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  2. Stereochemistry - Wikipedia

    en.wikipedia.org/wiki/Stereochemistry

    Stereochemistry, a subdiscipline of chemistry, studies the spatial arrangement of atoms that form the structure of molecules and their manipulation. [1] The study of stereochemistry focuses on the relationships between stereoisomers, which are defined as having the same molecular formula and sequence of bonded atoms (constitution) but differing in the geometric positioning of the atoms in space.

  3. Tacticity - Wikipedia

    en.wikipedia.org/wiki/Tacticity

    The stereochemistry of macromolecules can be defined even more precisely with the introduction of triads. An isotactic triad (mm) is made up of two adjacent m diads, a syndiotactic triad (also spelled syndyotactic [4]) (rr) consists of two adjacent r diads, and a heterotactic triad (rm) is composed of an r diad adjacent to an m diad.

  4. Stereoisomerism - Wikipedia

    en.wikipedia.org/wiki/Stereoisomerism

    In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space.

  5. Le Bel–Van 't Hoff rule - Wikipedia

    en.wikipedia.org/wiki/Le_Bel–Van_'t_Hoff_rule

    In organic chemistry, the Le Bel–Van 't Hoff rule states that the number of stereoisomers of an organic compound containing no internal planes of symmetry is 2 n, where n represents the number of asymmetric carbon atoms.

  6. Stereocenter - Wikipedia

    en.wikipedia.org/wiki/Stereocenter

    In stereochemistry, a stereocenter of a molecule is an atom (center), axis or plane that is the focus of stereoisomerism; that is, when having at least three different groups bound to the stereocenter, interchanging any two different groups creates a new stereoisomer. [1] [2] Stereocenters are also referred to as stereogenic centers.

  7. Absolute configuration - Wikipedia

    en.wikipedia.org/wiki/Absolute_configuration

    Absolute configuration showing the determination of the R and S descriptors. In chemistry, absolute configuration refers to the spatial arrangement of atoms within a molecular entity (or group) that is chiral, and its resultant stereochemical description. [1]

  8. E–Z notation - Wikipedia

    en.wikipedia.org/wiki/E–Z_notation

    E–Z configuration, or the E–Z convention, is the IUPAC preferred method of describing the absolute stereochemistry of double bonds in organic chemistry. It is an extension of cis–trans isomer notation (which only describes relative stereochemistry) that can be used to describe double bonds having two, three or four substituents. E and Z ...

  9. Cahn–Ingold–Prelog priority rules - Wikipedia

    en.wikipedia.org/wiki/Cahn–Ingold–Prelog...

    Stereochemistry also plays a role assigning faces to trigonal molecules such as ketones. A nucleophile in a nucleophilic addition can approach the carbonyl group from two opposite sides or faces. When an achiral nucleophile attacks acetone , both faces are identical and there is only one reaction product.