Frontier Configurations and a New Classification of Annulenes

If we replace DIM by AHL theory so that the effect of parity on stereoselection can be seen , one obtains the Woodward-Hoffmann predictions that Mbbius CB will have lower energy than Huckel CB and, analogously, Mbbius TMM will be more stable than Huckel TMM. That is to say, TMM is predicted to close thermally to methylene cyclopropane by conrotation. 

Finally, I have added to the Table the predictions of DIM theory for the 

Solid lines are bonds and dashed lines antibonds. Wriggly line is a partial bond. 

Consider a 4/4 (4 electron-4 orbital) system wherein the orbitals are located at the corners of a square. There are two independent CW s having maximum open shell character, namely, the two Kekule CW s shown schematically below. 

consider a 4/4 system with the four orbitals arranged in a coll inear fashion. Now, one of the maximum open shell CW s attains a much lower energy than the other. 

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