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The boat and twist-boat conformations, as said, lie along a continuum of zero angle strain. If there are substituents that allow the different carbon atoms to be distinguished, then this continuum is like a circle with six boat conformations and six twist-boat conformations between them, three "right-handed" and three "left-handed".
The boat conformation (C, 6.9 kcal/mol, C 2v symmetry) is a local energy maximum for the interconversion of the two mirror image twist-boat conformers, the second of which is converted to the other chair confirmation through another half-chair. At the end of the process, all axial positions have become equatorial and vice versa.
The three eclipsed conformations with dihedral angles of 0°, 120°, and 240° are transition states between conformers. [6] Note that the two eclipsed conformations have different energies: at 0° the two methyl groups are eclipsed, resulting in higher energy (≈ 5 kcal/mol) than at 120°, where the methyl groups are eclipsed with hydrogens ...
There is a peak/local maximum at the boat conformation (C), and there are valleys/local minimums at the twist-boat conformations (B). In addition, cyclohexane conformations can be used to indicate if the molecule has any 1,3 diaxial-interactions which are steric interactions between axial substituents on the 1,3, and 5 carbons. [8]
The chair and twist-boat are energy minima and are therefore conformers, while the half-chair and the boat are transition states and represent energy maxima. The idea that the chair conformation is the most stable structure for cyclohexane was first proposed as early as 1890 by Hermann Sachse, but only gained widespread acceptance much later.
Conformations of five-membered rings are limited to two, envelope and twist. The envelope conformation has four atoms in a plane while the twist form only has three. In the envelope form two different scenarios can be envisioned; one where the ring oxygen is in the four atom plane and one where it is puckered above or below the plane.
Twistane (IUPAC name: tricyclo[4.4.0.0 3,8]decane [2]) is an organic compound with the formula C 10 H 16. [3] It is a cycloalkane and an isomer of the simplest diamondoid, adamantane, and like adamantane, is not very volatile.
Cycloheptane, synonym suberane, is a cycloalkane [citation needed] with the molecular formula C 7 H 14. [1] It is a poorly water soluble organic liquid (melting point –12 deg C, solubility in water <30 mg /liter at 25 deg C), [1] and is used as a nonpolar solvent for the chemical industry and as an intermediate in the manufacture of chemicals and pharmaceutical drugs.