Fluorous hydrophobic fluorescent (E)-Stilbene derivatives for application on security paper

Article abstract of DOI:10.1016/j.dyepig.2019.107597

(E)-Stilbene hydrophobic fluorophores possessing long perfluorinated or hydrocarbonated chains have been prepared through a stereoselective Wittig-Schlosser reaction. When covalently grafted upon paper, they give rise to a fluorescent-labeled paper upon i

Full text of DOI:10.1016/j.dyepig.2019.107597

DyesandPigments170(2019)107597
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Dyes and Pigments
journal homepage: www.elsevier.com/locate/dyepig
Fluorous hydrophobic fluorescent (E)-Stilbene derivatives for application on
security paper
Albert Granados, Adelina Vallribera∗
Department of Chemistry and Centro de Innovación en Química (ORFEO-CINQA), Universitat Autònoma de Barcelona, Campus UAB, 08193, Cerdanyola del Vallès,
Barcelona, Spain
A B S T R A C T
(E)-Stilbene hydrophobic fluorophores possessing long perfluorinated or hydrocarbonated chains have been prepared through a stereoselective Wittig-Schlosser
reaction. When covalently grafted upon paper, they give rise to a fluorescent-labeled paper upon irradiation with UV light. The hydrophobicity and oleophobicity of
the fluorous (E)-stilbene derivative furnish self-cleaning properties. Application in the detection of money counterfeiting is envisioned.
1. Introduction
(Fig. 1). Azo [18] (Fig. 1), anthraquinone [19] and triarylmethane [20]
derivatives have been used with success affording new hydrophobic
coloured fibers. We got inspired by this previous research to design a
reactive molecule that could be used as a fluorescent label to verify the
authenticity of high added value paper (Fig. 1). The design structure
consists on a (E)-stilbene based moiety possessing long perfluorinated
or hydrocarbonated tails, responsible of the self-cleaning properties,
and a reactive group to covalently link the fluorophore onto paper's
surface. (E)-stilbene derivatives were selected due to their well known
fluorophore properties and the possibility to introduce different sub-
stituents in the aromatic positions using cheap starting materials. These
fluorescent-labeled papers, which change color upon irradiation with
UV light, could be applied for security and authentication purposes.
The so-called safety papers need to be protected from any attempts
of falsification [1,2]. Official documents such as passports, checks,
stamps and other high added value papers, as well as paper money, are
some examples. A security document is usually made by using a paper
which has specific properties to prevent forgery and allow the user to
authenticate the document. Currently, the detection of counterfeited
paper money is a severe problem [3]. The means to prevent forgery are
based upon special chemical compounds which will show a visible
mark. One of the many techniques utilized in safety paper production is
the use of luminescence substances [4–6]. Of particular significance is
the work of H. El-Saied and coworkers about the use of fluorescent 3-
pyridinecarbonitrile containing compounds for dip dyeing process of
papers [7,8]. The same authors have reported the preparation of na-
noparticles based on pyridine dicarbonitriles which were sprayed using
an automatic atomizer on a paper sheet [9]. Security papers could also
be obtained through a covalent link of the chromatic moiety onto the
paper surface, thus avoiding the leaching of the fluorophore [10]. As far
as we know, very few examples can be found in the literature. One of
them is the grafting of photochromic spiropyran ether methacrylate
onto the paper surface through atom transfer radical polymerization
[4–6].
2. Materials and methods
2.1. General information
All starting materials were purchased from Sigma Aldrich or
Fluorochem, and used without further purification. All chemical shifts
are given in δ (ppm) and coupling constants (J) in Hz. The following
abbreviations are used to indicate the multiplicity: s = singlet;
d = doublet: t = triplet; q = quartet; m = multiplet. 1H NMR and 13C
NMR are refereed with respect to TMS and 19F NMR with respect to
CCl3F. Contact angle measurements: the hydrophobic/oleophobic tests
performed were the measurement of the contact angle of a water dro-
plet (4 μL), olive oil (4 μL) and hexadecane droplet (4 μL) deposited on
top of each fabric or glass. These experiments were carried out in
Institut de Ciència de Materials de Barcelona (ICMAB) installations with
a Contact Angle Measuring System DSA 100 from KRÜSS which is
On the other hand, the interest in highly water and oil repellent
materials has grown in recent years, in part due to the promise of
creating self-cleaning surfaces [11–17]. Given that cotton fibers almost
inevitably undergo a dying process we envisaged that the process of
dyeing may also be used to incorporate hydrophobicity. Thus, we de-
signed some reactive dyes possessing long perfluorinated or hydro-
carbonated chains that could be covalently link to a cotton surface
∗ Corresponding author.
E-mail addresses: albert.granados@uab.cat (A. Granados), adelina.vallribera@uab.cat (A. Vallribera).
https://doi.org/10.1016/j.dyepig.2019.107597
Received 28 March 2019; Received in revised form 28 May 2019; Accepted 28 May 2019
Availableonline30May2019
0143-7208/©2019PublishedbyElsevierLtd.

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
vacuo. The product was purified by flash chromatography through si-
lica gel using hexane/ethyl acetate (9/1) to yield a white solid (0.54 g,
0.90 mmol, 92% yield).
2.4. General procedure for the Wittig reactions (Scheme 1)
In a well dried Schlenk methyltriphenylphosphonium bromide salt
(0.55 g, 1.56 mmol) was dissolved in THF (4 mL). The mixture was
cooled at 0 °C and then n-BuLi (2.5 M in hexanes, 2.5 eq) was added
dropwise through a syringe. The mixture was stirred for 30 min. Once
the phosphonium ylide was formed, a solution of the corresponding
aldehyde 3 (0.72 mmol, 1 eq.) in 2 mL of THF was added dropwise. The
reaction was stirred from 0 °C to room temperature and after 4 h the
reaction poured into methyl-tert-buthylether. The solution was filtered
through silica gel, and the solvent was evaporated under vacuum,
yielding the desired styrene derivative 4 (Scheme 1).
2.5. General procedure for the Heck reactions (Scheme 1)
A solution of the corresponding styrene 4 (350 mg, 1.46 mmol), Pd
(OAc)2 (5%), tri(o-tolyl)phosphine (7%), and 4-iodophenol (310 mg,
1.42 mmol) in dry NEt3 (3 mL) was stirred for 1 day at 110 °C. After the
reaction was complete, the reaction was poured in water and extraction
with CH2Cl2 were done. The organics were dried over Na2SO4, and the
solvent was evaporated. The crude product was purified by column
chromatography on silica gel (eluent hexane (9): ethyl acetate (1)) to
obtain a solid which was characterized as the corresponding stilbene 1.
Fig. 1. Example of azo based dyes anchored on a cotton surface (previous work)
and structure design for fluorescent-labeled paper.
located in a physico-chemical laboratory (humidity and temperature
control).
2.2. General procedure for the alkylation reactions of 2 (Scheme 1)
2.6. General procedure for the Wittig-Schlosser reaction (Scheme 3)
To a solution of the corresponding aldehyde 2 (0.28 mmol) in dry
DMF (4 mL) were added the corresponding iodide (3 eq) and potassium
carbonate (0.11 g, 3 eq). The reaction mixture was stirred under argon
atmosphere at reflux over 16 h. The reaction was monitored via TLC.
Once the reaction was finished it was quenched with water. The pro-
duct was extracted with dichloromethane (3 × 15 mL) and washed
with water. The organics were dried under vacuum and the crude was
purified by flash chromatography through silica gel using hexane/ethyl
acetate (9/1) as eluent yielding compounds 3 (Scheme 1).
In a dried Schlenk the phosphonium salt 6 (0.13 g, 0.30 mmol) and
LiBr (0.04 g, 0.50 mmol) were dissolved in THF (6 mL). The mixture
was cooled at 0 °C and then n-BuLi (2.5 M in hexanes, 7.5 eq) was added
dropwise. The mixture was stirred for 30 min. Once the phosphonium
ylide was formed a solution of the corresponding alkylated aldehyde 3
(0.15 g, 0.24 mmol) in THF (6 mL) was added dropwise. The reaction
was stirred from 0 °C to room temperature and after 4 h the reaction
was quenched with ammonium chloride. The product was extracted
with CH2Cl2 three times and after evaporation the residue was purified
by flash chromatography through silica gel using hexane/ethyl acetate
(9/1) as eluent to give the corresponding pure (E)-stilbene 1.
2.3. Synthesis of 4-((4,6-bis(dodecylthio)-1,3,5-triazin-2-yl)oxy)
benzaldehyde, 3 g
2.7. General procedure for the synthesis of the reactive fluorescent
A two-neck flask was fitted with a pressure-equalizing addition
funnel and charged with 4-hydroxybenzaldehyde (0.23 g, 1.89 mmol)
and potassium carbonate (2.5 eq.) in 8 mL of dried DMF. Under inert
atmosphere, a solution (2 mL) of the triazine derivative (1 eq.) was
added dropwise over 10 min and allowed to stir overnight at 50 °C. The
reaction was quenched with water, and the product was extracted with
dichloromethane (3 × 20 mL), dried over Na2SO4, and concentrated in
carbamates 7 (Scheme 4)
The corresponding (E)-4-hydroxystilbene 1 (0.27 mmol) was dis-
solved in anhydrous THF (5.5 mL) in a dried Schlenk. To the solution,
triethylamine (0.1 mL, 0.3 mmol) and 3-(triethoxysilyl)propylisocya-
nate (0.17 mL, 0.27 mmol) were added. The reaction was stirred at
room temperature over 16 h. After completion of the reaction, the
Scheme 1. Preparation of target compounds (E)-1.
2

