Acceptor-π-Acceptor-Acceptor/Donor systems containing dicyanovinyl acceptor group with substituted 1,2,3-triazole motif – synthesis, photophysical and theoretical studies

Article abstract of DOI:10.1016/j.molstruc.2019.127488

An efficient synthetic route (target products obtained with yields 65–85%) for obtaining of malononitrile derivatives containing triazole motif substituted in the way providing the electronic architecture Acceptor-π-Acceptor-Acceptor/Donor (–CH₂(CN)₂/–C₆H₄–/triazole/substituent) is presented. As the substituents phenyl (A1), p-pentyloxyphenyl (A2), pyrid-2-yl (A3), 9,9-dimethylfluoren-2-yl (A4), 9-octyl-9H-carbazol-3-yl (A5), dibenzo[b,d]thiophen-2-yl (A6) and 2,2′-bithiophenyl-5-yl (A7) were used. The structures of compounds were confirmed by ¹H and ¹³C NMR spectroscopy. The thermal, optical and photophysical properties of obtained target compounds were checked. Understanding of obtained data was supported by quantum-chemical calculations based on DFT methods (time-dependent calculations, NTO analysis, structural parameters). Moreover, the druglikeness analysis was performed based on the commonly known rules.

Full text of DOI:10.1016/j.molstruc.2019.127488

Journal Pre-proof
Acceptor-π-Acceptor-Acceptor/Donor systems containing dicyanovinyl acceptor group
with substituted 1,2,3-triazole motif – synthesis, photophysical and theoretical studies
Dawid Zych, Aneta Slodek
PII:
S0022-2860(19)31597-2
DOI:
https://doi.org/10.1016/j.molstruc.2019.127488
MOLSTR 127488
Reference:
To appear in: Journal of Molecular Structure
Received Date: 12 October 2019
Revised Date: 26 November 2019
Accepted Date: 27 November 2019
Please cite this article as: D. Zych, A. Slodek, Acceptor-π-Acceptor-Acceptor/Donor systems
containing dicyanovinyl acceptor group with substituted 1,2,3-triazole motif – synthesis, photophysical
and theoretical studies, Journal of Molecular Structure (2019), doi: https://doi.org/10.1016/
j.molstruc.2019.127488.
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Acceptor-π-Acceptor-Acceptor/Donor systems containing
dicyanovinyl acceptor group with substituted 1,2,3-triazole motif
–
synthesis, photophysical and theoretical studies
[a]*
[b]
Dawid Zych and Aneta Slodek
[
a] Institut für Silizium-Photovoltaik, Helmholtz-Zentrum Berlin für Materialien und Energie
GmbH, Kekuléstraße 5, 12489 Berlin, Germany
b] Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland
Corresponding Author: dawidzych92@gmail.com (Dr. Dawid Zych)
[
*
D. Zych ORCID 0000-0002-7757-7321
A. Slodek ORCID 0000-0003-2600-6518
Graphical abstract
Highlights
•
Acceptor-π-Acceptor-Acceptor/Donor (-CH (CN) /-C H -/triazole/substituent)
2 2 6 4
systems
•
Effective synthetic routes for the synthesis of compounds containing dicyanovinyl
acceptor group with substituted 1,2,3-triazole motif
•
•
Photophysical investigations supported by quantum-chemical calculations
Druglikeness analysis based on the physicochemical properties and lipophilicity
Abstract
An efficient synthetic route (target products obtained with yields 65-85%) for obtaining of
malononitrile derivatives containing triazole motif substituted in the way providing the
electronic architecture Acceptor-π-Acceptor-Acceptor/Donor (-CH (CN) /-C H -/triazole/
2
2
6
4
substituent) is presented. As the substituents phenyl (A1), p-pentyloxyphenyl (A2), pyrid-2-yl
A3), 9,9-dimethylfluoren-2-yl (A4), 9-octyl-9H-carbazol-3-yl (A5), dibenzo[b,d]thiophen-2-
(

yl (A6) and 2,2'-bithiophenyl-5-yl (A7) were used. The structures of compounds were
1
13
confirmed by H and C NMR spectroscopy. The thermal, optical and photophysical
properties of obtained target compounds were checked. Understanding of obtained data was
supported by quantum-chemical calculations based on DFT methods (time-dependent
calculations, NTO analysis, structural parameters). Moreover, the druglikeness analysis was
performed based on the commonly known rules.
Keywords: Acceptor-Donor system; 1,2,3-triazole motif; dicyanovinyl group; optical and
photophysical properties; theoretical studies; druglikeness analysis
1
. Introduction
Molecules built from electron-donating and electron-accepting groups have become the
interest of researcher due to the wide spectrum of possible applications [1–4]. Moreover, the
constant development of chemical reactions, including the discovery of Cu(I)-catalyzed
Huisgen 1,3-dipolar cycloaddition reaction caused that more and more molecules contain in
the structure triazole bridges as versatile linkers [5–10]. When we also add next well-
established reaction - Knoevenagel condensation, the broad area of the functionalization
appears [11]. Taking into account compounds containing triazole and malononitrile groups,
they were reported as materials which can be used as chemosensors [12–14] and
chromophores [15]. In the case of chemosensors, all described in literature examples are
dedicated to the sensing of cyanide anion [8–10]. Introduction of malononitrile moiety to the
structure of molecules can also result in obtaining of materials which can be used as
chemosensors for thiocyanate [16] and sulfite anion [17].
Peter D. Jarowski et al. presented 1,2,3-triazoles as conjugative π-linkers in push-pull
chromophores and the influence of isomeric charge-transfer between the 1,2,3-triazole motif
and dicyanovinyl group on the optical properties of target systems [15]. They reported that
the change of the maxima absorption is about 50 nm (experimentally) and 100 nm
(theoretically calculated) depending on the position of the substituent.
Compounds structurally similar to molecules, which are a subject of our study, containing
malononitrile group connected to phenyl ring which is substituted at the para position by
hetero)aryl group are in the great interest of scientist during the last years. That compounds
(
contain one or two malononitrile moieties. Molecules with two malononitrile groups were
reported by G. Marianetti et al. with application as solar collectors based on 2,5-

