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In stereochemistry, prochiral molecules are those that can be converted from achiral to chiral in a single step. [1] [2] An achiral species which can be converted to a chiral in two steps is called proprochiral. [2] If two identical substituents are attached to an sp 3-hybridized atom, the descriptors pro-R and pro-S are used to distinguish ...
Instead, both effects can also occur when the propagation direction of the electromagnetic wave together with the structure of an (achiral) material form a chiral experimental arrangement. [10] [11] This case, where the mutual arrangement of achiral components forms a chiral (experimental) arrangement, is known as extrinsic chirality. [12] [13]
One example is the chiral amino acid alanine, which has two optical isomers, and they are labeled according to which isomer of glyceraldehyde they come from. On the other hand, glycine , the amino acid derived from glyceraldehyde, has no optical activity, as it is not chiral (it's achiral).
Helices, chiral characteristics (properties), chiral media, [2] order, and symmetry all relate to the concept of left- and right-handedness. [ 3 ] [ 4 ] Types of chirality
An achiral molecule having chiral conformations could theoretically form a mixture of right-handed and left-handed crystals, as often happens with racemic mixtures of chiral molecules (see Chiral resolution#Spontaneous resolution and related specialized techniques), or as when achiral liquid silicon dioxide is cooled to the point of becoming ...
In this approach, an enantiomerically pure compound, the chiral selector, is added to the mobile phase and separation happens on a conventional achiral column. When a mixture of enantiomers is introduced into the chromatographic system, the individual enantiomers form transient diastereomeric complexes with the chiral mobile phase additive.
In stereochemistry, a chiral auxiliary is a stereogenic group or unit that is temporarily incorporated into an organic compound in order to control the stereochemical outcome of the synthesis. [1] [2] The chirality present in the auxiliary can bias the stereoselectivity of one or more subsequent reactions. The auxiliary can then be typically ...
The simplest chiral knot is the trefoil knot, which was shown to be chiral by Max Dehn. All nontrivial torus knots are chiral. The Alexander polynomial cannot distinguish a knot from its mirror image, but the Jones polynomial can in some cases; if V k ( q ) ≠ V k ( q −1 ), then the knot is chiral, however the converse is not true.