An efficient novel receptor for sensing acetate

Article abstract of DOI:10.1007/s10847-010-9871-8

A novel highly sensitive colorimetric receptor 1 for acetate based on N-(4-oxa-3-one-phenanthrene-2-carbonyl)-p-nitrophenylhydrazine was designed, synthesized and characterized. Experiments showed that the receptor 1 can selectively recognize acetate in D

Full text of DOI:10.1007/s10847-010-9871-8

J Incl Phenom Macrocycl Chem (2011) 70:129–133
DOI 10.1007/s10847-010-9871-8
ORIGINAL ARTICLE
An efficient novel receptor for sensing acetate
•
•
•
Weiwei Huang Hongyan Su Hai Lin
Huakuan Lin
Received: 5 July 2010 / Accepted: 11 September 2010 / Published online: 28 October 2010
Ó Springer Science+Business Media B.V. 2010
Abstract A novel highly sensitive colorimetric receptor 1
for acetate based on N-(4-oxa-3-one-phenanthrene-2-car-
bonyl)-p-nitrophenylhydrazine was designed, synthesized
and characterized. Experiments showed that the receptor 1
can selectively recognize acetate in DMSO solution and
aqueous solution. The ability of recognition and the bond
between receptor 1 and anions were determined using
Introduction
Many efforts have been devoted to the development of
chemosensor for anions such as dihydrogenphosphate,
fluoride, acetate, iodide and so on due to their fundamental
role in a wide range of chemical and biological process [1–
4]. It is well known that carboxylate anions [5] exhibit
specific biochemical functions in the enzymes, antibodies
and critical components of numerous metabolic processes.
Acetate is one of the carboxylate anions with a unique
trigonal chemical structure, which can form the strongest
hydrogen-bond interaction with hydrogen-bond donors. A
lot of examples are available about the selective receptor
molecules for acetate anion in the literatures [6–8]. For -
instance, a set of receptors for acetate ion in dry DMSO
were reported by Han et al. [9]. Ito and coworker reported
that a novel Fipronil-based receptor could selectively rec-
ognize acetate among a group of anions in DMSO [10]. We
also found that the phenylhydrazone-based indole receptor
was an effective sensor for acetate ion in dry DMSO [11].
Despite these remarkable achievements, there are still
many disadvantages recognized in many examples of the
literatures. Generally speaking, the recognition studies
were performed in aprotic media (e.g. DMSO, acetonitrile,
CHCl3 etc.), to avoid the competition from the protic sol-
vent (e.g., water or alcohols) working as another hydrogen-
bonding donor [12]. Thus, it is urgent to develop sensors
that are able to bind anions within the competitive media,
and to be simultaneously accompanied with the ‘naked-
eyed’ detectable color changes.
1
visual inspection, UV–Vis analyses and H NMR experi-
ments. In particular, the UV–Vis analyses showed the
whole process included two stages: in the first step, the
hydrazine form of 1 interacted with acetate through
hydrogen bonding with an obvious color change from
yellow to purple upon addition of a small amount of AcO-.
In the second step, as increasing the addition of AcO-, the
color changed from purple to deep yellow, which displayed
the deprotonation of the receptor 1.
Keywords Acetate ꢀ Anion recognition ꢀ Selectivity ꢀ
Carbonyl hydrazine
W. Huang ꢀ H. Su ꢀ H. Lin (&)
Department of Chemistry, Nankai University,
Tianjin 300071, People’s Republic of China
e-mail: hklin@nankai.edu.cn
In this paper, our research group prepared a novel col-
orimetric anion receptor based on 4-oxa-3-one-phenan-
threne derivative. This receptor contains the hydrogen-
bond-donor group (phenyl hydrazine) and the colorimetric
group (nitrophenyl). The experimental results show that
H. Lin
Key Laboratory of Functional Polymer Materials of Ministry
of Education, Nankai University, Tianjin 300071,
People’s Republic of China
123

130
J Incl Phenom Macrocycl Chem (2011) 70:129–133
Synthesis of receptor 1
receptor 1 is highly selective and effective to recognize
acetate in dry DMSO and aqueous solution.
The receptor 1 was synthesized in four steps (see Scheme 1)
starting from compound 4-oxo-3-one-phenanthrene-2-car-
boxylic acid (3) that was prepared by the literature [13].
