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  2. Strain (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Strain_(chemistry)

    Van der Waals strain, or steric strain, occurs when atoms are forced to get closer than their Van der Waals radii allow. [4]: 5 Specifically, Van der Waals strain is considered a form of strain where the interacting atoms are at least four bonds away from each other. [5]

  3. Steric effects - Wikipedia

    en.wikipedia.org/wiki/Steric_effects

    Steric hindrance is often exploited to control selectivity, such as slowing unwanted side-reactions. Steric hindrance between adjacent groups can also affect torsional bond angles. Steric hindrance is responsible for the observed shape of rotaxanes and the low rates of racemization of 2,2'-disubstituted biphenyl and binaphthyl derivatives.

  4. Ring strain - Wikipedia

    en.wikipedia.org/wiki/Ring_strain

    Angle strain destabilizes a molecule, as manifested in higher reactivity and elevated heat of combustion. Maximum bond strength results from effective overlap of atomic orbitals in a chemical bond. A quantitative measure for angle strain is strain energy. Angle strain and torsional strain combine to create ring strain that affects cyclic ...

  5. Eclipsed conformation - Wikipedia

    en.wikipedia.org/wiki/Eclipsed_conformation

    A dihedral angle can indicate staggered and eclipsed orientation, but is specifically used to determine the angle between two specific atoms on opposing carbons. Different conformations have unequal energies, creating an energy barrier to bond rotation which is known as torsional strain. In particular, eclipsed conformations tend to have raised ...

  6. Carbohydrate conformation - Wikipedia

    en.wikipedia.org/wiki/Carbohydrate_conformation

    The chair conformation of six-membered rings have a dihedral angle of 60° between adjacent substituents thus usually making it the most stable conformer. Since there are two possible chair conformation steric and stereoelectronic effects such as the anomeric effect, 1,3-diaxial interactions, dipoles and intramolecular hydrogen bonding must be taken into consideration when looking at relative ...

  7. Newman projection - Wikipedia

    en.wikipedia.org/wiki/Newman_projection

    This projection most commonly sights down a carbon-carbon bond, making it a very useful way to visualize the stereochemistry of alkanes. A Newman projection visualizes the conformation of a chemical bond from front to back, with the front atom represented by the intersection of three lines (a dot) and the back atom as a circle.

  8. Rotamers - Wikipedia

    en.wikipedia.org/wiki/Rotamers

    For each molecule, the three substituents emanating from each carbon–carbon bond are staggered, with each H–C–C–H dihedral angle (and H–C–C–CH 3 dihedral angle in the case of propane) equal to 60° (or approximately equal to 60° in the case of propane). The three eclipsed conformations, in which the dihedral angles are zero, are ...

  9. Ring flip - Wikipedia

    en.wikipedia.org/wiki/Ring_flip

    The chair conformation minimizes both angle strain and torsional strain by having all carbon-carbon bonds at 110.9° and all hydrogens staggered from one another. [2] The conformational changes that occur in a cyclohexane ring flip take place over several stages. Structure D (10.8 kcal/mol) is the highest energy transition state of the process.