diarylimidazoles [18], R. Dominguez and co-workers presented tetraaryl-1,4-
dihydropyrrolo[3,2-b]pyrrole dedicated to organic solar cells [19] and also by P. Wen et al.
with carbazole moiety as a lead structure which exhibits remarkable solvatochromism effect
[
1]. In the case of monosubstituted by dicyanovinyl group, the work of Z. Li et al. can be
found where authors described multi-modulated photochromic behaviour of a D-A type
dithienylethene [20], and results of Y. J. Chang and co-workers with carbazole-based small
molecules for vacuum-deposited organic photovoltaic devices with promising parameters
[
21].
We have recently reported the synthesis and comprehensive characterization of the
derivatives of 4'-(1,2,3-triazol-4-yl)phenyl-2,2':6',2''-terpyridine with various (hetero)aryl
substituents, where the first approach to their synthesis started with the substitution of the
nitro group in 4-nitrobenzaldehyde by the azide anion which was subjected to a 1,3-dipolar
cycloaddition reaction with ethynyl derivatives of (hetero)aryls followed by aldol
condensation reaction what resulted in target products with low yields [22]. Here we decided
to present the other possibility of using of 4-(4-substituted-1H-1,2,3-triazol-1-
yl)benzaldehyde, this time in the synthesis of malononitrile derivatives (with architecture
Acceptor-π-Acceptor-Acceptor/Donor (-CH (CN) /-C H -/triazole/substituent) with the
2
2
6
4
studies of their optical and photophysical properties supported by quantum-chemical
calculations based on DFT methods. Moreover, the druglikeness analysis was performed
based on the published in literature Lipiński, Ghose, Veber, Egan and Muegge rules.
2
. Results and discussion
2
.1. Synthesis and structural characterization
The structures of target compounds 3A1-7 and route for their synthesis are presented in
Scheme 1. 4-(4-Substituted-1H-1,2,3-triazol-1-yl)benzaldehydes were obtained by using the
way which was already reported by us, starting from substitution of nitro group of 4-
nitrobenzaldehyde by azide group followed by Cu(I)-catalyzed Huisgen 1,3-dipolar
cycloaddition with ethynyl derivatives of (hetero)aryls what resulted in 2A1-7 with
satisfactory yields in the range of 60-78% [22]. These intermediates were used in the next
step - Knoevenagel condensation with malononitrile by using the heterogeneous phase as an
inorganic catalyst - aluminium oxide in dichloromethane solution what resulted in target
products 3A1-7 with yields 65-85% [23]. The structures of compounds were confirmed
1
13
by H and C NMR spectroscopy (Supporting Information S1-S21).

A1
A2
A3
A
A
N
N
N
A5
-
8 17
C H
N
+
N
N
N
NO
N
N
2
N
OC H
5
11
a
b
c
S
A6
A7
NC
H
O
H
O
H
O
N
CN
S
S
1
2
3
A4
3
H C
CH
3
Scheme 1. Synthesis of compounds 1, 2A1-7, and 3A1-7. Reagents and conditions: a) NaN3,
HMPA, room temp., 72 h, 90% yield; b) ethynyl-derivative of A1-7, CuSO ꢀ5H O, sodium
4
2
ascorbate, pyridine, EtOH, H O, room temp., 24 h; c) malononitrile, Al O , DCM, room
2
2
3
temp., 24 h.
2
.2. Theoretical calculations
To gain the structural parameters and deep insight into optical and photophysical
properties, the quantum-chemical calculations based on DFT and TD-DFT methods were
conducted. In order to obtain the results which are sublimely correlated with the experimental
data, various exchange-correlation functionals were applied: B3LYP [24], CAM-B3LYP
[
25], wB97XD [26] and M06 [27] with 6-31G** basis set implemented in the Gaussian 09
program [28]. All geometries were optimized in a chloroform solution in the polarisable
continuous model (PCM) [29]. Obtained values of the energy gaps confronted with the values
of optical energy gaps (the absolute value of the difference between Eg opt and the result of
calculation ǀꢁǀ) are presented in Table 1.
Table 1. Energy gaps for 3A1-7 obtained from DFT calculations with various hybrid
potentials and 6-31G(d,p) basis set in chloroform compared with optical energy gaps.
ꢀ
E [eV]
Eg opt
[
eV]
B3LYP
3.26
ǀꢀǀ CAM-B3LYP ǀꢀǀ
wB97XD
6.92
ǀꢀǀ
M06
3.73
3.25
3.94
3.15
2.90
ǀꢀǀ
3
3
3
3
3
A1 3.13
A2 2.92
A3 3.19
A4 2.89
A5 2.65
0.13
0.14
0.28
0.17
0.23
5.79
5.29
6.02
5.19
4.86
2.66
2.37
2.83
2.30
2.21
3.79
3.50
3.94
3.42
3.31
0.60
0.33
0.75
0.26
0.25
2.78
6.42
3.47
7.13
2.72
6.31
2.42
5.96

3
3
A6 2.93
A7 2.74
2.82
2.50
0.11
0.24
5.30
5.04
2.37
2.30
6.41
6.16
3.48
3.42
3.23
2.95
0.30
0.21
The values of energy gaps obtained as the result of calculations with B3LYP hybrid
potential are the closest to the experimental values and followed the same trend:
3
A5<3A7<3A4<3A2<3A6<3A1<3A3, the energy gap of compound 3A3 containing 2-
pyridyl substituents is the highest, whereas 3A5 containing carbazyl unit has the lowest
energy difference between frontier orbitals. Moreover, the results obtained with M06
exchange-correlation functional have also physical sense, but the differences are higher in
comparison to B3LYP. Also, the trend is changed, the energy gap of 3A6 is lower than of
3
A2. In the case of CAM-B3LYP and wB97XD, the values are much higher, even doubled.
Based on the above-presented results, the B3LYP/6-31G(d,p) contours of frontier orbitals
with the contribution in their creation of particular parts of molecules 2A1-7 and 3A1-7
(
-CHO or -CH (CN) /-C H -/triazole/substituent) are presented in Table 2. Furthermore, the
2 2 6 4
theoretical investigations were also extended to the substrates of Knoevenagel condensation -
aldehydes 2A1-7, what is also presented in Table 2. All orbitals were computed at an isovalue
3
of 0.03 e/bohr .
Table 2. The optimized structures B3LYP/6-31G(d,p) with contours of HOMOs and LUMOs
and the contribution of the individual part of molecules (-CHO or -CH (CN) /-C H -
2
2
6
4
/
triazole/substituent) in their creation, and energies of frontier orbitals for 2A1-7 and 3A1-7.
HOMO
LUMO
HOMO
LUMO
2
2
A1
A2
3A1
3A2
1
/8/42/49
34/48/16/2
-2.19 eV
4/9/40/47
-6.27 eV
60/32/7/1
-3.01 eV
-6.22 eV
0
/3/25/72
34/49/16/1
1/3/24/72
60/32/7/1
-5.71 eV
-2.16 eV
-5.77 eV
-2.99 eV
2
2
A3
A4
3A3
3A4
2
-
/11/45/42
6.45 eV
33/48/17/2
-2.20 eV
8/14/41/37
-6.49 eV
60/32/7/1
-3.02 eV
0
/3/20/77
34/48/16/2
1/2/19/78
60/32/7/1

