Optical activity of oriented molecules

Kuball, H.‐G.; Karstens, Ties; Schönhofer, Alfred

doi:10.1016/0301-0104(76)80105-x

Cited by 44 publications

(13 citation statements)

References 40 publications

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“…The results of 2 have been discussed earlier. 4•17 For the 5/3-androstenones the degree of polarization is about zero. But certainly this does not mean that there is no orientation, because all other compounds of similar structure are oriented to a large extent.…”

Section: Resultsmentioning

confidence: 99%

“…AiA(F) (Figures [3][4][5][6][7][8][9][10][11][12][13] or the RT's (Table I) of the molecules studied exhibit a very different behavior. In spite of the fact that the series A (1,3,4, and 5) and B (6,7, and 8) have a very similar negative CD in the isotropic solution, the anisotropic CD (AeA(F) changes its sign or has a bisignated curvature for series A, while there is only a very small or no change in the CD for series B.…”

Section: Resultsmentioning

confidence: 99%

“…4 if the light propagates parallel to the axis x,, ( a = 1 , 2, 3; x i = x; x 2 = J J ; x j = z ) as shown in Figure I . 4 if the light propagates parallel to the axis x,, ( a = 1 , 2, 3; x i = x; x 2 = J J ; x j = z ) as shown in Figure I .…”

Section: Introductionmentioning

confidence: 99%

“…For the series A an increase of p in the sequence 3 (p = 0.24), 4 (0.26), 5 (0.27), and 1 (0.32) occurs. The longer the chain of the 17/3 substituent is, the larger the order will be.…”

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confidence: 99%

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Optical activity of oriented molecules. 5. .alpha.,.beta.-Unsaturated keto steroids

Kuball¹,

Acımış²,

Altschuh³

1979

J. Am. Chem. Soc.

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Venkataram Prasad, 8. V.: Prashanth, D.; Balaram, P. international Symposium on Biomolecular Structure, Conformation, Function and Evolution, Madras, 1978, Abstract 130IH17. Reisse, J.; Ottinger, R,: Bickart, P.; Mislow, K. J. Am. Chem. Soc. 1978, 100,911-915. Mislow, K.; Raban. M. Top. Stereochem. 1967, 7, 1--38. Klotz, I. M.; Russo. S. F.: Hanlon, S.; Stake, M. A. J. Am. Chem. SOC. 1964, 86, 4774-4778. Abu Khaled, Md.; Urry, D. W.; Okamoto, K. Biochem. Biophys. Res. Commun. 1976, 72, 162-169. Avignon, M.; Huong, P. V.; Lascombe, J.; Marraud, M.; Neel, J. Biopoiymers 1969, 8, 69-89.Abstract: The CD (IC)'(;)) of a transition K k -N n of :in anisotropic solution is determined b) order coefficients g,,33, the tensor of rotation R;"". and its frequency dependence G;,Yhk: A t ' ( ; ) = \-' -,=, \" gi,l~R~""kG~;". For cholest-4-en-3-one. the l7$-substituted testosterones. Swandrost-I -en-3-oncs, and 53-androst-I -en-3-ones oriented in 11 liquid crystal matrix (cholesteryl chloride/cholcster).i laurate) it is shown that the information from the C D o f t h e anisotropic solution goes beyond t h a t obtained from the isotropic CD. E.g.. compound5 which have nearly identical C D hpectru in the isotropic state behave very differently in the oriented state. Furthermore. AtZ(l') depends on the I73 substitution. This can be explained b) 11 variation of the order parameter as ;I function of the length of the substituent: i.c.. for cholcst-4-en-3-one and the testosterones the order increases in the succession -OH. -0COCH3, -0COCH2CHj. -CH(CH3)CH$~H2CH2CH(CH3)2. The coordinates KplK + and K;: of the tcnsor of rotation arc estimated and ;in estimation of the contribution of thequadrupole transition moment is attempted

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…For the series A an increase of p in the sequence 3 (p = 0.24), 4 (0.26), 5 (0.27), and 1 (0.32) occurs. The longer the chain of the 17/3 substituent is, the larger the order will be.…”

mentioning

confidence: 99%

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Optical activity of oriented molecules. 5. .alpha.,.beta.-Unsaturated keto steroids

Kuball¹,

Acımış²,

Altschuh³

1979

J. Am. Chem. Soc.

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“…Dij is the tensor of the electric dipole transition moments, R Y K k is the tensor of rotation [5], FNnKk(V) and GNnKk(V) are the spectral functions of the vibronic transition INn) --* IKk) for UV and CD, respectively, and V is the wavenumber. is equal to zero iff = f ( B ) or in the special cases where p = 0 or 1.…”

Section: Theorymentioning

confidence: 99%

Optical Activity of Oriented Molecules. 10.Analysis of the n‐π Transition of 4‐en‐3‐one Steroids and Comparison of the Order Parameters of Host and Guest in a Compensated Nematic Phase

Altschuh

Weiland

Kosack

et al. 1984

Ber Bunsenges Phys Chem

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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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Temperature Dependence of the Intrinsic Pitch in Induced Cholesteric Systems

Finkelmann

Stegemeyer

1978

Ber Bunsenges Phys Chem

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Based on the molecular‐statistical theory of Goossens a model has been developed to explain the temperature dependence of the intrinsic pitch in cholesteric systems induced in nematic host phases by chiral guest molecules. In the case of a rotational symmetric distribution function around the long axis of the chiral molecule the helix inducing dipole‐quadrupole interaction forces level out. Consequently, only a hindered long‐axis rotation causes the helical structure whose pitch increases with increasing temperature. The theoretically predicted value of the relative temperature gradient of reciprocal pitch 1/p−1 (dp−1/dT) are in good agreement with the presented experimental data. The influence of structure of the chiral guest molecules on the helical twisting power as well as that of the nematic host phases also can be understood in terms of the proposed model.

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Optical activity of oriented molecules

Cited by 44 publications

References 40 publications

Optical activity of oriented molecules. 5. .alpha.,.beta.-Unsaturated keto steroids

Optical activity of oriented molecules. 5. .alpha.,.beta.-Unsaturated keto steroids

Optical Activity of Oriented Molecules. 10.Analysis of the n‐π Transition of 4‐en‐3‐one Steroids and Comparison of the Order Parameters of Host and Guest in a Compensated Nematic Phase

Temperature Dependence of the Intrinsic Pitch in Induced Cholesteric Systems

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