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
solvent was removed under vacuum. The crude was purified by chro-
matography through silica gel using hexane/ethyl acetate (9/1) as
eluent to give the final reactive carbamates 7.
NMR (91 MHz, [D]CHCl3): δ = 189.0 (C]O), 155.7 (ArC, C-O), 152.9
(ArC, C-O), 125.1 (ArC), 123.9 (ArC), 114.2 (ArC), 111.3 (ArC), 67.5
3
(OCH2CH2), 67.0 (OCH2CH2), 27.9 (t, JC,F = 22.3 Hz; CF3CH2), 22.5
(m, OCH2CH2); IR (ATR): ν˜ = 2860, 1678 cm−1; HRMS (ESI): m/z
calcd for C29H16F34O3Na 1081.0454 [M + Na+]; found 1081.0449.
2.8. Characterization of compounds
The description of all the compounds prepared in this manuscript is
2.8.4. 1-((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
perfectly described in the suplementary information. 1H (250 MHz), 13
C
heptadecafluoroundecyl)oxy)-4-methoxy benzaldehyde, 3e
Yellowish oil; Isolated yield: 89% (2.9 mmol, 1.78 g from 500 mg of
starting material); 1H NMR (400 MHz, CDCl3): δ = 10.45 (s, 1H, CHO),
(62.5 MHz) and 19F (253.2 MHz) NMR spectra have been registered in a
Brucker AC-250 spectrometer. 1H and 13C NMR spectra have also been
registered in a 360 MHz and 90 MHz respectively in a Brucker Avance
360 spectrometer or in a 400 MHz and 101 MHz Brucker Avance 400
spectrometer. IR spectra (neat) were performed in a Bruker Tensor 27
using an ATR (Attenuated Total Reflectance) Golden Gate modulus
provided with a diamond tip. UV–Vis spectra were performed using a
Hewlett-Packard 8453 model with diode array and 1 cm quartz cells.
Confocal measurements were analyzed by Confocal TCS SP2 (Leica)
equipped with three detectors for fluorescence and AOBS (Acousto-
Optical Beam Splitter) system. HR-ESI (High Resolution-ElectroSpray
Ionization) experiments were performed using a MicroTof-Q from
Bruker daltronics. Melting points were measured in a bloc Kofler ap-
paratus from Reichert or in a B-545 apparatus from Büchi and are un-
corrected. Column chromatographies were performed with commercial
silica gel (SDS or Fluka) of 35–70 μm grain size.
4
3
7.33 (d, JH,H = 3.2 Hz, 1H; ArH), 7.12 (dd, JH,H = 9.0 Hz,
3
4JH,H = 3.2 Hz, 1H; ArH), 6.93 (d, JH,H = 9.0 Hz, 1H; ArH), 4.12 (t,
3JH,H = 6.0 Hz, 2H; OCH2), 3.80 (s, 3H; OCH3), 2.34 (m, 2H,
OCH2CH2CH2), 2.17 (m, 2H, OCH2CH2CH2); 19F NMR (376 MHz,
CDCl3): δ = −126.4 (m, 2F), −123.6 (m, 2F), −123.0 (m, 2F), −122.0
3
3
(m, 6F), −114.5 (t, JF,F = 13.8 Hz, 2F), −81.2 (t, JF,F = 9.9 Hz, 3F;
CF3); 13C NMR (101 MHz, [D]CHCl3): δ = 188.8 (C]O), 155.4 (ArC, C-
O), 153.9 (ArC, C-O), 125.1 (ArC), 123.2 (ArC), 118.3 (m, CF2), 114.1
(ArC), 111.0 (m, CF2), 110.4 (ArC), 67.5 (OCH2CH2), 55.6 (OCH3), 27.8
3
3
(t, JC,F = 22.5 Hz; CF3CH2), 20.5 (t, JC,F = 3.6 Hz; OCH2CH2); IR
(ATR): ν˜ = 2948, 1681 cm−1
.
HRMS (ESI): m/z calcd for
C19H13F17O3Na 635.0485 [M + Na+]; found 635.0500.
2.8.5. 4-((4,6-bis(dodecylthio)-1,3,5-triazin-2-yl)oxy)benzaldehyde, 3g
White solid; Isolated yield: 92% (3.8 mmol, 2.26 g from 500 mg of
starting material); 1H NMR (360 MHz, CDCl3): δ = 10.02 (s, 1H; CHO),
7.95 (d, 3J(H,H) = 8.5 Hz, 2H; ArH), 7.35 (d, 3J(H,H) = 8.5 Hz, 2H; ArH),
2.8.1. 4-Bis(dodecyloxy)benzaldehyde, 3a
Colorless oil; Isolated yield: 75% (5.4 mmol, 2.57 g from 1.00 g of
starting material); 1H NMR (250 MHz, CDCl3): δ = 10.48 (s, 1H; CHO),
3.00 (t, J(H,H) = 6.7 Hz, 4H; CH3(CH2)10CH2S), 1.63 (m, 4H;
3
4
4
7.32 (d, JH,H = 3.2 Hz, 1H; ArH), 7.10 (dd, JH,H = 3.2 Hz,
CH3CH2(CH2)9CH2S), 1.26 (broad singlet, 36H; CH3CH2(CH2)9CH2S),
3JH,H = 9.1 Hz, 1H; ArH), 6.91 (d, JH,H = 9.1 Hz, 1H; ArH), 4.02 (t,
0.88 (t, J(H,H) = 6.7 Hz, 6H; CH3CH2(CH2)9CH2S); 13C NMR (91 MHz,
3
3
3JH,H = 6.5 Hz, 2H; CH2O), 3.93 (t, 3JH,H = 6.5 Hz, 2H; CH2O), 1.79 (m,
4H; CH2CH2O), 1.79 (m, 4H; CH3CH2), 1.28 (broad singlet, 32H; CH2),
0.89 (t, 3JH,H = 6.6 Hz, 6H; CH3); 13C NMR (63 MHz, CDCl3): δ = 190.0
(C]O), 156.7 (ArC, C12H25O-C), 153.4 (ArC, C12H25O-C), 125.5 (ArC),
124.4 (ArC), 114.7 (ArC), 111.2 (ArC), 69.6 (OCH2(CH2)10CH3), 69.0
(OCH2(CH2)10CH3), 32.3 (CH3(CH2)11O), 30.0 (CH3(CH2)11O), 29.8
(CH3(CH2)11O), 29.6 (CH3(CH2)11O), 26.5 (CH3(CH2)11O), 26.4
(CH3(CH2)11O), 23.1 (CH3(CH2)11O), 14.5 (CH3(CH2)11O); IR (ATR):
[D]CHCl3): δ = 190.7 (CHO), 183.6 (ArC, C-SC12H25), 167.4 (ArC,
N]C-O), 156.4 (ArC, O-C), 134.0 (ArC, C-CHO), 131.1 (ArC), 122.5
(ArC), 31.9 (CH3(CH2)11S),. 30.5 (CH3(CH2)11S), 29.6 (CH3(CH2)11S),
29.5 (CH3(CH2)11S), 29.3 (CH3(CH2)11S), 29.1 (CH3(CH2)11S), 28.8
(CH3(CH2)11S), 22.7 (CH3(CH2)11S), 14.1 (CH3(CH2)11S); . HRMS (ESI):
m/z calcd for C34H55N3O2S2Na 624.3633 [M + Na+]; found 624.3635.
2.8.6. 1,4-Bis(dodecyloxy)-2-vinylbenzene, 4a
ν˜ = 2919, 1678 cm−1
;
HRMS (ESI): m/z calcd for C31H54O3Na
Colorless oil; Isolated yield: 96% (0.40 mmol, 190 mg from 200 mg
of starting material); 1H NMR (250 MHz, CDCl3): δ = 7.37 ppm (s, 1H;
ArH), 7.09 (m, 2H; CH]CH2), 6.80 (s, 1H; ArH), 5.78 (d,
3Jtrans(H,H) = 17.5 Hz, 1H; CH]CH2), 5.29 (d, 3Jcis(H,H) = 11.1 Hz, 1H;
CH]CH2), 3.96 (t, 3J(H,H) = 6.7 Hz, 4H; CH3CH2(CH2)9CH2O), 1.81 (m,
4H; CH3CH2(CH2)8CH2CH2O), 1.50 (m, 4H; CH3CH2(CH2)9CH2O), 1.32
(broad singlet, 32H; CH3CH2(CH2)8CH2CH2O), 0.93 (t, 3J(H,H) = 6.7 Hz,
6H; CH3CH2(CH2)9CH2O); 13C NMR (63 MHz, CDCl3): δ = 153.2 (ArC,
C12H25O-C), 150.7 (ArC, C12H25O-C), 133.7 (ArC), 131.7 (ArC), 128.7
(ArC), 127.7 (ArC), 114.6 (ArC), 114.3 (ArC), 113.6 (ArC), 112.4 (ArC),
69.3 (OCH2(CH2)10CH3), 68.8 (OCH2(CH2)10CH3), 31.9 (CH3(CH2)11O),
29.7 (CH3(CH2)11O), 29.5 (CH3(CH2)11O), 29.4 (CH3(CH2)11O), 26.2
(CH3(CH2)11O), 26.1 (CH3(CH2)11O), 22.7 (CH3(CH2)11O), 14.2
(CH3(CH2)11O); HRMS (ESI): m/z calcd for C32H56O2Na 495.4178
[M + Na+]; found 495.4172.
497.3965 [M + Na+]; found 497.3961.
2.8.2. 1,4-Bis(4,4,4-trifluorobutoxy)benzaldehyde, 3c
Colorless oil; Isolated yield: 74% (0.95 mmol, 96 mg from 500 mg of
starting material); 1H NMR (250 MHz, CDCl3): δ = 10.44 (s, 1H; CHO),
3
3
7.31 (d, JH,H = 2.5 Hz, 1H; ArH)), 7.13 (dd, JH,H = 2.5 Hz,
3JH,H = 10.0 Hz, 1H; ArH), 6.93 (d, JH,H = 10.0 Hz, 1H, ArH), 4.10 (t,
3
3JH,H = 6.4 Hz, 2H; CH2CF3), 4.00 (t, 3JH,H = 6.3 Hz, 2H, CH2CF3), 2.31
(m, 4H; OCH2CH2CH2), 2.25 (m, 4H; OCH2CH2CH2); 19F NMR
(235 MHz, [D]CHCl3): δ = −68.9; 13C NMR (63 MHz, CDCl3):
δ = 189.3 (C]O), 156.1 (ArC), 153.3 (ArC), 127.5 (q,
1JC,F = 245.1 Hz; CF3CH2),127.4 (q, JC,F = 245.1 Hz; CF3), 125.6
1
(ArC), 124.1 (ArC), 114.6 (ArC), 111.8 (ArC), 67.6 (OCH2CH2), 67.0
(OCH2CH2), 31.0 (q, 2JC,F = 29.1 Hz, CF3CH2), 22.5 (t, 3JC,F = 2.54 Hz,
OCH2CH2); IR (ATR): ν˜ = 2948, 1681 cm−1. HRMS (ESI): m/z calcd for
C
15H16F6O3Na 381.0901[M + Na+]; found 381.0905.
2.8.7. 1,3-Bis(dodecyloxy)-5-vinylbenzene, 4b
Colorless oil; Isolated yield: 96% (0.39 mmol, 180 mg from 200 mg
of starting material); 1H NMR (250 MHz, CDCl3): δ = 6.68 ppm (dd,
3Jtrans(H,H) = 17.5 Hz, 3Jcis(H,H) = 11.1 Hz, 1H; CH]CH2) 6.60 (d,
4J(H,H) = 2.0 Hz, 2H; ArH), 6.43 (s, 1H, ArH), 5.76 (d,
3Jtrans(H,H) = 17.5 Hz, 1H; CH]CH2), 5.27 (d, 3Jcis(H,H) = 11.1 Hz, 1H;
CH]CH2), 3.98 (t, 3J(H,H) = 6.7 Hz, 4H; CH3(CH2)9CH2CH2O), 1.82 (m,
4H; CH3(CH2)9CH2CH2O), 1.50 (m, 4H; (CH3(CH2)9CH2CH2O), 1.33
(broad singlet, 36H; CH3(CH2)9CH2CH2O), 0.95 (t, 3J(H,H) = 6.7 Hz, 6H;
CH3CH2(CH2)9CH2O); 13C NMR (63 MHz, CDCl3): δ = 160.9 (ArC, C-O-
2.8.3. 1,4-bis((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
heptadecafluoroundecyl)oxy) benzaldehyde, 3d
Yellowish oil; Isolated yield: 75% (1.36 mmol, 1.48 g from 250 mg
of starting material); 1H NMR (250 MHz, CDCl3): δ = 10.47 (s, 1H;
4
4
CHO) 7.31 (d, JH,H = 3.2 Hz, 1H; ArH), 7.16 (dd, JH,H = 3.2 Hz,
3
3JH,H = 9.1 Hz, 1H; ArH), 6.96 (d, JH,H = 9.1 Hz, 1H; ArH), 4.16 (t,
3JH,H = 5.9 Hz, 2H; CH2CF3), 4.06 (t, 3JH,H = 5.9 Hz, 2H; CH2CF3), 2.35
(m, 4H; OCH2CH2CH2), 2.16 (m, 4H; OCH2CH2CH2); 19F NMR
(376 MHz, CDCl3): δ = 126.1 (m, 4F). 123.4 (m, 4F), 122.7 (m, 4F),
C
12H25), 139.9 (ArC, C-CH]CH2), 137.5 (CH]CH2), 114.4 (CH]CH2),
3
121.7 (m, 12F), 114.3 (m, 4F), −80.8 (t, JC,F = 9.9 Hz, 6F; CF3); 13C
105.2 (ArC), 101.4 (ArC), 68.4 (OCH2(CH2)10CH3), 32.3
3

