A dipyrromethane based receptor as a dual colorimetric sensor for F? and Cu2+ ions

Article abstract of DOI:10.1016/j.tetlet.2017.11.042

A novel dipyrromethane based receptor has been synthesized. It works as a highly selective colorimetric sensor for F^? and Cu²⁺ ions, which can be used for their necked eye detection with evident colour change of its solution.

Full text of DOI:10.1016/j.tetlet.2017.11.042

Accepted Manuscript
−
A dipyrromethane based receptor as a dual colorimetric sensor for F and
2
+
Cu ions
Pradeep K. Muwal, Aradhana Nayal, Manish K. Jaiswal, Pramod S. Pandey
PII:
S0040-4039(17)31456-9
https://doi.org/10.1016/j.tetlet.2017.11.042
TETL 49485
DOI:
Reference:
To appear in:
Tetrahedron Letters
Received Date:
Revised Date:
Accepted Date:
27 September 2017
2 November 2017
19 November 2017
Please cite this article as: Muwal, P.K., Nayal, A., Jaiswal, M.K., Pandey, P.S., A dipyrromethane based receptor
−
2+
as a dual colorimetric sensor for F and Cu ions, Tetrahedron Letters (2017), doi: https://doi.org/10.1016/j.tetlet.
017.11.042
2
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A dipyrromethane based receptor as a dual colorimetric
− 2+
sensor for F and Cu ions
Leave this area blank for abstract info.
Pradeep K. Muwal, Aradhana Nayal, Manish K. Jaiswal and Pramod S. Pandey*
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016

1
Tetrahedron Letters
journal homepage: www.els evier.com
−
A dipyrromethane based receptor as a dual colorimetric sensor for F and
2
Cu ions
+
Pradeep K. Muwal, Aradhana Nayal, Manish K. Jaiswal and Pramod S. Pandey*
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India 110016
*
pramod@chemistry.iitd.ac.in, Mobile: 91-9910678428
ARTICLE INFO
ABSTRACT
Article history:
Received
A novel dipyrromethane based receptor has been synthesized. It works as a highly selective
− 2+
colorimetric sensor for F andCu ions, which can be used for their necked eye detection with
Received in revised form
Accepted
evident colour change of its solution
.
2
017 Elsevier Ltd. All rights reserved.
Available online
Keywords:
Dipyrromethane
Colorimetric sensor
−
F recognition
2
+
Cu recognition
1
. INTRODUCTION
2. RESULTS AND DISCUSSION
2.1. Synthesis
Development of artificial receptors for the selective detection of
biologically and environmentally relevant anions and metal ions
1
,2
The dipyrromethane based receptor 4 was synthesized by
following the sequence of reactions given in Scheme 1.
Treatment of acetophenone 1 with pyrrole in the presence of HCl
has attracted considerable attention in recent years. Among the
anions, fluoride ions play important role in treatment in dental
decay and osteoporosis. However, the excess of fluoride ions can
lead to several diseases such as fluorosis, gastrointestinal and
kidney disorders. Among the various metal ions, copper ions play
significant role in many fundamental biological processes and
enzyme-catalysed reactions involving superoxide dismutase,
cytochrome c oxidase and tyrosinase. Moreover, Cu is an
environmental pollutant and its excess amount can cause serious
health problems such as Alzheimer’s and Parkinson’s diseases.
Hence, there has been continuously growing interest to design
in water resulted in the formation of meso-methyl-meso-phenyl-
2
11
,2’-pyrromethane 2. The Vilsmeier reaction of compound 2
12
gave compound 3. The refluxing of the acetonitrile solution of 3
and p-nitrophenylhydrazine in 1:1 molar ratio led to the
formation of compound 4.
2+
-
2+
3,4
new sensors for F and Cu ions.
Recently, dipyrromethane and its derivatives have been found to
show great potential for the design of receptors for anion and
metal ion recognition. Sessler and co-workers synthesized
various dipyrromethane based receptors which showed selective
recognition of hydrogen sulphate, acetate, dihydrogen phosphate
5
and pyrophosphate ions. Jurazak and co-workers reported the
binding ability of a series of 7,7’-diurido-2,2’-diindolylmethane
-
4
6
derivatives towards
H
2
PO
ion.
Azamacrocyclic and
azacryptand receptors containing dipyrromethane units were
reported by Mani and co-workers showing their ability to bind
7
fluoride ion. Majerski and co-workers synthesized various
admantane based dipyrromethane derivatives which were
selective for fluoride and acetate ions. Pandey and co-workers
8
reported the binding ability of meso-glycosyl dipyrromethane
derivatives which exhibited fluorescent ‘turn on’ and ‘turn off’
2+
2+
9
signaling for Cd and Cu ions.
Our research group has considerable interest in anion and metal
1
0
ion recognition. Herein, we report a novel and easily accessible
dipyrromethane based receptor as a colorimetric sensor for the
Scheme 1. Synthesis of dipyrromethane based receptor
-
2+
dual sensing of F as well as Cu ions which can be used for the
naked eye detection of these ions in acetonitrile solution.

