Rayleigh-Wing Scattering by Aromatic Liquids

Measurements are reported of the intensities of the diffuse line and background components of the depolarized light scattered from six aromatic liquids (nitrobenzene, quinoline, bromobenzene, and the three nitrotoluenes), and their variation with temperature. Intensity of the diffuse line in nitrobenzene and its temperature dependence, together with half-width measurements, are compatible with the suggestion that it originates from orientational relaxation by tumbling of mostly uncorrelated molecules. In quinoline a more appreciable orientational correlation between neighboring molecules apparently exists. The background component of these liquids increases with temperature in a manner suggestive of fluctuations from momentary orientational equilibrium.