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
(CH3(CH2)11O), 30.1 (CH3(CH2)11O), 29.9 (CH3(CH2)11O), 29.8
(CH3(CH2)11O), 26.5 (CH3(CH2)11O), 23.1 (CH3(CH2)11O), 14.5
(CH3(CH2)11O); HRMS (ESI): m/z calcd for C32H56O2Na 495.4178;
found 495.4172 [M + Na+].
(CH3(CH2)11O), 29.8 (CH3(CH2)11O), 26.5 (CH3(CH2)11O), 23.1
(CH3(CH2)11O), 14.5. (CH3(CH2)11O); HRMS (ESI): m/z calcd for
C
32H56O2Na 495.4178 [M + Na+]; found 495.4172.
2.8.12. 2,4-Bis(dodecylthio)-6-(4-vinylphenoxy)-1,3,5-triazine, 4g
Colorless oil; Isolated yield: 97% (0.30 mmol, 140 mg from 200 mg
of starting material); 1H NMR (360 MHz, CDCl3): δ = 7.44 (d,
2.8.8. 1,4-bis(4,4,4-trifluorobutoxy)-2-vinylbenzene, 4c
Colorless oil; Isolated yield: 95% yield (0.53 mmol, 0.189 g from
0.20 g of starting material); 1H NMR (250 MHz, CDCl3): δ = 7.38 ppm
(s, 1H, ArH), 7.06 (m, 2H, ArH and CH]CH2), 6.81 (s, 1H, ArH), 5.78
(d, 3Jtrans(H,H) = 17.6 Hz, 1H, CH]CH2), 5.34 (d, 3Jcis(H,H) = 11.1 Hz,
3
3J(H,H) = 8.5 Hz, 2H; ArH), 7.13 (d, J(H,H) = 8.5 Hz, 2H; ArH), 6.73
(dd, 3Jtrans (H,H) = 17.6 Hz, 3Jcis (H,H) = 10.9 Hz, 1H; CH]CH2), 5.74 (d,
3Jtrans (H,H) = 17.6 Hz, 1H; CH]CH2), 5.27 (d, 3Jcis (H,H) = 10.9 Hz, 1H;
3
3
1H CH]CH2), 4.03 (t, J(H,H) = 6.3 Hz, 4H, OCH2CH2), 2.36 (m, 4H,
CH]CH2), 3.00 (t, J(H,H) = 6.7 Hz, 4H; CH3(CH2)10CH2S), 1.62 (m,
CH2CF3), 2.10 (m, 4H, CH2CH2CH2); 19F NMR (235 MHz, CDCl3):
δ = −66.8 (s, 6F, CF3); 13C NMR (63 MHz, [D]CHCl3): δ = 153.1 (ArC,
4H;
CH3CH2(CH2)9CH2S),
1.27
(broad
singlet,
36H;
CH3(CH2)9CH2CH2S), 0.90 (t, J(H,H) = 6.7 Hz, 6H; CH3(CH2)11S); 13C
NMR (91 MHz, CDCl3): δ = 183.3 (TriazineC-SC12H25), 167.9
(TriazineC-O), 151.3 (ArC, O-C), 135.8 (CH]CH2), 135.3 (ArC, C-
CH]CH2), 127.1 (ArC), 121.8 (ArC), 114.0 (CH]CH2), 31.9
(CH3(CH2)11S), 30.5 (CH3(CH2)11S), 29.6 (CH3(CH2)11S), 29.5
(CH3(CH2)11S), 29.4 (CH3(CH2)11S), 29.2 (CH3(CH2)11S), 28.8
(CH3(CH2)11S), 22.7 (CH3(CH2)11S), 14.1 (CH3(CH2)11S); HRMS (ESI):
m/z calcd for C35H57N3OS2Na 622.3841[M + Na+]; found 622.3844.
3
C
12H25O-C), 150.3 (ArC, C12H25O-C), 131.2 (ArC), 127.5 (q,
1J(C,F) = 245.1 Hz, CF3), 127.4 (q, 1J(C,F) = 245.1 Hz, CF3), 131.1 (ArC),
128.9 (CH]CH2), 127.8 (ArC), 114.5 (CH]CH2), 112.2 (ArC), 67.3
(OCH2(CH2)2CF3), 66.6 (OCH2(CH2)2CF3), 31.5 (m, OCH2(CH2)2CF3),
22.3 (m, OCH2(CH2)2CF3); HRMS (ESI): m/z calcd for C16H18F6O2Na
379.1109 [M + Na+]; found 379.1108.
2.8.9. 1,4-Bis((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
heptadecafluoroundecyl)oxy)-2-vinylbenzene, 4d
2.8.13. (E)-4-(2,5-Bis(dodecyloxy)styryl)phenol, 1a
Colorless oil; Isolated yield: 93% (0.18 mmol, 185 mg from 200 mg
of starting material); 1H NMR (360 MHz, CDCl3): δ = 7.01 (m, 2H,
CH]CH2 and ArH), 6.79 (bs, 2H, ArH), 5.74 (d, 3Jtrans(H,H) = 17.1 Hz,
1H, CH]CH2, trans), 5.31 (d, 3Jcis(H,H) = 11.1 Hz, 1H, CH]CH2, cis),
White solid; Isolated yield: 97% (0.20 mmol, 116 mg from 100 mg of
starting material); m.p. 135-137 °C; 1H NMR (360 MHz, CDCl3):
δ = 7.43 ppm (d, 3J(H,H) = 7.9 Hz, 1H; ArH), 7.34 (d, 3J(H,H) = 16.4 Hz,
3
1H; CH]CH), 7.15 (d, J(H,H) = 1.9 Hz, 1H; ArH), 7.07 (d,
3
4.03 (t, J(H,H) = 5.7 Hz, 4H, OCH2CH2CH2(CF2)7CF3), 2.33 (m, 2H,
3Jtrans(H,H) = 16.4 Hz, 1H; CH]CH), 6.84 (m, 3H; ArH), 6.78 (dd,
4
3
-OCH2CH2CH2(CF2)7CF3) and 2.12 (m, 2H, -OCH2CH2 CH2(CF2)7CF3);
3J(H,H) = 8.5 Hz, J(H,H) = 1.9 Hz, 1H; ArH), 3.98 (t, J(H,H) = 6.7 Hz,
4H; CH3CH2(CH2)9CH2O), 5.11 (s, 1H; OH), 1.83 (m, 4H;
CH3(CH2)9CH2CH2O), 1.49 (m, 4H; CH3CH2(CH2)9CH2O), 1.30 (broad
19F NMR (235 MHz, CDCl3): δ = −126.6 (m, 4F), −123.9 (m, 4F),
3
−123.2 (m, 4F), −122.4 (m, 12F), −114.8 (t, J(F,F) = 13.8 Hz, 4F),
3
3
−81.3 (t, J(F,F) = 9.9 Hz, 6F; CF3); 13C NMR (63 MHz, [D]CHCl3):
singlet, 32H; CH3CH2(CH2)8CH2CH2O), 0.91 (t, J(H,H) = 6.7 Hz, 6H;
δ = 153.0 (ArC, C-O), 150.2 (ArC, C-O), 131.0 (ArC), 128.0 (CH]CH2),
114.5 (CH]CH2), 113.6 (ArC), 112.6 (ArC), 111.7 (ArC), 67.7
(OCH2CH2), 66.9 (OCH2CH2), 27.9 (m, CF3CH2), 20.6 (m, OCH2CH2);
CH3CH2(CH2)9CH2O); 13C NMR (91 MHz, CDCl3): δ = 153.2 (ArC,
C
12H25O-C), 153.2 (ArC, C12H25O-C), 150.7 (ArC, C12H25O-C),
133.7(ArC), 131.7 (CH]CH), 128.7 (ArC), 127.7 (CH]CH), 114.6
(ArC), 114.3 (ArC), 113.6 (ArC), 112.4 (ArC), 69.3 (OCH2(CH2)10CH3),
68.8 (OCH2(CH2)10CH3), 31.9 (CH3(CH2)11O), 29.7 (CH3(CH2)11O),
29.5 (CH3(CH2)11O), 29.4 (CH3(CH2)11O), 26.2 (CH3(CH2)11O), 26.1
(CH3(CH2)11O), 22.7 (CH3(CH2)11O), 14.2 (CH3(CH2)11O); IR (ATR):
ν˜ = 3317, 2919, 1231 cm−1; UV/vis (CH3CN): λmax (ε) = 298 nm
(12235 mol−1 dm3 cm−1); fluorescence (CH3CN): (λem) = 405 nm;
HRMS (ESI): m/z calcd for C38H61O3 565.4615 [M + H+]; found
565.4615.
C
30H18F34O2Na 1079.0662 [M + Na+]; found 1079.0665.
2.8.10. 1-((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
Heptadecafluoroundecyl)oxy)-4-metoxy-2-vinylbenzene, 4e
Colorless oil; Isolated yield: 97% (0.26 mmol, 164 mg from 160 mg
of starting material); 1H NMR (250 MHz, CDCl3): δ = 7.36 (broad
singlet, 1H; ArH), 7.06 (m, 2H; ArH and CH]CH2), 6.81 (d,
3
4J(H,H) = 1.6 Hz, 2H; ArH), 5.78 (d, Jtrans (H,H) = 17.7 Hz, 1H;
3
CH]CH2), 5.33 (d, Jcis (H,H) = 11.1 Hz, 1H; CH]CH2), 4.03 (t,
3J(H,H) = 6.8 Hz, 2H; OCH2), 3.82 (s, 3H; OCH3), 2.36 (m, 2H;
OCH2CH2CH2), 2.13 (m, 2H; OCH2CH2CH2); 19F NMR (235 MHz,
CDCl3): δ = −126.6 (m, 2F), −123.9 (m, 2F), −123.2 (m, 2F), −122.4
(m, 6F), −114.8 (t, 3J(F,F) = 13.8 Hz, 2F), −81.3 (t, 3J(F,F) = 9.9 Hz, 3F;
CF3); 13C NMR (63 MHz, [D]CHCl3): δ = 154.1 (ArC, C-O), 150.1 (ArC,
C-O), 131.2 (ArC), 128.0 (CH]CH), 114.7 (CH]CH), 113.8 (ArC),
113.6 (ArC), 111.7 (ArC), 67.7 (OCH2CH2), 55.5 (OCH3), 28.0 (t,
2.8.14. (E)-4-(2,5-bis(4,4,4-trifluorobutoxy)styryl)phenol, 1c
White solid; Isolated yield: 89% (0.74 mmol, 334 mg from 300 mg of
starting material); m.p. 117-118 °C; 1H NMR (360 MHz, CDCl3):
δ = 7.43 ppm (d, 3J(H,H) = 8.6 Hz, 2H; ArH),. 7.28 (d, 3J(H,H) = 16.4 Hz,
3
1H; CH]CH), 7.15 (d, J(H,H) = 2.9 Hz, 1H; ArH), 7.06 (d,
3
3J(H,H) = 16.4 Hz, 1H; CH]CH), 6.86 (d, J(H,H) = 8.6 Hz, 2H; ArH),
3
3
6.83 (d, J(H,H) = 8.9 Hz, 1H; ArH), 6.77 (dd, J(H,H) = 8.8 Hz,
2J(C,F) = 22.5 Hz, CF3CH2), 22.7 (t, J(C,F) = 3.6 Hz, OCH2CH2);
4J(H,H) = 2.9 Hz, 1H, ArH), 5.01 (s, 1H; OH), 4.05 (t, J(H,H) = 6.3 Hz,
3
3
C
20H15F17O2Na 633.0698 [M + Na+]; found 633.0694.
4H; CH2CF3), 2.38 (m, 4H; OCH2CH2CH2), 2.10 (m, 4H; OCH2CH2CH2);
19F NMR (376 MHz, [D]CHCl3): δ = −66.3 (s, CF3); 13C NMR
(101 MHz, CDCl3 [D]CHCl3) δ = 153.3 (ArC, C-O). 150.0 (ArC, C-O),
150.3 (ArC, C-O), 130.5 (ArC), 129.2 (CH]CH), 127.9 (ArC), 127.5 (q,
2.8.11. 1,3-Bis(dodecyloxy)-2-vinylbenzene, 4f
Colorless oil; Isolated yield: 96% (0.30 mmol, 140 mg from 150 mg
of starting material); 1H NMR (250 MHz, CDCl3): δ = 6.85 (t,
3J(H,H) = 8.5 Hz, 1H, ArH). 6.68 (dd, 3Jtrans(H,H) = 17.5 Hz,
3Jcis(H,H) = 11.1 Hz, 1H; CH]CH2), 6.40 (d, 3J(H,H) = 8.5 Hz, 2H, ArH),
1
1J(C,F) = 245.1 Hz, CF3CH2), 127.4 (q, J(C,F) = 245.1 Hz, CF3CH2),
120.7 (ArC), 115.6 (ArC), 115.0 (ArC), 113.9 (CH]CH), 113.8 (ArC),
112.2 (ArC), 67.5 (OCH2CH2), 66.6 (OCH2CH2), 30.7 (m, CF3CH2),22.3
(m, OCH2CH2); IR (ATR): ν˜ = 3332, 2937 cm−1; UV/vis (CH3CN): λmax
5.76
(d,
3Jtrans(H,H) = 17.5 Hz,
1H,
CH]CH2),
5.27
(d,
3Jcis(H,H) = 11.1 Hz, 1H, CH]CH2), 3.98 (t, J(H,H) = 6.7 Hz, 4H,
(ε) = 296 nm
(20340 mol−1 dm3 cm−1);
fluorescence
emission
3
CH3CH2(CH2)9CH2O), 1.82 (m, 4H, CH3CH2CH2(CH2)8CH2O), 1.50 (m,
(CH3CN): (λem) = 405 nm; HRMS (ESI): m/z calcd for C22H22F6O3Na
4H,
CH3CH2(CH2)9CH2O),
0.95
1.33
(t,
(broad
singlet,
36H,
6H,
449.155 [M + Na+]; found 449.1546.
CH3CH2(CH2)9CH2O),
3J(H,H) = 6.7 Hz,
CH3CH2(CH2)9CH2O). 13C NMR (63 MHz, CDCl3): δ = 160.9 (ArC,
2.8.15. (E)-4-(2,5-bis(((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
heptadecafluoroundecyl)oxy)styryl)phenol, 1d
C
12H25O-C), 139.9 (ArC), 137.5 (CH]CH2), 114.4 (CH]CH2), 105.2
(ArC), 101.4 (ArC), 68.4 (OCH2(CH2)10CH3), 32.3 (CH3(CH2)11O), 29.9
White solid; Isolated yield: 80% (0.06 mmol, 70 mg from 80 mg of
4

