Chorand crown ether macrocycle–alkali metal cation 1:1 complexes ‘Host-guest’ effect investigated directly by mass spectrometry

Abstract

An electrospray mass spectrometer is used to investigate the interaction between chorand crown ether macrocycles (12C4, 15C5, 18C6) and alkali metal cations (M⁺:Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺) in solution. The ‘host–guest’ effect can be investigated for the first time directly from solution. It is observed that the best fit ‘hole-size’ rule is not obeyed, although comparison with calculations show that, in competition, the relative abundances of different complexes correlate well with their relative stabilities. Structures and binding energies of the 1:1 complexes are determined by the empirical force field CHARMm and are compared to abinitio calculations.

References

1. (a) C. J. Pedersen, J. Am. Chem. Soc., 1967, 89, 7017; (b) C. J. Pedersen, J. Am. Chem. Soc., 1970, 92, 386.
2. See for instance (a) J. D. Dunitz, M. Dobler, P. Seiler and R. P. Phizackerley, Acta Crystallogr., Sect. B, 1974, 30, 2733; (b) R. M. Izatt, R. E. Terry, B. L. Haymore, L. D. Hansen, N. K. Dalley, A. G. Avondet and J. J. Christensen, J. Am. Chem. Soc., 1976, 98, 7620; (c) J. D. Lamb, R. M. Izatt, C. S. Swain, J. S. Bradshaw and J. J. Christensen, J. Am. Chem. Soc., 1980, 102, 479.
3. R. W. Kozac, T. A. Waldmann, R. W. Atcher and O. A. Gansow, Trends Biotechnol., 1985, 4, 259.
4. (a) J. M. Lehn, Acc. Chem. Res., 1978, 11, 49; (b) D. J. Cram, Science, 1983, 219, 1177; (c) G. Michaux and J. Reisse, J. Am. Chem. Soc., 1982, 104, 6895; (d) G. W. Gokel, D. M. Goli, C. Minganti and L. Echegoyen, J. Am. Chem. Soc., 1983, 105, 6786.
5. E. Leize, A. Jaffrezic and A. Van Dorsselaer, J. Mass Spectrom., 1996, 31, 537.
6. A. Wakisaka, R. Ludwig, H. Abdoul-Carime and W. Kleinkofort, to be submitted.
7. (a) M. Dole, L. L. Mack, R. L. Hines, R. C. Mobley, L. D. Ferguson and M. B. Alice, J. Chem. Phys., 1968, 49, 2240; (b) J. V. Iribane and B. A. Thomson, J. Chem. Phys., 1976, 64, 2287; (c) K. M. W. Siu, R. Guevremont, J. C. Y. Le-Blanc, R. T. O'Brien and S. S. Berman, Org. Mass. Spectrom., 1993, 28, 579.
8. P. Kebarle and L. Tang, Anal. Chem., 1993, 65A, 972.
9. J. Gasteiger and M. Marsili, Tetrahedron, 1980, 36, 3219.
10. E. D. Glendering, D. Feller and M. A. Thompson, J. Am. Chem. Soc., 1994, 116, 10657.
11. T. Yamabe, K. Hori, K. Akagi and K. Fukui, Tetrahedron, 1979, 35, 1065.
12. See for instance H. K. Frensdorff, J. Am. Chem. Soc., 1971, 93, 600.