2
Tetrahedron
2
.2. Ions binding studies
However, no measurable change in its spectrum on addition of
− − − − −
Cl , Br , I , HSO
4
3
and CH COO anions was observed,
The anion binding property of receptor4 was investigated by UV-
Vis titration method. The change in the absorbance bands after
suggesting no or very weak binding for these anions to receptor
4. The colorimetric anion sensing ability of sensor 4 was
examined by the anion-induced colour changes in the solution of
sensor 4 in acetonitrile before and after the addition of an anion.
Sensor 4 showed significant colour change in the presence of
fluoride. Upon addition of 0.3 equivalents of fluoride ion
(TBAF), the pale yellow solution of receptor 4 became violet,
which can be used for the “naked-eye” detection of this anion. In
+
−
4 4 2 4 3
addition of Bu N X (X = F, Cl, Br, I, HSO , H PO , CH COO)
to the solution of receptor was monitored to determine the
binding affinity of this receptor towards anions.
-
Receptor 4 showed the highest selectivity towards F ion. The
-
binding affinity of receptor 4 towards F anion was investigated
+
−
by monitoring the absorbance changes on addition of Bu
4
N F (1
3
CN. As
-
5
mM) to the solution of compound 4 (1 × 10 M) in CH
2 4
the case of dihydrogen phosphate ion (TBAH PO ), the pale
shown in Figure 1, the absorbance bands at 295 and 420 nm
decreased and a new band around 531 nm developed with a
yellow solution of receptor 4 became dark yellow after 5 equiv
addition. No colour change was observed on addition of other
anions such as chloride, bromide, iodide sulphate and acetate
ions even up to 8 equiv (Fig. 3).
-
isosbestic point at 462 nm, on incremental addition of F ion (0-
1
.2 equiv).
-
-
-
-
-
-
-
I
H PO
AcO
5
F
Cl
Br
2
4
HSO4
−
5
Figure 3: Photograph of receptor 4 (1× 10 M) in CH
3
CN and
after addition of 0.3 equiv of F , 5 equiv H PO and 8 equiv of
−
−
2 4
−
−
Cl , Br , I , HSO
−
−
−
4 3
, CH COO
-
The mode of binding of F ion with compounds 4 was ascertained
1
-
by H NMR spectroscopy. After addition of F ion to the solution
of compound 4 (10 mM) in CD CN, N-H protons of pyrrole ring,
amino and –N=CH protons of hydrazone group shifted downfield
3
-
Figure 1: Absorbance spectra of compound 4 (1 × 10 M) in
5
-
-
3
CH CN in the presence of F ion (0-1.2 equiv).
(
The NMR showed fast disappearance of –NH protons, however,
Fig. 4), indicating their involvement in H-bonding with F ion.
-
there was no peak observed for HF at 12-16 ppm.
The binding constant was calculated using Hildebrand-Benesi
−1
) vs [G] showed good linear
2
1
3
equation . The plot with A
0
/(A-A
0
2
relationship with correlation coefficient (R ) = 0.99. The binding
constant was obtained from the ratio of the y-intercept to the
3
slope and found to be 6.02 × 10 M (Fig. S8a). The Job’s plot
−1
−
indicated the 1:1 complex formation between receptor 4 and F
ion (Fig.S8b).
Significant spectral changes were also observed in the UV-Vis
−
spectrum of receptor 4 on addition of H
2
PO
4
anion (Fig. 2). As
shown in Figure 2, the absorbance bands at 300 and 420 nm
decreased and a new band around 450 nm developed with two
isosbestic points at 436 and 560 nm, on incremental addition of
−
4
H
2
PO
ion (0-1.5 equiv). The binding constant was found to be
.39 × 10 M (Fig. S9a) with 1:1 complex formation between
3
−1
3
−
2 4
receptor 4 and H PO anion (Fig. S9b).
-
Figure 4: (i) Proposed mode of binding of F with 4 based on
1
NMR data (ii) Partial H NMR spectra (300 MHz, CD
3
CN, δ in
ppm) of 4 showing chemical shift change in the presence of
incremental addition of TBAF (0-1.2 equiv).
2
+
-
Figure 2: Absorbance spectra of compound 4 (1 × 10 M) in
5
Receptor 4 also showed high selectivity towards Cu ion as
indicated by the change in the UV-Vis spectrum of receptor 4 on
addition of different metal ions. The binding affinity of receptor
-
3 2 4
CH CN in the presence of H PO ion (0-1.5 equiv).
2+
4 towards Cu ion was investigated by monitoring the
absorbance changes on addition of Cu(ClO4) (1 mM) to the
2

