| [Visitor (58.214.*.*)]answers [Chinese ] | Time :2020-09-28 | 1. Twisted boat type and half chair type.
1) Twisted boat conformation:
Twist the carbon of the boat-like conformation by about 30° to become the twisted-boat:
The twisted boat conformation of cyclohexane is compared with the boat type: the hydrogen non-bonding tension of the flagpole bond is reduced; it is 7kjmol-1 lower than the boat conformation
2) Half-chair conformation:
Lift up the carbon C6 of the chair leg to form a flat half-chair configuration with C1, C2, C4, and C5.
Cyclohexane half-chair conformation is compared with chair conformation: C2, C1, C6, C5, C4 have torsional tension. There is angular tension. 46kjmol-1 higher energy than chair type
3) Flip the ring:
When turning from one chair type to another chair type configuration, it has to go through two half chair types, two twisted boat types and one boat type.
4) Flat key and upright key:
In the chair conformation of cyclohexane, the six carbon atoms are in two parallel planes. C1, C3, C5 are on the upper plane, and C2, C4, C6 are on the lower plane. The cyclohexane ring has a triple axis of symmetry perpendicular to one of the planes. |
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