Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
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Tautomeric Fluxional Process in Metal Complexes. Insight into Cobalt(Ⅲ) and Pentamethylcyclopentadienylrhodium(Ⅲ) Complexes of 2-Mercaptopyrimidine Ligand

  • Published : 1999.06.20
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Abstract

Studies have been carried out on the unusual molecular nonrigidity of CoⅢ(PymS)3 and Cp* RhⅢ(PymS)2(PymS:2-mercaptopyrimidine). The crystal structure of CoⅢ(PymS)3 approximates to an octahedral mer isomer with 4-membered N-Schelating fashion. For Cp*RhⅢ(PymS)2, one PymS ligand bonds to the rhodium ion in an S-monodentate mode (Rh-S(2) = 2.366(1)Å) while the other ligand chelates to the metal ion in an N,S-bidentae mode (Rh-S(1)=2.414(1);Rh-N(1)=2.103(3)Å). Even though the conformations and configurations of both complexes are still retained in solution, an unusual nonrigidity for the protons of the PymS region is obsered in the solution. The broad proton signals of CoⅢ(PymS)3 exhibit a temperature-dependence in the range of -40∼40℃ with a free energy of activation ΔG=64.49kJ/mol(40℃). For Cp*RhⅢ(PymS)₂,such a fluxionality has been markedly observed in solution. This fluxional behavior can be explained in terms of "ligand tautomerism" in metal complexes containing potential tautomeric forms.

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References

  1. J. Crystallogr. Spectroscopic Res. v.21 Povey, D. C.;Smith, G. W.;Lobana, T. S.;Bhatia, P. K.
  2. Inorg. Chem. v.25 Rosenfield, S. G.;Swedberg, S. A.;Arora, S. K.;Mascharak, P. K.
  3. Polyhedron v.11 Jia, G.;Puddephatt, R. J.;Vital, J. J.
  4. Inorg. Chem. v.34 Reynolds, J. G.;Sendlinger, S. C.;Murray, A. M.;Huffman, J. C.;Christou, G.
  5. Inorg. Chem. v.35 Jung, O.-S.;Park, S. H.;Lee, Y.-A.;Cho, Y.;Kim, K. M.;Lee, S.;Chae, H. K.;Sohn, Y. S.
  6. J. Organomet. Chem. v.299 Deeming, A. J.;Meah, M. N. N.;Dawes, H. M.;Hursthouse, M. B.
  7. Inorg. Chem. v.26 Rosenfield, S. G.;Berends, H. P.;Gelmini, L.;Stephan, D. W.;mascharak, P. K.
  8. J. Chem. Soc. Dalton Trans. Deeming, A. J.;Hardcastle, K. I.;Meah, M. N.;Bates, P. A.;Dawes, H. M.;Hursthouse, M. B.
  9. Inorg. Chem. v.31 Yap, G. P. A.;Jensen, C. M.
  10. J. Chem. Soc. Dalton Trans. Cookson, P. D.;Tiekink, E. R. T.
  11. Inorg. Chem. v.32 Prammnik, A.;Bag, N.;Chakravorty, A.
  12. Inorg. Chem. v.35 Perez-Torrente, J. J.;Casado, M. A.;Ciriano, M. A.;Lahoz, F. J.;Oro, L. A.
  13. Inorg. Chem. Acta v.117 Deeming, A. J.;Meah, M. N.
  14. J. Am. Chem. Soc. v.98 Beak, P.;Fry, Jr., F. S.;Lee, J.;Steele, F.
  15. J. Phys. Chem. v.99 Ozeki, H.;Cockett, M. C. R.;Okuyama, K.;Takahashi, M.;Kimura, K.
  16. J. Phys. Chem. v.100 Wang, J.;Boyd. R. J.
  17. J. Am. Chem. Soc. v.116 Jung, O.-S.;Pierpont, C. G.
  18. J. Am. Chem. Soc. v.95 Rony, P.;Neff, R. O.;
  19. Bull. Korean Chem. Soc. v.19 Jung, O.-S.;Kim, Y. T.;Lee, Y.-A.;Chae, H. K.
  20. A Program for Structure Determination Sheldrick, G. M.
  21. SHELXL-93: A program for Structure Refinement Sheldrick, G. M.
  22. Organic Structural Analysis Lambert, J. B.;Shurvell, H. F.;Vervit, L.;Cooks, R. G.;Stout, G. H.
  23. Inorg. Chim. Acta v.24 Cartwright, B. A.;Goodgame, D. M. L.;Jeeves, I.;Langguth, P. O.;Skapski, A. C.
  24. Inorg. Chim. Acta v.176 Constable, E. C.;Palmer, C. A.;Tocher, D. A.
  25. Acta Cryst v.C47 Hu, Y.-H.;Weng, L.-H.;Huang, L.-R.;Chen, X.-T.;Wu, D.-X.;Kang, B.-S.
  26. Acta Cryst. v.C47 Hu, Y.-H.;Kang, B.-S.;Chen, X.-T.;Huang, L.-R.