In stereochemistry, gauche interactions hinder bond rotation. The different types of isomers. ... A chemical bond is the physical phenomenon (or phenomena) responsible for the attractive interactions betwen atoms that confers stability to di- and polyatomic chemical compounds. ...

For example, sighting along the C2-C3 bond in staggered butane, there are two possible relative potential energies. The two methyl groups can be in an anti-bonding relationship, or offset at sixty degree dihedral angles. In the latter configuration, the two methyls are said to be in a gauche relationship, and the relative potential energy of each methyl-methyl gauche interaction is 0.9 kilocalories per mole. In general a gauche rotamer is less stable than an anti rotamer. Butane, also called n-butane, is the unbranched alkane with four carbon atoms, CH3CH2CH2CH3. ... In the physical sciences, potential energy is energy which is captured within a physical system by virtue of the relative positions or configurations of objects, and which has the potential to be released when the system is allowed to attain a configuration with a lower energy state. ... In chemistry a methyl-group is a hydrophobic Alkyl functional group which is derived from methane (CH4). ... A calorie refers to a unit of energy. ... The mole (symbol: mol) is the SI base unit that measures an amount of substance. ...

Gauche effect

The Gauche effect characterizes any gauche rotamer which is actually more stable than the anti rotamer ^[1]. This effect is present in 1,2-difluoroethane (H₂FCCFH₂) for which the gauche conformation is more stable by 2.4 to 3.4 KJ/mole. Another example is 1,2-dimethoxyethane. In chemistry, a chemical conformation is the spatial arrangement of atoms in a molecule. ... The joule (symbol: J) is the SI unit of energy, which is defined as the potential to do work. ...

Key in the explanation of the gauche effect in difluoroethane is the increased p orbital character of both C-F bonds due to the large electronegativity of fluorine. As a result electon density builds up above and below to the left and right of the central C-C bond. The resulting reduced orbital overlap can be partially compensated when a gauche conformation is assumed, forming a bent bond. Electron configuration is the arrangement of electrons in an atom, molecule or other body. ... The electronegativities on this page are incorrect and need to be updated Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ...

The molecular geometry of both rotamers can be obtained experimentally by high resolution infrared spectroscopy augmented with in silico work ^[1]. In accordance with the model described above, the carbon - carbon bond length is higher for the anti rotamer (151.4 pm vs. 150). The steric repulsion between the fluorine atoms in the gauche rotamer causes increased CCF bond angles (by 3.2°) and increased FCCF dihedral angles (from the default 60° to 71°). Geometry of the water molecule Molecular geometry or molecular structure is the three dimensional arrangement of the atoms that constitute a molecule, inferred from the spectroscopic studies of the compound. ... IR spectrum of a thin film of liquid ethanol. ... in silico is an expression used to mean performed on computer or via computer simulation. ... In molecular geometry, bond length or bond distance is the distance between two bonded atoms in a molecule. ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ... Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ... In Aerospace engineering, the dihedral is the angle that the two wings make with each other. ...

In the related 1,2-difluorodiphenylethane (two protons replaced by phenyl) the threo isomer is found (by X-ray diffraction and from NMR coupling constants) to have an anti conformation between the two phenyl groups and the two fluorine groups and a gauche conformation is found for both groups for the erythro isomer ^[2]. According to in silico results this conformation is more stable by 0.21 kcal/mole. Diastereomers are stereoisomers that are not enantiomers or mirror images of each other. ... X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of x-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ... In physics, a coupling constant, usually denoted g, is a number that determines the strength of an interaction. ... In chemistry a staggered conformation is a chemical conformation that exists in any open chain single chemical bond connecting two sp3 hybridised atoms as a conformational energy minimum. ... In chemistry, the phenyl group or phenyl ring (often abbreviated as -Ph) is the functional group with the formula -C6H5 Picture where the six carbon atoms are arranged in a cyclic manner. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... Diastereomers are stereoisomers that are not enantiomers or mirror images of each other. ... in silico is an expression used to mean performed on computer or via computer simulation. ...

A related effect is the cis effect in alkenes. Cis-2-butene Trans-2-butene In chemistry, geometric isomerism or cis-trans isomerism is a form of stereoisomerism and describes the orientation of functional groups within the molecule. ...

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