0.48 g (3) (2.0 mmol), 20 mL SOCl2 and 3 drops of DMF
were refluxed for 5 h, then evaporated the SOCl2, and dried
in vacuum, faint yellow solid 4-oxo-3-one-phenanthrene-2-
carbonyl chloride (2) was obtained. It can be used for fur-
ther reaction directly without purification. The solution of
0.306 g p-nitrophenylhydrazine (2.0 mmol) in dry CHCl3
was added dropwise to the mixture of compound (2)
(0.5 mmol), 1 mL triethylamine and 20 mL CHCl3 in
10 min. After continuous stirring for about 24 h, the mix-
ture was filtrated and the precipitate was recrystallized by
DMF, and the pure receptor 1 N-(4-oxa-3-one-phenan-
threne-2-carbonyl)-p-nitrophenylhydrazine was gained.
This procedure yields 0.555 g (76%). 1H NMR (400 MHz,
DMSO-d6) dH: 6.93 (dd, 2H, Ar–H), 7,67 (t, 2H, Aromatic-
H), 7.79 (t, 1H, Aromatic-H), 8.10 (t, 3H, Aromatic-H),
8.36 (t, 1H, Aromatic-H), 8.67 (t, 1H, Aromatic-H), 9.36 (s,
1H, N–H), 9.43 (s, 1H, Aromatic-H), 10.45 (s, 1H, N–H).
ESI-MS (m/z): calcd. for C20H13N3O5 [M]?: 375.33, found:
375.21. Elemental analysis calcd. for C20H13N3O5: C,
64.00; H, 3.49; N, 11.20. Found: C, 64.57; H, 4.01; N,
11.61.
Experimental
Materials
All reagents for synthesis obtained commercially were
used without further purification. In the titration
experiments, all the anions were added in the form of
tetrabutylammonium (TBA) salts, which were purchased
from Sigma–Aldrich Chemical, stored in a vacuum
desiccator containing self-indicating silica and dried
fully before using. DMSO was dried with CaH2 and
then distilled in reduced pressure. HEPES (4-(2-
hydroxyethyl) piperazine-1-ethanesulfonic acid) is used
as a buffer reagent.
General method
1H NMR spectra were recorded on a Varian UNITY
Plus-400 MHz Spectrometer at the Key Laboratory of
Functional Polymer Materials of Ministry of Education,
Nankai University, UV–Vis spectroscopy titrations were
performed on a Shimadzu UV2450 Spectrophotometer at
298 K. Elemental analysis for C, H, and N were carried
out on
a Perkin-Elmer 240C element analyzer at
Results and discussion
the Institute of Elemento-Organic Chemistry, Nankai
University.
UV–Vis anion titration studies
A series of DMSO solutions having same host concen-
tration and different anion concentrations were prepared
respectively. The affinity constants Ks were obtained by the
determination of absorption of the series of solutions and
analysis of obtained absorption values with non-linear least
square calculation method for data fitting.
The tetrabutylammonium salts of anions were used to
evaluate the anions binding properties of receptor 1 in
DMSO. As shown in Fig. 1, there was a distinct change in
UV–Vis spectra when 1.0 equiv. AcO- was added. The
Scheme 1 The synthesis of
receptor 1
C6H5NH2
SOCl2
HOOCCH2COOH
OH
NC6H5
OH
O
CHO
HC
O
COOH
3
NH2
HN
0OC, CH2Cl2, 12h
O
O
O
O
C
C
NO2
O
NH NH
NO2
Cl
O
2
1
123

J Incl Phenom Macrocycl Chem (2011) 70:129–133
131
Fig. 1 Left: Absorption spectra
of receptor 1 (2 9 10-5 M) on
the addition of 1.0 equiv. of
0.9
Cl-,Br-,I- and 1
0.8
various anions such as AcO-,
0.7
H2PO4-, F-, Cl-, Br-, and I-
in DMSO. Right: Color changes
of receptor 1 in DMSO.