-5.68 eV
-2.18 eV
-5.73 eV
-3.01 eV
2
A5
3A5
0
/2/14/84
34/48/16/2
1/1/13/85
60/32/7/1
-5.36 eV
-2.14 eV
-5.40 eV
-2.98 eV
2
2
A6
A7
3A6
3A7
0
/2/16/82
34/48/16/2
-2.19 eV
1/2/15/82
-5.84 eV
60/32/7/1
-3.02 eV
-5.80 eV
0
/2/17/81
31/46/17/6
1/2/16/81
59/32/8/1
-5.48 eV
-2.22 eV
-5.52 eV
-3.02 eV
The energies of orbitals H-2, H-1, H, L, L+1, L+2 are depicted in Figure 1. It shows that
the exchange of aldehyde group into malononitrile moiety causes the significant reduction of
the energy of the lowest unoccupied orbitals (LUMO), what is desirable in the creation of
potential materials which can be applied in wide-known organic electronics. It is also worth
to emphasize that the energies of the rest of the presented orbitals are similar for the aldehyde
and corresponding malononitrile derivative.
Figure 1. Energies of orbitals (B3LYP/6-31G(d,p)): H-2, H-1, H, L, L+1, L+2 for 2A1-7 and
3
A1-7.
Described above dependence is related to the contribution of the individual part of
molecules in the creation of orbitals. In the case of HOMOs, the contribution of the

substituent for malononitrile, as well as for aldehyde is the highest for 2A5 (84%) and 3A5
85%) containing carbazyl group and the lowest for 2A3 (42%) and 3A3 (37%) with 2-
(
pyridyl group. Due to the stronger electron-accepting character of dicyanovinyl group in
comparison to the aldehyde group, the significant difference in the creation of the lowest
unoccupied orbitals, and therefore, their energies were observed. The contribution of -
CH (CN) group in the creation of LUMO for 3A1-7 equals about 60%, whereas the -CHO
2
2
builds HOMO of 2A1-7 in about 31-34%.
What is more, the structural parameters such as the angles between the surface of
benzaldehyde or benzylidenemalononitrile and substituted triazole ring were checked.
Obtained data are presented in Table 3.
Table 3. Calculated (B3LYP/6-31G(d,p)) angles between triazole and phenyl group.
Θ
A
N
G
N
N
Θ [°]
22.48
23.53
22.72
24.27
22.59
24.25
23.54
Θ [°]
18.36
18.11
17.63
20.65
18.79
20.25
19.86
2
2
2
2
2
2
2
A1
A2
A3
A4
A5
A6
A7
3A1
3A2
3A3
3A4
3A5
3A6
3A7
First of all, the significant angles difference between aldehydes and corresponding
malononitrile were observed, the values in the case of aldehyde are higher than for
corresponding malononitriles. The highest value of the angle in the group of aldehydes was
for 2A4 (24.27°), the lowest for 2A1 (22.48°), whereas in the case of malononitriles, the
highest for 3A4 (20.65°) and lowest for 3A3 (17.63°). The highest difference between the
groups of studied compounds was observed for compounds containing p-pentyloxyphenyl
substituent 2A2 and 3A2 (5.42°) and the lowest with 9,9-dimethylfluoren-2-yl 2A4 and 3A4
(3.62°).
2
.3.Optical and photophysical properties
Temperatures of thermal degradation, which correspond to 5 and 10% weight loss during
the heating were checked by using thermogravimetric analysis (TGA) under a nitrogen
atmosphere up to 900 °C. TGA thermograms and numerical values are presented in Figure 2

and Table 4. The results showed that studied molecules retain varied stability; the most stable
is compound 3A3 with decomposition temperature corresponding to 5% weight loss (T ) at
5
%
3
29 °C. Among examined molecules, 3A3 has the highest char residue at 900 °C. Compound
A6 exhibits the lowest value of T . The temperature of 10% weight loss (T10%) for all
3
5
%
examined compounds 3A1-7 is higher than 300 °C, the highest for 3A3, the lowest for 3A7.
Figure 2. TGA curves of 3A1-7.
Table 4. Thermal properties of the synthesized derivatives 3A1-7.
Char residue
T5% [°C] T10% [°C]
at 900 °C [%]
3
3
3
3
3
3
3
A1
A2
A3
A4
A5
A6
A7
292
324
329
312
306
188
283
302
364
393
329
339
325
300
29
57
66
54
1
1
54
The optical properties of 3A1-7 compounds were examined by UV-Vis spectra and
-5
photoluminescence (PL) spectroscopy techniques in chloroform solution (1×10 M) at
ambient temperature. The corresponding optical data and quantum yields are presented in
Table 5. The UV-Vis absorption spectra depicted in Figure 3a show several bands in the
range of 250-450 nm. The absorption bands in the UV region (250-350 nm) are assigned to
the π-π* transitions while the absorption bands appear between 350 and 450 nm which are
dominated by HOMO→LUMO transition can be ascribed to the intramolecular charge
transfer (ICT) between substituent (A) and -CN groups.

(a)
b)
Figure 3. Normalized absorption (a) and emission (b) spectra recorded in CHCl of 3A1-7.
3
Compounds 3A1-7 as the simple D-A systems present a strong correlation between the
electronic ability of substituents A and their absorption features. Given the electronic nature
of substituents A in compounds 3A1-7, a redshift alike of the π-π* and the ICT bands is
observed with increasing the electron-donating ability of substituents A in the following order
3
A3→3A1→3A6→3A2→3A4→3A7→3A5. Compound 3A3 containing pyridine motif with
electron-withdrawing character possess less electron releasing nature than bithienyl and
carbazyl groups in 3A7→3A5 causing the weaker ICT.
Table 5. Photophysical data for 3A1-7 recorded in the chloroform solution.
PL λem [nm] /
λmax[nm]
-1
Φ [%]
Stokes shift [cm ]
3
3
3
3
3
3
3
A1
A2
A3
A4
A5
350
367
407/3999
425/3718
401/3716
430/3626
451/2580
423/3682
454/3484
15
13
21
52
56
36
62
349
283, 320, 372
245, 283, 329, 404
A6 250, 266, 281, 325, 366
A7
332, 392
To more widely assess the effect of the substituent A in compounds 3A1-7 on the absorption
properties, TD-DFT calculations in chloroform done with four different hybrid potentials
were demonstrated. The results and UV-Vis simulated absorption spectra are depicted in
Table S1. TD-DFT calculations performed with CAM-B3LYP, B3LYP, wB97XD, and M06
methods confirmed the absorption spectra dependent on the nature of the substituent A.

Among four different methods, the B3LYP and M06 proved to best reflect the experimental
data. CAM-B3LYP and wB97XD hybrid potentials, although they gave a rational description
of the high energy absorption bands, did not indicate ICT transitions. The theoretical results
will be discussed predominately based on the B3LYP and M06 functionals. The B3LYP and
M06 methods gave the depiction of dominate transitions that are slightly shifted by
approximately 45 nm relative to experimental data. The red-shifted absorption bands for
compounds 3A4, 3A5, and 3A7 compared to the other were found, which is in good accord
with the experimental results. The presence of strongly electron-donating moieties in 3A4
(fluorene), 3A5 (carbazole), and 3A7 (bithiophene) induces effective charge transfer from
substituents A to the cyano groups, confirmed by the distribution of their HOMO orbitals
with 78-85% contribution of substituents A and LUMO orbitals mainly populated on the
cyano groups with a 60% share. Moreover, the deep insight into the absorption spectra was
done by using the natural transition orbitals analysis. The pairs occupied (holes) and
unoccupied (electrons) with contribution higher than 20% presenting the nature of absorption
spectra (6-31G(d,p)/M06) with the contribution of CH (CN) /-C H -/triazole/substituent is
2
2
6
4
presented for 3A1 in Table 6, NTO analysis for molecules 3A2-7 is presented in Supporting
Information as Tables S2-S7. For each state, the respective number of the state, transition
energy, and the oscillator strength are listed.
Table 6. Natural transition orbitals (NTOs) analysis for 3A1.
3A1
Hole
Electron
S1
.154 eV
0.560)
3
(
3
3
2
2
93.14 nm
28.23 nm
58.07 nm
49.59 nm
98%
0.04/0.08/0.34/0.54 0.60/0.33/0.07/0.00
0.34/0.42/0.12/0.12 0.60/0.33/0.07/0.00
0.04/0.08/0.34/0.54 0.15/0.18/0.47/0.21
0.04/0.08/0.34/0.54 0.00/0.37/0.24/0.38
S2
.777 eV
0.758)
3
(
97%
S6
.804 eV
0.107)
4
(
93%
S7
.968 eV
0.212)
4
(
88%