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
Scheme 2. Hydroxy-substituted phenolic benzaldehydes 3.
Scheme 3. Wittig-Schlosser reaction conditions applied to the selective synthesis of (E)-1a,g.
starting material); m.p. 124-127 °C; 1H NMR (400 MHz,
OCH2CH2CH2); 19F NMR (376 MHz, [D6]CH3COCH3): δ = −126.7 (m,
4F), −123.9 (m, 4F), −123.2 (m, 4F), −122.3 (m, 12F), −114.7 (t,
3J(F,F) = 13.8 Hz, 4F), −81.7 (m, 6F; CF3); 13C NMR (101 MHz,
[D6]CH3COCH3): δ = 157.4 (ArC, C-OH), 153.3 (ArC, C-O)) 150.4 (ArC,
C-O), 129.4 (ArC), 129.3 (CH]CH), 128.0 (ArC), 127.7 (ArC), 119.7
(CH]CH), 115.5 (ArC), 114.0 (ArC), 113.9 (ArC), 111.9 (ArC), 67.5
3
[D6]CH3COCH3): δ = 8.51 (s, 1H, OH), 7.43 (d, J(H,H) = 8.5 Hz, 2H;
ArH), 7.34 (d, 3Jtrans(H,H) = 16.5 Hz, 1H; CH]CH), 7.27 (d,
4J(H,H) = 2.9 Hz, 1H; ArH), 7.20 (d, 3Jtrans(H,H) = 16.5 Hz, 1H; CH]CH),
3
6.96 (d, J(H,H) = 8.6 Hz, 1H; ArH), 6.84 (m, 3H; ArH), 4.15 (q,
3J(H,H) = 5.8 Hz, 4H; OCH2), 2.51 (m, 4H; OCH2CH2CH2), 2.16 (m, 4H;
5

