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  2. Ring strain - Wikipedia

    en.wikipedia.org/wiki/Ring_strain

    In some molecules, torsional strain can contribute to ring strain in addition to angle strain. One example of such a molecule is cyclopropane. Cyclopropane's carbon-carbon bonds form angles of 60°, far from the preferred angle of 109.5° angle in alkanes, so angle strain contributes most to cyclopropane's ring strain. [10]

  3. Phosphiranes - Wikipedia

    en.wikipedia.org/wiki/Phosphiranes

    Phosphirane functional group is a very strained structure - the C-P-C bond angle in phosphirane ring structure is 49°, [1] even lower than the C-N-C angle in aziridine and the C-C-C angle in cyclopropane (60°). This high angle strain causes a higher inversion barrier as well as the increased s-character of the lone pair on the phosphorus atom ...

  4. Cyclopropane - Wikipedia

    en.wikipedia.org/wiki/Cyclopropane

    The small size of the ring creates substantial ring strain in the structure. Cyclopropane itself is mainly of theoretical interest but many of its derivatives - cyclopropanes - are of commercial or biological significance. [3] Cyclopropane was used as a clinical inhalational anesthetic from the 1930s through the 1980s. The substance's high ...

  5. Cycloalkane - Wikipedia

    en.wikipedia.org/wiki/Cycloalkane

    Containing only C–C and C–H bonds, cycloalkanes are similar to alkanes in their general properties. Cycloalkanes with high angle strain, such as cyclopropane, have weaker C–C bonds, promoting ring-opening reactions. Cycloalkanes have higher boiling points, melting points, and densities than alkanes.

  6. Bicyclobutane - Wikipedia

    en.wikipedia.org/wiki/Bicyclobutane

    Bicyclobutane is noted for being one of the most strained compounds that is isolatable on a large scale — its strain energy is estimated at 63.9 kcal mol −1. It is a nonplanar molecule, with a dihedral angle between the two cyclopropane rings of 123°. [2]

  7. Bent bond - Wikipedia

    en.wikipedia.org/wiki/Bent_bond

    Bent bonds are found in strained organic compounds such as cyclopropane, oxirane and aziridine. In these compounds, it is not possible for the carbon atoms to assume the 109.5° bond angles with standard sp 3 hybridization. Increasing the p-character to sp 5 (i.e. 1 ⁄ 6 s-density and 5 ⁄ 6 p-density) [5] makes it possible to reduce the bond ...

  8. Eclipsed conformation - Wikipedia

    en.wikipedia.org/wiki/Eclipsed_conformation

    In chemistry an eclipsed conformation is a conformation in which two substituents X and Y on adjacent atoms A, B are in closest proximity, implying that the torsion angle X–A–B–Y is 0°. [1] Such a conformation can exist in any open chain, single chemical bond connecting two sp 3-hybridised atoms, and it is normally a conformational ...

  9. Ring-opening polymerization - Wikipedia

    en.wikipedia.org/wiki/Ring-opening_polymerization

    Ring-opening of cyclic monomers is often driven by the relief of bond-angle strain. Thus, as is the case for other types of polymerization, the enthalpy change in ring-opening is negative. [ 3 ] Many rings undergo ROP.