The emission spectra of 3A1-7 are depicted in Figure 3b. Compounds 3A1-7 demonstrate
strong blue-greenish photoluminescence (PL) in chloroform solution with the peaks located
in the range of 400 - 455 nm. The structural changes associated with the position 4 of the
triazole unit of 3A1-7 are quite pronounced and the impact of their electronic capacity on the
emission spectrum cannot be ignored. When the bithiophene and carbazole motifs with strong
electron-donating character were adopted to the triazole unit in 3A5 and 3A7, respectively,
the fluorescence peaks of presented compounds exhibited redshifts about 50 nm with relative
to 3A3, which possess strong electron-withdrawing pyridine unit. p-Pentyloxyphenyl,
fluorenyl, and dibenzothiophenyl substituents on triazole unit of 3A2, 3A4 and 3A6,
respectively, also led to a bathochromic shift similar to compounds 3A5 and 3A7, but smaller
about 20 nm compared with compound 3A3. Insertion of phenyl unit possessing weak
donating ability in the triazole ring in 3A1 resulting in a slightly shifted (6 nm) emission
maximum compared to 3A3. As confirmed by emission spectra, the use of various
substituents in the examined compounds 3A1-7 strongly determines photoluminescent
behaviour. Concluding from TD-DFT calculations carried out with CAM-B3LYP, B3LYP,
wB97XD, and M06; the CAM-B3LYP and wB97XD hybrid potential showed the best fit for
the experimental data. The theoretical calculations confirm that the extent of the shift of
emission maximum depends on the electron-donating facilities of the substituents in
compounds 3A1-7 (Table 7 and S8).
Table 7. TD-DFT calculated wavelengths of emission with oscillator strengths for 3A1-7.
Calculated
Exp
wavelengths
[nm] (oscillator
strengths)
ꢀ
[nm]
Transitions
[
nm]
HOMO→LUMO (78%),
H-1→LUMO (19%),
HOMO→LUMO (73%),
H-1→LUMO (23%)
HOMO→LUMO (69%),
H-1→LUMO (26%)
HOMO→LUMO (50%),
H-1→LUMO (45%)
HOMO→LUMO (88%),
H-1→LUMO (9%)
HOMO→LUMO (85%),
H-1→LUMO (12%)
HOMO→LUMO (59%),
H-1→LUMO (35%)
H-1→LUMO (55%),
HOMO→LUMO (38%)
CAM-B3LYP 390.27 (1.4988)
17
19
21
31
14
17
29
38
3
3
3
3
A1 407
wB97XD
CAM-B3LYP 403.94 (1.3892)
wB97XD 393.95 (1.5522)
CAM-B3LYP 386.45 (1.4923)
wB97XD 383.73 (1.4702)
CAM-B3LYP 401.15 (1.6523)
wB97XD 392.17 (1.7418)
387.96 (1.4928)
A2 425
A3 401
A4 430

HOMO→LUMO (74%),
H-2→LUMO (19%)
H-2→LUMO (45%),
HOMO→LUMO (42%)
HOMO→LUMO (49%),
H-2→LUMO (43%)
H-2→LUMO (56%),
HOMO→LUMO (33%)
HOMO→LUMO (62%),
HOMO→L+1 (27%),
H-1→LUMO (9%)
CAM-B3LYP 419.56 (1.1600)
wB97XD 399.43 (1.5936)
CAM-B3LYP 394.40 (1.6037)
wB97XD 389.67 (1.6332)
CAM-B3LYP 434.58 (1.5677)
wB97XD 424.08 (1.5251)
31
52
29
33
3
3
A5 451
A6 423
19
30
3
A7 454
HOMO→L+1 (66%),
HOMO→LUMO (27%)
The respective fluorescence quantum yields for 3A1-7 are in the range of 13 to 62%
Table 5). For the tested compounds 3A1-7, the attachment of a strong donor such as
(
fluorene, carbazole, and bithiophene groups to the triazole ring gives rise to an increased
quantum yield by up to 62% in the case of compound 3A7 with bithiophene group. The
similar substituent effects of the donor group on quantum yield was observed in the case of
terpyridine derivatives [30]. Among the specific compounds, compound 3A2, which contains
an electron-donating p-pentyloxyphenyl group, displays significantly reduced quantum yield
(Φ3A2 = 13%) compared to the compound with fluorene substituent 3A4 (Φ3A4 = 52%). This
probably indicates that the higher quantum efficiency of 3A4 is prominently affected by the
larger π-conjugated system of fluorene group.
2
.4. Druglikeness analysis
Followed the trend of computational considerations which allow to predict ADME
parameters (absorption, distribution, metabolism, and excretion), pharmacokinetic properties,
druglike nature and medicinal chemistry friendliness, the calculations were done for 2A1-7
and 3A1-7 by using the web tool SwissADME [31]. The data obtained for target compounds,
i.e. Log Po/w (average values of all available predictions), topological polar surface area
(
TPSA), molar refractivity (AMR), number of H-bond acceptors (HBA) and donors (HBD)
are presented in Table 8. Druglikeness for all compounds was checked by using the Lipiński
L) [32], Ghose (G) [33], Veber (V) [34], Egan (E) [35] and Muegge (M) [36] rules. The
(
obtained result showed that in the case of aldehydes 2A1-7 only 2A5 containing carbazyl
substituent does not meet the conditions of Ghose, Egan and Muegge rules, while there is no
violation for the rest of compounds. The same investigation for malononitrile derivatives

3
A1-7 showed that the derivative of aldehyde 2A5, i.e. 3A5 does not meet the same rules
druglikeness rules, what is more, 3A4, 3A6 and 3A7 also do not meet at least one of the rules.
Table 8. Druglikeness of molecules 2A1-7 and 3A1-7 based on Lipiński (L), Ghose (G),
Veber (V), Egan (E) and Muegge (M) rules.
L G V E M MW [g/mol Log Po/w TPSA [Ų] AMR HBA HBD
2
2
2
2
2
2
2
3
3
3
3
3
3
3
A1
A2
A3
A4
A5
A6
A7
A1
A2
A3
A4
A5
A6
A7
249.27
335.40
250.26
365.43
450.57
355.41
337.42
297.13
383.45
298.30
413.47
498.62
403.46
385.46
2.48
3.81
1.73
4.53
5.99
4.44
3.80
2.72
4.09
2.05
4.77
6.16
4.67
4.06
47.78
57.01
60.67
47.78
52.71
76.02
104.26
78.29
87.52
91.18
78.29
83.22
106.53
134.77
72.18
97.90
3
4
4
3
3
3
3
4
5
5
4
4
4
4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
69.98
110.13
140.10
105.07
93.37
86.00
111.72
83.79
123.94
153.91
118.89
107.19
3
. Conclusions
The target molecules 3A1-7 were obtained based on the presented efficient synthetic route
with the yields in the range of 65-85%. The structures of the malononitrile derivatives have
following electronic architecture Acceptor-π-Acceptor-Acceptor/Donor (-CH (CN) /-C H -
2
2
6
4
1
13
/
triazole/ substituent). The structures of compounds were confirmed by H and C NMR
spectroscopy. Obtained target compounds are thermally stable, exhibit several absorption
bands in the UV-Vis range. Furthermore, the molecules demonstrate strong blue-greenish
photoluminescence in chloroform solution with the peaks located in the range of 400 - 455
nm. The nature of the optical properties was studied based on the results of DFT and TD-
DFT results, it allowed to find the impact of the electron character of the substituent on the
properties. The structural changes associated with position 4 of the triazole unit of 3A1-7 are
quite pronounced and the impact of their electronic capacity is significant. In the case of the