0.6
A
B
C
D
E
F
G
AcO-
0.5
0.4
[1] = 2.0 9 10-5M,
[anion] = 1.0 equiv.: A = free
0.3
H2PO4-
receptor, B = AcO-, C = F-,
F-
0.2
D = H2PO4-, E = Cl-,
0.1
F = Br- and G = I-
0.0
300
400
500
600
700
800
Wavelength/nm
A
B
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.5
0.4
0.3
0.2
0.1
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
[host]/([host]+[AcO-])
[host]/([host]+[AcO-])
100 equiv
0 equiv
35 equiv
0 equiv
300
400
500
600
700
800
300
400
500
600
700
800
Wavelength/nm
Wavelength/nm
Fig. 2 UV absorption changes of 1 (2 9 10-5 M) with AcO- in a DMSO and b DMSO/H2O (90:10, v/v; HEPES 20 mM). Inset: Job’s plot for
complexation of 1 with AcO- determined by UV–Vis in DMSO, [1] ? [AcO-] = 2.0 9 10-2
M
color of the solution was changed from light yellow to
purple. While minor responses were observed when adding
the same amount of H2PO4-, F-, Cl-, Br- and I- ions to
O
O
the solution. These results suggest that receptor 1 can
distinguish AcO- from other anions.
Hb
O
+ AcO-
O
H
Then UV–Vis titrations were carried out in DMSO at a
concentration of 2.0 9 10-5 M by adding tetrabutylam-
monium salt of AcO- (see Fig. 2). The presence of acetate
resulted in the intensity of the absorbance band at 376 nm
decreasing gradually and that at 561 nm increasing grad-
ually, accompanied by the formation of an isosbestic point
at 405 nm. The significant color changes from light yellow
to purple upon addition a small amount of anions, which
indicates the intramolecular charge-transfer (ICT) between
the anion binding with –NH moiety and the electron-defi-
cient –NO2 moiety [14]. Specifically, the changes in
UV–Vis spectra are attributed to the interactions between
the –NH sites of the hydrazine subunits and acetate ions via
H-bond (see Scheme 2). Additionally, as the intensity of
the polarization is increased by the –NO2 substituent, the
C
H
C
O
O
N
N
O
N
N
O
H
H
Ha
NO2
NO2
Scheme 2 The possible binding model of the receptor 1 with AcO-
and its signaling transduction mechanism
electron density of the hydrazine is transferred to the nitro
moiety resulting in the possibility of realizing visual
inspection. Of particular note in this process, as increasing
the addition of AcO-, two new absorption bands at about
450 and 489 nm appeared, and red-shifted, the absorbance
123

132
J Incl Phenom Macrocycl Chem (2011) 70:129–133
Table 1 The affinity constants of receptor
298.2 0.1 K
1 with anions at
Anions (M-1
)
AcO-
H2PO4
F-
Cl-
Br-
I-
-
NDd
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
a
log Kass
4.67
3.82
2.73
3.46
2.29
1.85
b
log Kass
c
log Kass
a
The affinity constants determined by UV–Vis in dry DMSO
Fig. 3 Color changes of the receptor 1 (2 9 10-5 M) with different
acetate concentrations in DMSO. From left to right: (a) only 1; (b)
1.0 equiv. of AcO2; (c) excess equivalent of AcO2
b
The affinity constants determined by UV–Vis in DMSO/H2O (95:5,
v/v; HEPES, pH 7.4, 20 mM)
c
The affinity constants determined by UV–Vis in DMSO/H2O
(90:10, v/v; HEPES, pH 7.4, 20 mM)
band at 561 nm decreasing gradually, accompanied with a
color change from purple to dark yellow of the solution
(see Fig. 3). It means a new complex was obtained. A
rational explanation for this is that increased concentration
of acetate will caused the deprotonation of receptor 1.
In order to examine the potential application in analyt-
ical chemistry, the selectivity of receptor 1 for AcO- in
aqueous medium has been investigated. Specifically, 5%,
10% aqueous system (DMSO/H2O = 95:5, 90:10, v/v;
buffer solution: HEPES, pH 7.4, 20 mM) were further
adopted for UV–Vis study, and similar changes in UV
absorption spectra was also observed (see Fig. 2).
d
ND = cannot determined
anion guest correspondingly, Kass is the affinity constant of
host–guest complexation [16].
