A spherical 24 butyrate aggregate with a hydrophobic cavity in a capsule with flexible pores: Confinement effects and uptake-release equilibria at elevated temperatures

Angewandte Chemie - International Edition

Volumn 48, Issue 43, 2009, Pages 8051-8056

  Schäffer, Christian ^b   Bögge, Hartmut ^b   Merca, Alice ^b   Weinstock, Ira A ^c   Rehder, Dieter ^a   Haupt, Erhard T K ^a   Müller, Achim ^b  

^a UNIVERSITY OF HAMBURG   (Germany)

^b BIELEFELD UNIVERSITY   (Germany)

^c BEN GURION UNIVERSITY OF THE NEGEV   (Israel)

Author keywords

Confinement effect; Hydrophobic effect; NMR spectroscopy; Polyoxometalates; Porous capsules

Indexed keywords

CONFINEMENT EFFECT; HYDROPHOBIC EFFECT; NMR SPECTROSCOPY; POLYOXOMETALATES; POROUS CAPSULES;

ENCAPSULATION; NUCLEAR MAGNETIC RESONANCE; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY;

HYDROPHOBICITY;

EID: 70349970573     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200903910     Document Type: Article

References (58)

1. Handbook of Porous Solids, Five Vols. (Eds.: F. Schüth, K. S. W. Sing, J. Weitkamp), Wiley-VCH, Weinheim, 2002.
2. Comprehensive Supramolecular Chemistry, Vol. 7 (Eds. : J. L. Atwood, J. E. D. Davies, D. D. MacNicol, F. Vögtle), Pergamon, Oxford, 1996.
3. a) A. Müller, H. Reuter, S. Dillinger, Angew. Chem. 1995, 107, 2505-2539;
4. Angew. Chem. Int. Ed. Engl. 1995, 34, 2328-2361;
5. b) P. N. W. Baxter in Comprehensive Supramolecular Chemistry, Vol. 9 (Eds.: J. L. Atwood, J. E. D. Davies, D. D. MacNicol, F. Vögtle), Pergamon, Oxford, 1996, pp. 165-211;
6. see also c) D. H. Busch, A. L. Vance, A. G. Kolchinski in Comprehensive Supramolecular Chemistry, Vol. 9 (Eds. : J. L. Atwood, J. E. D. Davies, D. D. MacNicol, F. Vögtle), Pergamon, Oxford, 1996, pp. 1-42.
7. a) L. Cronin in Comprehensive Coordination Chemistry II, Vol. 7 (Eds.: J. A. McCleverty, T. J. Meyer), Elsevier, Amsterdam, 2004, pp. 1-56;
8. b) D-L. Long, L. Cronin, Chem. Eur. J. 2006, 12, 3698-3706; c)
9. L. Cronin, Angew. Chem. 2006, 118, 3656-3658;
10. Angew. Chem. Int. Ed. 2006, 45, 3576-3578;
11. d) D.-L. Long, L. Cronin, Chem. Soc. Rev. 2007, 36, 105-121;
12. e) A. Proust, R. Thouvenot, P. Gouzerh, Chem. Commun. 2008, 1837-1852;
13. f) P. Gouzerh, M. Che, Actual. Chim. 2006, 298, 9-22;
14. g) M. T. Pope in Comprehensive Coordination Chemistry II, Vol. 4 (Eds. : J. A. McCleverty, T. J. Meyer), Elsevier, Amsterdam, 2004, pp. 635-678;
15. h) M. T. Pope in Encyclopedia of Inorganic Chemistry, Vol. VII, 2nd ed. (Ed.: R. B. King), Wiley, Chichester, 2005, pp. 4575-4586.
16. a) A. Müller, P. Kögerler, C. Kuhlmann, Chem. Commun. 1999, 1347-1358;
17. b) A. Müller, S. Roy, Coord. Chem. Rev. 2003, 245, 153-166;
18. c) A. Müller, S. Roy in The Chemistry of Nano-materials: Synthesis Properties and Applications (Eds.: C. N. R. Rao, A. Müller, A. K. Cheetham), Wiley-VCH, Weinheim, 2004, pp. 452-475;
19. d) A. Müller, S. Roy, Eur. J. Inorg. Chem. 2005, 3561-3570 (micro review);
20. e) A. Müller, S. Roy, J. Mater. Chem. 2005, 15, 4673-4677.
21. M. Gross, Chem. Br. 2003, 39, 18
22. and Chemistry World 2004, 1, Nov. Issue, 18.
23. a) L. Cronin, E. Diemann, A. Müller in Inorganic Experiments (Ed.: J. D Woollins), Wiley-VCH, Weinheim, 2003, pp. 340-346;
24. b) A. Müller, S. K. Das, E. Krickemeyer, C Kuhlmann, Inorg. Synth. 2004, 34, 191-200 (Ed.: J. R. Shapley);
25. c) A. Müller, E. Krickemeyer, H. Bögge, M. Schmidtmann, F. Peters, Angew. Chem. 1998, 110, 3567-3571;
26. Angew. Chem. Int. Ed. 1998, 37, 3359-3363.
27. a) E. T. K. Haupt, C Wontorra, D Rehder, A. Müller, Chem. Commun. 2005, 3912-3914;
28. b) A. Müller, D Rehder, E. T. K. Haupt, A. Merca, H. Bögge, M. Schmidtmann, G Heinze-Brückner, Angew. Chem. 2004, 116, 4566-4570;
29. Angew. Chem. Int. Ed. 2004, 43, 4466-4470;
30. erratum: A. Müller, D Rehder, E. T. K. Haupt, A. Merca, H. Bögge, M. Schmidtmann, G. Heinze-Brückner, Angew. Chem. 2004, 116, 5225;
31. Angew. Chem. Int. Ed. 2004, 43, 5115;
32. c) D Rehder, E. T. K. Haupt, H. Bögge, A. Müller, Chem. Asian J. 2006, 1-2, 76-81;
33. d) A. Merca, E. T. K. Haupt, T. Mitra, H. Bögge, D Rehder, A. Müller, Chem. Eur. J. 2007, 13, 7650-7658;
34. e) A. M. Todea, A. Merca, H. Bögge, T. Glaser, L. Engelhardt, R. Prozorov, M. Luban, A. Müller, Chem. Commun. 2009, 3351-3353.