bithiophene and carbazole motifs with strong electron-donating character were adopted to the
triazole unit in 3A5 and 3A7, respectively, the fluorescence peaks of presented compounds
exhibited red shifts about 50 nm with relative to 3A3, which possess strong electron-
withdrawing pyridine unit. The respective fluorescence quantum yields for 3A1-7 are in the
range of 13 to 62%. For the tested compounds 3A1-7, the attachment of a strong donor such
as fluorene, carbazole, and bithiophene groups to the triazole ring gives rise to an increased
quantum yield by up to 62% in the case of compound 3A7 with bithiophene group. The
druglikeness analysis based on the parameters of the well-known in literature Lipiński,
Ghose, Veber, Egan and Muegge rules, showed that in the case of aldehydes 2A1-7 only 2A5
containing carbazyl substituent does not meet the conditions of Ghose, Egan and Muegge
rules, while there is no violation for the rest of compounds. The same investigation for
malononitrile derivatives 3A1-7 showed that 3A5 does not meet the same rules druglikeness
rules as the aldehyde 2A5, what is more, 3A4, 3A6 and 3A7 also do not meet at least one of
the rules. Obtained results and their deep analysis have emphasized the validity of synthesis
of 4-(4-substituted-1H-1,2,3-triazol-1-yl)benzaldehyde as materials which exhibit interesting
optical, photophysical and also biological properties, what can predestine them as materials
dedicated to organic electronics and medicine. We believe that presented work will be an
inspiration for other scientists.
Acknowledgement
This work was supported by the Ministry of Science and Higher Education, Poland
Diamentowy Grant number 0215/DIA/2015/44. D. Zych was financed by the National
Science Centre of Poland ETIUDA 6 2018/28/T/ST5/00005.
Calculations have been carried out using resources provided by Wroclaw Centre for
Networking and Supercomputing (http://wcss.pl), grant No.18.
4
. Experimental Section
General Procedure for the synthesis of 2A1-2A7: In a 100 mL round-bottom flask,
-azidobenzaldehyde (0.080 g, 0.54 mmol), ethanol (21 mL) and water (9 mL) were placed.
The mixture was saturated with argon for 15 minutes and then appropriate ethynyl aryl
0.66 mmol) (in the case of ethynyl derivatives protected by trimethylsilyl, the silyl group is
4
(
removing in situ by using KF (0.051 g, 0.88 mmol)), sodium ascorbate (0.132 g, 0.66 mmol),
CuSO ꢀ5H O (0.165 g, 0.66 mmol), and pyridine (0.5 mL) were added. The mixture was
4
2

stirred at room temperature for 48 h. Then, chloroform (30 mL) and 5% solution of ammonia
20 mL) were added, and the mixture was stirred for additional 30 min. The mixture was
(
extracted with water (50 mL) and CHCl (2 x 50 mL). The combined organic layers were
3
evaporated, and the crude product was dissolved in a small amount of CHCl and the excess
3,
of hexane was added and put in the centrifuge tube into an ultrasonic bath for 5 min. The
obtained precipitate was filtrated through the fritted funnel G3 and washed with water and
diethyl ether.
1
4
-(4-Phenyl-1H-1,2,3-triazol-1-yl)benzaldehyde (2A1) (105 mg, 78%) as solid H NMR
(
400 MHz, CDCl ) δ 10.09 (s, 1H), 8.29 (s, 1H), 8.12 – 8.06 (m, 2H), 8.06 – 8.00 (m, 2H),
3
1
3
7
.96 – 7.90 (m, 2H), 7.54 – 7.45 (m, 2H), 7.44 – 7.37 (m, 1H). C NMR (101 MHz, CDCl )
3
δ 190.77, 149.13, 141.16, 136.15, 131.55, 129.90, 129.17, 128.94, 126.10, 120.56, 117.34.
4
-(4-(4-Pentyloxyphenyl)-1H-1,2,3-triazol-1-yl)benzaldehyde (2A2) (139 mg, 77%) as
1
solid H NMR (400 MHz, CDCl ) δ 10.09 (s, 1H), 8.17 (s, 1H), 8.07 (d, J = 8.7 Hz, 2H), 8.01
3
(d, J = 8.5 Hz, 2H), 7.83 (d, J = 8.8 Hz, 2H), 7.00 (d, J = 8.8 Hz, 2H), 4.02 (t, J = 6.6 Hz,
13
2
H), 1.87 – 1.77 (m, 2H), 1.48 – 1.35 (m, 4H), 0.96 (t, J = 7.1 Hz, 3H). C NMR (126 MHz,
CDCl ) δ 190.80, 159.79, 149.02, 141.17, 135.97, 131.49, 127.35, 122.23, 120.41, 116.40,
3
1
15.08, 68.25, 29.06, 28.32, 22.59, 14.15.
1
4
-(4-Pyrid-2-yl-1H-1,2,3-triazol-1-yl)benzaldehyde (2A3) (85 mg, 63%) as solid H NMR
(
400 MHz, CDCl ) δ 10.09 (s, 1H), 8.69 (s, 1H), 8.63 (d, J = 4.4 Hz, 1H), 8.26 (d, J = 7.9 Hz,
3
1
3
1
H), 8.07 (q, J = 8.6 Hz, 4H), 7.83 (td, J = 7.8, 1.7 Hz, 1H), 7.32 – 7.26 (m, 1H). C NMR
(
126 MHz, CDCl ) δ 190.77, 149.75, 149.62, 141.06, 137.25, 136.21, 131.57, 123.55,
3
1
20.72, 120.54, 119.89.
4
-(4-(9,9-Dimethylfluoren-2-yl)-1H-1,2,3-triazol-1-yl)benzaldehyde (2A4) (128 mg, 65%)
1
as solid H NMR (400 MHz, CDCl ) δ 10.10 (s, 1H), 8.32 (s, 1H), 8.10 (d, J = 7.7 Hz, 2H),
3
8
.05 (d, J = 7.0 Hz, 3H), 7.86 (d, J = 7.0 Hz, 1H), 7.81 (d, J = 7.8 Hz, 1H), 7.76 (d, J = 5.7
1
3
Hz, 1H), 7.47 (d, J = 6.1 Hz, 1H), 7.36 (d, J = 2.9 Hz, 2H), 1.57 (s, 6H). C NMR (101
MHz, CDCl ) δ 190.55, 154.76, 154.19, 149.65, 141.29, 140.17, 138.79, 136.30, 131.48,
3
1
28.86, 127.82, 127.27, 125.16, 122.83, 120.61, 120.49, 120.34, 117.21, 47.23, 27.31.

