Efficient synthesis of pyrene-1-carbothioamides and carboxamides. Tunable solid-state fluorescence of pyrene-1-carboxamides

Article abstract of DOI:10.1039/c4ra07045c

Pyrene reacts with potassium thiocyanate and organic isothiocyanates in the presence of trifluoromethanesulfonic acid to afford primary and secondary pyrene-1-carbothioamides in high yields. These compounds were efficiently oxidatively desulfurized with O

Full text of DOI:10.1039/c4ra07045c

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Efficient synthesis of pyrene-1-carbothioamides
and carboxamides. Tunable solid-state
Cite this: RSC Adv., 2014, 4, 56003
fluorescence of pyrene-1-carboxamides†
a
a
b
Anna Wrona-Piotrowicz, Janusz Zakrzewski, Remi Metivier, Arnaud Brosseau,b
*
*
´
´
Anna Makalc and Krzysztof Wozniakc
´
Pyrene reacts with potassium thiocyanate and organic isothiocyanates in the presence of
trifluoromethanesulfonic acid to afford primary and secondary pyrene-1-carbothioamides in high yields.
These compounds were efficiently oxidatively desulfurized with Oxone® to the corresponding
carboxamides. The amides display solid-state fluorescence with quantum efficiencies up to 62%,
originating from monomers, aggregates (such as preformed dimers), and/or excimers, depending on the
substituent at the nitrogen atom. Single crystal X-ray diffraction characterization of one highly emissive
compound supports this assumption.
Received 13th July 2014
Accepted 23rd October 2014
DOI: 10.1039/c4ra07045c
www.rsc.org/advances
In this paper we report an efficient method of synthesis of
primary and secondary pyrene-1-carbothioamides directly from
Introduction
pyrene via a Friedel–Cras-type reaction with potassium thio-
cyanate and organic isothiocyanates, respectively. The thio-
amides were then desulfurized into the corresponding amides
using Oxone®. Furthermore, we discovered that most of the
synthesized amides are uorescent not only in solution, as was
reported earlier, but also in the solid state. Solid-state emission
is a phenomenon of great practical importance,25–27 but is
relatively rare in the case of planar aromatic compounds such as
pyrene and its derivatives. We found that the solid-state emis-
sive properties of synthesized pyrene-1-carboxamides strongly
depend on the substituent on the nitrogen atom and for bulky
substituents uorescence quantum yields as high as 60% were
obtained.
Pyrene derivatives have attracted signicant interest as mate-
rials for organic electronics,1 uorescent molecular probes,2–4
monomers,5 triplet sensitizers6 and sensors.3,7–9 Considerable
attention has been paid to the development of synthetic routes
to pyrenes bearing various substituents1,10,11 and to studies on
their uorescence properties.11–13
Several recent works have focused on environmentally-
responsive emission of pyrene-1-carboxamides which is
strongly dependent on the substituents at the nitrogen
atom.12,14–16 Moreover, these compounds were used in the
synthesis of polymers with tunable luminescent properties17
and in the labelling of nucleosides.7,8,18–22
In contrast to amides, pyrene-1-carbothioamides are only
weakly uorescent23,24 because of the internal quenching effect
of the thiocarbonyl group. Since some chemical species desul-
furize thioamides (e.g. Oxone®, H2O2 in the presence of Zr4+) to
uorescent amides, pyrene thioamides were used as uorescent
Results and discussion
A Friedel–Cras-type reaction of organic isothiocyanates with
aromatic compounds is a straightforward synthetic route to
secondary thioamides.28–31 We recently reported that a reaction
of pyrene with ethoxycarbonylisothiocyanate afforded N-
ethoxycarbonyl-pyrene-1-carbothioamide in 95% yield.32
Primary thioamides were obtained in a reaction of electron-rich
arenes (1,2-diethoxybenzene, ferrocene) with potassium thio-
cyanate in methanesulfonic acid.28,33,34
Herein we report that pyrene reacts with potassium thiocy-
anate in the presence of 4 equiv. of TfOH to afford the primary
thioamide 1a in 63% yield (Scheme 1). The reaction was per-
formed in dichloromethane at room temperature. Under the
same conditions, reaction of pyrene with alkyl- and aryl iso-
thiocyanates afforded secondary thioamides 1b–j in 78–96%
yield. Thioamides 1a–j were conveniently isolated, aer
“turn-on” sensors of such species23,24
.
The reported synthetic route to pyrene-1-carboxamides relies
on the reaction of pyrene-1-carboxylic acid chloride with
amines. The amides can then be transformed into thioamides
via a reaction with Lawesson reagent.17,23,24
a
´ ´
Department of Organic Chemistry, Faculty of Chemistry, University of Łodz, Tamka
´ ´
12, 91-403 Łodz, Poland. E-mail: janzak@uni.lodz.pl
bPPSM, ENS Cachan, CNRS, UniverSud, 61 av President Wilson, 94230 Cachan,
France. E-mail: metivier@ppsm.ens-cachan.fr
cFaculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warszawa, Poland
† Electronic supplementary information (ESI) available. CCDC 1006140. For ESI
and crystallographic data in CIF or other electronic format see DOI:
10.1039/c4ra07045c
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Scheme 2 Synthesis of pyrene-1-carboxamides 2k–m.
All synthesized compounds were fully characterized by
spectroscopic methods and elemental analyses.
Solid-state uorescence of pyrene-1-carboxamides 2a–m
Solution uorescence of various pyrene-1-carboxamides was
recently thoroughly studied by Konishi et al.14–16 During the
course of our synthetic work, we discovered that these
compounds are also solid-state emitters. Organic solid-state
uorescence is of great interest currently because of its rele-
vance to numerous practical applications, e.g. in organic light-
emitting diodes, organic light-emitting eld-effect transistors,
Scheme 1 Synthesis of thioamides 1a–j and amides 2a–j.
quenching the reaction mixtures with water and extraction, via solid-state lasers and sensors.25–27 It critically depends on
column chromatography on silica gel. interactions of molecular uorophores (p–p interactions,
Aer having elaborated an efficient direct method for thio- formation of H- or J-aggregates, excimers, etc.) in powders,
amidation of pyrene, we explored the possibility of extending crystals or solid lms.38
this method to the synthesis of pyrenyl amides using isocya-
We measured solid-state excitation spectra, emission spectra
nates instead of isothiocyanates. We chose the reaction of pyr- and uorescence quantum yields of amides 2a–d, g, h, k–m
ene with phenyl isocyanate as a model. Unfortunately, we found (compound 2j proved non uorescent). Corresponding spectra
that this reaction provided the expected N-phenylpyrene-1- are displayed in Fig. 1 and spectroscopic data are gathered in
carboxamide only in low (ꢀ30%) yield. Because of this unsat- Table 1.
isfactory result, we changed our approach in order to nd
It is visible in Table 1 that substituents at the nitrogen atom
another synthetic route to pyrenyl amides.
strongly inuence solid-state emissive properties of the
Since a variety of simple and efficient methods of desulfur- synthesized amides. On one side, the primary amide 2a shows a
ization of thioamides to amides has been reported in the liter- weak structured violet uorescence (FF ¼ 6%), that is similar in
ature,35 we decided to check whether this transformation could shape to its uorescence spectrum when dissolved in chloro-
be applied to the synthesis of pyrenyl amides.
form (Fig. 2A). However, compared to the solution spectrum,
We decided to use a commercially available and inexpensive the solid-state emission spectrum of 2a is red-shied by 25 nm,
oxidant, Oxone® (2KHSO5$KHSO4$K2SO4), for the desulfuriza- and a long tail can be observed at wavelengths over 450 nm.
