Dynamic stereochemistry refers to the study of stereochemical aspects of molecules that are in constant motion or undergoing rapid conformational changes. Unlike traditional stereochemistry, which often focuses on static conformations and fixed spatial arrangements of atoms in molecules, dynamic stereochemistry examines how these arrangements can change over time due to factors like heat, solvent interactions, or reactions.
Enantiomer self-disproportionation is a phenomenon observed in asymmetric reactions where a racemic mixture (a 1:1 mixture of two enantiomers) separates into two fractions that have differing concentrations of the enantiomers. In simpler terms, it describes a process in which two enantiomers in a mixture can separate such that one of the enantiomers is more prevalent in one portion of the mixture than in the other.
Enantiomeric excess (ee) is a measure of the purity of a chiral compound in terms of the proportion of one enantiomer relative to the other. Enantiomers are pairs of molecules that are non-superimposable mirror images of each other, and they often differ in their biological activity and properties.
Enantioselective synthesis refers to a process in chemistry where a chemical reaction produces one enantiomer (a specific chiral form) over another in a preferential manner. Enantiomers are molecules that are non-superimposable mirror images of each other, similar to how left and right hands are related.
An epimer is a type of stereoisomer that differs from another compound in the configuration around just one specific stereogenic center (chiral center). This means that while the two compounds have the same molecular formula and may be very similar overall, they have different spatial arrangements of atoms at only one of their chiral centers. Epimers are particularly common in carbohydrate chemistry. For example, glucose and galactose are epimers because they differ at only one carbon atom (C4).
The term "Eudysmic ratio" is not widely recognized in mainstream scientific literature, and it may not refer to a well-defined concept in fields such as biology, medicine, or related sciences. It could be a term used in a specific niche or by a particular research group.
E–Z notation is a system used in organic chemistry to describe the stereochemistry of alkenes, specifically the relative positions of substituents attached to the double bond. It is particularly useful when there are multiple substituents on both sides of the carbon-carbon double bond (C=C). The notation is based on the Cahn-Ingold-Prelog priority rules, which assign priorities to different substituents based on atomic number and other factors.
A Fischer projection is a two-dimensional representation of a three-dimensional organic molecule, specifically used for depicting the stereochemistry of carbohydrates and amino acids. It was developed by Emil Fischer in the early 20th century. In a Fischer projection, the molecule is represented as a vertical and horizontal arrangement of bonds. The vertical lines represent bonds that project away from the viewer (into the plane of the paper), while the horizontal lines represent bonds that project towards the viewer (out of the plane of the paper).
The Gauche effect refers to a conformational preference observed in certain organic molecules, particularly in butane and other alkanes. In these molecules, the Gauche conformation is one where two substituents (or hydrogen atoms) are positioned approximately 60 degrees apart, which can lead to steric interactions and influences on the overall stability of the molecule.
Homochirality refers to the phenomenon where biological molecules, such as amino acids and sugars, exhibit a preferential uniformity in their chirality, meaning they exist in one specific enantiomeric form rather than a mixture of both. In molecular chemistry, chirality describes the property of a molecule that is not superimposable on its mirror image, much like left and right hands.
Homometric structures refer to a concept in geometry and topology that pertains to the idea that two or more shapes can have the same or indistinguishable measurements, such as lengths or angles, despite being different in form or arrangement. In other words, two structures are considered homometric if they can be transformed into one another through a series of isometries (like rotation, translation, or reflection) while maintaining the same metric properties.
The Le Bel–Van 't Hoff rule, also known as the Le Bel-Van 't Hoff rule of stereochemistry, relates to the spatial arrangement of molecules and their optical activity. Specifically, it provides insight into the relationship between the number of stereocenters in a molecule and the number of possible stereoisomers.
A meso compound is a type of stereoisomer that has multiple stereocenters but is achiral due to an internal plane of symmetry. This means that even though it has chiral centers, the overall molecule is not optically active because one half is a mirror image of the other. Meso compounds typically have symmetrical structures, and this symmetry leads to their achirality.
Molecular configuration refers to the three-dimensional arrangement of atoms within a molecule, particularly how these atoms are bonded together and oriented in space. This includes aspects such as: 1. **Bond Lengths**: The distances between the nuclei of bonded atoms. 2. **Bond Angles**: The angles formed between adjacent bonds at a particular atom. 3. **Dihedral Angles**: The angles between two plane sections formed by four atoms in a molecule.
Mosher's acid, also known as (S)-(+)-2-methyl-2-(trifluoromethyl)benzoic acid, is a chiral auxiliary used in asymmetric synthesis. It is particularly useful for the resolution of enantiomers and for studying stereochemistry due to its ability to form stable complexes with chiral compounds.
Mutarotation is a phenomenon observed in solutions of certain carbohydrates, primarily reducing sugars, where the optical rotation of the solution changes over time until it reaches a stable equilibrium. This change in optical rotation occurs due to the interconversion between different anomeric forms of the sugar, particularly in the case of aldoses and ketoses. In aqueous solution, many aldoses can exist in two cyclic forms (anomers): the alpha (α) and beta (β) forms.
Noyori asymmetric hydrogenation is a chemical reaction developed by Japanese chemist Ryoji Noyori, which allows for the selective hydrogenation of prochiral ketones and other similar compounds to produce enantiomerically enriched alcohols. This reaction is particularly significant in the field of asymmetric synthesis, where the goal is to produce one specific enantiomer of a chiral product over the other.
Optical rotatory dispersion (ORD) is a phenomenon in which the optical rotation of a chiral substance varies with the wavelength of light. When plane-polarized light passes through a chiral medium, the plane of polarization is rotated by an amount that depends on the wavelength of the light. This effect is a consequence of the interaction between the light and the chiral molecules in the substance.
Protein primary structure refers to the unique sequence of amino acids that make up a protein. This sequence is determined by the genetic code and is crucial because it ultimately dictates how the protein will fold and function. Amino acids are linked together by peptide bonds to form a polypeptide chain, and the order of these amino acids is specified by the mRNA sequence during translation.