4
-(4-(9-Octyl-9H-carbazol-3-yl)-1H-1,2,3-triazol-1-yl)benzaldehyde (2A5) (170 mg, 70%)
1
as solid H NMR (400 MHz, CDCl ) δ 10.08 (s, 1H), 8.66 (d, J = 1.4 Hz, 1H), 8.32 (s, 1H),
3
8
.16 (d, J = 7.7 Hz, 1H), 8.10 – 8.02 (m, 4H), 8.00 (dd, J = 8.5, 1.6 Hz, 1H), 7.53 – 7.46 (m,
H), 7.43 (d, J = 8.1 Hz, 1H), 7.28 (d, J = 7.2 Hz, 1H), 4.32 (t, J = 7.2 Hz, 2H), 1.97 – 1.82
2
1
3
(
m, 2H), 1.44 – 1.31 (m, 4H), 1.31 – 1.19 (m, 6H), 0.87 (t, J = 6.8 Hz, 3H). C NMR (101
MHz, CDCl ) δ 190.79, 150.18, 141.26, 141.04, 140.79, 135.93, 131.46, 126.23, 123.91,
3
1
3
23.42, 122.92, 120.71, 120.65, 120.36, 119.36, 118.17, 116.36, 109.26, 109.10, 43.38,
1.92, 29.50, 29.31, 29.13, 27.45, 22.73, 14.19.
4
-(4-Dibenzo[b,d]thiophen-2-yl-1H-1,2,3-triazol-1-yl)benzaldehyde (2A6) (146 mg, 76%)
1
as solid H NMR (400 MHz, CDCl ) δ 10.09 (s, 1H), 8.77 (s, 1H), 8.39 (s, 1H), 8.30 – 8.23
3
(m, 1H), 8.12 – 8.02 (m, 4H), 7.95 (s, 2H), 7.91 – 7.83 (m, 1H), 7.55 – 7.44 (m, 2H).
1
3
C NMR (126 MHz, CDCl ) δ 190.79, 149.15, 141.11, 140.02, 139.99, 136.37, 136.16,
3
1
1
35.43, 131.57, 127.31, 126.33, 124.81, 124.60, 123.49, 123.08, 122.02, 120.55, 119.07,
17.33.
4
-(4-(2,2'-Bithiophenyl-5-yl)-1H-1,2,3-triazol-1-yl)benzaldehyde (2A7) (109 mg, 60%) as
1
solid H NMR (400 MHz, CDCl ) δ 10.09 (s, 1H), 8.19 (s, 1H), 8.09 (d, J = 8.5 Hz, 2H), 8.01
3
(d, J = 8.6 Hz, 2H), 7.41 (d, J = 3.7 Hz, 1H), 7.24 (d, J = 3.6 Hz, 2H), 7.19 (d, J = 3.7 Hz,
1
H), 7.05 (dd, J = 5.0, 3.7 Hz, 1H).
General Procedure for the synthesis of 3A1-3A7: In 25 mL Schlenk flask, 2A1-2A7
0.2 mmol) and aluminium oxide (0.050 g) were placed, and the flask was three times
(
evacuated and refilled with argon. During this time in the vial, dichloromethane (5 mL) was
saturated with argon for 15 minutes, and then malononitrile (0.052 g, 0.8 mmol) was
dissolved. The obtained mixture was added to the Schlenk flask by using a syringe and stirred
for 24 h at room temperature. After that time, the crude product was purified by using the
column chromatography (SiO /DCM:EtOAc:Et O).
2
2
2
-[4-(4-Phenyl-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile (3A1) (50 mg, 81%) as
1
solid H NMR (400 MHz, CDCl ) δ 8.29 (s, 1H), 8.13 (d, J = 8.8 Hz, 2H), 8.04 (d, J = 8.8
3
Hz, 2H), 7.93 (d, J = 7.2 Hz, 2H), 7.82 (s, 1H), 7.49 (t, J = 7.5 Hz, 2H), 7.41 (t, J = 7.3 Hz,
1
H).

2
-[4-(4-(4-Pentyloxyphenyl)-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile
(3A2)
1
(
65 mg, 85 %) as solid H NMR (400 MHz, CDCl ) δ 8.19 (s, 1H), 8.11 (d, J = 8.7 Hz, 2H),
3
8
.03 (d, J = 8.7 Hz, 2H), 7.83 (d, J = 10.2 Hz, 3H), 7.00 (d, J = 8.7 Hz, 2H), 4.02 (t, J = 6.6
Hz, 2H), 1.87 – 1.77 (m, 2H), 1.49 – 1.35 (m, 4H), 0.95 (t, J = 7.1 Hz, 3H).
2
-[4-(4-Pyrid-2-yl-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile (3A3) (47 mg, 79 %)
1
as solid H NMR (400 MHz, CDCl ) δ 8.72 (s, 1H), 8.64 (d, J = 4.1 Hz, 1H), 8.27 (d, J = 7.9
3
Hz, 1H), 8.13 (d, J = 8.8 Hz, 2H), 8.06 (d, J = 8.8 Hz, 2H), 7.88 – 7.80 (m, 2H), 7.34 – 7.29
(m, 1H).
2
-[4-(4-(9,9-Dimethylfluoren-2-yl)-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile (3A4)
1
(
62 mg, 75 %) as solid H NMR (400 MHz, CDCl ) δ 8.34 (s, 1H), 8.14 (d, J = 8.7 Hz, 2H),
3
8
7
.07 (d, J = 9.0 Hz, 3H), 7.84 (q, J = 8.2 Hz, 3H), 7.79 – 7.74 (m, 1H), 7.49 – 7.45 (m, 1H),
.40 – 7.32 (m, 2H), 1.26 (s, 6H).
2
-[4-(4-(9-Octyl-9H-carbazol-3-yl)-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile
1
(
3A5) (78 mg, 78 %) as solid H NMR (400 MHz, CDCl ) δ 8.63 (d, J = 1.3 Hz, 1H), 8.29 (s,
3
1
1
2
H), 8.15 (d, J = 7.7 Hz, 1H), 8.04 (q, J = 8.9 Hz, 4H), 7.98 (dd, J = 8.5, 1.6 Hz, 1H), 7.73 (s,
H), 7.54 – 7.41 (m, 3H), 7.29 (d, J = 7.1 Hz, 1H), 4.33 (t, J = 7.2 Hz, 2H), 1.94 – 1.83 (m,
13
H), 1.45 – 1.31 (m, 4H), 1.31 – 1.18 (m, 6H), 0.86 (t, J = 6.8 Hz, 3H). C NMR (126 MHz,
CDCl ) δ 157.94, 150.38, 141.04, 140.88, 132.57, 130.53, 126.34, 123.91, 123.43, 122.88,
3
1
4
20.73, 120.50, 120.37, 119.44, 118.22, 115.96, 113.56, 112.54, 109.32, 109.16, 83.72,
3.42, 31.92, 29.51, 29.32, 29.15, 27.46, 22.74, 14.21.
2
-[4-(4-Dibenzo[b,d]thiophen-2-yl-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile (3A6)
1
(
66 mg, 82 %) as solid H NMR (400 MHz, CDCl ) δ 8.78 (s, 1H), 8.40 (s, 1H), 8.28 (dd,
3
J = 6.2, 3.0 Hz, 1H), 8.11 (dd, J = 24.5, 8.8 Hz, 4H), 7.96 (d, J = 1.0 Hz, 2H), 7.89 (dd, J =
6
.3, 2.8 Hz, 1H), 7.83 (s, 1H), 7.53 – 7.50 (m, 2H).
2
-[4-(4-(2,2'-Bithiophenyl-5-yl)-1H-1,2,3-triazol-1-yl)benzylidene]malononitrile
(3A7)
1
(
50 mg, 65 %) as solid H NMR (400 MHz, CDCl ) δ 8.19 (s, 1H), 8.12 (d, J = 8.8 Hz, 2H),
3
8
.02 (d, J = 8.7 Hz, 2H), 7.82 (s, 1H), 7.43 (d, J = 3.6 Hz, 1H), 7.25 – 7.23 (m, 2H), 7.19 (d,
J = 3.8 Hz, 1H), 7.08 – 7.03 (m, 1H).

