In conclusion, for the first time, the approach of squaraine
chemodosimeter for nucleophilic analytes was coupled with
the FRET principle in the construction of cassettes SN-1 and
SN-2. In our design concept, the nucleophilic attacks on
electron-deficient squaraine center switched off the FRET
process by completely canceling the spectra overlap, and thus
resulted in the recovery of emission from the naphthalimide
donor and the quenching of emission from the squaraine
acceptor, simultaneously. SN-2 proved to be an efficiently
ratiometric sensor of the fluoride and cyanide anions, supporting
our tentative idea. It should be noted that, ‘turn-off’
chemodosimeters are common, and not just confined to
squaraine. Thus, the chemically ‘switching FRET off’ strategy
is of universal importance and should find more applications
in the transformation of various ‘turn-off’ chemodosimeters
into ratiometric sensors.
N. Park and J. S. Kim, Org. Lett., 2008, 10, 213–216;
(d) G. Q. Shang, X. Gao, M. X. Chen, H. Zheng and J. G. Xu,
J. Fluoresc., 2008, 18, 1187–1192; (e) Z. G. Zhou, M. X. Yu,
H. Yang, K. W. Huang, F. Y. Li, T. Yi and C. H. Huang, Chem.
Commun., 2008, 3387–3389.
7 X. Zhang, Y. Xiao and X. Qian, Angew. Chem., Int. Ed., 2008, 47,
8025–8029.
8 (a) J. J. Gassensmith, J. M. Baumes and B. D. Smith, Chem.
Commun., 2009, 6329–6338; (b) J. V. Ros-Lis, B. Garcı
´
a,
D. Jimenez, R. Martınez-Manez, F. Sancenon, J. Soto,
´
´
´
´
F. Gonzalv and M. C. Valldecabres, J. Am. Chem. Soc., 2004,
126, 4064–4065.
9 (a) K. Y. Law, Chem. Rev., 1993, 93, 449; (b) A. Ajayaghosh, Acc.
Chem. Res., 2005, 38, 449–476; (c) E. Arunkumar, P. Chithra and
A. Ajayaghosh, J. Am. Chem. Soc., 2004, 126, 6590–6598;
(d) E. Arunkumar, A. Ajayaghosh and J. Daub, J. Am. Chem.
Soc., 2005, 127, 3156–3164.
10 (a) L. Liu, K. Nakatani and E. Ishow, New J. Chem., 2009, 33,
1402–1408; (b) G. Jiao, A. Loudet, H. B. Lee, S. Kalinin,
L. Johansson and K. Burgess, Tetrahedron, 2003, 59, 3109–3116;
(c) S. Webster, S. A. Odom, L. A. Padilha, O. V. Przhonska,
D. Peceli, H. Hu, G. Nootz, A. D. Kachkovski, J. Matichak,
S. Barlow, H. L. Anderson, S. R. Marder, D. J. Hagan and Eric
W. Van Stryland, J. Phys. Chem. B, 2009, 113, 14854–14867.
11 C. Cornelissen-Gude, W. Rettig and R. Lapouyade, J. Phys. Chem.
A, 1997, 101, 9673–9677.
12 (a) M. N. Berberan-Santos, J. Canceill, J. C. Brochon, L. Jullien,
J. M. Lehn, J. Pouget, P. Tauc and B. Valeur, J. Am. Chem. Soc.,
1992, 114, 6427–6436; (b) M. N. Berberan-Santos, P. Choppinet,
A. Fedorov, L. Jullien and B. Valeur, J. Am. Chem. Soc., 1999,
121, 2526–2533.
13 Both PET and FRET are modulated by the distance between the
donor and acceptor. PET, which can also act as a quencher of
FRET, is a competing mechanism in FRET systems. Electron
transfer is usually faster over a relatively shorter distance. Over a
longer distance, the electron transfer can be suppressed. However,
the distance in which FRET can take place is determined by the
Forster critical radius, R0, which is longer than the distance of
PET. So we lengthen the spacer of SN-1 in order to suppress the
PET effect.
