Trans-Cyclooctene

rdf:langString Trans-Cyclooctene

rdf:langString trans-Cyclooctene

rdf:langString trans-Cyclooctene

rdf:langString Trans-Cyclooctene.png

rdf:langString trans-Cyclooctene

rdf:langString -Cyclooctene

rdf:langString trans-Cyclooctene is a cyclic hydrocarbon with the formula [–(CH2)6CH=CH–], where the two C–C single bonds adjacent to the double bond are on opposite sides of the latter's plane. It is a colorless liquid with a disagreeable odor. Cyclooctene is notable as the smallest cycloalkene that is readily isolated as its trans-isomer. The cis-isomer is much more stable; the ring-strain energies being 16.7 and 7.4 kcal/mol, respectively. A planar arrangement of the ring carbons would be too strained, and therefore the stable conformations of the trans form have a bent (non-planar) ring. Computations indicate that the most stable "crown" conformation has the carbon atoms alternately above and below the plane of the ring. A "half-chair" conformation, with about 6 kcal/mol higher energy, has carbons 2,3,5,6, and 8 on the same side of the plane of carbons 1,4, and 7. All conformations of trans-cyclooctene are chiral (specifically, what some call planar-chiral) and the enantiomers can be separated. In theory, conversion of between the enantiomers can be done, without breaking any bonds, by twisting the whole –CH=CH– group, rigidly, by 180 degrees. However, that entails passing one of its hydrogens through the crowded ring.

rdf:langString trans-Cyclooctene

rdf:langString (E)-Cyclooctene