2
SAYIN
(
Ant-AzClx) as highly sensitive and selective along with marked
carboxaldehyde (0.206 g, 1.0 mmol) in 10 ml tetrahydrofuran (THF),
and the reaction mixture was stirred under reflux. The reaction was
monitored using thin layer chromatography (TLC). After 57 h, the pre-
cipitate formed during the reaction process was filtered, and washed
1
13
extraction affinity towards dichromate anions. H-NMR, C-NMR,
ESI-MS, and elemental analysis techniques were performed to deter-
mine its structure. Its anion binding behaviours were evaluated
ꢀ
3ꢀ
4ꢀ
3ꢀ
72ꢀ
42ꢀ
against F , HCO , H
2
PO , NO , Cr
2
O
and SO ions. In
with EtOH. The crude product was recrystallized from EtOH. Ant-
1
addition, the extraction capabilities of Ant-AzClx towards
Cr(VI) anions at different pH were investigated using a liquid–liquid
extraction method.
AzClx was obtained in 67% yield. H NMR (400 MHz, DMSO-d
6
): δ
), 3.47
), 4.07 (t, 2H,
-Ar), 4.53 (s, 4H,
), 6.61 (t, 2H, J = 7.2 Hz, ArH [Calix]), 6.81 (t, 2H, J = 7.6 Hz,
2.94 (t, 4H, J = 4.0 Hz, N-CH
(d, 4H, J = 12.8 Hz, Ar-CH -Ar), 3.53 (brs, 4H, N-CH
J = 6.4 Hz, N-CH ), 4.29 (d, 4H, J = 12.8 Hz, Ar-CH
O-CH
2 2
), 3.02 (t, 2H, J = 7.2 Hz, N-CH
2
2
2
2
2
2
2
|
EXPERIMENTAL
| General
ArH [Calix]), 7.04 (d, 4H, J = 7.6 Hz, ArH [Calix]), 7.17 (d, 4H,
J = 7.6 Hz, ArH [Calix]), 7.54 (p, 4H, J = 8.0 Hz, ArH), 8.09 (s, 2H,
OH), 8.12 (d, 2H, J = 7.2 Hz, ArH), 8.39 (t, 2H, J = 5.6 Hz, NH), 8.49
.1
13
(
d, 2H, J = 8.0 Hz, ArH), 8.68 (s, 1H, ArH), 9.39 (s, 1H, N=CH). C-
A Bruker Avance III 400 MHz spectrometer was used to record the
NMR (100 MHz, CDCl ): δ 31.12, 38.87, 55.55, 56.16, 61.58, 74.86,
3
1
13
nuclear magnetic resonance ( H and C NMR) spectra of calixarenes.
A Costech ECS 4010 analyzer was used to obtain elemental analyses.
An Agilent 6230 apparatus was performed to record electrospray ioni-
zation (ESI) mass spectra. Absorbance measurements for the
calixarene derivative and its complexes with metal ions used were
measured on a Mapada UV-6100 PCS Double Beam UV–visible spec-
trophotometer. The fluorescence spectra was recorded on a Varian
Carry Eclipse spectrophotometer. Starting materials and reagents
were obtained from Merck and Alfa Aesar commercial sources, and
used without further purification.
120.32, 124.76, 125.22, 126.18, 126.72, 127.84, 127.87, 128.88,
128.97, 129.48, 129.95, 131.24, 132.17, 151.06, 152.34, 161.22,
168.19. ESI-MS: m/e = 839.37 [M + 1]. Anal. Calcd. For
C H
53 50
N O
4 6
: C, 75.87; H, 6.01; N, 6.68. Found (%); C, 75.79; H,
6.11; N, 6.61.
2.3
|
Spectrophotometry and spectrofluorometry
studies
ꢀ
5
Stock solutions of Ant-AzClx (2 ꢁ 10 M) were prepared in DMSO.
ꢀ
3
3ꢀ
Stock solutions (2 ꢁ 10 M) of sodium salts of anions (NO and
2ꢀ
2
.2
|
The synthesis of organic compounds
Cr
2
O
7
) were prepared in DMSO, and the stock solutions of anions
were diluted with DMSO to receive the concentrations needed in the
ꢀ
3
The compounds p-tert-butylcalix[4]arene (1), calix[4]arene (2), 1,3-O-
dimethyl ester calix[4]arene derivative (3) and calix[4]triazacrown-5
sensing studies. Furthermore, stock solutions (2 ꢁ 10 M) of sodium
ꢀ
ꢀ
ꢀ
ꢀ
2ꢀ
42ꢀ
and SO ) were
salts of anions (F , HCO
3
, H
2
PO
4
, NO
3
, Cr
2
O
7
[
26–30]
(
4) were synthesized according to literature procedures.
The
prepared in 20% buffer–DMSO (acetate buffer, pH 5.0), and the stock
solutions of anions were diluted with 20% buffer–DMSO (acetate
buffer, pH 5.0) to receive the concentrations needed in the sensing
studies. To adjust the effective concentrations of the probe Ant-
AzClx and anions to half of that used in the absorbance and fluores-
cence experiments, an equal amount of stock solution of Ant-AzClx
and the solution of each anion were mixed. For all fluorescent mea-
surements, excitation was at 370 nm with the excitation and emission
slit widths at 5 and 10 nm, respectively. For fluorescence titration
experiments, A 10 μM solution of Ant-AzClx in DMSO was used
against various concentration of the anions in DMSO. The binding
constant of the complex formed between Ant-AzClx and dichromate
anthracene functionalized calix[4]triazacrown-5 (Ant-AzClx) is synthe-
sized here for the first time.
2
.2.1
|
Synthesis of calix[4]triazacrown-5 (4)
1
Yield; 70.5%. H-NMR (400 MHz, CDCl
3
): δ 2.13–2.33 (m, 2H, NH
-N), 2.74–2.81 (m, 6H, CH ), 3.46 (d, 4H,
), 4.21 (d, 4H,
2
),
2
.53 (t, 2H, J = 5.6 Hz, CH
2
2
J = 13.6 Hz, Ar-CH
-Ar), 3.53–3.56 (m, 4H, CH
2 2
J = 13.6 Hz, Ar-CH
2
2
-Ar), 4.55 (s, 4H, O-CH ), 6.73–6.79 (m, 4H, ArH),
6
2
.85 (d, 4H, J = 7.6 Hz, ArH), 7.12 (d, 4H, J = 7.6 Hz, ArH), 7.19 (s,
H, OH), 8.32 (t, 2H, J = 5.6 Hz, NH). Anal. Calcd. For
[
31]
anion was determined according to the literature procedure.
limit of detection (LOD) for the complex (Ant-Calix@Cr
The
2
7
ꢀ
C
H N
38 42 4
O
6
: C, 70.13; H, 6.51; N, 8.61. Found (%); C, 70.05; H,
2
O
)
6
.63; N, 8.55.
regarding fluorescence titration data was calculated according to
Equation 1:
3
S
2
.2.2
|
Synthesis of anthracene functionalized calix
LOD ¼ K
ð1Þ
[
4]triazacrown-5 (Ant-AzClx)
To a mixture of calix[4]triazacrown-5 (4) (542.7 mg, 0.834 mmol)
in CH OH (10 ml) were added solution of 9-anthracene
where K and S are the slope of the straight-fit line, and the standard
3
a
deviation of the blank solution, respectively.