Anisotropic sample / Liquid Crystals / Order parameters / Spectroscopy, CD-ORD / Spectroscopy, UltravioletWhile different substitution in the 17 p-position of 4-en-3-one steroids (testosterones, progesterones) does not influence the CD spectra, the CD of the anisotropic solutions (ACD) undergoes a drastic variation of the band shape connected with a change from negative to positive curves. From this variation and the wavelength dependence of the degree of polarization of the UV spectra results that at least two progressions of vibrations (iim + nii, and Vo0 + 1, + n 1 , ) are responsible for the band structure of the n-A* transition of the 4-en-3-one chromophore where the totally symmetric (Y1) and the non-totally symmetric vibration (V,) are about 1200 and 600 cm-', respectively. Furthermore, this variation of the ACD spectra for constant temperature and solute (guest) to solvent (host: cholesteryl chloride/cholesteryl laurate) ratio is a consequence of a change of the order parameter of the guest and the host which have been determined in the same solution by ACD and AORD, respectively. Most variation of the guest order can be understood by the proportionality to the anisotropy of the polarizability 2a33-a22-a,, or the length to width ratio 2/3-/2-/, if no hydroxy group is present. Here a very high order exists. For some compounds the high order of the guest is connected with a strong decrease of the host order. In general, the alteration of the host order is not a function of the order of the guest i.e. at least one molecular property responsible for the ordering of the guest should be different from those properties of the guest which alterate the order of the host.
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