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
Scheme 4. Synthesis of the reactive fluorescent carbamates 7a, 7d and 7e.
Table 1
Results of reactions of Scheme 1and fluorescent properties of stilbene deriva-
tives (E)-1.
Entry Wittig Step
yield %
Heck Step
Z/E
Heck Step (E)-1
yield %
Emissiona (E)-
1
ϕb (E)-1
λmax (nm)
1
2
3
4
5
6
7
4a
96%
4b
96%
4c
95%
4d
93%
4e
97%
4f
96%
4g
35/65
38/62
25/75
30/70
30/70
31/69
40/60
1a
60%
1b
61%
1c
70%
1d
Mixture
1e
32%
1f
42%
1g
405
392
405
407
408
406
390
0.36
0.29
0.15
0.38
0.12
0.22
0.25
97%
57%
a
Fluorescence maximum measured in acetonitrile under 280 nm wavelength
irradiation.
Fig. 3. Fluorescence emission spectra of (E)-1 (10−8 M in acetonitrile) under
b
Fluorescent quantum yields were measured relative to ϕ = 0.023 for trans-
280 nm wavelength irradiation.
stilbene in acetonitrile (Roberts and Pincock 2006).
(OCH2CH2), 66.6 (OCH2CH2), 27.5 (m, CF3CH2), 20.5 (m, OCH2CH2);
IR (ATR): ν˜ = 3332, 2937 cm−1; UV/vis (CH3CN): λmax (ε) = 283 nm
(56195 mol−1 dm3 cm−1);
fluorescence
emission
(CH3CN):
(λem) = 407 nm; HRMS (ESI): m/z calcd for C36H21F34O3Na 1148.1010
[M + Na+]; found 1148.1021.
2.8.16. (E)-4-(2-((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
heptadecafluoroundecyl)oxy)-5-metoxy) styryl)phenol, 1e
White solid; Isolated yield: 81% (0.13 mmol, 93 mg from 100 mg of
starting material); m.p. 142-145 °C; 1H NMR (400 MHz,
3
[D6]CH3COCH3): δ = 8.51 (s, 1H; OH), 7.44 (d, J(H,H) = 8.5 Hz, 2H;
3
ArH), 7.34 (d, J(H,H) = 16.5 Hz, 1H; CH]CH), 7.22 (m, 2H; ArH and
CH]CH), 6.97 (d, 3J(H,H) = 9.0 Hz, 1H, ArH), 6.86 (d, 3J(H,H) = 8.5 Hz,
2H; ArH), 6.80 (dd, 3J(H,H) = 9.0 Hz, 2J(H,H) = 2.9 Hz, 1H; ArH), 4.17 (t,
3J(H,H) = 6.0 Hz, 2H; OCH2), 3.81 (s, 3H; OCH3), 2.57 (m, 2H;
OCH2CH2CH2), 2.19 (m, 2H; OCH2CH2CH2); 19F NMR (376 MHz,
[D6]CH3COCH3): δ = −126.7 (m, 2F), −123.9 (m, 2F), −123.2 (m,
3
2F), −122.3 (m, 6F), −114.7 (t, J(F,F) = 13.8 Hz, 2F), −81.6 (t,
3J(F,F) = 9.9 Hz, 3F; CF3); 13C NMR (101 MHz, [D6]CH3COCH3)
δ = 157.3 (ArC, C-O). 154.3 (ArC, C-O), 150.1 (ArC, C-OH), 129.4
Fig. 2. Structures of compounds 4.
6

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
Fig. 4. Confocal fluorescence microscopy images and fluorescence emission spectra of solid 1a (top row) and solid 1d (bottom row). Note each color on the graph
corresponds to the excitation of a different area of the solid. (For interpretation of the references to color in this figure legend, the reader is referred to the Web
version of this article.)
3J(C,F) = 3.6 Hz, OCH2CH2); IR (ATR): ν˜ = 3371, 2945 cm−1; UV/vis
Table 2
(CH3CN): λmax (ε) = 283 nm (50615 mol−1 dm3 cm−1); fluorescence
Measured contact angles of a drop of different solvents (4 μL) on a modified
glass surface previously coated with 7 (addition of 0.15 mL of a 1,9.10−3 M
emission (CH3CN): (λem) = 408 nm; HRMS (ESI): m/z calcd for
26H19F17O3Na 725.0955 [M + Na+]; found 725.0948.
solution in THF). Maximum fluorescence emission and quantum yields of 7.
C
Entry
Compound
Water[a]
Hexadecane[a]
Emission λmax (nm)
ϕ
1
2
3
7a
7d
7e
120
115
119
0
95
0
408
410
412
0.34
0.42
0.18
2.8.17. (E)-4-(2,6-bis(dodecyloxy)styryl)phenol, 1f
White solid; Isolated yield: 85% (0.17 mmol, 102 mg from 100 mg of
starting material); m.p.: 132-133 °C. 1H NMR (360 MHz, CDCl3):
δ = 7.43 ppm (t, 3J (H,H) = 7.9 Hz, 1H, ArH), 7.34 (d, 3J (H,H) = 16.4 Hz,
1H, CH]CH), 7.15 (d, 3J (H,H) = 7.9 Hz, 2H, ArH), 7.07 (d, 3J
aAverage of three measurements.
bFluorescence maximum measured in acetonitrile under 280 nm wavelength
irradiation.
(H,H) = 16.4 Hz, 1H, CH]CH), 6.84 (m, 3H, ArH), 6.78 (dd, 3J
4
(H,H) = 8.5 Hz, J (H,H) = 1.9 Hz, 1H, ArH), 5.11 (s, 1H, OH), 3.98 (t, 3
J
4H,
cFluorescent quantum yields were measured relative to ϕ = 0.023 for trans-
stilbene (Niembro et al., 2008).
(H,H) = 6.7 Hz,
4H,
CH3CH2(CH2)9CH2O),
1.83
(m,
CH3(CH2)9CH2CH2O), 1.49 (m, 4H, CH3CH2(CH2)9CH2O), 1.30 (broad
singlet, 32H, CH3CH2(CH2)8CH2CH2O), 0.91 (t, 3J (H,H) = 6.7 Hz, 6H,
CH3CH2(CH2)9CH2O). 13C NMR (91 MHz, CDCl3): δ = 155.5 (ArC,
(ArC), 129.2 (CH]CH), 127.9 (ArC), 127.6 (ArC), 119.8 (CH]CH),
115.4 (ArC), 114.1 (ArC), 113.2 (ArC), 110.9 (ArC), 67.6 (OCH2CH2),
54.9 (OCH3), 27.5 (t, 2J(C,F) = 21.9 Hz, CF3CH2), 20.5 (t,
C
12H25O-C), 153.2 (ArC, C12H25O-C), 150.7 (ArC, C12H25O-C),
7

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
Fig. 5. Fluorescence emission spectra of solid 7a (left graphic) and solid 7d (right graphic).
3
3
δ = 7.51 (d, J(H,H) = 8.6 Hz, 2H; ArH). 7.42 (d, J(H,H) = 8.6 Hz, 2H;
ArH), 7.14 (d, J(H,H) = 8.6 Hz, 2H), 7.04 (d, 3Jtrans(H,H) = 16.3 Hz, 1H;
3
CH]CH), 6.96 (d, 3Jtrans(H,H) = 16.3 Hz, 1H; CH]CH), 6.85 (d,
3J(H,H) = 8.6 Hz, 2H; ArH), 5.02 (s, 1H; OH), 3.01 (t, J(H,H) = 6.7 Hz,
3
4H; CH3 (CH2)10CH2S), 1.64 (m, 4H; CH3CH2(CH2)9CH2S), 1.25 (broad
3
singlet, 36H; CH3(CH2)9CH2CH2S), 0.90 (t, J(H,H) = 6.8 Hz, 6H;
CH3(CH2)11S); 13C NMR (91 MHz, CDCl3): δ = 183.3 (TriazineC-
SC12H25) 168.0 (ArC, TriazineC-O), 155.5 (ArC, O-C), 150.8 (ArC, C-
OH), 135.4 (C-CH]CH), 130.1 (CH]CH-C), 128.4 (CH]CH), 127.9
(ArC), 127.0 (ArC), 125.5 (CH]CH), 121.9 (ArC), 115.7 (ArC), 31.9
(CH3(CH2)11S), 30.5 (CH3(CH2)11S), 29.6 (CH3(CH2)11S), 29.5
(CH3(CH2)11S), 29.4 (CH3(CH2)11S), 29.2 (CH3(CH2)11S), 28.8
(CH3(CH2)11S), 22.7 (CH3(CH2)11S),14.1 (CH3(CH2)11S); UV/vis
(CH3CN): λmax (ε) = 285 nm (31220 mol−1 dm3 cm−1); fluorescence
emission (CH3CN): (λem) = 390 nm; HRMS (ESI): m/z calcd for
C
41H61N3O2S2Na 714.4103 [M + Na+]; found 714.4105.
2.8.19. (E)-4-(2,5-bis(dodecyloxy)styryl)phenyl (3-(triethoxysilyl) propyl)
carbamate, 7a
White solid; Isolated yield: 92% (0.24 mmol, 199 mg from 150 mg of
starting material); m.p.: 117-118 °C; 1H NMR (360 MHz, CDCl3):
δ = 7.51 ppm
(d,
3J(H,H) = 8.5 Hz,
2H;
ArH);
7.41
(d,
3Jtrans(H,H) = 16.4 Hz, 1H; CH]CH), 7.10 (m, 4H; ArH and CH]CH),
3
3
6.83 (d, J(H,H) = 8.9 Hz, 1H; ArH), 6.78 (dd, J(H,H) = 8.5 Hz,
4J(H,H) = 1.9 Hz, 1H; ArH), 5.43 (t, J(H,H) = 6.6 Hz, 1H; NHCH2CH2),
3
3.97 (t, 3J(H,H) = 6.7 Hz, 4H; CH3CH2(CH2)9CH2O), 3.87 (q,
3J(H,H) = 7.0 Hz, 6H; Si(OCH2CH3)3), 3.30 (q, J(H,H) = 6.6 Hz, 2H;
3
Fig. 6. Schematic representation of covalently modified paper with carbamates
7a (left image) and 7d (right image). Photograph: UV irradiation of modified
and unmodified filter papers images. Left: paper modified with 7a. Center:
unmodified paper. Right: paper modified with 7d.
NHCH2CH2), 1.78 (m, 6H, CH3(CH2)9CH2CH2O and CH2CH2CH2Si),
1.50
(m,
4H,
CH3CH2(CH2)9CH2O),
1.27
(m,
41H
3
CH3CH2(CH2)8CH2CH2O and Si(OCH2CH3)3), 0.90 (t, J(H,H) = 6.6 Hz,
3
6H; CH3CH2(CH2)10), 0.71 (t, J(H,H) = 9.0 Hz, 2H; CH2Si); 13C NMR
(101 MHz, CDCl3) δ = 154.6 (O]C-NH) 153.3 (ArC, C-O-C]O), 150.9
133.7(ArC), 131.7 (CH]CH), 128.7 (ArC), 127.7 (CH]CH), 114.6
(ArC), 114.3 (ArC), 113.6 (ArC), 112.4 (ArC), 69.3 (OCH2(CH2)10CH3),
68.8 (OCH2(CH2)10CH3), 31.9 (CH3(CH2)11O), 29.7 (CH3(CH2)11O),
29.4 (CH3(CH2)11O), 29.3 (CH3(CH2)11O), 26.2 (CH3(CH2)11O), 26.1
(CH3(CH2)11O), 22.7 (CH3(CH2)11O), 14.2 (CH3(CH2)11O); IR (ATR):
ν˜ = 3320, 2919, 1230 cm−1; UV/vis (CH3CN): λmax (ε) = 297 nm
(12235 mol−1 dm3 cm−1); fluorescence (CH3CN): (λem) = 406 nm;
HRMS (ESI): m/z calcd for C38H61O3 565.4615 [M + H+]; found
565.4615.
(ArC,
C12H25O-C), 150.4 (ArC, C12H25O-C), 135.1 (ArC), 128.2
(CH]CH), 127.5 (ArC), 127.3 (ArC), 123.4 (CH]CH), 121.7 (ArC),
114.5 (ArC), 113.8 (ArC), 112.3 (ArC), 69.5 (OCH2(CH2)10CH3), 68.6
(OCH2(CH2)10CH3), 68.6 (OCH2(CH2)10CH3), 58.5 (Si(OCH2CH3)3),
43.6 (NHCH2CH2), 31.9 (CH3(CH2)11O), 29.7 (CH3(CH2)11O), 29.5
(CH3(CH2)11O), 29.4 (CH3(CH2)11O), 26.3 (CH3(CH2)11O), 26.1
(CH3(CH2)11O), 23.1 (CH2CH2CH2Si), 22.7 (CH3(CH2)11O), 18.3 (Si
(OCH2CH3)3), 14.1 (CH3(CH2)11O), 7.7 (CH2Si); IR (ATR): ν˜ = 3360,
2918,
1752 cm−1
;
UV/vis
(CH3CN):
fluorescence
λmax
(ε) = 279 nm
(104970 mol−1 dm3 cm−1);
emission
(dte):
2.8.18. (E)-4-(4-((4,6-bis(dodecylthio)-1,3,5-triazin-2-yl)oxy)styryl)
phenol, 1g
(λem) = 408 nm; HRMS (ESI): m/z calcd for C48H81NO7SiNa 834.5675
[M + Na+]; found 834.5682.
White solid; Isolated yield: 81% (0.10 mmol, 75 mg from 80 mg of
starting material); m.p.: 142-145 °C; 1H NMR (360 MHz, CDCl3):
8

