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Many chiral molecules have point chirality, namely a single chiral stereogenic center that coincides with an atom. This stereogenic center usually has four or more bonds to different groups, and may be carbon (as in many biological molecules), phosphorus (as in many organophosphates), silicon, or a metal (as in many chiral coordination compounds).
Chirality (/ k aɪ ˈ r æ l ɪ t i /) is a property of asymmetry important in several branches of science. The word chirality is derived from the Greek χείρ (kheir), "hand", a familiar chiral object. An object or a system is chiral if it is distinguishable from its mirror image; that is, it cannot be superposed (not to be confused with ...
A chirality center (chiral center) is a type of stereocenter. A chirality center is defined as an atom holding a set of four different ligands (atoms or groups of atoms) in a spatial arrangement which is non-superposable on its mirror image. Chirality centers must be sp 3 hybridized, meaning that a chirality center can only have single bonds. [5]
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 ...
are arranged around the chiral center carbon atom. With the hydrogen atom away from the viewer, if the arrangement of the CO→R→N groups around the carbon atom as center is counter-clockwise, then it is the L form. [14] If the arrangement is clockwise, it is the D form. As usual, if the molecule itself is oriented differently, for example ...
R-S isomerism of thalidomide. Chiral center marked with a star(*). Hydrogen (not drawn) is projecting behind the chiral centre. Enantiomers are molecules having one or more chiral centres that are mirror images of each other. [2] Chiral centres are designated R or S. If the 3 groups projecting towards you are arranged clockwise from highest ...
Axial chirality differs from central chirality (point chirality) in that axial chirality does not require a chiral center such as an asymmetric carbon atom, the most common form of chirality in organic compounds. Bonding to asymmetric carbon has the form Cabcd where a, b, c, and d must be distinct groups.
[5]: 1138ff First, while nevertheless appearing to be twisted, they yet may have a chiral center making them analogous to any simple chiral compound, and second, while again appearing twisted, the specific location of substituents, as with alkylidenecycloalkanes, may make a spiro compound display central chirality (rather than axial chirality ...