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Optical activity occurs due to molecules dissolved in a fluid or due to the fluid itself only if the molecules are one of two (or more) stereoisomers; this is known as an enantiomer. The structure of such a molecule is such that it is not identical to its mirror image (which would be that of a different stereoisomer, or the "opposite enantiomer").
For example, if a solution of β-D-glucopyranose is dissolved in water, its specific optical rotation will be +18.7°. Over time, some of the β-D-glucopyranose will undergo mutarotation to become α-D-glucopyranose, which has an optical rotation of +112.2°. The rotation of the solution will increase from +18.7° to an equilibrium value of +52 ...
Specific rotation is an intensive property, distinguishing it from the more general phenomenon of optical rotation. As such, the observed rotation ( α ) of a sample of a compound can be used to quantify the enantiomeric excess of that compound, provided that the specific rotation ( [α] ) for the enantiopure compound is known.
where v is a vibrational quantum number and α is a vibration-rotation interaction constant which can be calculated if the B values for two different vibrational states can be found. [ 7 ] For other molecules, if the spectra can be resolved and individual transitions assigned both bond lengths and bond angles can be deduced.
In all materials the rotation varies with wavelength. The variation is caused by two quite different phenomena. The first accounts in most cases for the majority of the variation in rotation and should not strictly be termed rotatory dispersion. It depends on the fact that optical activity is actually circular birefringence.
Two enantiomers of a generic amino acid that is chiral. Chiral molecules have two forms (at each point of asymmetry), which differ in their optical characteristics: The levorotatory form (the (−)-form) will rotate counter-clockwise on the plane of polarization of a beam of light, whereas the dextrorotatory form (the (+)-form) will rotate clockwise on the plane of polarization of a beam of ...
Le Bel-van't Hoff rule states that for a structure with n asymmetric carbon atoms, there is a maximum of 2 n different stereoisomers possible. As an example, D-glucose is an aldohexose and has the formula C 6 H 12 O 6. Four of its six carbon atoms are stereogenic, which means D-glucose is one of 2 4 =16 possible stereoisomers. [20] [21]
Glucose is a sugar with the molecular formula C 6 H 12 O 6.It is overall the most abundant monosaccharide, [4] a subcategory of carbohydrates.It is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight.