR (62.5 MHz, CDCl3/TMS) d (ppm): 12.0,
43.4, 43.8, 44.6, 52.0, 59.3, 111.3, 121.8, 122.6, 123.8, 123.9,
124.3, 127.9, 128.0, 128.3, 128.4, 128.6, 128.9, 130.0, 132.0,
133.8, 136.7, 136.9, 137.7, 139.3, 141.4, 147.6. Anal. cal.
2-1-2-[2-(2,4-Bis-methanesulfonyl-phenyl)-vinyl]-6-vinyl-
naphthalene (D)
C
32H33NO5S2 (575.7): C, 66.76; H, 5.78; N, 2.43; O, 13.89; S,
11.14; found: C, 66.74; H, 5.73; N, 2.47.
A sealed Schlenk tube was charged with 1-bromo-2,4-bis-
methanesulfonyl-benzene (A; 1 mmol, 0.313 g), 2,6-divinyl-
naphthalene (C; 1 mmol, 0.18 g), and K2CO3 (2.5 mmol, 0.345
Conflicts of interest
g), Pd(OAc)2 (1.2 mol%, 2.7 mg), DPEPhos ligand (2.4 mol%, The authors declare no competing nancial interests.
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11 D. N. Kanekar, S. Chacko and R. M. Kamble, Synthesis and
Investigation of the Photophysical, Electrochemical and
Theoretical Properties of Phenazine–Amine Based Cyan
Blue-Red Fluorescent Materials for Organic Electronics,
New J. Chem., 2020, 44(8), 3278–3293, DOI: 10.1039/
C9NJ06109F.
Acknowledgements
Financial support from the research councils of Shiraz Univer-
sity and Amirkabir University of Technology are gratefully
acknowledged.
12 J. Du, N. Xie, X. Wang, L. Sun, Y. Zhao and F. Wu, Optical
Limiting Effects of Cyano Substituted Distyrylbenzene
Derivatives, Dyes Pigm., 2016, 134, 368–374, DOI: 10.1016/
j.dyepig.2016.07.035.
References
´
1 J. Shi, M. A. Izquierdo, S. Oh, S. Y. Park, B. Milian-Medina,
´
D. Roca-Sanjuan and J. Gierschner, Inverted Energy Gap
Law for the Nonradiative Decay in Fluorescent Floppy 13 A. Mahmoodi, F. Panahi, F. Eshghi and E. Kimiaei, A Novel
Molecules: Larger Fluorescence Quantum Yields for
Smaller Energy Gaps, Org. Chem. Front., 2019, 6(12), 1948–
1954, DOI: 10.1039/C9QO00259F.
Tetra-Stilbene-Based Fluorescent Compound: Synthesis,
Characterization and Photophysical Properties Evaluation,
J. Lumin., 2018, 199, 165–173, DOI: 10.1016/
j.jlumin.2018.03.033.
´
¨
2 J. Gierschner, L. Luer, B. Milian-Medina, D. Oelkrug and
H.-J. Egelhaaf, Highly Emissive H-Aggregates or 14 S. Zhang, D. Chen, L. Yan, Y. Xie, X. Mu and J. Zhu, A Near-
Aggregation-Induced
Photophysics of All-Trans Para-Distyrylbenzene, J. Phys.
Chem. Lett., 2013, 4(16), 2686–2697, DOI: 10.1021/jz400985t.
Emission
Quenching?
The
Infrared Fluorescence Probe for Hydrazine Based on
Dicyanoisophorone, Microchem. J., 2020, 157, 105066, DOI:
10.1016/j.microc.2020.105066.
3 H. Zhang, E. A. Kotlear, S. Kushida, S. Maier, F. Rominger, 15 G. Lv, Y. Xu, J. Yang, W. Li, C. Li and A. Sun, Novel D–p-A
J. Freudenberg and U. H. F. Bunz, Linear and Star-Shaped
Extended Di- and Tristyrylbenzenes: Synthesis,
Characterization and Optical Response to Acid and Metal
Type near-Infrared Fluorescent Probes for the Detection of
Ab40 Aggregates, Analyst, 2020, 145(20), 6579–6585, DOI:
10.1039/D0AN01180K.
