B. Seyednoruziyan, M.R. Zamanloo, M.D. Esrafili et al.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 261 (2021) 120062
2
. Experimental
the mixture at 40 °C overnight, it was cooled down to room tem-
perature to form a purple precipitate. The precipitate was filtered
and purified by silica-gel (mesh = 80) column chromatography
using n-hexane/ethylacetate (1:7) as the eluent to afford the com-
pound 1a.p.
2.1. Materials
All chemical compounds (N,N-dimethyl aniline, 5-Amino isoph-
thalic acid and N-phenyl-N,N-iminodiethanol) were purchased
from Aldrich chemical company and were recrystallized from etha-
nol/distilled water mixture. Sodium nitrite (Panreac) was dried at
(179 mg, 85.0% Yield), m.p. 268–272 °C.
FTIR (KBr) cm : 3414 (OH stretching); 1698 (C = O); 1597
(N = N).
ꢂ1
1H NMR (400 MHz, DMSO d
): d (400 MHz, DMSO d
(br, s, 1H Carboxyl), 8.53 (s, 2H, Ar), 8.48 (s, 1H, Ar), 7.88 (d,
J = 8.8 Hz, 4H, Ar), 6.86 (d, J = 8.8 Hz, 4H, Ar), 3.08 (s, 12H, –CH ).
): d 162.87, 149.63, 149.00, 145.41,
1
05 °C and stored in a desiccator until use. All other chemicals
6
6
): d 11.37
and solvents were purchased from commercial sources and used
without further purification.
3
1
3
C NMR (100 MHz, DMSO d
35.41, 126.75, 124.28, 121.23, 121.14, 41.17. Mass (M ): calcu-
lated 416.47 for C23 , found 415.4.
6
+
1
2.2. Equipment
24 6 2
H N O
The above procedure was applied for the synthesis of 1b.p with
the coupling of 1-diethanolamine-4-nitrosobenzene with 3,5-
diamino benzoic acid. The purple precipitate was filtered and puri-
fied by silica-gel (mesh = 80) column chromatography using n-
hexane/ethylacetate (1:8) as the eluent to afford the compound
Melting point of the compounds were measured with a Stuart
SMP-3 melting point apparatus with a heating rate of 2 °C/min
and not corrected. FTIR spectra were recorded on a Shimadzu
800 s Fourier transform infrared spectrophotometer with KBr pel-
4
lets. Raman spectra were obtained using a Jobin–Yvon Horiba
LABRAM-HR visible spectrometer with an argon-ion continuous-
wave laser (488 nm) as the excitation source. 1H and C NMR
spectra were recorded using a Bruker 400 MHz and 100 MHz spec-
1
b.p.
(214 mg, 80.0% Yield), m.p. 278–283 °C.
13
ꢂ1
FTIR (KBr) cm : 3414 (OH stretching); 1685 (C = O); 1596
N = N).
1H NMR (400 MHz, DMSO d
s, 1H, Ar), 8.39 (s, 2H, Ar), 7.79 (d, J = 12.0 Hz, 4H, Ar), 6.92 (d,
(
6 3
trometer, respectively in DMSO d and CDCl using TMS as an
internal reference. The absorption spectra of the dyes were
inscribed on a Shimadzu UV-1601 PC spectrophotometer with a
0 mm quarts cell. Mass spectra were operated with an Agilent
GC-Mass 5977A. Fluorescence spectra of dye solution were mea-
6
): d 11.40 (br, s, 1H Carboxyl), 8.40
(
J = 12.0 Hz, 4H, Ar), 4.95 (br, s, 4OH), 4.20 (t, J = 8.0 Hz, 8H, –CH
OH), 3.80 (t, J = 8.0 Hz, 8H, –NCH -).
): d 166.95, 154.19, 153.15, 152.61,
43.12, 142.84, 133.33, 130.40, 126.34, 126.24, 113.91, 112.06,
2
-
1
2
1
3
2
C NMR (100 MHz, DMSO d
6
sured with a Hitachi F-4500 spectrophotometer, in a 1 ꢁ 1 cm
1
5
5
quartz glass cuvette with 90° incident excitation using a PTI UV–
Vis fluorometer (Photon Technology International, Inc.) with slit
widths of 0.25 mm (1 nm resolution) at room temperature.
