Physical Principles and Applications of Magnetochemistry

Abstract

BY his classical researches during the years 1908-13, Pascal was able to snow that the magnetic susceptibility of any diamagnetic compound can be considered as the sum of the ‘atomic susceptibilities' of the constituent atoms, plus constitutive constants depending on the structure of the molecule, the presence of double bonds and so on. In the determination of the susceptibility the chemist thus possesses a means of supplementing purely chemical evidence as to the nature of any substance. For example, the experimental value for anthraquinone agrees within one per cent with that calculated on the assumption that the substance is a derivative of anthracene, but there is a discrepancy of eleven per cent if the molecule is supposed to contain two benzene rings connected by aliphatic linkages. The (3-ketonic esters exist as equilibrium mixtures of two forms of the molecule (keto and enol). Pascal's determinations show that ethyl acetoacetate consists mainly of the ketonic form while the opposite is the case with ethyl benzylacetate, in accordance with the chemical behaviour of these compounds.

Physical Principles and Applications of Magnetochemistry

By Prof. S. S. Bhatnagar Dr. K. N. Mathur. Pp. xiv + 375. (London: Macmillan and Co., Ltd., 1935.) 21s. net.