R Samuel
Articles written in Proceedings – Section A
Volume 1 Issue 6 December 1934 pp 398-406
Volume 1 Issue 8 February 1935 pp 542-554
Volume 1 Issue 9 March 1935 pp 623-662
Volume 1 Issue 10 April 1935 pp 723-726
Volume 2 Issue 1 July 1935 pp 30-45
Volume 3 Issue 1 January 1936 pp 346-359
Volume 3 Issue 4 April 1936 pp 346-359
Volume 3 Issue 5 May 1936 pp 399-419
Volume 3 Issue 5 May 1936 pp 466-481
Electronic configuration and bond energy
The original interpretation of the method of molecular orbitals as a theory of valency, in which the single electron possesses bonding power was based on the assumption that non-premoted electrons are bonding and premoted ones are anti-bonding or non-bonding. This assumption is not the outcome of any requirements of theory but is an empirical postulate, which seeks justification in experimental facts. Earlier attempts at correlation between the electronic levels of molecules and the energy states of the constituent atoms indeed appeared to lend support to this assumption. Later investigations have, however, shown that completely different correlations are possible and are absolutely necessary to satisfy the experimental facts. For example, in a molecule like BeO the stable triplet term, which should arise from unexcited atoms according to the older correlation, is not found and by the correlation of certain excited terms to anomalous terms of the metal atom it is shown, that a non-premoted odd electron in the configuration of the ground level lowers its dissociation energy. Similar remarks apply to the types BeF and NO and the new correlation of molecular terms to atomic states from the pair-bond view is shown to be satisfactory without exception in a larger number of molecules of these three classes, recently.
These three types represent molecules with free valencies and indeed just in such molecules the difference of the two view-points must become apparent. For other such molecules with free valencies, whose band spectrum is investigated in detail,
Volume 3 Issue 5 May 1936 pp 487-511
On the absorption spectra and linkage of inorganic nitrates and sulphates in the vapour state
Volume 3 Issue 6 June 1936 pp 562-565
Volume 5 Issue 3 March 1937 pp 235-243
Some remarks on the birge-sponer method of vibrational extrapolation
Volume 5 Issue 3 March 1937 pp 244-248
Note on the structure of N2+ and its bearing on the theory of valency
Volume 6 Issue 5 November 1937 pp 257-265
Volume 12 Issue 6 December 1940 pp 513-518
R K Asundi S Mujtaba Karim R Samuel
From the experimental conditions under which the spectra are obtained it is assumed that they are due to molecular radiation. Thermochemical and spectrascopic data enable one to illustrate the relation among the energy levels of the various systems in the formation of the multi-atomic molecules from their constituent atoms. Such simplified Franck-Condon diagrams are constructed for SnCl4 (which includes SnCl2) and SiCl4. An interpretation, uniform in all cases, of the observed continuous bands in terms of the transitions among the energy levels, transitions, which of course involve a repulsive state for their final level, is suggested.
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