tion of thioamides 1a–j. This reagent has already been used for This observation suggests that the interaction of uorophores
desulfurization of other thioamides.14,15,36,37 Furthermore, the inuencing solid-state uorescence is in this case rather
reaction of Oxone® with N,N-diethyl-1-pyrene-carboxamide was limited. On the other side, the solid-state excitation/emission
applied for uorescence sensing of this oxidant.24
spectra of the secondary amides have a wide variety of shapes,
We found that Oxone® reacts smoothly with thioamides 1a–j with corresponding quantum efficiencies varying from 0.2% to
in acetonitrile–water at room temperature to afford the corre- 62%, as a function of the substituents. When analyzing in detail
sponding amides 2a–j in high yields (86–100%, Scheme 1).
the solid-state emission spectra, we can distinguish several
In order to complete the series for photophysical studies, we cases: (i) one compound (2g) shows a clear monomer contri-
also synthesized pyrene amides 2k–m bearing bulky substitu- bution, peaking at 414 nm, associated with a structured shape
ents at the nitrogen atom (Scheme 2). Since the isothiocyanates and a very low uorescence quantum yield (FF ¼ 0.2%); (ii)
required for syntheses of these compounds via Friedel–Cras several compounds (2b–c, 2k–m) display a large red-shied
reaction were not available we prepared them from pyrene-1- single band, with quantum yields in the 7–62% range; and
carboxylic acid and the corresponding amines in the presence (iii) two compounds (2d and 2h) show a well-apparent shoulder
of N,N0-dicyclohexylcarbodiimide (DCC). The isolated yields of at the violet edge of the spectrum (406–416 nm) and a main
2k–m were in the range of 85–90%.
emission band in the range of 450–600 nm, with intermediate
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Fig.
2
Normalized solution (CHCl3) and solid-state fluorescence
emission spectra of 2a (A) and 2c (B).
Fig. 1 Normalized solid-state excitation (left) and emission (right)
spectra of pyrene-1-carboxamides 2a–d, g, h, k–m.
observation supports the presence of aggregates in the ground
state. In spite of this variety of uorescence properties, a general
tendency can be drawn i.e. that: the increase of the size of the
alkyl substituent at the nitrogen atom brings about an increase
in the uorescence quantum yield. Indeed, the amides 2c and 2j
bearing a bulky N-tert-butyl and 1-adamantyl groups are the
most efficient solid-state emitters of the series (FF ¼ 59% and
62%, respectively). On the other hand, N-phenyl substitution
(compound 2g) leads practically to disappearance of the solid-
state emissive properties. The N-benzyl amide 2h shows
moderate uorescence quantum yield (20%) and the attach-
ment of the second and third phenyl ring to the sp3 carbon
(amides 2l and 2m, respectively) brings about decrease of the
uorescence quantum yield.
Table 1 Solid-state absorption and emission data of pyrene-1-car-
boxamides 2a–d, g, h, k–m
Amide
Excitationa lmax/nm Emissiona lmax/nm FF/%
2a (R ¼ H)
369
367, 410(sh)
364
363, 415(sh)
367
366, 400(sh)
408, 430
504
463
406(sh), 466
414
416(sh), 488
477
6
17
59
12
2b (R ¼ iso-Pr)
2c (R ¼ t-Bu)
2d (R ¼ n-hexyl)
2g (R ¼ Cy)
0.2
2h (R ¼ Bn)
20
62
12
7
2k (R ¼ 1-adamantyl) 364
2l (R ¼ CHPh2)
2m (R ¼ CPh3)
365
365, 433
428
542
a
Shoulders are noted (sh).
Practically, the colors of solid-state uorescence emitted by
the investigated series of amides are shown in the CIE diagram
(Fig. 3). As a consequence of the different uorescence spectral
shapes of these pyrene derivatives, the solid-state emission
expands over a wide range of colors, from violet-blue to green
and even yellow, depending on the substituents.
It is worth noting that the most efficient compounds (2c and
2j) emit in the blue region. Interestingly, the former compound
has co-ordinates close to those required for deep-blue emission
(y < 0.15; x + y < 0.30, cf. ESI†).39 The substituents at the nitrogen
quantum yields (12% and 20%, respectively). The spectral
signatures highlighted in the two latter cases are clear indica-
tions that the solid-state emission originates from aggregates
such as preformed dimers, or excimers. Moreover, the excita-
tion spectra depicted in Fig. 1 all show a main maximum band
around 363–369 nm, but also eventually a shoulder (or even a
well-dened separated band) at longer wavelengths, in the
range of 400–433 nm (amides 2b, 2d, 2h, 2l, see Table 1). This
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Fig. 3 CIE chromacity diagram for compounds 2a–d, h, k–m.
atom shi the uorescence into the blue-green (compound 2b)
or even the green-yellow region (compound 2l). However, this
bathochromic shi is accompanied by a decrease in emission
efficiency.
In order to deepen our investigation of the photophysical
properties of pyrene carboxamide derivatives in the solid-state,
we recorded uorescence decays for the whole series 2a–d, g–h,
k–m at variable emission wavelengths. The time-correlated
single photon counting (TCSPC) method was employed for
short decays (decay time constants < 35 ns), whereas the laser
ash uorometry was used for longer decays (including decay
time constants > 35 ns). The Fig. 4 displays the solid-state
uorescence decay curves of the compounds 2a–d, g–h, k–m
recorded using these experimental methods, at their respective
maximum emission wavelengths. In all cases, the uorescence
decays reveal a multiexponential behavior, which reects the
complexity of these systems in the solid-state. They were satis-
factorily tted with a sum of two, three or four exponentials, and
the corresponding parameters are compiled in the Table 2. As
was mentioned in the previous paragraph, the derivatives 2a
and 2g mostly show monomer emission, and constitute a rst
group of compounds. This translates into relatively short uo-
rescence decays, with time constants in the range of a few
nanoseconds for 2a, and even in the range of several hundreds
of picoseconds for 2g. Thus, the different time constants may
represent different populations of monomers in the solid. The
time-resolved uorescence investigations reveal a very specic
situation for compounds 2b, 2d and 2h (the second group of
compounds). Indeed, they show a strong emission wavelength
dependence of their uorescence decays, as is highlighted in
Fig. 5, with a multiexponential decay at short emission wave-
length (recorded at the blue edge of the emission spectrum),
and a short rise time followed by multiexponential decay at long
Fig. 4 Fluorescence decays of 2a, b, d, g, h, l, m in the solid state,
recorded by the TCSPC system at lexc ¼ 370 nm (A), or laser flash
fluorometry at lexc ¼ 355 nm (B).
emission wavelength (recorded at the red edge of the emission
spectrum). A global analysis was carried out on these data sets
(see Table 2), which shows that the short rise time measured at
long emission wavelength (0.3–1.6 ns) has the same order of
magnitude as the shorter decay time recorded at short emission
wavelength (0.5–0.7 ns). This nding may be consistent with the
dynamics of fast excimer formation in the solid-state, and is
rather compatible with the spectral features described in the
previous paragraph. In this frame the longest decay time
constant, determined for 2b, 2d and 2h to be 23.7 ns, 24.8 ns,
and 34.1 ns, respectively, corresponds specically to excimer
emission, since its relative fraction of intensity increases at
longer emission wavelength (Table 2). Then the last group of
four compounds, namely 2c and 2j–l, exhibits intermediate
behavior between purely monomeric emission (such as 2a and
2g) and well-dened excimer formation (such as 2b, 2d and 2h).