ꢀ
X ¼ X0 þ ðXlim ꢁ X0Þ CH þ CG þ 1=Kass
ꢁꢂ
h
Affinity constants of receptor 1 for anionic species are
i
1=2
2
ꢁ ðCH þ CG þ 1=KassÞ ꢁ4CHCG
2CH ð1Þ
calculated and listed in the Table 1 below.
According to the results from Job’s plot, the proposed
mode for the host–guest bonding in solution was depicted
in Scheme 2. In the structure, anions are located on one
side of receptor 1 via N–Hꢀꢀꢀ anion hydrogen bonds.
Receptor 1 could selectively recognize AcO- ascribed to
the relatively strong basicity of AcO- and the shape
complementarity between the receptor and the anionic
guests [17]. Due to its triangular shape, the angle of O–C–
O in AcO- is about 120° while the angle of O–P–O in
Determination of the binding constant
and stoichiometry
A Job’s plot is used to determine the stoichiometry of a
binding event. In this method, the total molar concentration
of host and guest are held constant, but their mole fractions
are varied. A measurable parameter that is proportional to
complex formation (such as absorption signal) is plotted
against the mole fractions of these two components.
In Fig. 4, Job’s plot [15] of receptor 1 and AcO- in
DMSO and 9/1 DMSO/H2O (v/v) shows the maximum at a
molar fraction of 0.5. This result indicates that receptor 1
binds acetate anion guest with a 1:1 ratio (see Fig. 2).
For a complex of 1:1 stoichiometry, the relation in Eq. 1
could be derived easily, where X is the absorption inten-
sity, and CH or CG is the concentration of the host or the
-
H2PO4 is about 108°. The distance between two oxygen
atoms of AcO- might be more fit to the distance between
the two recognition sites of receptor 1, forming a seven-
member ring structure. That is, the configuration of AcO-
is more matching with 1 than F- and H2PO4
-
.
1H NMR titrations
To further elucidate the nature of intermolecular interac-
tions between anions and receptor 1, 1H NMR spectral
changed upon addition of AcO- in DMSO-d6 solution of 1
(1.0 9 10-2 M) were investigated. Figure 4 showed 1H
NMR spectral changes of receptor 1 (1.0 9 10-2 M) in
DMSO-d6 in the absence and presence of different equiv-
alent of acetate ions. Obviously, the proton signal at 9.36
and 10.85 ppm which were assigned to the –NH group can
be observed in the absence of the AcO-. Upon addition of
0.4 equiv. of AcO-, the signals of the –NH moiety
broadened, and aromatic rings exhibited upfield shift
slightly, it is showed that a hydrogen-bond complex is
2.0 equiv
Hb
1.0 equiv
Ha
Ha
Hb
0.4 equiv
0 equiv
Hb
11
10
9
ppm
8
7
Fig. 4 1H NMR titration of 1 in DMSO-d6 with AcO2
123

J Incl Phenom Macrocycl Chem (2011) 70:129–133
133
based sensor for carbonate. Electrochim. Acta 52, 951–957
(2006)
4. Jain, A.K., Gupta, V.K., Raisoni, J.R.: A newly synthesized
macrocyclic dithioxamide receptor for phosphate sensing. Ta-
lanta 69, 1007–1012 (2006)
5. Gunnlaugsson, T., Davis, A.P., O’Brien, J.E., Glynn, M.: Fluo-
rescent sensing of pyrophosphate and bis-carboxylates with
charge neutral PET chemosensors. Org. Lett. 4, 2449–2452
(2002)
6. Hossain, M.A., Llinares, J.M., Powell, D., Bowman-James, K.:
Multiple hydrogen bond stabilization of a sandwich complex of
sulfate between two macrocyclic tetraamides. Inorg. Chem. 40,
2936–2937 (2001)
formed at this stage [18]. As increasing the addition of
AcO-, the signals of –NH group (10.85 ppm) downshifted
and eventually disappeared, the –NH group (9.36 ppm)
shifted to low-field, and a broad peak formed, which dis-
played the complete deprotonation of receptor 1. The
results of the 1H NMR titrations also supported the
hypothesis obtained according to the results of UV–Vis
titrations.
