Theory of induced infra-red absorption

✍ Scribed by J. van Kranendonk

• Publisher: Elsevier Science
• Year: 1957
• Weight: 675 KB
• Volume: 23
• Category: Article
• ISSN: 0031-8914
• DOI: 10.1016/s0031-8914(57)94898-x

✦ Synopsis

Synopsis

A general formalism is developed for the calculation of the density and temperature dependence of the intensity of forbidden rotation-vibration bands that are induced by the intermolecular forces. Expressions are derived for the integrated absorption coefficients, and a qualitative discussion is given of the translational absorption arising from the dependence of the induced dipole moments on the intermolecular separations. The expansion of the total integrated absorption coefficient in powers of the density is given, expressions are derived for the binary and ternary absorption coefficients appearing in this expansion, and the interference effects occurring in the absorption due to clusters of three and more molecules are discussed. Expressions for the integrated absorption coefficients corresponding to definite rotational transitions, and their density expansions, are also given. The concepts of single and double transitions are introduced, and the interference effects are shown to appear only for single transitions.