On the one hand, the 2c and 2k–m derivatives do not show any
rise time at long wavelength emission, which excludes the
excimer formation mechanism in these cases. On the other
hand, their uorescence decays are rather long and their
emission spectra are broad, red-shied, without any vibrational
structure, which is inconsistent with simple monomer emis-
sion. We could then assume that, for 2c and 2k–m, solid-state
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Table 2 Fitting parameters of solid-state fluorescence decays (si, Ai, fi) for compounds 2a–d, g–h, k–m, recorded by the time-correlated single
photon counting system (TCSPC) or by the laser flash photolysis spectrometer
b
b
b
b
lema (nm)
s1 (ns)
s2 (ns)
s3 (ns)
s4 (ns)
A1 (f1
)
A2 (f2
)
A3 (f3
)
A4 (f4
)
cr2c
2ad
2bd
410
460
505
570
420
465
520
410
465
520
415
420
490
550
440
480
540
430
540
1.3
0.7
1.6
1.6
9
2.3
8.8
9.9
10.6
42
10.4
23.7
23.7
23.7
—
—
—
0.47 (0.32)
0.20 (0.01)
ꢁ0.21 (ꢁ0.02)
ꢁ0.45 (ꢁ0.04)
0.85 (0.54)
0.81 (0.48)
0.77 (0.46)
0.61 (0.28)
0.52 (0.65)
0.65 (0.60)
0.97 (0.64)
1.06 (0.57)
0.15 (0.46)
0.19 (0.52)
0.23 (0.54)
0.34 (0.47)
2.17 (0.57)
3.05 (0.46)
0.02 (0.11)
0.38 (0.39)
0.28 (0.02)
0.29 (0.01)
0.20 (0.65)
0.42 (0.81)
0.46 (0.82)
0.30 (0.41)
0.27 (0.12)
0.01 (0.03)
0.15 (0.38)
0.25 (0.39)
0.39 (0.47)
—
—
—
1.13
1.20
1.05
1.15
—
2ce
—
—
10
11
46
45
2dd
0.7
0.3
0.3
0.15
0.5
0.5
0.5
9
12
14
1.3
0.3
2.2
2.2
2.2
0.7
2.1
2.1
2.1
68
70
77
3.4
1.8
7.2
7.2
7.2
—
9.3
9.3
9.3
—
24.8
24.8
24.8
—
34.1
34.1
34.1
—
0.05 (0.22)
0.38 (0.34)
0.73 (0.36)
—
0.08 (0.35)
1.08 (0.28)
1.64 (0.26)
—
0.01 (0.03)
0.05 (0.15)
0.15 (0.25)
—
0.01 (0.13)
0.78 (0.72)
1.30 (0.75)
—
1.02
1.11
1.08
1.08
1.08
1.18
1.20
—
ꢁ1.60 (ꢁ0.06)
ꢁ2.92 (ꢁ0.06)
0.98 (0.89)
2gd
2hd
0.54 (0.14)
ꢁ1.14 (ꢁ0.02)
ꢁ2.23 (ꢁ0.02)
0.80 (0.35)
0.58 (0.19)
0.54 (0.18)
2ke
2ld
14.4
7.7
—
19.6
0.66 (0.36)
0.44 (0.03)
0.04 (0.24)
0.18 (0.35)
—
1.10
1.09
2md
0.10 (0.49)
a
Selected emission wavelength by means of a monochromator with a 50 nm bandwidth. b Intensity fractions were calculated using the following
equation: fi ¼ Aisi/SAjsj. c Global cr2, obtained for a global analysis of the full set of uorescence decay curves, calculated for TCSPC experiments.
d
Recorded by the TCSPC system, lexc ¼ 370 nm. e Recorded by the laser ash photolysis spectrometer, lexc ¼ 355 nm.
Fig. 5 Fluorescence decays of (A) 2b, (B) 2d, (C) 2h in the solid state, recorded by the TCSPC system at two different emission wavelengths: blue
edge of the emission spectrum (blue dots) and red edge of the emission spectrum (red dots) (lexc ¼ 370 nm).
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uorescence arises from strongly emissive aggregates or dimers
preformed in the ground state. Several populations of emitters
may exist in the solid state, as is suggested by the multi-
exponential decays recorded for these compounds. It is worth
noting that the situation of compounds 2c and 2k is quite
unique, with extremely long decay components (s1 ꢀ 10 ns and
s2 ꢀ 45 ns for 2c; s1 ꢀ 12 ns and s2 ꢀ 70 ns for 2k) associated
with unprecedented high quantum yields (59% and 62%,
respectively). Therefore, for these two derivatives we expect that
the formation of aggregates in the crystalline structure and the
specic p–p interaction between pyrenyl groups are extremely
favorable, thus leading to such effective solid-state
uorescence.
Fig. 7 Dimers of p-stacked molecules of 2c, related by the crystal-
lographic center of symmetry.
state uorescence quantum yield of the 2c derivative, which is
associated with its very slow uorescence decay.
Solid-state excimer emission is
a relatively common
phenomenon for polycyclic aromatic compounds (including
pyrene).40–42
The intermolecular N1 – H1/O1 hydrogen bonds formed
between the molecules packed along the crystallographic c
direction bring about the formation of innite chains of H-
bonded molecules, with the N/O vector almost parallel to c
direction and adjacent pyrenyl moieties in the crystal structure
located at an angle of 63.0(3) degrees (Fig. 8).
Crystal packing viewed along b direction conrms the
formation of columns of p-stacked dimers of 2c. Along the
crystallographic a direction the crystal structure is stabilized
only by van-der Waals interactions of the tert-butyl moieties
(Fig. 9).
X-ray diffraction study of 2c
We intended to compare molecular packings in the crystals of
the synthesized amides but we were able to obtain crystals
suitable for X-ray diffraction analysis only for 2c. The compound
crystallized in the space group P21/c of the monoclinic system
aer a long period of standing (2–3 weeks) in a concentrated
solution in DMSO in an open tube (presumably moisture slowly
diffused into the solution and decreased the solubility of 2c).
The molecular structure of 2c is shown in Fig. 6.
The pyrenyl moiety is slightly bent, with the angle
between the planes of rings C1–C2–C3–C4–C15–C14 and
C7–C8–C9–C10–C11–C16 ꢀ4ꢂ. The amide group is twisted by
60.6(2) degrees from the average plane of the pyrenyl moiety.
˚
Together with the C1–C17 bond length greater than 1.5 A this
suggests that there is only a very weak electronic conjugation
between these units.
The crystallographic structure reveals that the molecules of
2c form p-stacked dimers with short C/C distances (Fig. 7),
thus suggesting strong electronic interactions between the two
pyrenyl moieties, which is in very good agreement with the
photophysical investigations that were described and discussed
in the previous section. This strong p–p interaction in the
ground state seems to be at the origin of the very high solid-
Fig. 8 View of the N–H/O hydrogen bond in the context of crystal
packing of 2c along a* direction. The atoms directly involved in the
H-bond network are represented with thermal ellipsoids at 90%
probability level, to enhance the pattern. The remaining atoms are
Fig. 6 Molecular structure of 2c (ORTEP representation). Displace- represented as wires in gray or in green in order to differentiate
ment ellipsoids were drawn at 50% probability level.
between the adjacent p/p interacting chains of H-bonded atoms.
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Na2SO4 and evaporated. Flash chromatography (silica gel/
CH2Cl2) afforded pure products.
1a. Yellow powder (165 mg, 63%), m.p. 179–180 ꢂC; 1H NMR:
d 10.40 (s, 1H), 9.93 (s, 1H), 8.39 (d, J ¼ 9 Hz, 1H), 8.32 (t, J ¼ 6.6
Hz, 2H), 8.28 (d, J ¼ 6.6 Hz, 1H), 8.25 (d, J ¼ 9 Hz, 1H), 8.20 (q, J
¼ 9 Hz, 2H), 8.10 (t, J ¼ 7.8 Hz, 1H), 8.02 (d, J ¼ 7.8 Hz, 1H); 13
C
NMR: d 202.76, 138.82, 130.77, 130.64, 130.22, 127.75, 127.11,
126.48, 125.60, 125.29, 125.18, 124.30, 124.15, 123.71, 123.60; IR
(cmꢁ1) 3396, 3242, 3047, 1615, 1397, 1291, 914, 846 cmꢁ1; anal.
calcd for C17H11NS: C, 78.13; H, 4.24; N, 5.36; S, 12.27; found: C,
78.15; H, 4.22; N, 5.41%.
1b. Yellow powder (291 mg, 96%), m.p. 186.5–187 ꢂC; 1H
NMR: d 8.25–8.26 (m, 1H), 8.18 (t, J ¼ 9.6 Hz, 2H), 8.05–8.09 (m,
3H), 7.99–8.02 (m, 3H), 7.52 (s, 1H), 4.98–5.04 (m, 1H), 1.43 (d, J
¼ 6.8 Hz, 6H), 13C NMR: d 199.33, 138.72, 131.64, 131.23,
130.65, 128.53, 128.12, 127.10, 127.08, 126.26, 126.12, 125.73,
125.43, 124.64, 124.55, 124.51, 124.49, 123.49, 47.93, 21.37; IR
(KBr) 3267, 3041, 2968, 2926, 1523, 1394, 849 cmꢁ1; anal. calcd
for C20H17NS: C, 79.17; H, 5.65; N, 4.62; S, 10.57; found: C,
79.15; H, 5.69; N, 4.66%.
Fig. 9 Crystal packing of 2c viewed along the crystallographic (a) b-
axis (b) c-axis. H-bonds marked in cyan.
Conclusion
1c. Yellow powder (292 mg, 93%), m.p.: 184–185 ꢂC; 1H NMR:
d 8.30 (d, J ¼ 9 Hz, 1H), 8.19 (t, J ¼ 7.2 Hz, 2H), 8.13 (dd, J1 ¼ 2.4
Hz, J2 ¼ 9.0 Hz, 2H), 8.08 (d, J ¼ 9 Hz, 1H), 8.03 (dd, J1 ¼ 2.4 Hz,
J2 ¼ 7.8 Hz, 2H), 8.01 (d, J ¼ 9 Hz, 1H), 7.48 (s,1H), 1.79 (s, 9H);
13C NMR: d 200.23, 140.54, 131.44, 131.32, 130.74, 129.53,
128.59, 128.02, 127.16, 126.28, 125.79, 125.72, 125.39, 124.75,
124.64, 124.32, 123.54, 56.83, 27.87; IR (KBr): 3355, 3039, 2966,
1512, 1400, 1362, 843 cmꢁ1; anal. calcd for C21H19NS: C, 79.45;
H, 6.03; N, 4.41; S, 10.10; found: C, 79.39; H, 6.07; S, 10.04%.
1d. Yellow powder (314 mg, 91%), m.p. 156–157 ꢂC; 1H NMR:
d 8.27 (d, J ¼ 9 Hz, 1H), 8.20 (d, J ¼ 7.8 Hz, 1H), 8.19 (d, J ¼ 7.2
Hz, 1H), 8.07–8.11 (m, 3H), 8.01–8.03 (m, 3H), 7.62 (s, 1H), 3.96
(t, J ¼ 7.2 Hz, 1H), 3.95 (t, J ¼ 7.2 Hz, 1H), 1.8 (kwintet, J ¼ 7.4
Hz, 2H), 1.44–1.48 (m, 2H), 1.34–1.38 (m, 4H), 0.93 (t, J ¼ 7.2 Hz,
3H); 13C NMR: d 200.70, 138.76, 131.74, 131.29, 130.72, 128.53,
128.21, 127.14, 126.31, 126.29, 125.78, 125.47, 124.69, 124.65,
124.57, 124.53, 123.71, 46.60, 31.42, 28.09, 26.78, 22.53, 13.96;
IR (KBr) 3169, 3036, 2930, 1545, 1397, 1071, 847 cmꢁ1. Anal.
calcd for C23H23NS: C, 79.96; H, 6.71; N, 4.05; S, 9.28; found: C,
79.88; H, 6.70; N, 4.16%.
We have developed a simple and efficient synthetic route to
primary and secondary pyrene-1-carbothioamides and carbox-
amides. The amides emit uorescence in the solid state with
quantum efficiencies up to ꢀ60%. The primary amide in the
solid state mainly displays structured monomer emission,
whereas several secondary amides show a dynamic excimer
formation leading to red-shied emission. The strong solid-
state uorescence of the most efficient uorophores, N-tert-
butyl- and N-(adamant-1-yl)pyrene-1-carboxamide can be
attributed to preformed dimers or aggregates in the ground
state, associated with very long decay times.
Experimental
Solvents were puried before use by reported methods. All
reagents were purchased from Sigma-Aldrich and used without
1
further purication. H and 13C NMR spectra were recorded in
CDCl3 (if not indicated) or in DMSO-d6 on a Bruker ARX 600
1
MHz (600 MHz for H and 151 MHz for 13C). Chemical shis
1e. Yellow powder (323 mg, 94%), m.p.: 206–207 ꢂC; 1H NMR:
d 10.60 (d, J ¼ 7.2 Hz, 1H), 8.32 (d, J ¼ 9.6 Hz, 1H), 8.30 (d, J ¼
10.8 Hz, 1H), 8.28 (d, J ¼ 10.8 Hz, 1H), 8.17–8.23 (m, 4H), 8.10 (t,
J ¼ 7.8 Hz, 1H), 7.93 (d, J ¼ 7.8 Hz, 1H), 4.62–4.64 (m, 1H), 2.17
(d, J ¼ 9.6 Hz, 2H), 1.83 (d, J ¼ 12.6 Hz, 2H), 1.67 (d, J ¼ 13.2 Hz,
1H), 1.38–1.48 (m, 4H), 1.19–1.23 (m, 1H), 13C NMR: d 196.64,
139.09, 130.76, 130.47, 130.23, 127.81, 127.62, 127.11, 126.45,
125.55, 125.23, 124.46, 124.31, 123.99, 123.72, 123.63, 54.52,
30.60, 25.06, 24.56; IR (KBr) 3346, 2928, 2856, 1519, 1396, 845
cmꢁ1; anal. calcd for C23H21NS: C, 80.42; H, 6.16; N, 4.08; S,
9.34; found: C, 80.39; H, 6.22; N, 4.16%.
were referenced relative to solvent signals. Spectra were recor-
ded at room temperature (291 K), chemical shis are in ppm
and coupling constants in Hz. IR spectra were run on an FT-IR
Nexus spectrometer. Column chromatography was carried out
on silica gel 60 (0.040–0.063 mm, 230–400 mesh, Fluka).
Elemental analyses were performed at the Laboratory of
Microanalysis in the Centre of Molecular and Macromolecular
´
´
Studies in Łodz, Poland.