3
-
5
3
solution of compound 4 (1 × 10 M) in CH CN. As shown in
Figure 5, the absorbance band at 295 increased and at 420 nm
decreased. A new band at 597 nm developed with a sharp
2
+
isosbestic point at 509 nm, on the incremental addition of Cu
ion (0-1.2 equiv).
-
Figure 5: Absorbance spectra of compound 4 (1 × 10 M) in
5
2
+
3
CH CN in the presence of Cu ion (0-1.2 equiv).
−
1
2+
Figure 7: (i) Proposed mode of binding of Cu with 4 based on
The plot with A0/(A-A0) vs [G] showed good linear
relationship with correlation coefficient R = 0.99. The binding
constant for complex formation between receptor 4 and Cu ion
2
1
3
NMR data.(ii) Partial H NMR spectra (300 MHz, CD CN, δ in
2+
ppm) of 4 showing chemical shift change in the presence of
2+
incremental addition of Cu ion (0-1.0 equiv).
3
= 9.82 × 10 M (Fig. S10a). The Job’s plot
−1
was found as K
indicated the 1:1 complex formation between receptor 4 and Cu
a
2
+
anion (Fig. S10b). However, no significant change was observed
in the absorbance spectrum of compound 4 with other metal ions,
suggesting no or very weak binding for these ions to receptor 4.
3
. CONCLUSION
dipyrromethane based receptor containing two p-
A
nitrophenylhydrazone groups has been synthesized. The receptor
showed highly selective binding and colorimetric sensing
towards F and Cu ions, which can be used for the naked eye
detection of these ions.
The colorimetric metal sensing ability of sensor 4 was examined
by the metal-induced colour change in the solution of sensor 4 in
acetonitrile before and after the addition of a metal. Sensor 4
-
2+
2+
showed significant colour change in the presence of Cu ion.
2+
Upon addition of 0.2 equivalents of Cu the pale yellow solution
of receptor 4 became colourless (pale blue) which can be used for
the “naked-eye” detection of this cation. No colour change was
observed on addition of other metal ions even up to 5 equiv (Fig.
Acknowledgments
PKM and AN thank the Council of Science and Industrial
Research, New Delhi, for the research fellowships.
6
).
Supplementary Material
Cu2+
Zn2+
Co2+
Pb2+
Hg2+
Cd2+
Mg2+
Na+
Li+
Supplementary data (experimental details, characterization data
for compounds, NMR spectra, Hildebrand-Benesi plots, Job’s
plots) associated with this article can be found, in the online
version, at
14
References
−4
Figure 6:A photograph of (1× 10 M) soln of receptor 4 in
1
.
(a) Gale, P. A. Acc. Chem. Res. 2006, 39, 465. (b) Sessler,
J. L.; Gale, P. A.; Cho, W.-S. Anion Receptor Chemistry,
Royal society of Chemistry: Cambridge, UK, 2006. (c)
Gale, P. A.; Garcia-Garrido, S. E.; Garric, J. Chem. Soc.
Rev. 2008, 37, 151. (d) Caltagirone, C.; Gale, P. A. Chem.
Soc. Rev. 2009, 38, 520.(e) Gale, P. A.; Gunnlaugsson, T.
eds.: Supramolecular chemistry of anionic species themed
issue, Chem. Soc. Rev. 2010, 39, 3595. (f) Wenzel, M.;
Hiscock, J. R.; Gale, P. A. Chem. Soc. Rev.2012, 41, 480.
2+
3
CH CN and after addition of 0.2 equiv of Cu and 5 equiv of
other metals.
2
+
The mode of binding of Cu ion with compounds 4 was
1
2+
ascertained by H NMR spectroscopy. After addition of Cu ion
to the solution of compound 4 (10 mM) in CD CN, N-H protons
of pyrrole ring and -NH and -CH protons of hydrazone group
3
2
+
shifted downfield, which showed the binding of Cu ion with the
receptor as shown in Figure 7.
(
e) Busschaert, N.; Caltagirone, C.; Rossom, W. V.; Gale,
P. A. Chem. Rev.2015, 115, 8038. (f) Pedro, P. M.;
Zapata, F.; Caballero A. Chem. Rev.2017, 117, 9907.
2
.
(a) Hancock, R. D.; Melton, D. L.; Harrington, J. M.;
McDonald, F. C.; Gephart, R. T.; Boone, L. L.; Jones, S.

