Letter | Published:

Variable Magnetic Moments of Cobaltous Compounds

Nature volume 139, pages 374375 (27 February 1937) | Download Citation



IN the course of an investigation on the magnetism of cobalt compounds, we have found a notable difference between the magnetic moments of the blue and violet forms of bispyridylcobaltous chloride, (Co2PyCl2). The violet form, which is stable at room temperature, was first prepared in 1894 by Reitzenstein1; the blue form was obtained in 1927 by Hantzsch and Schlegel2 by dissolving the violet form in chloroform and precipitating the substance by dilution with ligroin. The blue form can also be prepared by heating the stable form to 120°; it is unstable at room temperature and reverts to the violet form in a few days. Much work has been done on the absorption spectra, molecular weight, and conductivity of these substances3.

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    Lieb. Ann., 282, 267 (1894).

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    , Z. Phys., 43, 864 (1927).

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    , ” Theory of Electric and Magnetic Susceptibilities”, (Oxford Univ. Press, 1932, p. 287).

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  1. Birkbeck College, London, E.C.4.

    • E. D. P. BARKWORTH
    •  & S. SUGDEN


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