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
Fig. 7. X-ray photoelectron spectroscopy (XPS) spectra of modified paper 7d.
Fig. 8. Fluorescence emission spectra of paper and modified papers with 7d prior and after water immersion.
2.8.20. (E)-4-(2,5-bis(((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
(ArC), 127.2 (ArC), 122.5 (CH]CH), 121.7 (ArC), 114.3 (ArC), 113.8
(ArC), 112.4 (ArC), 67.8 (C8F17CH2CH2CH2O), 66.9
heptadecafluoroundecyl)oxy)styryl)
carbamate, 7d
phenyl
(3-(triethoxysilyl)propyl)
(C8F17CH2CH2CH2O), 58.4 (Si(OCH2CH3)3), 43.5 (NHCH2CH2), 28.0 (t,
2J(C,F) = 22.4 Hz, C8F17CH2CH2CH2), 28.0 (t, 2J(C,F) = 22.4 Hz,
C8F17CH2CH2CH2), 23.0 (CH2CH2CH2Si), 20.7 (m, C8F17CH2CH2CH2),
20.6 (m, C8F17CH2CH2CH2), 18.2 (Si(OCH2CH3)3), 7.7 (CH2Si); IR
(ATR): ν˜ = 3336, 2931, 1740 cm−1); UV/vis (CH3CN): λmax
(ε) = 282 nm (357554 mol−1 dm3 cm−1); fluorescence emission
White solid; Isolated yield: 75% (0.08 mmol, 109 mg from 120 mg of
starting material); m.p.: 112-114 °C; 1H NMR (400 MHz, CDCl3):
3
δ = 7.49 (d, J(H,H) = 8.2 Hz, 2H; ArH). 7.35 (d, 3Jtrans(H,H) = 16.4 Hz,
1H; CH]CH), 7.13 (m, 4H; ArH and CH]CH), 6.84 (d,
3
4
3J(H,H) = 8.9 Hz, 1H; ArH), 6.79 (dd, J(H,H) = 8.8 Hz, J(H,H) = 2.2 Hz,
3
1H; ArH), 5.39 (t, J(H,H) = 5.5 Hz, 1H; NHCH2CH2), 4.07 (t,
(CH3CN):
C
(λem) = 412 nm;
HRMS
(ESI):
m/z
calcd
for
3J(H,H) = 5.0 Hz, 4H; C8F17(CH2)2CH2O), 3.87 (t, J(H,H) = 7.0 Hz, 6H;
43H43F34NO7SiNa 1418.2158 [M + Na+]; found 1418.2156.
3
3
O(CH2CH3)3), 3.31 (q, J(H,H) = 6.4 Hz, 2H; NHCH2CH2), 2.39 (m, 4H;
OCH2CH2CH2), 2.16 (m, 4H; OCH2CH2CH2), 1.74 (m, 2H;
3
2.8.21. (E)-4-(2-(((4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-
CH2CH2CH2Si), 1.27 (t, J(H,H) = 7.0 Hz, 9H; Si(OCH2CH3)3), 0.72 (t,
3J(H,H) = 8.0 Hz, 2H; CH2Si); 19F NMR (376 MHz, CDCl3): δ = −126.7
(m, 2F), −123.9 (m, 2F), −123.2 (m, 2F), −122.3 (m, 6F), −114.7 (t,
heptadecafluoroundecyl)oxy)-5-methoxystyryl)phenyl
propyl)carbamate, 7e
(3-(triethoxysilyl)
3
3J(F,F) = 13.8 Hz, 2F), −81.6 (t, J(F,F) = 9.9 Hz, 3F; CF3); 13C NMR
White solid; Isolated yield: 84% (0.17 mmol, 159 mg from 140 mg of
starting material); m.p.: 125-128 °C; 1H NMR (400 MHz, CDCl3):
(101 MHz, CDCl3) δ = 154.4 (O]C-NH). 152.1 (ArC, C-O-C]O), 150.6
(ArC, O-C), 150.5 (ArC, O-C), 134.6 (ArC), 128.9 (CH]CH), 127.8
3
δ = 7.49 (d, J(H,H) = 8.5 Hz, 2H; ArH), 7.36 (d, 3Jtrans(H,H) = 16.4 Hz,
1H; CH]CH), 7.13 (m, 4H; ArH and CH]CH), 6.84 (d,
9

