Cyclooctatetraene, dianion geometry

Problem 15.7 Cyclooctatetraene readily reacts with potassium metal to form the stable cycio-octatetraone dianion, C8H82. Why do you suppose this reaction occurs so easily What geometry do you expect for the cyclooctatetraene dianion ... 

SINDOl calculations, which successfully reproduced both the geometry and the aromaticity of the cyclooctatetraene dianion, predict a high degree of bond localization and nonplanarity for 1,4-dioxocin and its derivatives (84JOC4475). 

Examine the geometry of cyclooctatetraene dianion. Is it planar If not, describe its shape. Are all the carbon-carbon bond lengths the same If so, are they the same length as those in benzene If not, do they alternate between single and double bonds Do your observations suggest that cyclooctatetraene dianion is aromatic Is this in accord with Hiickel s rule ... 

Cyclooctatetraene readily reacts with potassium metal to form a dianion. Discuss the electronic structure and geometry of this dianion and explain why it is formed so readily. 

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