A free radical is an atom or group of atoms having a total of one unpaired electron. If an electron is unpaired, it can be easily bonded to another atom or molecule which causes a chemical reaction. When oxidative reactions occur resulting in an atom or molecule containing at least one unpaired electron the result is called a radical or free radical. Free radicals are reactive chemical species which tend to pair their unpaired electrons by reacting with other molecules and thereby reaching stability.
The various arrangements of ligands which are generated by the rotation of a single bond are conformations. If a certain conformation is stabilized energetically, it is said to be a conformer. Conformational isomers, or conformers, quickly interconvert around single bonds by rotation. Configuration isomers only convert with difficulty, and usually require bond breakage if they do. Conformational isomers vary only in the way their atoms are spatially oriented, they too are stereoisomers. Like any kind of stereoisomers a pair of conformers may or may not be mirror images of each other.
Free Radicals Chemistry
Most free radicals are electrically neutral, but some are ionic; in most cases, the unpaired electrons make free radicals extremely reactive. Free radicals typically are fragments of compounds that have been split apart by UV radiation or by chemical reactions between compounds and other free radicals and the unpaired electrons that cause these atoms or molecules to be classified as free radicals, and the unpaired electrons that cause these atoms or molecules to be classified as free radicals are the remnants of paired electrons that once occupied a single chemical bond in a molecule.
Free radicals are so unstable and reactive is the high energy state of the unpaired electron. This electron will seek to find another electron with which to pair up and create a stable chemical bond. Often, in order to pair up the high energy electron, the free radical will react with a molecule containing paired electrons in doing so the reaction will create a new free radical. In some cases, two free radicals will react and the result is molecules that are no longer free radicals, but usually, the result is the formation of a free radical chain reaction where a reaction of a free radical with a molecule containing paired electrons produces a new free radical and new molecule containing paired valence electrons and so on.
Stability of Conformers
Stereochemistry can be classified into configurational and conformational isomers, which are sometimes distinguished based on their stereochemistry stability. Interconversion of configurational isomers often requires bond breaking, whereas conformational isomers usually isomerize without bond breaking. Accordingly, a relatively high energy barrier to racemization or diastereomerization is commonly associated with configurational isomerism.
Conformational analysis is a description of stable conformers that assesses their molecular geometry and relative thermodynamics stability. Thus in the original understanding, this term reflects a static molecular shape usually it is not used when considering conformational dynamics. The molecular shape is conformational space where all the elements appear as pairs of related conforms interconverting with certain rates dependent on ambient conditions, that is it is an arranged set of stable conformers with related lifetimes.