4
Tetrahedron
B.; Dean, N. E.; Whitehead, J. R.; Cockrell, G. M. Coord.
(j) Muwal, P. K.; Pandey, S.; Pandey, P.S. RSC Adv, 2014,
4, 21531.(k) Jaiswal, M. K.; Muwal P. K.; Pandey
S.; Pandey, P. S. Tetrahedron Lett., 2017, 58, 2153.
Chem. Rev.2007, 251, 1678. (b) Freisinger, E.; Sigel, R.
K. O. Coord. Chem. Rev. 2007, 251, 1834. .(c) Nolan, E.
M.; Lippard, S. J. Chem. Rev.2008, 108, 3443. (d) Nolan,
E. M.; Lippard, S. J. Acc. Chem. Res. 2009, 42, 193. (e)
Quang, D. T.; Kim, J. S. Chem. Rev. 2010,110, 6280. (f)
Xu, Z.; Yoon, J.; Spring, D. R. Chem. Soc. Rev. 2010, 39,
11. Alemayehu, A.; Conradie, M. M.; Ghosh, A. J.
Porphyrins Phthalocyanines 2012, 16, 695.
1996. (g) Kim, H. N.; Ren, W. X.; Kim, J. S.; Yoon, J.
Chem. Soc. Rev. 2012, 41, 3210.
12. (a) Geier, G. R.; Callinan, J. B.; Rao, P. D.; Lindsey, J. S.;
J. Porphyrins Phthalocyanines 2001, 5, 810. (b) Bruckner
C.; Posakony J. J.; Johnson C. K.; Boyle R. W.; James B.
R; Dolphin D. J. Porphyrins Phthalocyanines 1998, 2,
455.
3
.
(a) Song, E. J.; Kim, H.; Hwang, I. H.; Kim, K. B.; Kim,
A. R.; Noh, I.; Kim, C.; Sens. Actuator B-Chem. 2014,
1
95, 36. (b) Xu, Y.; Wang, Y.; Zhao, S.; Guan, R.; Cao,
D.; Wu, Q.; Yu, X.; Sun Y.; Inorg. Chem. Commun. 2017,
8, 52. (c) You, D. K.; Lee, S. H.; lee, J.H.; Kwak, S.W.;
7
Hwang, H.; Lee, J.; Chung, Y.; Park, M. H.; Lee, K. M.
RSC Adv. 2017, 7,10345.
4
.
(a) Kumar, M.; Kumar, N.; Bhalla, V.; Sharma, P. R.;
Kaur, T. Org. Lett., 2012, 14, 406. (b) Ji, X. F.; Yao, Y.;
Li, J. Y.; Yan, X. Z.; Huang, F. H. J. Am. Chem.
Soc.2013, 135, 74. (c) Park, G. J.; Hwang, I.H.; Song,
E.J.; Kim, H.; Kim, C. Tetrahedron 2014, 70, 2822 (d)
Kim, H.; Na, Y.J.; Song, E.J., Kim, K.B.; Bae, J.M.; Kim,
C., RSC Adv. 2014, 4, 22463. (e) Liu, Y.-W.; Chir, J.-L.;
Wang, S.-T.; Wu, A.-T. Inorg. Chem. Commun., 2014, 45,
112. (f) Udhayakumari, D.; Velmathi, S.; Venktesan, P.;
Wu, S.- P. J. Luminescence, 2015, 161, 411.
5
.
(a) Sessler, J. L.; Roznyatovskiy, V.; Pantos, G. D.;