Ions, Chem.–Eur. J., 2020, 26(36), 8137–8143, DOI: 10.1002/ 16 M. Sachs, R. S. Sprick, D. Pearce, S. A. J. Hillman, A. Monti,
chem.202000893.
4 F. S. Miri, S. Gorji Kandi and F. Panahi, Photophysical
Properties of
Derivative in Solution and Solid State, J. Fluoresc., 2020,
30(4), 917–926, DOI: 10.1007/s10895-020-02567-2.
A. A. Y. Guilbert, N. J. Brownbill, S. Dimitrov, X. Shi, F. Blanc,
M. A. Zwijnenburg, J. Nelson, J. R. Durrant and A. I. Cooper,
Understanding Structure-Activity Relationships in Linear
Polymer Photocatalysts for Hydrogen Evolution, Nat.
Commun., 2018, 9(1), 4968, DOI: 10.1038/s41467-018-07420-
6.
a
Donor-p-Acceptor Distyrylbenzene
´
5 S. E. Estrada-Florez, F. S. Moncada, A. E. Lanterna,
C. A. Sierra and J. C. Scaiano, Spectroscopic and Time- 17 C. Huang and C. Ding, Dicyanostilbene-Derived Two-Photon
Dependent DFT Study of the Photophysical Properties of
Substituted 1,4-Distyrylbenzenes, J. Phys. Chem. A, 2019,
123(30), 6496–6505, DOI: 10.1021/acs.jpca.9b04492.
Fluorescence Probe for Lead Ions in Live Cells and Living
Tissues, Anal. Chim. Acta, 2011, 699(2), 198–205, DOI:
10.1016/j.aca.2011.05.015.
6 A. Granados and A. Vallribera, Fluorous Hydrophobic 18 C. Huang, A. Ren, C. Feng and N. Yang, Two-Photon
Fluorescent (E)-Stilbene Derivatives for Application on
Security Paper, Dyes Pigm., 2019, 170, 107597, DOI:
10.1016/j.dyepig.2019.107597.
Fluorescent Probe for Silver Ion Derived from Twin-Cyano-
Stilbene with Large Two-Photon Absorption Cross Section,
Sens. Actuators, B, 2010, 151(1), 236–242, DOI: 10.1016/
j.snb.2010.09.013.
7 Aruna, B. Rani, S. Swami, A. Agarwala, D. Behera and
R. Shrivastava, Recent Progress in Development of 2,3- 19 J.-S. Yang, Y.-H. Lin and C.-S. Yang, Palladium-Catalyzed
Diaminomaleonitrile (DAMN) Based Chemosensors for
Sensing of Ionic and Reactive Oxygen Species, RSC Adv.,
2019, 9(52), 30599–30614, DOI: 10.1039/C9RA05298D.
Synthesis of Trans-4-(N,N-Bis(2-Pyridyl)Amino)Stilbene. A
New Intrinsic Fluoroionophore for Transition Metal Ions,
Org. Lett., 2002, 4(5), 777–780, DOI: 10.1021/ol017260l.
8 H. Y. Chung, J. Oh, J.-H. Park, I. Cho, W. S. Yoon, J. E. Kwon, 20 A. J. Zucchero, J. Tolosa, L. M. Tolbert and U. H. F. Bunz,
D. Kim and S. Y. Park, Spectroscopic Studies on
Intramolecular Charge-Transfer Characteristics in Small-
Molecule Organic Solar Cell Donors: A Case Study on ADA
Bis(40-Dibutylaminostyryl)Benzene: Spectroscopic Behavior
upon Protonation or Methylation, Chem.–Eur. J., 2009,
15(47), 13075–13081, DOI: 10.1002/chem.200900608.