35. Complex math equation.
36. I. D Brown in Structure and Bonding in Crystals, Vol. II (Eds. : M. O'Keeffe, A. Navrotsky), Academic Press, New York, 1981, pp. 1-30.
37. 2O at room temperature, or ten equivalents of n-butyric acid are added to the solution of the sodium salt of a capsule with acetate ligands (50 mg), uptake-release equilibria are observed in less than one hour. Note that in both cases the additional acid stimulates the exchange process (see Ref. [12b]).
38. b) As the p K a value of butyric acid at room temperature is 4.81 and the pH value of the investigated solution is about 4.0, most of the species called "free butyrates" in the text are protonated; for the pKa, see CRC Handbook of Chemistry and Physics: A Ready-Reference Book of Chemical and Physical Data, 64th ed. (Ed. : R. C. Weast), CRC, Boca Raton, FL, 1984.
39. c) This is valid, for example, for bidentate ligands like acetates and oxalates coordinated to the {Mo2} linkers but also for the 7Li NMR spectroscopy signals of integrated Li+ ions in the case of solutions of Li+-type capsules.[8a-d]
40. a) With the O···O separation of butyric acid of approximately 2.25 Â (F J. Strieter, D H. Templeton, Acta Crystallogr. 1962, 15, 1240-1244) and taking into account the van der Waals radii of the two oxygen atoms, we obtain a related value of the carboxylate group which is larger than the pore openings (ca. 3 A; for details see Figure SI-5 in the Supporting Information).
41. b) The qualitative observation of the related pore flexibility (see title) was mentioned earlier, for example, in Ref. [20] of T. Mitra, P. Miro, A.-R. Tomsa, A. Merca, H. Bögge, J. B. Ävalos, J. M. Poblet, C Bo, A. Müller, Chem. Eur. J. 2009, 15, 1844-1852
42. "In this context it is important to note that this ligand exchange (acetate versus sulfate) is based on some flexibility of the pores regarding partial opening which is one of the most important properties of the capsules. [...] At lower pH the acetate ligands get (upon addition of H2SO4) protonated while correspondingly leaving the capsule and sulfate ions are taken up" (for the corresponding synthesis, see A. Müller, Y. Zhou, H. Bögge, M. Schmidtmann, T. Mitra, E. T. K. Haupt, A. Berkle, Angew. Chem. 2006, 118, 474-479;
43. Angew. Chem. Int. Ed. 2006, 45, 460-465).
44. c) For more sophisticated evidence of pore widening, see the kinetic study in A. Ziv, A. Grego, S. Kopilevich, L. Zeiri, P. Miro, C Bo, A. Müller, I. A. Weinstock, J. Am. Chem. Soc. 2009, 131, 6380-6382. But it has to be admitted that details about pore opening are not known.
45. a) A. M. Todea, A. Merca, H. Bögge, J. Van Slageren, M. Dressel, L. Engelhardt, M. Luban, T. Glaser, M. Henry, A. Müller, Angew. Chem. 2007, 119, 6218-6222;
46. Angew. Chem. Int. Ed. 2007, 46, 6106-6110;
47. b) A. Müller, Nat. Chem. 2009, 1, 13-14 (Feature article);
48. c) C. Schäffer, A. Merca, H. Bögge, A. M. Todea, M. L. Kistler, T. Liu, R. Thouvenot, P. Gouzerh, A. Müller, Angew. Chem. 2009, 121, 155-159;
49. Angew. Chem. Int. Ed. 2009, 48, 149-153.
50. T. Douglas, M. Young, Nature 1998, 393, 152-155.
51. a) A. J. Olson, Y. H. E. Hu, E. Keinan, Proc. Natl. Acad. Sci. USA 2007, 104, 20731-20736;
52. b) J.-M. Lehn, Supramolecular Chemistry: Concepts and Perspectives, Wiley-VCH, Weinheim, 1995;
53. c) M. Fujita in Comprehensive Supramolecular Chemistry, Vol. 9 (Eds.: J. L. Atwood, J. E. D. Davies, D. D. MacNicol, F Vögtle), Pergamon, Oxford, 1996, pp. 253-282 (note related subtitle: "Supramolecular Self-assembly through Coordination").
54. See for example, a) M. Yoshizawa, J. K. Klosterman, M. Fujita, Angew. Chem. 2009, 121, 3470-3490;
55. Angew. Chem. Int. Ed. 2009, 48, 3418-3438 and
56. b) D Ajami, J. Rebek Jr., Nat. Chem. 2009, 1, 87-90). In the latter case it was stated in the graphical abstract: "Molecules confined to small volumes (e.g. "in self-assembled capsules") can contort themselves into unusual conformations that differ from those usually observed when no constraints are placed on them." Regarding the future of inorganic chemistry research under confined conditions, see also Ref. [13b].
57. NMR Spectroscopy Explained (Ed.: NE. Jacobsen), Wiley, Hoboken, 2007.
58. J. A. Ernst, R. T. Clubb, H.-X. Zhou, A. M. Gronenborn, G M. Clore, Science, 1995, 267, 1813-1817.