Borisova, N. E.; Reshetova, M. D.; Lynch, V. M.;
Khrustalev, V. N.; Ustynyuk, Y. A.; Org. Lett. 2005, 7,
5277. (b) Katayev, E. A.; Boev, N.; V.; Khrustalev, V.
N.; Ustynyuk, Y. A.; Tananaev, I. G.; Sessler, J. L. J. Org.
Chem. 2007, 72, 2887. (c) Sessler, J. L.; Cai, J.; Gong, H.-
Y.; Yang, X.; Arambula, J. F.; Hay, B. P. J. Am. Chem.
Soc. 2010, 132, 14058. (d) Bill, N. L.; Kim, D. S.; Kim, S.
K.; Park, J. S.; Lynch, V. M.; Young, N. J.; Hay, B. P.;
Yang, Y.; Anslyn, E. V.; Sessler, J. L. Supramol. Chem.
2012, 24, 72.(e) Deliomeroglu, M. K.; Lynch, V. M.;
Sessler, J. L. Chem Comm. 2014, 50, 11863.
6
7
.
.
Dydio, P.; Zielinski, T.; Jurazak, J. Org. Lett. 2010, 12,
1076.
(a) Mani, G.; Guchhait, T.; Kumar, R.; Kumar, S. Org.
Lett. 2010, 12, 3910. (b) Guchhait, T.; Mani, G. J.
Org.Chem. 2011, 76, 10114.
8
9
.
.
Aleskovi, M.; Basari, N.; Halasz, I.; Liang, X.; Qin, W.;
Majerski. K. M. Tetrahedron 2013, 69, 1725.
Biswas, A.; Pandey, R.; Kushwaha, D.; Shahid, M.;
Tiwari, V. K.; Misra, A.; Pandey. D. S. Tetrahedron Lett.
2013, 54, 4193.
1
0. (a) Khatri, V. K.; Shailesh, U.; Pandey, P. S. Org. Lett.
006, 8, 1755.(b) Khatri, V. K.; Chahar, M.; Pavani, K.;
2
Pandey, P. S. J. Org. Chem. 2007, 72, 10224.(c) Chahar,
M.; Shailesh, U.; Pandey, P. S. Tetrahedron. 2007, 63,
171.(d) Chahar, M.; Pandey, P. S. Tetrahedron. 2008, 64,
6488.(e) Kumar, A.; Pandey, P. S. Org Lett, 2008,
10,165.(f) Kumar, A.; Pandey, P. S. Tetrahedron
Lett.,2009,50, 5842 (g) Chhatra, R. K.; Kumar, A.;
Pandey, P. S. J. Org. Chem. 2011, 76, 9086. (h) Tripathi,
A; Pandey, P. S. Tetrahedron Lett. 2011, 52, 3558. (i)
Nayal, A.; Pandey, P. S. Tetrahedron 2015, 71, 6991.

5
Highlights
ꢀ
A dipyrromethane-based receptor
containing two p-
nitrophenylhydrazone groups has
been synthesized.
ꢀ
ꢀ
ꢀ
This receptor shows excellent
-
colorimetric sensing for F as well as
2
Cu ions.
+
The binding studies were carried out
1
by UV-Vis and H NMR
spectroscopy.
The binding studies show 1:1
complex formation in both cases.