Cyclooctatetraene, bond lengths reactivity

The next higher annulene, cyclooctatetraene, is nonaromatic. The bond lengths around the ring alternate as expected for a polyene. The C=C bonds are 1.334 A while the C—C bonds are 1.462 A in length. Thermodynamic data provide no evidence of any special stability. Cyclooctatetraene is readily isolable, and the chemical reactivity is normal for a polyene. The structure determination shows that the molecule is tub-shaped and therefore is not a system to which the Hiickel rule applies. 

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