Optical anisotropies of nematogens from the depolarized rayleigh spectra

Authors:

• G. Floudas,
• Adam Patkowski,
• G. Fytas,
• M. Ballauff

Abstract

Depolarized Rayleigh spectra recorded with a planar Fabry-Perot interferometer have been used to determine the intrinsic optical anisotropy γ² oligomers of several p-oxybenzoate oligomers and several solvents. The VH (V, vertical; H, horizontal) spectrum of benzene was used as a standard with the absolute Rayleigh ratio R_VH(25°C) = 2.67 × 10^-6 cm^-1 at 488 nm. The broad collision-induced background can be excluded since the Fabry-Perot interferometry allows the determination of the much narrower Lorentzian line of the depolarized spectra that contains the molecular anisotropy γ². The constitutive scheme for construction of the anisotropy of the molecular polarizability tensor with the group increments is in agreement with the experimental γ² of the oligomers. This corroborates the notion that measurements of γ² are highly useful for determination of conformational parameters. © 1990 American Chemical Society.