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Such optical activity due to extrinsic chirality was observed in the 1960s in liquid crystals. [28] [29] In 1950, Sergey Vavilov [30] predicted optical activity that depends on the intensity of light and the effect of nonlinear optical activity was observed in 1979 in lithium iodate crystals. [31] Optical activity is normally observed for ...
Laurence David Barron FRS, FRSE (born 12 February 1944 in Southampton, England) has been Gardiner Professor of Chemistry at the University of Glasgow since 1998 (now Emeritus). [1] He is a chemist who has conducted pioneering research into the properties of chiral (right- or left-handed) molecules — defined by Lord Kelvin as those that cannot ...
The optical activity of enantiomers is additive. If different enantiomers exist together in one solution, their optical activity adds up. That is why racemates are optically inactive, as they nullify their clockwise and counter clockwise optical activities. The optical rotation is proportional to the concentration of the optically active ...
Louis Pasteur - pioneering stereochemist. Chirality can be traced back to 1812, when physicist Jean-Baptiste Biot found out about a phenomenon called "optical activity." [10] Louis Pasteur, a famous student of Biot's, made a series of observations that led him to suggest that the optical activity of some substances is caused by their molecular asymmetry, which makes nonsuperimposable mirror ...
An object that cannot be superimposed on its mirror image is said to be chiral, and optical rotatory dispersion and circular dichroism are known as chiroptical properties. Most biological molecules have one or more chiral centers and undergo enzyme-catalyzed transformations that either maintain or invert the chirality at one or more of these ...
In chemistry, racemization is a conversion, by heat or by chemical reaction, of an optically active compound into a racemic (optically inactive) form. This creates a 1:1 molar ratio of enantiomers and is referred to as a racemic mixture (i.e. contain equal amount of (+) and (−) forms).
Chiral resolution, or enantiomeric resolution, [1] is a process in stereochemistry for the separation of racemic mixture into their enantiomers. [2] It is an important tool in the production of optically active compounds, including drugs. [3]
Raman optical activity can be observed in a number of forms, depending on the polarization of the incident and the scattered light. For instance, in the scattered circular polarization (SCP) experiment, the incident light is linearly polarized and differences in circular polarization of the scattered light are measured.