References
[
[
[
[
1] P. Wen, Z. Gao, R. Zhang, A. Li, F. Zhang, J. Li, J. Xie, Y. Wu, M. Wu, K. Guo, A–
π–D–π–A carbazole derivatives with remarkable solvatochromism and
mechanoresponsive luminescence turn-on, J. Mater. Chem. C. 5 (2017) 6136–6143.
doi:10.1039/C7TC00559H.
2] S. Kotowicz, M. Siwy, M. Filapek, J.G. Malecki, K. Smolarek, J. Grzelak, S.
Mackowski, A. Slodek, E. Schab-Balcerzak, New donor-acceptor-donor molecules
based on quinoline acceptor unit with Schiff base bridge: synthesis and
characterization, J. Lumin. 183 (2017) 458–469. doi:10.1016/J.JLUMIN.2016.11.058.
3] S. Sambathkumar, S. Priyadharshini, M. Fleisch, D.W. Bahnemann, G. Gnana Kumar,
S. Senthilarasu, R. Renganathan, Design and synthesis of imidazole-triphenylamine
based organic materials for dye sensitized solar cells, Mater. Lett. 242 (2019) 28–31.
doi:10.1016/j.matlet.2019.01.091.
4] A. Slodek, D. Zych, S. Golba, S. Zimosz, P. Gnida, E. Schab-Balcerzak, Dyes based
on the D/A-acetylene linker-phenothiazine system for developing efficient dye-
sensitized solar cells, J. Mater. Chem. C.
doi:10.1039/C9TC01727E.
7
(2019) 5830–5840.
[
[
5] M.J. Jurı´cěk, P.H.J. Kouwer, A.E. Rowan, Triazole: a unique building block for the
construction of functional materials, This J. Is Cite This Chem. Commun. 47 (2011)
8
740–8749. doi:10.1039/c1cc10685f.
6] G. de Miguel, M. Wielopolski, D.I. Schuster, M.A. Fazio, O.P. Lee, C.K. Haley, A.L.
Ortiz, L. Echegoyen, T. Clark, D.M. Guldi, Triazole Bridges as Versatile Linkers in
Electron Donor–Acceptor Conjugates, J. Am. Chem. Soc. 133 (2011) 13036–13054.
doi:10.1021/ja202485s.
[
[
[
7] M.A. Fazio, O.P. Lee, D.I. Schuster, First Triazole-Linked Porphyrin−Fullerene
Dyads, Org. Lett. 10 (2008) 4979–4982. doi:10.1021/ol802053k.
8] L. Yet, Five-Membered Ring Systems: With More than One N Atom, Prog.
Heterocycl. Chem. 23 (2011) 231–266. doi:10.1016/B978-0-08-096805-6.00008-5.
9] D. Zych, A. Slodek, Pyrene derivatives with two types of substituents at positions 1, 3,
6
,
and
8
–
fad or necessity?, RSC Adv.
9
(2019) 24015–24024.
doi:10.1039/C9RA04503A.
[
10] D. Zych, A. Slodek, D. Matuszczyk, S. Golba, Comprehensive Study of Mononuclear
Osmium Complexes with Various Pyrene Ligands, Eur. J. Inorg. Chem. 2018 (2018)

5
117–5128. doi:10.1002/ejic.201801199.
[
11] L.L. Zanin, D.E.Q. Jimenez, L.P. Fonseca, A.L. Meleiro Porto, Knoevenagel
Condensation Reactions of Cyano Malononitrile-Derivatives Under Microwave
Radiation,
Curr.
Org.
Chem.
22
(2018)
519–532.
doi:10.2174/1385272822666180123145819.
[
[
[
12] Y. Chen, W. Shi, Y. Hui, X. Sun, L. Xu, L. Feng, Z. Xie, A new highly selective
fluorescent turn-on chemosensor for cyanide anion, Talanta. 137 (2015) 38–42.
doi:10.1016/J.TALANTA.2015.01.018.
13] Y. Li, J. Chen, T.-S. Chu, Sensing mechanism for a fluorescent off–on chemosensor
for
cyanide
anion,
J.
Lumin.
179
(2016)
203–210.
doi:10.1016/J.JLUMIN.2016.07.024.
14] Z. Xie, X. Kong, L. Feng, J. Ma, Y. Li, X. Wang, W. Bao, W. Shi, Y. Hui, A novel
highly selective probe with both aggregation-induced emission enhancement and
intramolecular charge transfer characteristics for CN− detection, Sensors Actuators B
Chem. 257 (2018) 154–165. doi:10.1016/J.SNB.2017.10.167.
[
[
15] P.D. Jarowski, Y.-L. Wu, W.B. Schweizer, F. Diederich, 1,2,3-Triazoles as
Conjugative π-Linkers in Push−Pull Chromophores: Importance of Substituent
Positioning on Intramolecular Charge-Transfer, Org. Lett. 10 (2008) 3347–3350.
doi:10.1021/ol801253z.
16] P. Luo, Y. Yu, D. Wu, X. Li, C. Dai, X. Chen, G. Li, Y. Wu, Simultaneous
determination of cyanide and thiocyanate in swine plasma by high-performance liquid
chromatography with fluorescence detection based on a novel D–π–A carbazole-based
turn-on fluorescence labeling reagent, Anal. Methods. 11 (2019) 2983–2990.
doi:10.1039/C9AY00784A.
[
17] T. Gao, X. Cao, P. Ge, J. Dong, S. Yang, H. Xu, Y. Wu, F. Gao, W. Zeng, A self-
assembled fluorescent organic nanoprobe and its application for sulfite detection in
food samples and living systems, Org. Biomol. Chem. 15 (2017) 4375–4382.
doi:10.1039/C7OB00580F.
[
[
18] G. Marianetti, M. Lessi, V. Barone, F. Bellina, A. Pucci, P. Minei, Solar collectors
based on luminescent 2,5-diarylimidazoles, Dye. Pigment. 157 (2018) 334–341.
doi:10.1016/J.DYEPIG.2018.04.062.
19] R. Domínguez, N.F. Montcada, P. de la Cruz, E. Palomares, F. Langa, Pyrrolo[3,2- b
]
pyrrole as the Central Core of the Electron Donor for Solution-Processed Organic
Solar Cells, Chempluschem. 82 (2017) 1096–1104. doi:10.1002/cplu.201700158.