Cyclic voltammetry (CV) measurements were conducted on a
BHP2064 + electrochemical analysis system in acetonitrile solution
+
8.61, 53.82. Mass (M ): calculated 536.58 for C27
36.30.
32 6 6
H N O , found
2.4. Preparation of DSSCs
(
0.05 M) using a three electrode set with Pt wire as working and
Doctor blade method was employed to fabricate the required
photoanode for DSSCs based on 2a.s and 2b.s dyes pursuant to
[13].
counter electrodes, and standard calomel electrode (SCE) as refer-
ence electrode. All electrode potentials were calibrated towards
ferrocene/ferrocenium (Fe/Fe ) redox couple and as the supporting
electrolyte tetrabutylammonium bromide (TBAB, 0.1 M) was
added to the solution. The overall internal resistance of DSSC was
evaluated by electrochemical impedance spectroscopy (EIS) mea-
surements with an EIS workstation (model zive sp 5 won A Tech-
Korea).
+
The required photoanodes of 1a.p and 1b.p was also fabricated
by Doctor blade method using a paste of anatase-TiO
cles (ca. 20 nm diameter and 7 mm thickness) which coated on
the precleaned fluorine doped SnO (FTO, sheet resistance 10–
sq and transmission ˃ 90% in visible light) to form a trans-
2
nanoparti-
2
-1
15 X
2
parent layer with an active area of 0.25 cm . A second layer of TiO
(ca. 400 nm and 5 mm thickness) was coated on the absorbing layer
as light scattering layer. The double-layer TiO -coated FTO glass
was dried and sintered at 500 °C for 30 min in air atmosphere to
avoid the absorption of water on TiO surface. Further treatment
of the double-layer TiO annealed films was accomplished with a
.04 M aqueous solution of TiCl at 70 °C for 60 min. The films were
then washed with deionized water and again sintered at 500 °C for
0 min.
The annealed TiO
2
Photo current–voltage (J-V) characteristics were recorded under
2
illumination with 1.5 AM solar simulator (100 mW/cm ) using a
Bunko- Keiki CEP-2000 system.
2
2
2
.3. Synthesis of the sensitizers (azo dyes)
2
0
4
The series dyes, 2a.s & 2b.s were synthesized according to our
previous paper [13].
6
2
thin film was cooled down to 80 °C and
-
5
2
.3.1. Synthesis of parallel-azo dyes (1a.p & 1b.p)
N,N-dimethyl aniline (0.5 mmol, 60.58 mg) was dissolved in
immersed in 4 ꢁ 10 M azo dye solution in ethanol and main-
tained overnight at room temperature. After sensitization, the pho-
toanode was rinsed with water/ethanol (1:1) mixture to remove
excess dye.
cold hydrochloric acid (0.4 mL conc. HCI in 20.0 mL distilled water)
in an ice bath (0–5 °C). After dissolving amine, 2.0 mL of ice-cold
aqueous solution of sodium nitrite (0.53 mmol, 37.00 mg) was
added dropwise to the solution over 5 min period under vigorous
stirring at 0–5 °C. The reaction mixture was stirred for 4 h while
the temperature was maintained below 5 °C. Finally, the dark yel-
low precipitate was filtered, washed with cold water and acetone
and dried in a vacuum oven at 45 °C.
2
The dye-adsorbed TiO electrode as the photoanode and Pt-
coated FTO as the counter electrode was assembled together into
a sandwich-type cell and the cell interior was separated and sealed
by Surlyn hot-melt polymer. The electrolyte solution containing LiI
2
0.1 M and I 0.05 M in acetonitrile/valeronitrile (1:1) solution was
then injected through a hole in the back of counter electrode.
Thereafter, the hole was sealed using Surlyn polymer to prevent
leakage of the electrolyte. The photovoltaic performance of DSSCs
The obtained 1-dimethylamino-4-nitrosobenzene (1.0 mmol,
1
50.15 mg) was dissolved in 20 mL of a mixture of acetic acid/ethy-
lacetate (1/1) and then 3,5-diamino benzoic acid (0.5 mmol,
6.05 mg) was directly added to the reaction solution. After stirring
2
was measured in active area of 0.25 cm under AM 1.5 irradiation
2
7
simulated sun light (100 mW/cm ).
3