Letter | Published:

Catalytic Racemization of tris(Ethylenediamine)Cobalt(III) Ion

Naturevolume 187pages10221023 (1960) | Download Citation



ALTHOUGH the optical isomers of the tris(ethylenediamine)cobalt(III) ion, ([Coen3]3+), are stable indefinitely in aqueous solution at 100° C., complete racemization can be effected at 90° C. in 2 min. in the presence of activated carbon1. It has been proposed that racemization is a surface phenomenon, and no decomposition of the complex cation occurs1. More recently2, the isomerization of lævo-tris(l-propylenediamine)cobalt(III) ion to the equilibrium mixture of the d and l forms of the complex cation was arried out with activated carbon in aqueous solution at 20° C. in 15 min. These reactions are obviously of the same nature as the rapid equilibration of mixtures of cobalt(III) complexes in various preparative procedures3,4 brought about by activated carbon, for which no satisfactory explanation has yet been proposed.

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  1. 1

    Douglas, B. E., J. Amer. Chem. Soc., 76, 1020 (1954).

  2. 2

    Dwyer, F. P., and Garven, F. L., J. Amer. Chem. Soc., 81, 290 (1959).

  3. 3

    Bjerrum, J., “Metal Ammine Formation in Aqueous Solution”, 235 (P. Haase and Son, Copenhagen, 1941).

  4. 4

    Bailar, J. C., and Work, J. B., J. Amer. Chem. Soc., 67, 176 (1945).

  5. 5

    Ellis, K. W., and Gibson, N. A., Anal. Chim. Acta, 9 (3), 275 (1953).

  6. 6

    Lewis, W. B., Coryell, C. D., and Irvine, J. W., J. Chem. Soc., Supp. Issue, 2, S386 (1949).

  7. 7

    Dwyer, F. P., and Sargeson, A. M. (to be published).

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  1. John Curtin School of Medical Research, Australian National University, Canberra

    • F. P. DWYER
    •  & A. M. SARGESON


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