Info

FIGURE 3 The rotation of plane-polarized light by the 1- and e/-enantiomers of an optically active substance. In the illustration the plane-polarized light is being propagated in a plane perpendicular to the plane of the page.

levorotatory I- isomer dextrorotatory d-isomer

FIGURE 3 The rotation of plane-polarized light by the 1- and e/-enantiomers of an optically active substance. In the illustration the plane-polarized light is being propagated in a plane perpendicular to the plane of the page.

as the specific rotation [a] of a substance, and is expressed by the following formulas (2); For liquid substances, [a]'x = a/Id; for solutions, [a]lx = 100 a/Ic; where a is the corrected observed rotation in degrees at temperature t and wavelength x; 1 is the length of the polarimeter tube in decimeters; d is the specific gravity of the liquid at the temperature of observation; c is the concentration of the solution expressed as the number of grams of substance per 100 ml of solution. As indicated by these formulas, the specific rotation is dependent on the concentration of the solution or density of the pure liquid, the distance through which the light travels, the wavelength of the light, and the temperature at which the measurements are made.

Was this article helpful?

0 0

Post a comment