H. Kim, J. Kang / Tetrahedron Letters 46 (2005) 5443–5445
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Supplementary data
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References and notes
. (a) Gale, P. A. Coord. Chem. Rev. 2003, 240, 191; (b) Beer,
P. D.; Gale, P. A. Angew. Chem., Int. Ed. 2001, 40, 486; (c)
Gale, P. A. Coord. Chem. Rev. 2001, 213, 79; (d) Gale,
P. A. Coord. Chem. Rev. 2000, 199, 181.
1
0
0.2
0.4
0.6
0.8
1
Host mole fraction
2
. (a) Mart ´ı nez-M a´ n˜ ez, R.; Sancen o´ n, F. Chem. Rev. 2003,
1
Figure 4. Job plot between the receptor 2 and iodide.
03, 4419; (b) Keefe, M. H.; Benkstein, K. D.; Hupp, J. T.
Coord. Chem. Rev. 2000, 205, 201; (c) De Silva, A. P.;
Gunaratne, H. Q.; Gunnlaugsson, N. T.; Huxley, A. J. M.;
McCoy, C. P.; Rademacher, J. T.; Rice, T. E. Chem. Rev.
ciation constant for fluoride from fluorescent titration
experiment since the emission intensity did not consis-
tently decrease upon the addition of fluoride ion. How-
ever, we note that the order of association constants is
1
997, 97, 1515.
3
4
. (a) Llinares, J. M.; Powell, D.; Bowman-James, K. Coord.
Chem. Rev. 2003, 240, 57; (b) Bondy, C. R.; Loeb, S. J.
Coord. Chem. Rev. 2003, 240, 77; (c) Ilioudis, C. A.; Steed,
J. W. J. Supramol. Chem. 2001, 1, 165.
. (a) Ihm, H.; Yun, S.; Kim, H. G.; Kim, J. K.; Kim, K. S.
Org. Lett. 2002, 4, 2897; (b) Yun, S.; Ihm, H.; Kim, H. G.;
Lee, C. I.; Indrajit, B.; Oh, K. S.; Gong, Y. J.; Lee, J. W.;
Yoon, J.; Lee, H. C.; Kim, K. S. J. Org. Chem. 2003, 68,
À
À
À
1
I > Br > Cl from the H NMR titration and fluores-
cence titration. Complementarity of receptor to the
anion is critical factor in achieving selectivity due to
1
2
diverse geometry of anions. The complementarity for
halides is generally achieved by the size of receptor bind-
ing site as halides are spherically shaped. The preference
for iodide withreceptor 2 suggests that the cavity
formed by four C(2)–H is more complementary to the
size of the iodide ion than to the size of other halide
ions.
2
467; (c) Chellappan, K.; Singh, N. J.; Hwang, I.-C.; Lee,
J. W.; Kim, K. S. Angew. Chem., Int. Ed. 2005, 44, 2.
. (a) Kim, S. K.; Singh, N. J.; Kim, S. J.; Kim, H. G.; Kim,
J. K.; Lee, J. W.; Kim, K. S.; Yoon, J. Org. Lett. 2003, 5,
5
6
2
083; (b) Yoon, J.; Kim, S. K.; Singh, N. J.; Lee, J. W.;
We also investigated the binding of other anions with
receptor 2 withfluorescence titration. In case of hy dro-
gen sulfate, cyanide, and benzoate, the Job plots were
not symmetric and showed maxima when the mole frac-
tion of host is between 0.4 and 0.5, which indicates a
mixed stoichiometry. Therefore, it was not possible to
obtain accurate association constants for these anions.
Yang, Y. J.; Chellappan, K.; Kim, K. S. J. Org. Chem.
2004, 69, 581.
. Kim, S. K.; Kang, B.-G.; Koh, H. S.; Yoon, Y. J.; Jung, S.
J.; Jeong, B.; Lee, K.-D.; Yoon, J. Org. Lett. 2004, 6,
4
. In, S.; Kang, J. Supramolecular Chem., in press.
655.
7
8
9
. In, S.; Kang, J. J. Incl. Phenom., in press.
. Hynes, M. J. J. Chem. Soc. Dalton Trans. 1993, 311.
1
0. Job, P. Ann. Chim. 1928, 9, 113.
In summary, we have designed and synthesized fluores-
cent imidazolium receptor 2, which displays selectivity
for iodide over other halides.
1
1. Benesi, H.; Hildebrand, H. J. Am. Chem. Soc. 1949, 71,
2703.
12. Fabbrizzi, L.; Poggi, A. Chem. Soc. Rev. 1995, 197.