Vibration spectra of crystal hydrates of aluminum nitrate

Dependence of band intensity in pre‐resonance Raman scattering from molecules

“…5. This circumstance necessitates refinement of the evaluation of the role of both terms, which are under the sum sign in Eqn (2) and are given in Ref. 5.…”

“…Clearly, this indicates that resonance denominators influence the frequency dependence process of RS bands, i.e. degrees of removing the exciting ω 0 frequency from the actual electron absorption band ω j position contributing to the value of˛in the Eqn (2). Since this fact occurs in the experiment, one cannot neglect the dependence on ω 0 denominators in the Eqn (2).…”

“…degrees of removing the exciting ω 0 frequency from the actual electron absorption band ω j position contributing to the value of˛in the Eqn (2). Since this fact occurs in the experiment, one cannot neglect the dependence on ω 0 denominators in the Eqn (2). The location of actual bands, and thus the validity of the assumption of scattering by electron vibration transition, can be determined by selection of a suitable ω j value such that the best calculated curve of frequency dependence of RS lines intensity agrees with the experimental data.…”

“…1,2 These investigations showed that particularly fast growth of the RS line intensity occurs in those normal modes of a molecule which are largely deforming its electron shell. Thus, in benzene the vibration at 992 cm 1 causes significant deformation of the -electron shell of the molecule, which probably determines the abnormal intensity increase by a factor of 10.3 on passing from the exciting line of mercury at 435.8 nm to the line at 313.1 nm, while the intensity of the peripheral stretching vibrations of benzene at 3062 cm 1 increases only 4.1 fold.…”