Pyrene-1-carbothioamides 1a–j
General procedure. KSCN (97 mg, 1 mmol) or isothiocyanate
1f. Yellow oil (285 mg, 78%) 1H NMR: d 13.25 (s, 1H), 8.34 (d, J
(1.5 mmol) and TfOH (348 ml, 4 mmol) were added to a solution ¼ 7.8 Hz, 1H), 8.32 (d, J ¼ 7.8 Hz, 1H), 8.29 (d, J ¼ 7.8 Hz, 1H),
of pyrene (202 mg, 1 mmol) in CH2Cl2 (10 ml) at room 8.28 (d, J ¼ 9.6 Hz, 1H), 8.24 (d, J ¼ 9.0 Hz, 1H), 8.21 (d, J ¼ 9.0
temperature. Aer stirring for 2 h the reaction mixture was Hz, 1H), 8.19 (d, J ¼ 7.2 Hz, 1H), 8.10 (d, J ¼ 7.2 Hz, 1H), 8.07 (d,
poured into ice-water (50 ml) and extracted several times with J ¼ 7.8 Hz, 1H), 7.97 (d, J ¼ 7.8 Hz, 2H), 7.66 (t, J ¼ 7.2 Hz, 1H),
CH2Cl2. The combined extracts were dried over anhydrous 7.52 (t, J ¼ 7.8 Hz, 2H); 13C NMR: d 197.49, 165.11, 139.58,
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2a. White powder (210 mg, 86%), m.p.: 257 - 258 ꢂC; 1H NMR
(DMSO-d6): d 8.63 (d, J ¼ 9.6 Hz, 1H), 8.34 (t, J ¼ 9.0 Hz, 2H), 8.32
(d, J ¼ 7.8 Hz, 1H), 8.30 (d, J ¼ 7.8 Hz, 2H), 8.22 (d, J ¼ 9.0 Hz,
1H), 8.18 (d, J ¼ 9.0 Hz, 1H), 8.16 (s, 1H), 8.11 (t, J ¼ 7.8 Hz, 1H),
7.73 (s, 1H); 13C NMR (DMSO-d6): d 170.86, 131.76, 131.55,
130.66, 130.13, 128.17, 127.93, 127.72, 127.14, 126.46, 125.68,
125.48, 125.18, 124.80, 124.30, 123.81, 123.63; IR (KBr) 3339,
3169, 1660, 1622, 1399, 853 cmꢁ1; anal. calcd for C17H11NO: C,
83.25; H, 4.52; N, 5.71; O, 6.52; found: C, 83.38; H, 4.67; N,
5.53%.
137.97, 133.50, 133.31, 132.03, 130.99, 130.76, 130.08, 129.98,
129.06, 128.75, 128.44, 127.96, 127.18, 126.47, 125.85, 125.14,
124.97, 124.34, 123.35; IR (KBr) 1713, 1698, 1598, 1470, 1170,
846 cmꢁ1; anal. calcd for C24H15NOS: C, 78.88; H, 4.14; N, 3.83;
O, 4.38; S, 8.77; found: C, 79.03; H, 4.02; N, 3.97%.
1
1g. Yellow powder (287 mg, 85%) H NMR: d 12.32 (s, 1H),
8.35 (d, J ¼ 7.8 Hz, 1H), 8.34 (d, J ¼ 7.8 Hz, 1H), 8.33 (d, J ¼ 7.8
Hz, 2H), 8.26 (d, J ¼ 9.0 Hz, 1H), 8.24 (d, J ¼ 3.6 Hz, 2H), 8.12 (d,
J ¼ 7.8 Hz, 2H), 8.10 (d, J ¼ 7.8 Hz, 2H), 7.52 (t, J ¼ 7.8 Hz, 2H),
7.35 (t, J ¼ 7.2 Hz, 1H); 13C NMR: d 197.96, 139.73, 139.64,
130.79, 130.23, 128.62, 128.45, 128.15, 127.85, 127.13, 126.53,
126.38, 125.73, 125.57, 125.39, 124.70, 124.47, 123.94, 123.74,
123.68, 123.27, 123.24; IR (KBr) 3329, 3037, 1594, 1497, 1356,
846 cmꢁ1; anal. calcd for C23H15NS: C, 81.87; H, 4.48; N, 4.15; S,
9.50; found: C, 81.84; H, 4.51; N, 4.26%.
1
ꢂ
2b. White powder (273 mg, 95%), m.p.: 211.5–212.5 C; H
NMR (DMSO-d6): d 8.55 (d, J ¼ 7.8 Hz, 1H), 8.46 (d, J ¼ 9.6 Hz,
1H), 8.34 (d, J ¼ 6.6 Hz, 2H), 8.31 (d, J ¼ 7.8 Hz, 1H), 8.25 (d, J ¼
9.0 Hz, 1H), 8.24 (d, J ¼ 9.0 Hz, 1H), 8.21 (d, J ¼ 9.0 Hz, 1H), 8.10
(t, J ¼ 9.0 Hz, 2H), 4.26–4.31 (m, 1H), 1.28 (d, J ¼ 6.6 Hz, 6H); 13
C
1h. Yellow powder (302 mg, 86%), m.p.: 148–149 ꢂC, 1H NMR:
d 8.32 (d, J ¼ 9.0 Hz, 1H), 8.19 (d, J ¼ 12.2 Hz, 1H), 8.18 (d, J ¼
12.2 Hz, 1H), 8.10 (t, J ¼ 7.8 Hz, 1H), 8.08 (d, J ¼ 10.2 Hz, 1H),
8.06 (t, J ¼ 7.8 Hz, 2H), 8.02 (t, J ¼ 7.8 Hz, 1H), 8.01 (d, J ¼ 9.0 Hz,
1H), 7.84 (s, 1H), 8.02 (d, J ¼ 7.8 Hz, 2H), 7.38–7.41 (m, 2H),
7.33–7.36 (m, 1H), 5.17 (d, J ¼ 5.4 Hz, 2H); 13C NMR: d 200.81,
138.34, 136.04, 131.88, 131.28, 130.68, 129.06, 128.86, 128.63,
128.44, 128.32, 128.28, 127.63, 127.13, 126.43, 126.34, 125.83,
125.53, 124.71, 124.68, 124.53, 123.66, 50.81; IR (KBr) 3211,
3083, 3028, 1522, 1337, 1229, 948, 846 cmꢁ1; anal. calcd for
NMR (DMSO-d6): d 167.91, 132.45, 131.32, 130.69, 130.17,
128.06, 127.94, 127.63, 127.15, 126.46, 125.64, 125.45, 125.10,
124.58, 124.29, 123.73, 123.64, 41.13, 22.35; IR (KBr) 3278, 3047,
2975, 1326, 1545, 1530, 1285, 846 cmꢁ1; anal. calcd for
C
20H17NO: C, 83.59; H, 5.96; N, 4.87; O, 5.57; found: C, 83.49; H,
6.07; N, 4.93%.
2c. White powder (280 mg, 93%), m.p.: 232–233 ꢂC; 1H NMR:
d 8.53 (d, J ¼ 9 Hz, 1H), 8.22 (dd, J1 ¼ 2.4 Hz, J2 ¼ 10.0 Hz, 2H),
8.14 (t, J ¼ 7.8 Hz, 2H), 8.10 (d, J ¼ 9 Hz, 1H), 8.05 (d, J ¼ 7.8 Hz,
1H), 8.03 (t, J ¼ 7.2 Hz, 2H), 5.95 (s, 1H), 1.61 (s, 9H); 13C NMR: d
169.57, 132.68, 132.21, 131.23, 130.78, 128.78, 128.55, 128.41,
128.27, 127.15, 126.27, 125.69, 125.60, 124.80, 124.53, 124.38,
124.32, 52.29, 29.05; IR (KBr) 3325, 3046, 2977, 2958, 1639, 1523,
1298, 1223, 844 cmꢁ1; anal. calcd for C21H19NO: C, 83.69; H,
6.35; N, 4.65; O, 5.31; found: C, 83.76; H, 6.39; N, 4.53%.
