Rayleigh depolarization

B. Simic-Glavaski and D. A. Jackson, Rayleigh depolarized light scattered from isotropic and anisotropic molecular liquids. 5. Phys. (Paris), 55 C1 183-C1 189 (1972). 

Results shown for the liquid are averages. Dipole moments are in debye and dipole polarizabilities (average and anisotropic) are in a.u. Rayleigh depolarizations (cr for natural, planar and circular polarizations) are dimensionless. Standard deviations are also shown. 

By combining classical samplings with quantum chemistry semiempirical TDHF calculations the impact of dynamic fluctuations on the first hyperpolarizability of helical strands has been evidenced . In particular, these fluctuations are responsible for relative variations of 20% in the hyper-Rayleigh responses in both pyridine-pyrimidine (py-pym) and hydrazone-pyrimidine (hy-pym) strands. Dynamical disorder has an even more important impact on the electric field-induced second harmonic generation responses, whose variations can reach 2 (py-pym) or 5 (hy-pym) times their mean value. These results demonstrate that geometrical fluctuations have to be taken into account for a reliable description of the second-order NLO properties in flexible structures such as helical strands. This work has also highlighted the relationships between the nature of the unit cell and the helical conformation of foldamers and their second-order NLO responses. In particular, the value of the hyper-Rayleigh depolarization ratio, which is characteristics of octupolar symmetry, is related to the helix periodicity, of three unit cells per turn in both compounds. 

W.F. Murphy, The Rayleigh depolarization ratio and rotational Raman spectium of water vapor and the polarizability components for the water molecule. J. Chem. Phys. 67(12), 5877-5882 (1977)... 

W. F. Murphy, /. Chem. Phys., 67, 5877 (1977). The Rayleigh Depolarization Ratio and Rotational Raman Spectrum of Water Vapor and the Polarizability Components for the Water Molecule. 

The same information may be obtained from purely rotational far infrared spectroscopy (FIR) and depolarized Rayleigh spectra. Dielectric relaxation measurements are also used for the same goal, most successfully in combination with far-infrared data. The absorption coefficient of a periodic electric field... 

The moments are determined experimentally as for nitrogen in [5, 106] using Rayleigh and Raman depolarized scattering spectra. 

De Santis A., Sampoli M., Morales P, Signorelli G. Density evolution of Rayleigh and Raman depolarized scattering in fluid N2. Mol. Phys. 35, 1125-40 (1978). 

De Santis A., Nardone M., Sampoli M. Correlation functions from depolarized Raman and Rayleigh spectra of N2 at high density and 150 K, Mol. Phys. 41, 769-77 (1980). 

Conde O, Teixerira JJ. Hydrogen bond dynamics in water studied by depolarized Rayleigh scattering. Physics 1983 44 525-529. 

The processes observed in the depolarized Rayleigh spectrum correspond to internal modes of motion. Thus, they may have relaxation times which substantially exceed those obtained from the longitudinal or bulk relaxation alone. Nevertheless they are a part of the a relaxation process as it is normally observed in the creep compliance. All processes with the same shift factors make up the full a relaxation. In liquids with substantial depolarized Rayleigh scattering the slowly relaxing part of the W scattering is also dominated by the orientation fluctuations associated with the internal modes of motion. Each internal mode contributes some intensity, but it is believed that fairly short wavelength modes dominate the scattered intensity. 

A measurement of the Kerr relaxation times in succinoni-trile(SN)as a function of temperature is shown in Fig. 2. The Kerr relaxation times measured show the effect of temperature on the rotational motion of the SN molecules as they undergo a change from the liquid to the plastic crystal phase. The data obtained from the Kerr gate measurement is shown along with a best fit curve from depolarized Rayleigh scattering (dotted line), and a best fit curve from dielectric relaxation measure-... 

Keyes T, Kivelson D, McTague JP. Theory of k-independent depolarized Rayleigh wing scattering in liquids composed of anisotropic molecules. J Chem Phys 1971 55 4096-4100. 

Keyes T, Kivelson D. Depolarized light scattering theory of the sharp and broad Rayleigh lines. I Chem Phys 1972 56 1057-1065. 

Bauer DR, Braumann JI, Pecora R. Depolarized Rayleigh scattering and orientational relaxation of molecules in solution. IV. Mixtures of hexafluorobenzene with benzene and mesitylene. I Chem Phys 1975 63 53-60. 

Danninger W, Zundel G. Reorientational motion and orientational correlation functions in weakly associated organic liquids by depolarized Rayleigh scattering. Chem Phys Lett 1982 90 69-75. 

Patterson GD, Griffiths JE. Raman and depolarized Rayleigh scattering in the liquid state reorientational motions and correlations in orientation for symmetric top molecules. J Chem Phys 1975 63 2406-2413. 

Schmidt RL. Temperature dependence of Rayleigh light scattering and depolarization in pure liquids. J Colloid Interface Sci 1968 27 516-528. 

Bauer DR, Alms GR, Braumann JI, Pecor R. Depolarized Rayleigh scattering and 13C NMR studies of anisotropic molecular reorientation of aromatic compounds in solution. J Chem Phys 1974 61 2255-2261. 

Cheung CK, Jones DR, Wang CH. Single particle reorientation and pair correlations of methyl iodide solutions studied by depolarized Rayleigh and Raman scattering. J Chem Phys 1976 64 3567-3572. 

Kaye W, McDaniel JB (1974) Low-angle laser light scattering - Rayleigh factors and depolarization ratios Appl Opt 13 1934-1937... 

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