Optical rotary power

In the ab initio approach the desired answers are the experimental observables - spectral line positions, shapes, intensities scattering and reaction rates polarizabilities and optical rotary power etc. These are to be obtained from the Schrodinger equation by numerical methods which are mathematically well-defined and involve no intermediate parameters not appearing in the Schrodinger equation itself. 

Y. Suzuki, K. Ozawa, A. Hosoki, and K. Ichimura, Reversible change in the optical rotary power ofpoly(L-glutamate) thin film induced by photochromism of a spiropyran, Polym. Bull. 17, 285— 291 (1987). 

Optical rotary power - Angle by which the plane of polarization of a light beam is rotated by an optically active medium, divided by path length and by concentration of the active constituent. Depending on whether mass or molar concentration is used, the modifier specific or molar is attached. [2]... 

R. Williams, Optical-Rotary Power and Linear Electro-Optic Effect in Nematic Liquid Crystals of p-Azoxyanisole, J. Chem. Phys., Vol. 50, p. 1324 (1969) and D. Meyerhofer, A. Sussman, and R. Williams, Electro-Optic and Hydrodynamic Properties of Nematic Liquid Films with Free Surfaces, J. Appl. Phys., Vol. 43, p. 3685 (1972). J. S. Smart, Effective Field Theories of Magnetism, W. B. Saunders Co., Philadelphia, Pa. (1966). 

Lowry, T. M., Optical Rotary Power, New York, Dover, Mineola, NY, 1964. 

We very soon realized that in the majority of cases their optical activity depended on the chemical reactivity and not on conformational changes. At present we employ optical rotary power, ORD and CD for studying the chemical behaviour of macro-roolecules. 

It must be noted that the dispersive effect that complicates the ORD curves presents nevertheless an advantage. Measurements of optical rotary power or ORD far from the COTTON effects can give valuable information about the electronic transitions situated in the UV region and, consequently, about the corresponding chromophores. Moreover, an analytical comparison between ORD and CD will provide, by difference, information on the inaccessible COTTON effects. Finally since the COTTON effect can be positive or negative, transitions that are so frequently overlapped that they become almost indistinguishable on the absorption spectra can often be discerned - even only partially - on the CD curves. 

Simultaneous measurements of optical rotary power at 436 nm, of the pH and of the phenate-ion absorption at 293 in function of t show that there is a linear relation between variations in the optical activity and the degree of neutralisation (Figure 4)... 

Even in the more complex cases [16] if the optical rotary powers of the limiting forms are known then the pK s of the functions can be calculated from these straight lines by using the additivity law of contributions of different optically active species i ... 

Fig. 8. Variation in the optical rotary power of a 6.10 M/1 solution of (K) in methanoU-Ca02 in function of the proportion of CaCbCr = CaCh/CF)) at 300 nm and at 400 nm.

The modifications in the COTTON effects also affect the optical rotary power that is measured in the visible region in function of the degree of neutralisation (Figure 13). 

T he shapes of the curves are the same as for the model (Figure 4), but it must be noted that variations in the optical rotary power and in the absorption of the phenate ion do not vary in a linear fashion with the degree of neutralisation of the totality of ionizable groups and that the extreme values do not correspond to the theoretical equivalences of each of the functions. 

---