2d. White powder (316 mg, 96%); 1H NMR: d 8.46 (d, J ¼ 9.6
Hz, 1H), 8.16 (d, J ¼ 7.8 Hz, 2H), 8.03–8.05 (m, 2H), 7.99–8.02
(m, 2H), 7.93–7.96 (m, 2H), 6.29 (s, 1H), 3.54 (q, J ¼ 7.2 Hz, 2H),
1.67 (kwintet, J ¼ 7.2 Hz, 2H), 1.40–1.44 (m, 2H), 1.32–1.36 (m,
4H), 0.92–0.94 (m, 3H); 13C NMR: d 169.92, 132.24, 131.36,
131.07, 130.63, 128.41, 128.38, 128.34, 126.99, 126.17, 125.64,
125.55, 124.60, 124.36, 124.32, 124.15, 123.70, 40.27, 31.49,
29.68, 26.70, 22.55, 13.99; IR (KBr) 3299, 3037, 2928, 1625, 1536,
848 cmꢁ1; anal. calcd for C23H23NO: C, 83.85; H, 7.04; N, 4.25; O,
4.86; found: C, 83.89; H, 6.99; N, 4.31%.
C
24H17NS: C, 82.02; H, 4.88; N, 3.99; S, 9.12; found: C, 82.07; H,
4.85; N, 4.14%.
1i. Yellow powder (323 mg, 88%), m.p.: 189–190 ꢂC; 1H NMR:
d 12.19 (s, 1H), 8.32–8.36 (m, 3H), 8.30 (d, J ¼ 9.0 Hz, 1H), 8.26
(d, J ¼ 9.0 Hz, 1H), 8.22–8.24 (m, 2H), 8.11 (t, J ¼ 7.8 Hz, 2H),
8.00 (d, J ¼ 9.0 Hz, 2H), 7.06 (d, J ¼ 9.0 Hz, 2H), 3.83 (s, 3H); 13
C
NMR: d 196.87, 157.35, 139.70, 132.77, 130.79, 130.69, 130.24,
128.07, 127.79, 127.13, 126.51, 125.69, 125.60, 125.35, 124.89,
124.73, 124.69, 124.45, 124.02, 123.75, 123.69, 113.71, 55.30; IR
(KBr) 3155, 3049, 2961, 1594, 1509, 1247, 849 cmꢁ1; anal. calcd
for C24H17NOS: C, 78.45; H, 4.66; N, 3.81; O, 4.35; S, 8.73; found:
C, 78.37; H, 4.72; N, 3.95%.
1j. Yellow oil (332 mg, 87%), 1H NMR: d 12.77 (s, 1H), 8.47 (d,
J ¼ 8.4 Hz, 2H), 8.36–8.40 (m, 4H), 8.34 (d, J ¼ 7.8 Hz, 1H), 8.24–
8.28 (m, 4H), 8.15 (d, J ¼ 7.8 Hz, 1H), 8.13 (t, J ¼ 7.2 Hz, 1H); 13
C
2e. White powder (298 mg, 91%); m.p.: 236–237 ꢂC; 1H NMR:
d 8.52 (d, J ¼ 9.0 Hz, 1H), 8.19 (d, J ¼ 7.8 Hz, 2H), 8.11 (d, J ¼ 9.0
Hz, 1H), 8.09 (d, J ¼ 7.8 Hz, 1H), 8.08 (d, J ¼ 9.0 Hz, 1H), 8.04 (d,
J ¼ 7.8 Hz, 1H), 8.02 (t, J ¼ 7.8 Hz, 1H), 8.01 (d, J ¼ 9.0 Hz, 1H),
6.05 (d, J ¼ 7.8 Hz, 1H), 4.15–4.21 (m, 1H), 2.17–2.19 (m, 2H),
1.80 (dt, J1 ¼ 3.6 Hz, J2 ¼ 13.8 Hz, 2H), 1.69 (dt, J1 ¼ 3.6 Hz, J2 ¼
13.2 Hz, 1H), 1.50 (qt, J1 ¼ 3.6 Hz, J2 ¼ 12.0 Hz, 2H), 1.33 (qd, J1
¼ 3.6 Hz, J2 ¼ 12.0 Hz, 2H), 1.23 (qt, J1 ¼ 3.6 Hz, J2 ¼ 12.2 Hz,
1H); 13C NMR: d 169.10, 132.31, 131.66, 131.15, 130.70, 128.54,
128.44, 128.36, 127.08, 126.31, 126.24, 125.69, 125.60, 124.72,
124.42, 124.34, 124.26, 49.03, 33.28, 25.58, 24.93; IR (KBr) 3274,
3039, 2934, 2916, 1625, 1532, 1306, 848 cmꢁ1; anal. calcd for
NMR: d 199.86, 145.19, 144.27, 139.49, 131.07, 130.76, 130.16,
128.42, 128.11, 127.10, 126.62, 125.91, 125.62, 125.55, 124.87,
124.45, 123.73, 123.65, 123.62, 122.89; IR (KBr) 3299, 1595,
1551, 1498, 1332, 1317, 1303, 846, cmꢁ1; anal. calcd for
C
23H14N2O2S: C, 72.23; H, 3.69; N, 7.33; O, 8.37; S, 8.38; found:
C, 72.31; H, 3.59; N, 7.45%.
Pyrene-1-carboxamides 2a–i
General procedure. Oxone® (1.5 mmol in 10 ml of water) was
added to the thioamides 1a–i (1 mmol) dissolved in a mixture of
acetonitrile (30 ml) and water (20 ml). The resulting solution
was stirred at room temperature for 2 h, poured into water (100
ml) and extracted several times with CH2Cl2. The organic phase
was dried over anhydrous Na2SO4 and concentrated. The
products were puried by silica gel column chromatography
(CH2Cl2/MeOH 100 : 0 / 99 : 1).
C
23H21NO: C, 84.37; H, 6.46; N, 4.28; O, 4.89; found: C, 84.30; H,
6.52; N, 4.37%.
2f. Yellow oil (311 mg, 89%); 1H NMR: d 9.56 (s, 1H), d 88.58
(d, J ¼ 9.0 Hz, 1H), 8.20 (d, J ¼ 7.2 Hz, 2H), 8.11 (d, J ¼ 10.2 Hz,
56010 | RSC Adv., 2014, 4, 56003–56012
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2H), 8.08 (d, J ¼ 9.0 Hz, 2H), 8.03 (t, J ¼ 7.8 Hz, 1H), 8.00 (d, J ¼ acid (246 mg, 1 mmol) and amine (1.2 mmol) in CH2Cl2 (10 ml)
8.4 Hz, 1H), 7.46 (d, J ¼ 7.8 Hz, 2H), 7.39 (t, J ¼ 7.2 Hz, 2H), 7.32 and the mixture was stirred at rt for 24 h. The resulting
(t, J ¼ 7.8 Hz, 1H), 6.48 (s, 1H), 4.80 (d, J ¼ 5.4 Hz, 2H); 13C NMR: precipitate was ltered off. The solvent was evaporated and the
d 169.77, 138.25, 132.45, 131.07, 130.67, 130.61, 128.79, 128.57, residue chromatographed on silica gel using CH2Cl2 as eluent
128.56, 128.53, 128.03, 127.90, 127.59, 126.99, 126.22, 125.72, to afford the pure products.
1
125.64, 124.64, 124.39, 124.31, 124.29, 124.13, 44.29; IR (KBr)
2k. White powder (321 mg, 85%). H NMR: d 8.33 (d, J ¼ 7.2
3261, 1644, 1595, 1523, 1441, 1331, 845 cmꢁ1; anal. calcd for Hz, 1H), 8.32 (d, J ¼ 7.8 Hz, 1H), 8.26 (d, J ¼ 7.8 Hz, 1H), 8.22–
C
24H15NO2: C, 82.50; H, 4.33; N, 4.01; O, 9.16; Found: C, 82.63; 8.25 (m, 3H), 8.19 (t, J ¼ 7.8 Hz, 2H), 7.89 (d, J ¼ 7.8 Hz, 1H),
H, 4.45; N, 3.92%.