[
[
20] Z. Li, X. Li, H. Chen, C. He, L. Wang, Y. Yang, S. Wang, H. Guo, S.H. Liu, Multi-
modulated photochromic behavior of a D-A type dithienylethene, Dye. Pigment. 162
(2019) 712–720. doi:10.1016/J.DYEPIG.2018.11.003.
21] Y.J. Chang, J.-L. Hsu, Y.-H. Li, S. Biring, T.-H. Yeh, J.-Y. Guo, S.-W. Liu,
Carbazole-based small molecules for vacuum-deposited organic photovoltaic devices
with open-circuit voltage exceeding 1 V, Org. Electron. 47 (2017) 162–173.
doi:10.1016/J.ORGEL.2017.05.007.
[
22] D. Zych, A. Slodek, D. Zimny, S. Golba, K. Malarz, A. Mrozek-Wilczkiewicz,
Influence of the substituent D/A at the 1,2,3-triazole ring on novel terpyridine
derivatives: synthesis and properties, RSC Adv. 9 (2019) 16554–16564.
doi:10.1039/C9RA02655J.
[
[
[
23] F. Texier-Boullet, A. Foucaud, Knoevenagel condensation catalysed by aluminium
oxide., Tetrahedron Lett. 23 (1982) 4927–4928. doi:10.1016/S0040-4039(00)85749-4.
24] A.D. Becke, Density� functional thermochemistry. III. The role of exact exchange, J.
Chem. Phys. 98 (1993) 5648–5652. doi:10.1063/1.464913.
25] T. Yanai, D.P. Tew, N.C. Handy, A new hybrid exchange–correlation functional using
the Coulomb-attenuating method (CAM-B3LYP), Chem. Phys. Lett. 393 (2004) 51–
5
7. doi:10.1016/J.CPLETT.2004.06.011.
[
[
26] J.-D. Chai, M. Head-Gordon, Long-range corrected hybrid density functionals with
damped atom–atom dispersion corrections, Phys. Chem. Chem. Phys. 10 (2008) 6615.
doi:10.1039/b810189b.
27] Y. Zhao, D.G. Truhlar, The M06 suite of density functionals for main group
thermochemistry, thermochemical kinetics, noncovalent interactions, excited states,
and transition elements: two new functionals and systematic testing of four M06-class
functionals and 12 other functionals, Theor. Chem. Acc. 120 (2008) 215–241.
doi:10.1007/s00214-007-0310-x.
[
28] Frisch, G. Trucks, H. Schlegel, G. Scuseria, M. Robb, J. Cheeseman, G. Scalmani, V.
Barone, B. Mennucci, G. Petersson, H. Nakatsuji, M. Caricato, X. Li, H. Hratchian, A.
Izmaylov, J. Bloino, G. Zheng, J. Sonnenberg, M. Hada, M. Ehara, K. Toyota, R.
Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T.
Vreven, J. Montgomery, J. Peralta, F. Ogliaro, M. Bearpark, J. Heyd, E. Brothers, K.
Kudin, V. Staroverov, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J.
Burant, S. Iyengar, J. Tomasi, M. Cossi, N. Rega, J. Millam, M. Klene, J. Knox, J.
Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. Stratmann, O. Yazyev, A.

Austin, R. Cammi, C. Pomelli, J. Ochterski, R. Martin, K. Morokuma, V. Zakrzewski,
G. Voth, P. Salvador, J. Dannenberg, S. Dapprich, A. Daniels, Farkas, J. Foresman, J.
Ortiz, J. Cioslowski, D. Fox, Gaussian 09, Revision B.01, Gaussian 09, Revis. B.01,
Gaussian, Inc., Wallingford CT. (2009).
[
[
29] G. Scalmani, M.J. Frisch, Continuous surface charge polarizable continuum models of
solvation. I. General formalism, J. Chem. Phys. 132 (2010) 114110.
doi:10.1063/1.3359469.
30] D. Zych, A. Slodek, S. Krompiec, K. Malarz, A. Mrozek-Wilczkiewicz, R. Musiol, 4′-
Phenyl-2,2′:6′,2′′-terpyridine Derivatives Containing 1-Substituted-2,3-Triazole Ring:
Synthesis, Characterization and Anticancer Activity, ChemistrySelect. 3 (2018) 7009–
7
017. doi:10.1002/slct.201801204.
[
[
31] A. Daina, O. Michielin, V. Zoete, SwissADME: a free web tool to evaluate
pharmacokinetics, drug-likeness and medicinal chemistry friendliness of small
molecules, Sci. Rep. 7 (2017) 42717. doi:10.1038/srep42717.
32] C.A. Lipinski, F. Lombardo, B.W. Dominy, P.J. Feeney, Experimental and
computational approaches to estimate solubility and permeability in drug discovery
and development settings., Adv. Drug Deliv. Rev. 46 (2001) 3–26.
http://www.ncbi.nlm.nih.gov/pubmed/11259830 (accessed October 9, 2019).
33] A.K. Ghose, V.N. Viswanadhan, J.J. Wendoloski, A knowledge-based approach in
designing combinatorial or medicinal chemistry libraries for drug discovery. 1. A
qualitative and quantitative characterization of known drug databases., J. Comb.
Chem. 1 (1999) 55–68. http://www.ncbi.nlm.nih.gov/pubmed/10746014 (accessed
October 9, 2019).
[
[
34] D.F. Veber, S.R. Johnson, H.-Y. Cheng, B.R. Smith, K.W. Ward, K.D. Kopple,
Molecular Properties That Influence the Oral Bioavailability of Drug Candidates, J.
Med. Chem. 45 (2002) 2615–2623. doi:10.1021/jm020017n.
[
[
35] W.J. Egan, K.M. Merz,, J.J. Baldwin, Prediction of Drug Absorption Using
Multivariate Statistics, J. Med. Chem. 43 (2000) 3867–3877. doi:10.1021/jm000292e.
36] I. Muegge, S.L. Heald, D. Brittelli, Simple Selection Criteria for Drug-like Chemical
Matter, J. Med. Chem. 44 (2001) 1841–1846. doi:10.1021/jm015507e.

Author Contribution Statement
Dawid Zych: Conceptualization; Data collection; Funding acquisition; Investigation;
Methodology; Writing - original draft, review & editing.
Aneta Slodek: Data collection; Investigation; Methodology; Writing - original draft, review
&
editing.

Declaration of interests
☒
The authors declare that they have no known competing financial interests or personal relationships
that could have appeared to influence the work reported in this paper.
☐
The authors declare the following financial interests/personal relationships which may be considered
as potential competing interests: