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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").
Recording optical rotation with a polarimeter: The plane of polarisation of plane polarised light (4) rotates (6) as it passes through an optically active sample (5). This angle is determined with a rotatable polarizing filter (7). In chemistry, specific rotation ([α]) is a property of a chiral chemical compound.
Glucose circulates in the blood of animals as blood sugar. [5] [7] The naturally occurring form is d-glucose, while its stereoisomer l-glucose is produced synthetically in comparatively small amounts and is less biologically active. [7] Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose ...
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 ...
Finding when r = 0.85 shows that the optical rotation of the solution after hydrolysis is done is −12.7° this reaction is said to invert the sugar because its final optical rotation is less than zero. A polarimeter can be used to figure out when the inversion is done by detecting whether the optical rotation of the solution at an earlier ...
The other refers to Optical rotation, when looking at the source of light, the rotation of the plane of polarization may be either to the right (dextrorotary — d-rotary, represented by (+), clockwise), or to the left (levorotary — l-rotary, represented by (−), counter-clockwise) depending on which stereoisomer is dominant. For instance ...
The notation is not to be confused with D and L naming of molecules which refers to the similarity in structure to D-glyceraldehyde and L-glyceraldehyde. Also, (R)- and (S)- refer to the chemical structure of the molecule based on Cahn–Ingold–Prelog priority rules of naming rather than rotation of light. R/S notation is the primary notation ...
The existence of specific conformations is due to hindered rotation around sigma bonds, although a role for hyperconjugation is proposed by a competing theory. The importance of energy minima and energy maxima is seen by extension of these concepts to more complex molecules for which stable conformations may be predicted as minimum-energy forms.