1.63–1.83 (m, 6H), 1.24–1.34 (m, 3H), 0.69–1.11 (m, 6H); 13C
2g. Yellow powder (296 mg, 92%), m.p.: 253–255 ꢂC; 1H NMR: NMR: d 167.92, 131.83, 131.10, 130.59, 130.18, 128.02, 127.67,
d 10.71 (s, 1H), 8.48 (d, J ¼ 9.6 Hz, 1H), 8.40 (d, J ¼ 9.0 Hz, 1H), 127.18, 127.05, 126.43, 125.61, 125.44, 124.81, 124.63, 123.84,
8.37 (t, J ¼ 7.8 Hz, 2H), 8.30 (d, J ¼ 7.8 Hz, 1H), 8.29 (d, J ¼ 7.8 123.48, 123.46, 48.81, 30.99, 30.47, 25.46; IR (KBr) 3306, 3039,
Hz, 1H), 8.28 (t, J ¼ 9.0 Hz, 2H), 8.14 (t, J ¼ 7.2 Hz, 1H), 7.88 (d, J 2929, 2855, 1644, 1541, 1339, 847 cmꢁ1; anal. calcd for
¼ 7.8 Hz, 2H), 8.41 (t, J ¼ 7.8 Hz, 2H), 7.16 (t, J ¼ 7.2 Hz, 1H); 13
C
C27H25NO: C, 85.45; H, 6.64; N, 3.69; O, 4.22; found: C, 85.54; H,
NMR: d 167.56, 139.37, 131.84, 131.76, 130.68, 130.15, 128.69, 6.59; N, 3.76%.
128.43, 128.39, 127.76, 127.15, 126.60, 125.90, 125.68, 125.30,
2l. White powder (369 mg, 90%). 1H NMR (DMSO-d6): d 9.69
124.39, 124.30, 123.75, 123.69, 123.60, 119.86; IR (KBr) 3260, (d, J ¼ 8.4 Hz, 1H), 8.36 (d, J ¼ 9.0 Hz, 1H), 8.35 (d, J ¼ 7.2 Hz,
3038, 1645, 1524, 1441, 1331, 845 cmꢁ1; anal. calcd for 1H), 8.33 (d, J ¼ 7.8 Hz, 2H), 8.26 (d, J ¼ 9.0 Hz, 1H), 8.23 (d, J ¼
C
23H15NO: C, 85.96; H, 4.70; N, 4.36; O, 4.98; found: C, 85.88; H, 9.0 Hz, 1H), 8.22 (d, J ¼ 9.6 Hz, 1H), 8.17 (d, J ¼ 7.8 Hz, 1H), 8.12
4.76; N, 4.42%.
(t, J ¼ 7.2 Hz, 1H), 7.50 (d, J ¼ 7.8 Hz, 4H), 7.41 (t, J ¼ 7.8 Hz,
2h. Yellow powder (302 mg, 90%), m.p.: 161–162 ꢂC; 1H NMR: 4H), 7.30 (t, J ¼ 7.2 Hz, 2H), 6.61 (d, J ¼ 9.0 Hz, 1H); 13C NMR
d 8.58 (d, J ¼ 9.0 Hz, 1H), 8.20 (d, J ¼ 7.2 Hz, 2H), 8.11 (d, J ¼ 10.2 (DMSO-d6): d 168.21, 131.68, 131.52, 130.62, 130.11, 128.36,
Hz, 2H), 8.08 (d, J ¼ 9.0 Hz, 2H), 8.03 (t, J ¼ 7.8 Hz, 1H), 8.00 (d, 128.20, 128.04, 127.80, 127.43, 127.12, 126.96, 126.48, 125.73,
J ¼ 8.4 Hz, 1H), 7.46 (d, J ¼ 7.8 Hz, 2H), 7.39 (t, J ¼ 7.2 Hz, 2H), 125.52, 125.29, 124.36, 124.25, 123.69, 123.58, 56.55; IR (KBr)
7.32 (t, J ¼ 7.8 Hz, 1H), 6.48 (s, 1H), 4.80 (d, J ¼ 5.4 Hz, 2H); 13
C
3325, 3036, 2929, 1631, 1572, 848 cmꢁ1; anal. calcd for
NMR: d 169.77, 138.25, 132.45, 131.07, 130.67, 130.61, 128.79,
C30H21NO: C, 87.56; H, 5.14; N, 3.40; O, 3.89; found: C, 87.45; H,
128.57, 128.56, 128.53, 128.03, 127.90, 127.59, 126.99, 126.22, 5.23; N, 3.43%.
125.72, 125.64, 124.64, 124.39, 124.31, 124.29, 124.13, 44.29; IR
2m. White powder (421 mg, 86%), 1H NMR (DMSO-d6): d 8.48
(KBr) 3270, 3030, 2920, 1632, 1529, 1290, 848 cmꢁ1; anal. calcd (d, J ¼ 9.0 Hz, 1H), 8.34 (d, J ¼ 7.8 Hz, 1H), 8.32 (d, J ¼ 8.4 Hz,
for C24H17NO: C, 85.94; H, 5.11; N, 4.18; O, 4.77; found: C, 85.87; 2H), 8.24–8.27 (m, 3H), 8.19 (d, J ¼ 8.4 Hz, 1H), 8.13 (d, J ¼ 7.8
H, 5.09; N, 4.25%.
Hz, 1H), 8.11 (d, J ¼ 8.4 Hz, 1H), 7.71–7.74 (m, 6H), 7.50–7.52
2i. White powder (316 mg, 90%), m.p.: 251–252 ꢂC; 1H NMR: d (m, 3H), 7.44–7.46 (m, 6H); 13C NMR (150 MHz, DMSO): d
10.69 (s, 1H), 8.51 (d, J ¼ 9.0 Hz, 1H), 8.37 (d, J ¼ 9.8 Hz, 1H), 173.01, 153.80, 148.66, 131.97, 131.83, 131.25, 130.84, 129.11,
8.36 (t, J ¼ 7.8 Hz, 2H), 8.28 (d, J ¼ 9.0 Hz, 1H), 8.27 (d, J ¼ 9.0 128.50, 128.19, 128.14, 127.96, 127.93, 127.88, 127.33, 127.16,
Hz, 1H), 8.25 (t, J ¼ 7.8 Hz, 2H), 8.12 (t, J ¼ 7.2 Hz, 1H), 7.83 (d, J 126.71, 126.57, 126.47, 125.97, 125.87, 124.70, 124.52, 124.51,
¼ 4.8 Hz, 2H), 6.99 (d, J ¼ 4.8 Hz, 2H), 3.77 (s, 3H); 13C NMR: d 123.56, 122.67; IR (KBr) 3329, 2929, 2852, 1628, 1577, 1310, 847,
167.17, 155.59, 132.64, 131.97, 131.70, 130.70, 130.17, 128.36, 705 cmꢁ1; anal. calcd for C36H25NO: C, 88.68; H, 5.17; N, 2.87; O,
128.28, 127.82, 127.18, 126.57, 125.86, 125.64, 125.39, 124.46, 3.28; found: C, 88.63; H, 5.13; N, 2.99%.
124.40, 123.79, 123.64, 121.50, 113.86, 55.23; IR (KBr) 3323,
3039, 2929, 1643, 1540, 1340, 1234, 848 cmꢁ1; anal. calcd for
Acknowledgements
C
24H17NO2: C, 82.03; H, 4.88; N, 3.99; O, 9.11; found: C, 82.05;
H, 4.83; N, 3.91%.
Financial support from the National Science Centre Poland
1
2j. Yellow powder (289 mg, 79%), H NMR: d 11.32 (s, 1H), (NCN, Grant Harmonia UMO-2012/04/M/ST5/00712) is grate-
8.41 (d, J ¼ 8.4 Hz, 1H), 8.40 (d, J ¼ 7.8 Hz, 1H), 8.30–8.34 (m, fully acknowledged.
2H), 8.27 (d, J ¼ 7.8 Hz, 1H), 8.26 (d, J ¼ 9.0 Hz, 1H), 8.23 (d, J ¼
9.0 Hz, 1H), 8.13 (t, J ¼ 7.8 Hz, 1H), 8.08 (d, J ¼ 8.4 Hz, 1H), 7.86
References
(d, J ¼ 8.4 Hz, 2H), 7.09 (d, J ¼ 8.4 Hz, 2H) 13C NMR: d 168.15,
142.69, 133.13, 130.52, 129.88, 129.51, 129.21, 128.32, 127.86,
127.12, 126.92, 126.59, 126.35, 124.78, 124.39, 123.64, 123.15,
122.58, 120.64; IR (KBr) 3172, 1612, 1594, 1514, 1336, 1029, 987,
841 cmꢁ1; anal. calcd for C23H14NO3: C, 75.40; H, 3.85; N, 7.65;
O, 13.10; found: C, 75.51; H, 3.89; N, 12.89%.
1 T. M. Figueira-Duarte and K. Muellen, Chem. Rev., 2011, 111,
7260–7314.
2 G. Drummen, Molecules, 2012, 17, 14067–14090.
3 S. P. Sau and P. J. Hrdlicka, J. Org. Chem., 2012, 77, 5–16.
4 G. Bains, A. B. Patel and V. Narayanaswami, Molecules, 2011,
16, 7909–7935.
5 A. M. Breul, M. D. Hager and U. S. Schubert, Chem. Soc. Rev.,
2013, 42, 5366–5407.
Pyrene-1 carboxamides 2k–m
General procedure. A solution of DCC (412 mg, 2 mmol) in
CH2Cl2 (5 ml) was added to a solution of the pyrene-1-carboxylic
6 J. Zhao, W. Wu, J. Sun and S. Guo, Chem. Soc. Rev., 2013, 42,
5323–5351.
This journal is © The Royal Society of Chemistry 2014
RSC Adv., 2014, 4, 56003–56012 | 56011

View Article Online
RSC Advances
Paper
7 M. E. Ostergaard and P. J. Hrdlicka, Chem. Soc. Rev., 2011, 40, 25 S. P. Anthony, ChemPlusChem, 2012, 77, 518–531.
5771–5788.
26 M. Shimizu and T. Hiyama, Chem.–Asian J., 2010, 5, 1516–
1531.
27 Y. Hong, J. W. Y. Lam and B. Z. Tang, Chem. Commun., 2009,
4332–4353.
28 D. Plazuk, J. Zakrzewski, A. Rybarczyk-Pirek and
S. Domagała, J. Organomet. Chem., 2005, 690, 4302–4308.
29 A. Wesolowska, L. Gros, S. Westerlich and T. S. Jagodzinski,
ARKIVOC, 2008, 239–255.
8 A. Okamoto, Y. Saito and I. Saito, J. Photochem. Photobiol., C,
2005, 6, 108–122.
9 J. Xie, M. Menand, S. Maisonneuve and R. Metivier, J. Org.
Chem., 2007, 72, 5980–5985.
10 L. Zophel, V. Enkelmann and K. Mullen, Org. Lett., 2013, 15,
804–807.
11 J. M. Casas-Solvas, J. D. Howgego and A. P. Davis, Org.
Biomol. Chem., 2014, 12, 212–232.
´
´
30 T. Jagodzinski, Org. Prep. Proced. Int., 1990, 22, 755–760.
12 C. X. Yao, H. B. Kraatz and R. P. Steer, Photochem. Photobiol. 31 E. P. Papadopoulos, J. Org. Chem., 1976, 41, 962–965.
Sci., 2005, 4, 191–199.
32 A. Wrona-Piotrowicz, D. Plazuk, S. Domagala and
J. Zakrzewski, ARKIVOC, 2012, 412–420.
33 D. Plazuk, J. Zakrzewski, A. Rybarczyk-Pirek and
S. Domagala, J. Organomet. Chem., 2005, 690, 4302–4308.
34 S. Aki, T. Fujioka, M. Ishigami and J.-i. Minamikawa, Bioorg.
Med. Chem. Lett., 2002, 12, 2317–2320.
35 A. Corsaro and V. Pistara, Tetrahedron, 1998, 54, 15027–
15062.
36 I. Mohammadpoor-Baltork, M. M. Sadeghi and
K. Esmayilpour, Phosphorus, Sulfur Silicon Relat. Elem.,
2003, 178, 61–65.
13 M. Ottonelli, M. Piccardo, D. Duce, S. Thea and
G. Dellepiane, J. Phys. Chem. A, 2012, 116, 611–630.
14 Y. Niko, Y. Hiroshige, S. Kawauchi and G. I. Konishi, J. Org.
Chem., 2012, 77, 3986–3996.
15 Y. Niko, Y. Hiroshige, S. Kawauchi and G. I. Konishi,
Tetrahedron, 2012, 68, 6177–6185.
16 Y. Niko, Y. Cho, S. Kawauchi and G.-i. Konishi, RSC Adv.,
2014, 4, 36480–36484.
17 Y. Niko and G. I. Konishi, Macromolecules, 2012, 45, 2327–
2337.
18 F. Seela and S. A. Ingale, J. Org. Chem., 2010, 75, 284–295.
19 D. C. Knapp, J. D'Onofrio and J. W. Engels, Bioconjugate
Chem., 2010, 21, 1043–1055.
37 I. Mohammadpoor-Baltork, M. M. Sadeghi and
K. Esmayilpour, Synth. Commun., 2003, 33, 953–959.
38 N. S. S. Kumar, S. Varghese, C. H. Suresh, N. P. Rath and
S. Das, J. Phys. Chem. C, 2009, 113, 11927–11935.
20 S. Kodate, H. Wada, I. Suzuka, A. Okamoto, K. Tainaka,
Y. Saito and I. Saito, Nucleic Acids Symp. Ser., 2004, 2006, 39 M. Zhu and C. Yang, Chem. Soc. Rev., 2013, 42, 4963–4976.
211–212.
40 Z. Zhao, S. Chen, J. W. Y. Lam, Z. Wang, P. Lu, F. Mahtab,
H. H. Y. Sung, I. D. Williams, Y. Ma, H. S. Kwok and
B. Z. Tang, J. Mater. Chem., 2011, 21, 7210–7216.
21 S. T. Gaballah, Y. H. A. Hussein, N. Anderson, T. Q. T. Lian
and T. L. Netzel, J. Phys. Chem. A, 2005, 109, 10832–10845.
22 A. Okamoto, K. Kanatani and I. Saito, J. Am. Chem. Soc., 2004, 41 R. Katoh, K. Suzuki, A. Furube, M. Kotani and K. Tokumaru,
126, 4820–4827. J. Phys. Chem. C, 2009, 113, 2961–2965.
23 J. Hwang, M. G. Choi, S. Eor and S.-K. Chang, Inorg. Chem., 42 T. Seko, K. Ogura, Y. Kawakami, H. Sugino, H. Toyotama and
2012, 51, 1634–1639.
J. Tanaka, Chem. Phys. Lett., 1998, 291, 438–444.
24 S. Eor, J. Hwang, M. G. Choi and S.-K. Chang, Org. Lett., 2011,
13, 370–373.
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