A rational approach to selective recognition of NH4+ over K+

Angewandte Chemie - International Edition

Volumn 38, Issue 18, 1999, Pages 2756-2759

  Chin, Jik ^b   Walsdorff, Christian ^a   Stranix, Brent ^b   Oh, Jinho ^a   Chung, Hyun Jei ^a   Park, Su Moon ^a   Kim, Kimoon ^a  

^a Pohang University of Science and Technology (POSTECH)   (South Korea)

^b MCGILL UNIVERSITY   (Canada)

Author keywords

Ammonium ions; Cations; Electrodes; Receptors

Indexed keywords

AMMONIA; CATION; NONACTIN; POTASSIUM ION; RECEPTOR;

ARTICLE; CRYSTAL STRUCTURE; ENVIRONMENTAL MONITORING; HYDROGEN BOND; HYDROLYSIS; ION SELECTIVE ELECTRODE; MOLECULAR RECOGNITION; PROTON NUCLEAR MAGNETIC RESONANCE; RECEPTOR BINDING;

EID: 0033578904     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1521-3773(19990917)38:18<2756::AID-ANIE2756>3.0.CO;2-6     Document Type: Article

References (33)

1. P. Bühlmann, E. Pretsch, E. Bakker, Chem. Rev. 1998, 98, 1593-1687.
2. M. Dobler in Comprehensive Supramolecular Chemistry, Vol. 1 (Eds.: J. L. Atwood, J. E. D. Davies, D. D. MacNicol, F. Vögtle), Pergamon, Oxford. 1996, pp. 276-313.
3. S. S. Moore, T. L. Tarnowski, M. Newcomb, D. J. Cram, J. Am. Chem. Soc. 1977, 99, 6398-6405.
4. -1, respectively: J. Sunner, K. Nishizawa, P. Kebarle, J. Phys. Chem. 1981, 85, 1814-1820; C. A. Deakyne, M. Meot-Ner, J. Am. Chem. Soc. 1985, 707, 474-479.
5. -1, respectively: J. Sunner, K. Nishizawa, P. Kebarle, J. Phys. Chem. 1981, 85, 1814-1820; C. A. Deakyne, M. Meot-Ner, J. Am. Chem. Soc. 1985, 707, 474-479.
6. --bound receptor was obtained by molecular mechanics computation using Quantum Cache (version 3.11) from the Oxford Molecular Group. Preliminary ab initio computation also shows that the minimized structure is in good agreement with that obtained from X-ray crystallography.
7. Tris(pyrazol-1-ylmethyl)benzenes have been studied in metal-coordination chemistry. In line with our argument they do not act as mononucleating tridentate ligands of a single metal each, but rather bridge different metal centers: a) W.-K. Chang, S.-C. Sheu, G-H. Lee, Y. Wang, T.-I. Ho, Y.-C. Lin, J. Chem. Soc. Dalton Trans. 1993, 687-694;
8. b) C. M. Hartshorn, P. J. Steel, Chem. Commun. 1997, 541-542.
9. 6 -bound to the benzene ring and further coordinated by the three pyrazole nitrogen atoms. The benzene ring is deformed and the pyrazolylmethyl units are bent inwards: c) C. M. Hartshorn, P. J. Steel, Angew. Chem. 1996, 108, 2818-2820, Angew. Chem. Int. Ed. Engl. 1996, 35, 2655-2657. However, such a mode is hardly expected with alkaline metals.
10. 6 -bound to the benzene ring and further coordinated by the three pyrazole nitrogen atoms. The benzene ring is deformed and the pyrazolylmethyl units are bent inwards: c) C. M. Hartshorn, P. J. Steel, Angew. Chem. 1996, 108, 2818-2820, Angew. Chem. Int. Ed. Engl. 1996, 35, 2655-2657. However, such a mode is hardly expected with alkaline metals.
11. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
12. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
13. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
14. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
15. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
16. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
17. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
18. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
19. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
20. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
21. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
22. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
23. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
24. D. J. Iverson, G. Hunter, J. F. Blount, J. R. Damewood, Jr., K. Mislow J. Am. Chem. Soc. 1981, 103, 6073-6083; for other interesting examples, see T. D. P. Stack, J. A. Weigel, R. H. Holm, Inorg. Chem. 1990, 29, 3745-3760; C. Walsdorff, W. Saak, S. Pohl, J. Chem. Soc. Dalton Trans. 1997, 1857-1861; C. Walsdorff, W. Saak, D. Haase, S. Pohl, Chem. Commun. 1997, 1931 -1932; Z. Hou, T. D. P. Stack, C. J. Sunderland, K. N. Raymond, Inorg. Chim. Acta 1997, 263, 341 -355; A. Metzger, V. M. Lynch, E. V. Anslyn, Angew. Chem. 1997, 109, 911-914, Angew. Chem. Int. Ed. Engl. 1997, 36, 862-865; A. P. Bisson, V. M. Lynch, M.-C. K. Monahan, E. V. Anslyn, Angew. Chem. 1997, 109, 2435-2437, Angew. Chem. Int. Ed. Engl. 1997, 36, 2340-2342; B. F. Hoskins, R. Robson, D. A. Slizys, Angew. Chem. 1997, 109, 2861-2863, Angew. Chem. Int. Ed. Engl. 1997, 36, 2752-2755; T. Szabo, B. M. O'Leary, J. Rebek, Jr., Angew. Chem. 1998, 110, 3606-3609, Angew. Chem. Int. Ed. 1998, 37, 3410-3413; C. Walsdorff, S. Park, J. Kim, J. Heo, K.-M. Park, J. Oh, K. Kim, J. Chem. Soc. Dalton Trans. 1999, 923-929.
25. -3, 5198 independent reflections, R1 = 0.0631, wR2 = 0.1709 [I > 2σ(I)], R1 = 0.0729, wR2 = 0.1822 (all data), GOF = 1.062. Crystallographic data (excluding structure factors) for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-115195 (2) and CCDC-115196 (3). Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB21EZ, UK (fax: (+44)1223-336-033; e-mail: deposit@ccdc.cam.ac.uk).
26. 1H NMR signals due to the three methyl groups (δ = 0.8, t, 9 H) of the ethyl groups in 2 are equivalent at 297 °K. However, this signal splits into two (δ = 1.2, br, 3H; δ = 0.3, br, 6H) at 180 °K.
27. L. N. Kuleshova, P. M. Zorkii, Acta Crystallogr. Sect. B 1981, 37, 1363-1366.
28. We expected the three ethyl groups in ammonium-bound 2 to point away from the three pyrazole groups. It appears that crystal packing between two molecules of the complex within the unit cell forces one of the ethyl groups to point in the direction of the pyrazole rings : C. Walsdorff, K.-M. Park, J. Oh, K. Kim, Acta Crystallogr. Sect. C 1999, 55, 108-110.
29. + (pH 7.2 with 0.10M Tris buffer): Y. Umezawa, K. Umezawa, H. Sato, Pure. Appl. Chem. 1965, 67, 507-518.
30. + has been reported. However, the crytand is much too basic (more basic than ammonia) and hydrophilic for use as an ISE: E. Graf, J.-P. Kintzinger, J.-M. Lehn, J. LeMoigne, J. Am. Chem. Soc. 1982, 104, 1672-1678.
31. + than does 2.
32. 1,3,5-Tris(bromomethyl)-2.4,6-triethylbenzene was prepared as previously described: C. Walsdorff, W. Saak, S. Pohl, J. Chem. Res. (S) 1996, 282-283, J. Chem. Res. (M) 1996, 1601-1618.
33. 1,3,5-Tris(bromomethyl)-2.4,6-triethylbenzene was prepared as previously described: C. Walsdorff, W. Saak, S. Pohl, J. Chem. Res. (S) 1996, 282-283, J. Chem. Res. (M) 1996, 1601-1618.