´
´
´
and DAD Triad Donors, J. Phys. Chem. C, 2020, 124(34), 21 J. Tydlitat, S. Achelle, J. Rodrıguez-Lopez, O. Pytela,
´
´
T. Mikysek, N. Cabon, F. Robin-le Guen, D. Miklık,
18502–18512, DOI: 10.1021/acs.jpcc.0c06741.
ˇ
´
ˇ
˚ˇ
9 M. Zhu, Y. Xu, L. Sang, Z. Zhao, L. Wang, X. Wu, F. Fan,
Y. Wang and H. Li, An ICT-Based Fluorescent Probe with
a Large Stokes Shi for Measuring Hydrazine in Biological
and Water Samples, Environ. Pollut., 2020, 256, 113427,
DOI: 10.1016/j.envpol.2019.113427.
Z. Ruzickova and F. Bures, Photophysical Properties of
Acid-Responsive Triphenylamine Derivatives Bearing
Pyridine Fragments: Towards White Light Emission, Dyes
Pigm.,
2017,
146,
467–478,
DOI:
10.1016/
j.dyepig.2017.07.043.
10 X. Sun, T. Liu, J. Sun and X. Wang, Synthesis and Application 22 S. Samanta, U. Manna and G. Das, White-Light Emission
of Coumarin Fluorescence Probes, RSC Adv., 2020, 10(18),
10826–10847, DOI: 10.1039/C9RA10290F.
from Simple AIE–ESIPT-Excimer Tripled Single Molecular
174 | RSC Adv., 2021, 11, 168–176
© 2021 The Author(s). Published by the Royal Society of Chemistry

View Article Online
Paper
System, New J. Chem., 2017, 41(3), 1064–1072, DOI: 10.1039/
RSC Advances
Study of
a
Naphthalimide–Bithiophene–Triphenylamine
C6NJ03070J.
Push–Pull Dye in Solution, J. Phys. Chem. A, 2018, 122(25),
5533–5544, DOI: 10.1021/acs.jpca.8b05177.
23 M. Takahashi, Y. Enami, H. Ninagawa and M. Obata, A Novel
Approach to White-Light Emission Using
a
Single 35 Y. Zhang, M. Jiang, G.-C. Han, K. Zhao, B. Z. Tang and
Fluorescent Urea Derivative and Fluoride, New J. Chem.,
2019, 43(8), 3265–3268, DOI: 10.1039/C8NJ05105D.
24 M. Li, Y. Yuan and Y. Chen, Acid-Induced Multicolor
Fluorescence of Pyridazine Derivative, ACS Appl. Mater.
K. S. Wong, Solvent Effect and Two-Photon Optical
Properties of Triphenylamine-Based Donor–Acceptor
Fluorophores, J. Phys. Chem. C, 2015, 119(49), 27630–
27638, DOI: 10.1021/acs.jpcc.5b06762.
Interfaces, 2018, 10(1), 1237–1243, DOI: 10.1021/ 36 H. Song, Z. Kuang, X. Wang, Y. Guo, Q. Guo, H. Zhang and
acsami.7b16050.
25 D. K. Maiti, R. Bhattacharjee, A. Datta and A. Banerjee,
Modulation of Fluorescence Resonance Energy Transfer
A. Xia, Solvent Polarity Dependent Excited State Dynamics
of 20-Hydroxychalcone Derivatives, J. Phys. Chem. C, 2018,
122(27), 15108–15117, DOI: 10.1021/acs.jpcc.8b03133.
´
Efficiency for White Light Emission from a Series of 37 K. Anandhan, M. Ceron, V. Perumal, P. Ceballos, P. Gordillo-
´
´
Stilbene-Perylene Based Donor–Acceptor Pair, J. Phys.
Chem. C, 2013, 117(44), 23178–23189, DOI: 10.1021/
jp409042p.
Guerra, E. Perez-Gutierrez, A. E. Castillo, S. Thamotharan
and M. J. Percino, Solvatochromism and PH Effect on the
Emission of
a
Triphenylimidazole-Phenylacrylonitrile
26 Y. I. Park, O. Postupna, A. Zhugayevych, H. Shin, Y.-S. Park,
B. Kim, H.-J. Yen, P. Cheruku, J. S. Martinez, J. W. Park,
Derivative: Experimental and DFT Studies, RSC Adv., 2019,
9(21), 12085–12096, DOI: 10.1039/C9RA01275C.
