Structure and selectivity of a small dimeric encapsulating assembly

Chemistry - A European Journal

Volumn 2, Issue 8, 1996, Pages 989-991

  Valdés, Carlos ^a   Toledo, Leticia M ^a   Spitz, Urs ^a   Rebek Jr , Julius ^a  

^a NONE

Author keywords

Dimerization; Host guest chemistry; Hydrogen bonds; Self assembly; Structure elucidation

Indexed keywords

BINDING SELECTIVITY; HOSTGUEST CHEMISTRY; INTERMOLECULAR HYDROGEN BONDS; MOLECULAR CAPSULE; NMR STUDIES; STRUCTURE ELUCIDATION; THERMODYNAMIC PARAMETER; X RAY CRYSTAL STRUCTURES;

DIMERIZATION; METHANE; SELF ASSEMBLY;

HYDROGEN BONDS;

EID: 0040185042     PISSN: 09476539     EISSN: 15213765     Source Type: Journal    
DOI: 10.1002/chem.19960020814     Document Type: Article

References (19)

1. R. Wyler, J. de Mendoza, J. Rebek, Jr., Angew. Chem. 1993, 105, 1820;
2. Angew. Chem. Int. Ed. Engl. 1993, 32, 1699;
3. N. Branda, R. Wyler, J. Rebek. Jr., Science 1994, 263, 1267;
4. N. Branda, R. M. Grotzfeld, C. Valdés, J. Rebek. Jr., J. Am. Chem. Soc. 1995, 117, 85.
5. C. Valdés, U. P. Spitz, S. W. Kubik, J. Rebek, Jr., Angew. Chem. 1995, 107, 2031;
6. Angew. Chem. Int. Ed. Engl. 1995, 32, 1885;
7. C. Valdés, U. P. Spitz, L. M. Toledo, S. W. Kubik, J. Rebek, Jr., J. Am. Chem. Soc. 1995, 117, 12733.
8. Molecular modeling was performed with MacroModel 3.5X (MM2* force field). F. Mohamadi, N. G. Richards, W. C. Guida, R. Liskamp, M. Lipton, C. Caufield, G. Chang, T. Hendrickson, W. C. Still, J. Comput. Chem. 1990, 11, 440.
9. The centers of both dimers sit on the twofold axis, but these axes are offset from each other by rotations about the other two crystallographic axes.
10. Molecular modeling suggests that the dimer with a methanol molecule inside is highly favored, since methanol can form strong hydrogen bonds to the carbonyl oxygen. Inspection of the NMR spectra of the crystals did not indicate the presence of considerable amounts of solvent of crystallization. Other work in this group indicates that guests that hydrogen-bond from the inside are readily encapsulated: R. S. Meissner, J. Rebek, Jr., J. de Mendoza, Science 1995, 270, 1485.
11. 1H NMR spectrum of the pure dimer does not indicate the presence of methanol inside its cavity.
12. 1H NMR titration methods, but were unable to observe a signal corresponding to included water.
13. J. Canceill, M. Cesario, A. Collet, J. Guilhem, L. Lacombe, B. Lozach, C. Pascard, Angew. Chem. Int. Ed. Engl. 1989, 28, 1246;
14. D. J. Cram, H.-J. Choi, J. A. Bryant, C. B. Knobler, J. Am. Chem. Soc. 1992, 114, 7748;
15. D. J. Cram, M. T. Blanda, K. Paek, C. B. Knobler, ibid. 1992, 114, 7765.
16. Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-1220-16. Copies of the data can be obtained free of charge on application to the Director, CCDC, 12 Union Road, Cambridge CB2 1E2, UK (Fax: Int. code + (1223)336-033; e-mail: teched@chemcrys.cam.ac.uk).
17. SMART, V.4.0, Siemens Industrial Automation, Madison, WI, 1994.
18. SAINT, V.4.0, Siemens Industrial Automation, Madison, WI, 1995.
19. TeXsan: Single Crystal Analysis Package, V.1.7-1, Molecular Structure Corporation, The Woodlands, TX, 1995.