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
3J(H,H) = 8.9 Hz, 1H; ArH), 6.79 (dd, J(H,H) = 8.9 Hz, J(H,H) = 2.8 Hz,
in the studied range. Solutions of concentrations of the order of 10−8 M
in acetonitrile were used. The fluorimetry spectra of compounds 1 are
shown in Fig. 3. The fluorimetry experiments of all isolated (Z)-1 iso-
mers (except 1d, see Table 1) were performed presenting no fluores-
cence in the visible area. According to the results, (E)-stilbenes 1b and
1g (entry 2 and 7 of Table 1) do not emit fluorescence in the visible
range. If we compare the structure of these two with the set of stilbenes,
it seems necessary the presence of a donor alkoxide group in ortho
position with respect to the double bond. However, placing two alk-
oxides in the ortho positions does not cause the fluorescence emission to
take place at a longer wavelength (3f, entry 6). Different alkoxides (1a,
1c and 1d) do not provide significant differences in terms of the max-
imum emission of fluorescence (Table 1, Fig. 3) which is in consonance
with a basically resonance effect. The fluorescent quantum yields
(Table 1) of (E)-1a (ϕ = 0.36) and (E)-1d (ϕ = 0.38) in acetonitrile
were the biggest in the series and larger than that of trans-stilbene
(ϕ = 0.023) [30]. This is excellent for our purposes, mainly because
both compounds possess long hydrophobic chains.
3
4
3
1H; ArH), 5.46 (t, J(H,H) = 6.6 Hz, 1H; NHCH2CH2), 4.06 (t,
3J(H,H) = 5.9 Hz, 2H; C8F17(CH2)2CH2O), 3.87 (m, 9H; OCH3 and Si
3
(OCH2CH3)3), 3.31 (q, J(H,H) = 6.6 Hz, 2H; NHCH2CH2), 2.39 (m, 2H;
OCH2CH2CH2), 2.17 (m, 2H; OCH2CH2CH2), 1.74 (m, 2H;
3
CH2CH2CH2Si), 1.27 (t, J(H,H) = 7.1 Hz, 9H; Si(OCH2CH3)3), 0.72 (t,
3J(H,H) = 8.0 Hz, 2H; CH2Si); 19F NMR (376 MHz, [D6]CH3COCH3):
δ = −126.7 (m, 4F). −123.3 (m, 4F), −122.9 (m, 4F), −121.9 (m,
3
12F), −114.3 (t, J(F,F) = 13.8 Hz, 4F), −80.7 (t, 3J (F,F) = 9.9 Hz,
6F); 13C NMR (101 MHz, CDCl3) δ = 154.5 (O]C-NH), 154.1 (ArC, C-
O-C]O), 150.6 (ArC, O-C),150.2 (ArC, O-C), 134.6 (ArC), 128.7
(CH]CH), 127.7 (ArC), 127.2 (ArC), 122.7 (CH]CH), 121.7 (ArC),
113.9 (ArC), 113.7 (ArC), 111.5 (ArC), 67.8 (C8F17CH2CH2CH2O), 58.4
(Si(OCH2CH3)3), 55.6 (OCH3), 43.5 (NHCH2CH2), 28.0 (t,
2J(C,F) = 22.4 Hz, C8F17CH2CH2CH2), 23.0 (CH2CH2CH2Si), 20.7 (t, 3J
(C,F) = 3.5 Hz, C8F17CH2CH2CH2), 18.2 (Si(OCH2CH3)3), 7.7 (CH2Si); IR
(ATR): ν˜ = 3320, 2978, 1714 cm−1
;
UV/vis (CH3CN): λmax
fluorescence emission
m/z calcd for
(ε) = 285 nm
(50615 mol−1 dm3 cm−1);
(CH3CN):
(λem) = 410 nm;
HRMS
(ESI):
For our final application in security papers, compounds 1 should
emit fluorescence in solid state. Thus, a confocal fluorescence micro-
scopy was used to obtain a true 3D optical resolution image of the
stilbene (E)-1 derivatives in solid state. We selected 1a and 1d as re-
presentative of the series. The excitation of the fluorophores caused a
detectable fluorescence as shown in images of Fig. 4. The fluorescence
emission graphics show the uniformity of both samples (1a and 1d).
In view of the results, we decided to address the improvement of the
synthesis of pure (E)-1 derivatives. The alternative selected was a
Wittig-Schlosser olefination reaction [31–33] following previously re-
ported conditions by the group of Denmark [34]. The substituted al-
dehydes 3 reacted with the phosphonium salt 6 in the presence of LiBr
(2 equiv.) and a large excess of n-BuLi (10 equiv.). Nucleophilic addi-
tion reaction of triphenylphosphine hydrobromide and 4-hydro-
xybenzyl alcohol in acetonitrile (18 h) accomplished 6 in quantitative
yield. Using an excess of lithium bromide and an alkyl litiated base, an
equilibration of the lithiobetaines intermediates is obtained, resulting
in all the studied cases (1a-g) in the exclusive formation of (E)-stereo-
isomer. Other Wittig-type reactions using milder conditions in water
have already been reported [35,36] however, these protocols were not
effective due low solubility of compounds 3 in water medium. There-
fore, the Schlosser modification of the Wittig reaction has permitted to
stereoselectively afford (E)-stilbenes 1a-g in excellent yields (80–98%)
and in a really straightforward manner. Only (E)-stilbenes that emit
fluorescence in the visible range 1a, 1c, 1d, 1f and 1e were useful for
our purposes. Compounds belonging to the stilbene family have indeed
gained remarkable significance in pharmaceutical as well as material
science, thus the synthetic approach described in this work can be ex-
tremely useful for the stereoselective synthesis of (E)-stilbene scaffold
and related structures.
C36H40F17NO7SiNa 972.2195 [M + Na+]; found 972.2180.
3. Results and discussion
Our first goal was the synthesis of highly conjugated (E)-stilbene
derivatives of type 1 possessing fluorinated or hydrocarbonated chains
in their structure. At first it seemed that the (E)-configuration was a
requirement since the Z stereoisomer can photoisomerize as a compe-
titive process under UV light irradiation [21], although there are sev-
eral reports in which E isomer has also been found to photoisomerize
[22] Moreover, in the initial design, we took into account that most
intensive fluorescence would be obtained with electron donating
groups on the aromatic moiety. Thus, O-electron-donor substituents
were integrated with the expectation of achieving energetically lower-
lying emissive states. We addressed the synthesis [23] from commercial
phenolic aldehydes 2 through a first alkylation process, followed by
Wittig and Heck reactions (Scheme 1).
First, we selected some commercial phenolic aldehydes 2 (Scheme
1). Alkylation of 2 with different alkyl iodides (3 equiv.) using K2CO3 (3
equiv.) as a base in DMF, afforded compounds 3a-d (Scheme 2) in ex-
cellent yields (75–90%). For compound 3e (89% yield), we added 1.5
equivalents of the alkyl halide. Additionally, 3f was obtained by the
dialkylation of resorcinol followed by a Bouvealt aldehyde synthesis
(two steps: 70% yield, Scheme 2). Compound 3d (Scheme 2) was syn-
thesized though
a nucleophilic aromatic substitution of 4-hydro-
xybenzaldehyde. Another approach to introduce long hydrocarbonated
chains on the stilbene moiety was to use 1,3,5-triazine derivative 5 that
was prepared as previously described in the group [24].
Secondly, we followed the synthetic route through the Wittig ole-
fination (Scheme 1) [25]. The corresponding hydroxy-substituted phe-
nolic aldehydes 3, were added to the previous formed methyl-
triphenylphosphonium ylide [26], yielding the desired styrene
derivatives 4 (93–97% yield, Table 1, Fig. 2). At this point, the target
stilbene compounds 1 were accomplished by a Heck reaction (Scheme
1) [27,28]. The hydroxy-substituted styrenes 4 were mixed with 4-io-
dophenol, Pd(OAc)2 as catalyst (5 mol%) in the presence of tri-o-tolyl-
phosphine, and triethylamine as base in DMF [29]. The consumption of
the starting material was complete in all cases, with high yields, but the
reaction was not completely steroselective to the (E)-stereoisomer
(Table 1), giving Z/E mixtures. In most of the cases, stereoisomer (E)
was isolated though a silica gel column chromatography, affording the
pure (E)-stilbene derivatives in moderate to good yields (32–70%,
Table 1). Nevertheless, the (E)-1f could not be successfully isolated
(Table 1, entry 6). The main reason for the non-(E)-selectivity is at-
tributed to a C-C bond rotation previous to the syn-elimination step.
The fluorescence properties of the prepared (E)-stilbene derivatives
1a-g were determined in acetonitrile, since this solvent does not absorb
Next, we selected –Si(OEt)3 as the reactive group to covalently an-
chor the label molecule to the paper [7]. Compounds (E)-1 showing
best fluorescent properties were selected to be anchored. The addition
of the reactive group onto the 4-hydroxy-(E)-stilbenes, 1, was carried
out using 3-(triethoxysilyl)propyl isocyanate in anhydrous THF and in
the presence of dry triethylamine as a base. The reactive carbamates 7
were achieved successfully in excellent yields (75–92%, Scheme 4).
Afterwards, we proceeded to study the hydrophobic and the oleo-
phobic properties of compounds 7. Firstly, they were deposited on a
glass surface using the spin-coating technique (addition of 0.15 mL of a
1,9 10−3 M solution in THF, Table 2). Measurement of the contact angle
was performed by the addition of a drop of water on the previous
modified surfaces. In all the studied cases (7a, 7d and 7e) the contact
angle was approximately the same (115-119°) indicating high hydro-
phobicity. Compound 7d, possessing two long perfluorinated chains, is
the only one that has oleophobic capacity. Thus, a drop of hexadecane
deposited on the surface of a glass previously impregnated by a solution
of 7d, presents a contact angle of 95°. In consequence, we assume that
10