S. Tretiak and H.-L. Wang, A New PH Sensitive Fluorescent 38 A. J. Zucchero, P. L. McGrier and U. H. F. Bunz, Cross-
and White Light Emissive Material through Controlled
Intermolecular Charge Transfer, Chem. Sci., 2014, 6(1),
789–797, DOI: 10.1039/C4SC01911C.
Conjugated Cruciform Fluorophores, Acc. Chem. Res., 2010,
43(3), 397–408, DOI: 10.1021/ar900218d.
39 C. Dou, L. Han, S. Zhao, H. Zhang and Y. Wang, Multi-
Stimuli-Responsive Fluorescence Switching of a Donor–
Acceptor p-Conjugated Compound, J. Phys. Chem. Lett.,
2011, 2(6), 666–670, DOI: 10.1021/jz200140c.
27 S. Bhattacharya and S. K. Samanta, Unusual Salt-Induced
Color Modulation through Aggregation-Induced Emission
Switching of a Bis-Cationic Phenylenedivinylene-Based p
Hydrogelator, Chem.–Eur. J., 2012, 18(52), 16632–16641, 40 J. Tolosa, K. M. Solntsev, L. M. Tolbert and U. H. F. Bunz,
DOI: 10.1002/chem.201201940.
Unsymmetrical Cruciforms, J. Org. Chem., 2010, 75(3), 523–
28 J. Chaudhary, V. Mittal, S. Mishra, A. Daiya, R. Chowdhury,
534, DOI: 10.1021/jo901961a.
I. R. Laskar and R. K. Roy, A New Aggregation Induced 41 U. Balijapalli, S. Manickam, M. D. Thiyagarajan and
Emission Active Halochromic White Light Emissive
Molecule: Combined Experimental and Theoretical Study,
J. Phys. Chem. C, 2020, 124(28), 15406–15417, DOI: 10.1021/
acs.jpcc.0c01067.
S. K. Iyer, Highly Emissive, Naked-Eye Solvatochromic
Probe Based on Styryl Tetrahydrodibenzo[a,i]
Phenanthridine for Acidochromic Applications, RSC Adv.,
2016, 6(63), 58549–58560, DOI: 10.1039/C6RA09359K.
29 C. P. Sharma, N. M. Gupta, J. Singh, R. A. K. Yadav, 42 K. Yamaguchi, T. Murai, J.-D. Guo, T. Sasamori and
D. K. Dubey, K. S. Rawat, A. K. Jha, J.-H. Jou and A. Goel,
Synthesis of Solution-Processable Donor–Acceptor
Pyranone Dyads for White Organic Light-Emitting Devices,
J. Org. Chem., 2019, 84(12), 7674–7684, DOI: 10.1021/
acs.joc.9b00293.
N. Tokitoh, Acid-Responsive Absorption and Emission of 5-
N-Arylaminothiazoles: Emission of White Light from
a Single Fluorescent Dye and a Lewis Acid, ChemistryOpen,
2016, 5(5), 434–438, DOI: 10.1002/open.201600059.
´
´
43 S. Achelle, J. Rodrıguez-Lopez, C. Katan and F. Robin-le
Guen, Luminescence Behavior of Protonated Methoxy-
Substituted Diazine Derivatives: Toward White Light
Emission, J. Phys. Chem. C, 2016, 120(47), 26986–26995,
DOI: 10.1021/acs.jpcc.6b08401.
30 H. Karimi-Alavijeh, F. Panahi and A. Gharavi, Photo-
Switching Effect in Stilbene Organic Field Effect
Transistors, J. Appl. Phys., 2014, 115(9), 093706.
