Search results
Results from the WOW.Com Content Network
Chirality (chemistry) Two enantiomers of a generic amino acid that are chiral. (S)-Alanine (left) and (R)-alanine (right) in zwitterionic form at neutral pH. In chemistry, a molecule or ion is called chiral (/ ˈkaɪrəl /) if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational ...
A chiral molecule is a type of molecule that has a non-superposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom. [16] [17] The term "chiral" in general is used to describe the object that is non-superposable on its mirror image. [18]
Solvolysis. In chemistry, solvolysis is a type of nucleophilic substitution (S N 1/S N 2) or elimination where the nucleophile is a solvent molecule. [ 1 ] Characteristic of S N 1 reactions, solvolysis of a chiral reactant affords the racemate. Sometimes however, the stereochemical course is complicated by intimate ion pairs, whereby the ...
Mutarotation. In stereochemistry, mutarotation is the change in optical rotation of a chiral material in a solution due to a change in proportion of the two constituent anomers (i.e. the interconversion of their respective stereocenters) until equilibrium is reached. Cyclic sugars show mutarotation as α and β anomeric forms interconvert. [1]
There are three common naming conventions for specifying one of the two enantiomers (the absolute configuration) of a given chiral molecule: the R/S system is based on the geometry of the molecule; the (+)- and (−)- system (also written using the obsolete equivalents d- and l-) is based on its optical rotation properties; and the D/L system is based on the molecule's relationship to ...
The term chiral / ˈkaɪrəl / describes an object, especially a molecule, which has or produces a non-superposable mirror image of itself. In chemistry, such a molecule is called an enantiomer or is said to exhibit chirality or enantiomerism. The term "chiral" comes from the Greek word for the human hand, which itself exhibits such non ...
Optical rotation, also known as polarization rotation or circular birefringence, is the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials. Circular birefringence and circular dichroism are the manifestations of optical activity.
For example, the water molecule has three normal modes of vibration: symmetric stretch in which the two O-H bond lengths vary in phase with each other, asymmetric stretch in which they vary out of phase, and bending in which the bond angle varies. The molecular symmetry of water is C 2v with four irreducible representations A 1, A 2, B 1 and B 2.