Acknowledgements
This work was financially supported by the National Natural
Science Foundation of China (No. 20876022) and Program
for Changjiang Scholars and Innovative Research Team in
University (IRT0711).
Notes and references
1 (a) K. E. Sapsford, L. Berti and I. L. Medintz, Angew. Chem., 2006,
118, 4676–4704; (b) A. P. de Silva, H. Q. Nimal Gunaratne and
T. Gunnlaugsson, Chem. Rev., 1997, 97, 1515–1566.
2 (a) G.-S. Jiao, L. H. Thoresen and K. Burgess, J. Am. Chem. Soc.,
2003, 125, 14668–14669; (b) C. M. Augustin, B. Oswald and
O. S. Wolfbeis, Anal. Biochem., 2002, 305, 166–172;
(c) J. W. Han, J. C. Castro and K. Burgess, Tetrahedron Lett.,
2003, 44, 9359–9362.
14 (a) T. G. Kim, J. C. Castro, A. Loudet, J. G. S. Jiao,
R. M. Hochstrasser, K. Burgess and M. R. Topp, J. Phys. Chem.
A, 2006, 110, 20–27; (b) O. S. Finikova, T. Troxler, A. Senes,
W. F. DeGrado, R. M. Hochstrasser and S. A. Vinogradov,
J. Phys. Chem. A, 2007, 111, 6977–6990.
3 (a) J. Han, A. Loudet and K. Burgess, J. Am. Chem. Soc., 2009,
131, 1642–1643; (b) R. Guliyev, A. Cosk and E. U. Akkaya, J. Am.
Chem. Soc., 2009, 131, 9007–9013.
4 (a) R. M. Franzini and E. T. Kool, J. Am. Chem. Soc., 2009, 131,
16021–16023; (b) M. A. Phelps, A. B. Foraker, J. T. Dalton and
P. W. Swaan, Mol. Pharmaceutics, 2004, 1, 257–266;
(c) S. Nampalli, W. H. Zhang, T. S. Rao, H. G. Xiao,
L. P. Kotra and S. Kumar, Tetrahedron Lett., 2002, 43, 1999–2003.
5 (a) A. Harriman, L. J. Mallon, S. Goeb, G. Ulrich and R. Ziessel,
Chem.–Eur. J., 2009, 15, 4553–4564; (b) A. Coskun and
E. U. Akkaya, J. Am. Chem. Soc., 2005, 127, 10464–10465;
(c) C. C. Woodroofe and S. J. Lippard, J. Am. Chem. Soc., 2003,
125, 11458–11459.
15 (a) J. Wang, Y. Xiao, Z. Zhang and X. Qian, J. Mater. Chem.,
2005, 15, 2836–2839; (b) Y. Xiao, M. Fu, X. Qian and J. Cui,
Tetrahedron Lett., 2005, 46, 6289–6292.
16 (a) D. Keilin, Proc. R. Soc. London, Ser. B, 1929, 104, 206;
(b) B. Vennesland, E. E. Comm, C. J. Knownles, J. Westly and
F. Wissing, Cyanide in Biology, Academic Press, London,
1981.
17 (a) G. J. Kim and H. J. Kim, Tetra. Lett., 2010, 51, 185–187;
(b) Y.-K. Yang and J. Tae, Org. Lett., 2006, 8, 5721–5723.
18 J. Y. Han, O. Gonzalez, A. Aguilar-Aguilar, E. Pena-Cabrera and
K. Burgess, Org. Biomol. Chem., 2009, 7, 34–36.
6 (a) M. Beija, C. A. M. Afonso and J. M. G. Martinho, Chem. Soc.
Rev., 2009, 38, 2410–2433; (b) M. Suresh, S. Mishra and A. Das,
Org. Lett., 2009, 11, 2740–2743; (c) M. H. Lee, H. J. Kim, S. Yoon,
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