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  2. A value - Wikipedia

    en.wikipedia.org/wiki/A_value

    This means it costs 1.74 kcal/mol (7.3 kJ/mol) of energy to have a methyl group in the axial position compared to the equatorial position. A-values are numerical values used in the determination of the most stable orientation of atoms in a molecule (conformational analysis), as well as a general representation of steric bulk.

  3. Molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Molecular_geometry

    The position of each atom is determined by the nature of the chemical bonds by which it is connected to its neighboring atoms. The molecular geometry can be described by the positions of these atoms in space, evoking bond lengths of two joined atoms, bond angles of three connected atoms, and torsion angles (dihedral angles) of three consecutive ...

  4. Seesaw molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Seesaw_molecular_geometry

    An atom bonded to 5 other atoms (and no lone pairs) forms a trigonal bipyramid with two axial and three equatorial positions, but in the seesaw geometry one of the atoms is replaced by a lone pair of electrons, which is always in an equatorial position. This is true because the lone pair occupies more space near the central atom (A) than does a ...

  5. Ring flip - Wikipedia

    en.wikipedia.org/wiki/Ring_flip

    The conformer of methylcyclohexane with equatorial methyl is favored by 1.74 kcal/mol (7.3 kJ/mol) relative to the conformer where methyl is axial. In organic chemistry, a ring flip (also known as a ring inversion or ring reversal) is the interconversion of cyclic conformers that have equivalent ring shapes (e.g., from a chair conformer to ...

  6. Anomeric effect - Wikipedia

    en.wikipedia.org/wiki/Anomeric_effect

    The α- and β-anomers of D-glucopyranose.. In organic chemistry, the anomeric effect or Edward-Lemieux effect (after J. T. Edward and Raymond Lemieux) is a stereoelectronic effect that describes the tendency of heteroatomic substituents adjacent to the heteroatom in the ring in, e.g., tetrahydropyran to prefer the axial orientation instead of the less-hindered equatorial orientation that ...

  7. Bent's rule - Wikipedia

    en.wikipedia.org/wiki/Bent's_rule

    Trigonal bipyramid molecules have both with axial and equatorial positions. If there are two types of substituents, the more electronegative substituent will prefer the axial position as there are smaller bond angles between axial and electronegative substituents than between two equatorial substituents.

  8. Trigonal bipyramidal molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Trigonal_bipyramidal...

    In chemistry, a trigonal bipyramid formation is a molecular geometry with one atom at the center and 5 more atoms at the corners of a triangular bipyramid. [1] This is one geometry for which the bond angles surrounding the central atom are not identical (see also pentagonal bipyramid), because there is no geometrical arrangement with five terminal atoms in equivalent positions.

  9. Axial chirality - Wikipedia

    en.wikipedia.org/wiki/Axial_chirality

    Two types of molecules having axial chirality: allenes (left) and binaryl atropisomers (right) In chemistry, axial chirality is a special case of chirality in which a molecule contains two pairs of chemical groups in a non-planar arrangement about an axis of chirality so that the molecule is not superposable on its mirror image.