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
fluorophore 7d is the best candidate to obtain durable self-cleaning
print on safety paper.
Acknowledgements
Additionally, we studied the fluorescence properties of carbamates
7. The fluorimetry spectra showed λmax emissions over 400 nm in the
visible area (Table 2). Interestingly enough, 7a and 7d possessing long
hydrophobic chains had larger fluorescent quantum yields than 7e
(Table 2) and in consequence were selected to be anchored on paper.
Fluorous 7d presented the largest value (Table 2, ϕ = 0.42). The
fluorescence of this modified dyes 7a and 7d was also studied in the
solid state using the confocal microscopy. The measurements evidenced
well fluorescence homogeneity in both fluorophores structure. The
maximun fluorescence emision was at 450 nm in case of 7a and 455 nm
in case of 7d (Fig. 5).
The authors would like to thank the financial support from Spain’s
MICINN (CTQ2014-53662-P and RTI2018-097853-B-I00) and MEC
(CTQ2016-81797-REDC) and DURSI-Generalitat de Catalunya
(2017SGR465).
Appendix A. Supplementary data
Supplementary data to this article can be found online at https://
doi.org/10.1016/j.dyepig.2019.107597.
References
Then, we took pieces of commercial WhatmanTM Grade 1 filter
paper. The anchoring of compounds 7 on the paper was carried out in a
screw-top sealed tube, by shacking vigorously a piece of round filter
paper (diameter of 2.5 cm) in a solution of 23 mg of the corresponding
(E)-stilbene based reactive carbamate (7a or 7d) in anhydrous THF and
triethylamine. After three days the reaction was over, and the modified
paper was washed with further THF and ethanol. Afterwards, the
modified paper (Fig. 6) was well dried in a vacuum oven overnight.
Scanning electron microscope (SEM, see SI) was used to evaluate the
anchorage of the reactive molecules 7 onto the paper surface. The most
important difference observed was that the unmodified paper presented
thinner fibers than the modified. Furthermore, the energy dispersive
analysis (EDS, see SI) and the X-ray photoelectron spectroscopy (XPS,
Fig. 7) studies of modified paper 7d, confirmed the presence of this
highly fluorinated dye (34 F atoms) onto the paper surface due to the
presence of fluorine atoms in the performed analysis. The XPS spectrum
shows not only the binding energy of F1s state for an organic fluorine
(688 eV) but also the binding energy of C1s corresponding to the CF2
chemical state (292 eV). Hydrophobic and oleophobic properties of
modified papers could not be evaluated due to their intrinsic absorption
properties. Finally, the final proof that the (E)-stilbene based reactive
carbamates 7a and 7d were anchorage to the paper surfaces, as sche-
matically shown in Fig. 6, was that upon simple UV irradiation both
papers exhibited an intense bluish coloration.
The fluorescence spectroscopy in the modified papers was measured
in confocal microscopy. In both modified papers the fluorescence
emission was evidenced, observing a maximum at 480 nm (see SI) in-
dicating the possibility for the application to security paper. Moreover,
the stability of the fluorescent unit-linker was studied by an immersion
test of the modified paper with 7f in water. No leaching of the fluor-
ophore was observed after 5 min (control by GCS, see SI) and the
fluorescent emission rested identical (Fig. 8). Furthermore, the color-
fastness of the modified paper with 7d was tested measuring the
fluorescence in confocal microscopy after eight months of the dyeing
process without any special protection; the results indicate excellent
color stability which is important for industrial applications (see SI). We
appreciate the same wavelength maximum, the same shape of the wave
and only a slight loss of intensity (3%)”.
[1] Honnorat A, le Vieux A, Riou C, le Lac V, Raux L, Gevrier C (1988) Unfalsifiable
safety papers. United States Patent, 1988, Patent Number: 4.725.497.
[2] Rancien S. Les papiers de sécurité. Comment lutter contre les faussaires ? Actualite
Chimique 2005;282:6–11.
[3] Chia TH, Levene MJ. Detection of counterfeit U. S. paper money using intrinsic
fluorescent lifetime. Optic Express 2009;17:22054–61https://doi.org/10.1364/OE.
17.022054.
[4] Li M, Zhang Q, Wang J-R, Mei X. Mechanochromism triggered fluorescent color
switching among polymorphs of a natural fluorescence pigment. Chem Commun
2016;52:11288–91https://doi.org/10.1039/c6cc04958c.
[5] Tian H, Wang P, Liu J, Duan Y, Dong YQ. Construction of a tetraphenylethene
derivative exhibiting high contrast and multicolored emission switching. J Mater
Chem C 2017;5:12785–91https://doi.org/10.1039/c7tc04384h.
[6] Liu C, Xiaua G, Yang M, Zou B, Zhang ZL, Pang DW. Mechanofluorochromic carbon
nanodots: controllable pressure-triggered blue- and red-shifted photoluminescence
Angew. Chem. Int. Ed. 2018;57:1893–7https://doi.org/10.1002/anie.201711409.
[7] Basta AH, Grigis AS, El-Saied H. Fluorescent Behavior of new 3-pyridinecarboni-
triles containing compounds and their application in security paper. Dyes Pigments
2002;54:1–10https://doi.org/10.1016/S0143-7208(02)00009-8.
[8] Basta AH, Grigis AS, El-Saied H, Mohamed M. A Synthesis of fluorescent active
pyridinedicarbonitriles and studying their application in functional paper. Mater
Lett 2011;65:1713–8https://doi.org/10.1098/rsos.171964.
[9] Basta A, Missori M, Grigis M, De Spirito AS, Papi M, El-Saied H. Novel fluorescent
security marker. Part II: application of novel 6-alcoxy-2-amino-3,5-pyr-
idinecarbonitrile nanoparticles in safety paper. RSC Adv 2014;4:59614–25https://
doi.org/10.1007/s11051-011-0649-8.
[10] Tian X, Wang B, Li J, Zeng J, Chen K. Surface grafting of paper with photochromic
spiropyran ether methacrylate. BioResources 2016;11:8627–37.
[11] Sun T, Feng L, Gao X, Jiang L. Bioinspired surfaces with special wettability. Acc
Chem Res 2005;38:644–52https://doi.org/10.1021/ar040224c.
[12] Nyström D, Lindqvist J, Östmark E, Hult A, Malmström E. Superhydrophobic bio-
fibre surfaces via tailored grafting architecture. Chem Commun
2006:3594–6https://doi.org/10.1039/b607411a.
[13] Tuteja A, Choi W, Ma M, Mabry JM, Mazzella SA, Rutledge GC, Mckinley GH,
Cohen RE. Designing superoleophobic surfaces. Science 2007;318:1618–22https://
doi.org/10.1126/science.1148326.
[14] Celia E, Darmanin T, de Givenchy, et al. Amigoni S, Guittard FJ. Recent advances in
designing superhydrophobic surfaces. Colloid Interface Sci 2013;402:1–18https://
doi.org/10.1016/j.jcis.2013.03.041.
[15] Latthe SS, Terashima C, Nakata K, Fujishima A. Superhydrophobic surfaces devel-
oped by mimicking hierarchical surface morphology of Lotus leaf. Molecules
2014;19:4256–83https://doi.org/10.3390/molecules19044256.
[16] Si Y, Guo Z. Superhydrophobic nanocoatings: from materials to fabrications and to
applications. Nanoscale 2015;7:5922–46https://doi.org/10.1039/c4nr07554d.
[17] Zhang P, Lin L, Zhang D, Guo X, Liu M. Recent development of advanced materials
with special wettability for selective oil/water separation. Small
2016;12:2186–202https://doi.org/10.1002/smll.201503685.
[18] Soler R, Salabert J, Sebastián RM, Vallribera A, Roma N, Ricart S, Molins E. Highly
hydrophobic polyfluorinated azo dyes grafted on surfaces. Chem Commun
2011;47:2889–91https://doi.org/10.1039/c0cc04695g.
[19] Salabert J, Sebastián RM, Vallribera A. Anthraquinone dyes for superhydrophobic
cotton. Chem Commun 2015;51:14251–4https://doi.org/10.1039/c5cc06028a.
[20] Montagut AM, Gálvez E, Shafir A, Sebastián RM, Vallribera A. Triaryl methane dyes
for artificial repellent cotton fibers. Chem Eur J 2017;23:3810–4https://doi.org/10.
1002/chem.201605572.
[21] Meier H. Blue fluorescent exciplexes consisting of trans-stilbene and antibodies.
Angew Chem Int Ed 2001;40:1851–3https://doi.org/10.1002/1521-
3773(20010518)40:10%3c1851::AID-ANIE1851%3e3.0.CO;2-X.
[22] Fathalla M, Jayawickramarajah J. Configurational isomers of a stilbene-linked bis
(porphyrin) tweezer synthesis and fullerene-Binding Studies. Eur J Org Chem
2009:6095–9https://doi.org/10.1002/ejoc.200901002.
[23] Khan ZA, Iqbal A, Shahzad SA. Synthetic approaches toward stilbenes and their
related structures. Mol Divers 2017;21:483–509https://doi.org/10.3906/kim-
1801-104.
4. Conclusions
In summary, new fluorescent hydrophobic (E)-stilbene derivatives
have been prepared through a stereoselective and highly effective
Wittig–Schlosser reaction as a key step. The covalent link of these re-
active fluorescent compounds has resulted in new labeled papers with
potential applications in the so-called safety papers. Fluorous 7d was
the best in terms of fluorescent quantum yield value and self-cleaning
properties. After an immersion test no leaching of the fluorophore was
observed and the fluorescent emission of the modified paper with 7d
rested identical.
[24] Niembro S, Shafir A, Vallribera A, Alibés R. Palladium nanoparticles supported on
an organic−inorganic fluorinated hybrid material. Application to microwave-based
Heck reaction. Org Lett 2008;10:3215–8. https://doi.org/10.1021/ol7024845.
11

A. Granados and A. Vallribera
DyesandPigments170(2019)107597
Highligted in Synfacts 2008; 5:550-550.
2006;71:1480–92https://doi.org/10.1021/jo052123d.
[25] Wittig G, Schollkopf U. Über Triphenyl−phosphin−methylene als olefinbildende
Reagenzien vol. 97. 1954. p. 1318–30https://doi.org/10.1002/cber.19540870919.
[26] Falk A, Cavalieri A, Nichol GS, Vogt D, Schamlz H-G. Enantioselective nick-
el‐catalyzed hydrocyanation using chiral phosphine‐phosphite ligands: recent im-
provements and insights. Adv Synth Catal 2015;357:3317–20https://doi.org/10.
1002/adsc.201500644.
[27] Heck RF, Nolley JP. Palladium-catalyzed vinylic hydrogen substitution reactions
with aryl, benzyl, and styryl halides. J Org Chem 1972;37:2320–2https://doi.org/
10.1021/jo00979a024.
[31] Schlosser M, Christmann KF. Trans‐selective olefin syntheses. Angew Chem Int Ed
1966;5:126–7https://doi.org/10.1002/anie.196601261.
[32] Schlosser M, Christmann KF. Carbonyl olefination with α-substitution. Synthesis
1969:38–9https://doi.org/10.1055/s-1969-20370.
[33] Schlosser M, Christmann KF, Piskala A, Coffinet D. α-Substitution plus carbonyl
olefination via β-oxido Phosphorus Ylids (S. C. O. O. P. Y.-Reactions). Scope and
stereoselectivity. Synthesis 1971:29–31https://doi.org/10.1055/s-1971-21666.
[34] Denmark SE, Jaunet A. Catalytic, enantioselective, intramolecular carbosulfenyla-
tion of olefins. Preparative and stereochemical aspects. J Org Chem
2014;79:140–71https://doi.org/10.1021/jo4023765.
[28] Mizoroki T, Mori K, Ozaki KA. Arylation of olefin with aryl iodide catalyzed by
palladium. Bull Chem Soc Jpn 1971;44. 581-581 https://doi.org/10.1246/bcsj.44.
581.
[35] McNulty J, Das P. Highly stereoselective and general synthesis of (E)−stilbenes and
alkenes by means of an aqueous Wittig reaction. Eur J Org Chem
[29] Gehringer L, Guillon D, Donnio B. Liquid crystalline octopus: an alternative class of
mesomorphic dendrimers. Macromolecules 2003;36:5593–601https://doi.org/10.
1021/ma034038i.
[30] Roberts JC, Pincock JA. Methoxy-substituted stilbenes, styrenes, and 1-ar-
ylpropenes: photophysical propierties and photoadditions of alcohols. J Org Chem
2009:4031–5https://doi.org/10.1002/ejoc.200900634.
[36] McNulty J, Das P, McLeod D. Microwave‐assisted, aqueous Wittig reactions: orga-
nic‐solvent‐ and protecting‐group‐free chemoselective synthesis of functionalized
alkenes. Chem Eur J 2010;16:6756–60https://doi.org/10.1002/chem.201000438.
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