Self-assembled hydrogen-bonded dimeric capsules with high kinetic stability

Angewandte Chemie - International Edition

Volumn 39, Issue 7, 2000, Pages 1264-1267

  Vysotsky, Myroslav O ^a   Thondorf, Iris ^b   Böhmer, Volker ^a  

^a JOHANNES GUTENBERG UNIVERSITY   (Germany)

^b MARTIN LUTHER UNIVERSITY HALLE WITTENBERG   (Germany)

Author keywords

Calixarenes; Dimerizations; Host guest chemistry; Hydrogen bonding; Kinetics

Indexed keywords

CALIXARENE;

ARTICLE; CARBON NUCLEAR MAGNETIC RESONANCE; DERIVATIZATION; DIMERIZATION; DRUG STABILITY; HYDROGEN BOND; PROTEIN ASSEMBLY; PROTON NUCLEAR MAGNETIC RESONANCE; STRUCTURE ANALYSIS;

EID: 0034599653     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1521-3773(20000403)39:7<1264::AID-ANIE1264>3.0.CO;2-P     Document Type: Article

References (23)

1. a) K. D. Shimizu, J. Rebek, Jr., Proc. Nat. Acad. Sci. USA 1995, 92, 12403-12407;
2. b) O. Mogck, V. Böhmer, W. Vogt, Tetrahedron 1996, 52, 8489-8496;
3. c) B. C. Hammann, K. D. Shimizu, J. Rebek, Jr., Angew. Chem. 1996, 108, 1425-1427;
4. Angew. Chem. Int. Ed. Engl. 1996, 55, 1326-1329.
5. For reviews see: a) J. Rebek, Jr., Acc. Chem. Res. 1999, 32, 278-286;
6. b) V. Böhmer, O. Mogck, M. Pons, E. F. Paulus, Reversible Dimerization of Tetraureas Derived from Calix[4]arenes in NMR in Supramolecular Chemistry (Ed.: M. Pons), Kluwer Academic, Dordrecht, 1999.
7. The shape of such a capsule was confirmed for one example by a single-crystal X-ray analysis: O. Mogck, E. F. Paulus, V. Böhmer, I. Thondorf, W. Vogt, Chen. Commun. 1996, 2533-2534.
8. O. Mogck, M. Pons, V. Böhmer, W. Vogt, J. Am. Chem. Soc. 1997, 119, 5706-5712.
9. 10]p-xylene, but this refers to a very small concentration of benzene (probably about 1 mM) which is not reported exactly in ref. [1c].
10. a) Recent kinetic studies concerning the guest exchange in hydrogen-bonded capsules of the "softball" type were described: J. Santamaria, T. Martin, G. Hilmersson, S. L. Craig, J. Rebek, Jr., Proc. Natl. Acad. Sci. USA 1999, 96, 8344-8347;
11. b) for theoretical calculations concerning this guest exchange see: X. Wang, K. N. Houk, Org. Lett. 1999, 1, 591-594.
12. K.-K. D. Ng, H. Hart, Tetrahedron 1995, 51, 7883-7906.
13. H. Eckert, B. Foster, Angew. Chem. 1987, 99, 922-923;
14. Angew. Chem. Int. Ed. Engl. 1987, 26, 894-895.
15. For heterodimers between tetratolyl- and tetratosyl-ureas see: R. K. Castellano, J. Rebek, Jr., J. Am. Chem. Soc. 1998, 120, 3657-3663.
16. Integration of the initial spectrum proves the inclusion of one benzene molecule per dimer.
17. The undimerized 3 e remains dissolved in toluene, while it precipitates from p-xylene.
18. II⋯O = 2.48 Å in 3d/3d. Thus, the distinctly smaller cavity explains that homodimers 3e/3e are not formed in benzene, while the slight difference in size between 3d/3d and 3d/3e together with less favorable hydrogen-bond distances might explain that also heterodimers are impossible with larger guests such as toluene or p-xylene.
19. 12 in the latter case.
20. For a recent example of guest-controlled dimerization see: A. Shivanyuk, V. Böhmer, E. F. Paulus, Angew. Chem. 1999, 111, 3091-3094;
21. Angew. Chem. Int. Ed. 1999, 38, 2906-2909.
22. ‡; compare the "constrictive binding" defined by Cram for (hemi)-carceplexes: "Container Molecules and Their Guests": D. J. Cram, J. M. Cram in Monographs in Supramolecular Chemistry (Ed.: J. F. Stoddart), Royal Society of Chemistry, Cambridge, 1994.
23. These procedures would be analogous to the formation of rotaxanes by "slipping" or by "threading + capping".