Analytical application
7. Szumna, A., Jurczak, J.: A new macrocyclic polylactam-type
neutral receptor for anions-structural aspects of anion recogni-
tion. Eur. J. Org. Chem. 21, 4031–4039 (2001)
The potential application of receptor 1 in the analytical
chemistry field was evaluated in aqueous solution
(Table 1). The results show that 1 can be applied in
detection of acetate ion in organic solvent, even in aqueous
solution, so it may provide a potential way to recognize and
detect acetate.
8. Paul, D.B., Szemes, F., Balzani, V.: Anion selective recognition
and sensing by novel macrocyclic transition metal receptor sys-
tems. 1H NMR, electrochemical, and photophysical investiga-
tions. J. Am. Chem. Soc. 119, 11864–11875 (1997)
9. Han, F., Bao, Y.H., Yang, Z.G., Fyles, T.M., Zhao, J.Z., Peng,
X.J., Fan, J.L., Wu, Y.K., Sun, S.G.: Simple bis-
thiocarbonohydrazones as sensitive, selective, colorimetric, and
switch-on fluorescent chemosensors for fluoride anions. Chem.
Eur. J. 13, 2880–2892 (2007)
-
10. Maeda, H., Ito, Y.: BF2 complex of fluorinated dipyrrolyldike-
tone: a new class of efficient receptor for acetate anions. Inorg.
Chem. 45, 8205–8210 (2006)
Conclusions
To sum up, a novel and colorimetric charge-neutral
receptor has been successfully exploited, which could
recognize acetate among the anions investigated. The
whole processes can be observed by the ‘naked-eye’, for its
sharply color changes from light yellow to purple. So it is
expected to be applied for detection of acetate in analytical
chemistry for its easy synthesis and highly selective sens-
ing ability.
11. Shao, J., Wang, Y.H., Lin, H., Li, J.W., Lin, H.K.: A novel indole
phenylhydrazone receptor: synthesis and recognition for acetate
anion. Sens. Actuator B 134, 849–853 (2008)
12. Amendola, V., Esteban-Gomez, D., Fabbrizzi, L., Licchelli, M.:
What anions do to N-H-containing receptors. Acc. Chem. Res.
39, 343–353 (2006)
13. Aimin, S., Wang, X.B., Kit, S.L.: A convenient synthesis of
coumarin-3-carboxylic acids via Knoevenagel condensation of
Meldrum’s acid with ortho-hydroxyaryl aldehydes or ketones.
Tetrahedron Lett. 44, 1755–1758 (2003)
14. Shao, J., Lin, H., Shang, X.F., Chen, H.M., Lin, H.K.: A novel
neutral receptor for selective recognition of H2PO4-. J. Incl.
Phenom. Macrocycl. Chem. 59, 371–375 (2007)
Acknowledgment This project was supported by the National
Natural Science Foundation of China (20371028, 20671052).
15. Liu, Y., You, C.C., Zhang, H.Y.: Supramolecular Chemistry,
pp 453–455. Nankai University Press, Tianjin (2001)
16. Bourson, J., Pouget, J., Valeur, B.: Ion-responsive fluorescent
compounds. 4. Effect of cation binding on the photophysical
properties of a coumarin linked to monoaza- and diaza-crown
ethers. J. Phys. Chem. 97, 4552–4557 (1993)
17. Korendovych, I.V., Cho, M., Butler, P.L., Staples, R.J., Rybak-
Akimova, E.V.: Org. Lett. 8, 3171–3174 (2006)
18. Huang, W.W., Lin, H., Cai, Z.S., Lin, H.K.: A novel anthracene-
based receptor: highly sensitive fluorescent and colorimetric
receptor for fluoride. Talanta 81, 967–971 (2010)
References
´
´
´
1. Martınez-Man˜ez, R., Sancenon, F.: Fluorogenic and chromogenic
chemosensors and reagents for anions. Chem. Rev. 103, 4419–
4476 (2003)
2. Gupta, V.K., Goyal, R.N., Sharma, R.A.: Anion recognition using
newly synthesized hydrogen bonding disubstituted phenylhyd-
razone based receptors: poly(vinyl chloride) based sensor for
acetate. Talanta 76, 859–864 (2008)
3. Jain, A.K., Gupta, V.K., Raisoni, J.R.: Anion recognition using
newly synthesized hydrogen bonding diamide receptor: PVC
123