31 M. T. Sharbati, F. Panahi and A. Gharavi, Near-Infrared
Organic Light-Emitting Diodes Based on Donor-Pi-Acceptor 44 Z. Ibrahim Mohamed Allaoui, E. le Gall, A. Fihey, R. Plaza-
´
´
Oligomers, IEEE Photonics Technol. Lett., 2010, 22(22),
1695–1697.
32 M. T. Sharbati, F. Panahi, A.-R. Nekoei, F. Emami and
K. Niknam, Blue to Red Electroluminescence Emission
from Organic Light-Emitting Diodes Based on p-
Pedroche, C. Katan, F. Robin-le Guen, J. Rodrıguez-Lopez
and S. Achelle, Push–Pull (Iso)Quinoline Chromophores:
Synthesis, Photophysical Properties, and Use for White-
Light Emission, Chem.–Eur. J., 2020, 26(36), 8153–8161,
DOI: 10.1002/chem.202000817.
Conjugated Organic Semiconductor Materials, J. Photonics 45 Y. Yang, T. Wang, P. Yin, W. Yin, S. Zhang, Z. Lei, M. Yang,
Energy, 2014, 4(1), 043599.
33 F. S. Miri, S. G. Kandi and F. Panahi, Photophysical
Y. Ma, W. Duan and H. Ma, A General Concept for White
Light Emission Formation from Two Complementary
Colored Luminescent Dyes, Mater. Chem. Front., 2019, 3(3),
505–512, DOI: 10.1039/C8QM00599K.
Properties of
a
Donor-p-Acceptor Distyrylbenzene
Derivative in Solution and Solid State, J. Fluoresc., 2020, 1–
10.
46 M. V. R. Reddy, S. Reddy, P. V. R. Reddy, D. B. Reddy and
N. S. Reddy, Synthesis and cyclopropanation of E,E and
34 V. Maffeis, R. Brisse, V. Labet, B. Jousselme and
T. Gustavsson, Femtosecond Fluorescence Upconversion
Z,Z-1,3-bis(styrylsulfonyl)benzene,
Phosphorus,
Sulfur
© 2021 The Author(s). Published by the Royal Society of Chemistry
RSC Adv., 2021, 11, 168–176 | 175

View Article Online
RSC Advances
Paper
´
´
`
Silicon Relat. Elem., 1989, 44, 123–127, DOI: 10.1080/ 50 C. Garcıa-Simon, A. Monferrer, M. Garcia-Borras, I. Imaz,
10426508908043714.
D. Maspoch, M. Costas and X. Ribas, Size-selective
encapsulation of C60 and C60-derivatives within an
47 A. V. Joshi, M. Baidossi, S. Mukhopadhyay and Y. Sasson,
Org. Process Res. Dev., 2004, 8, 568–570, DOI: 10.1021/
op030055w.
adaptable
naphthalene-based
tetragonal
prismatic
supramolecular nanocapsule, Chem. Commun., 2019, 55,
798–801, DOI: 10.1039/C8CC07886F.
48 C. Monnereau, E. Blart, V. Montembault, L. Fontaine and
¨
F. Odobela, Synthesis of new crosslinkable co-polymers 51 G. Schroer, J. Deischter, T. Zensen, J. Kraus, A.-C. Poppler,
containing a push–pull zinc porphyrin for non-linear
optical applications, Tetrahedron, 2005, 61, 10113–10121,
L. Qi, S. Scott and I. Delidovich, Structure-performance
correlations of crosslinked boronic acid polymers as
adsorbents for recovery of fructose from glucose–fructose
mixtures, Green Chem., 2020, 22, 550–562, DOI: 10.1039/
C9GC03151K.
DOI: 10.1016/j.tet.2005.07.094.
49 B. Łukasik, J. Milczarek, R. Pawlowsk, R. Zurawinski and
˙
´
A.
Chworos,
Facile
Synthesis
of
Fluorescent
Distyrylnaphthalene Derivatives for Bioapplications, New J.
Chem., 2017, 41, 6977–6980, DOI: 10.1039/C7NJ00004A.
176 | RSC Adv., 2021, 11, 168–176
© 2021 The Author(s). Published by the Royal Society of Chemistry