Stone-Wales Rearrangements Involving Heptagonal Defects

Abstract

Abstract Three cases of Stone-Wales type rearrangements involving heptagonal rings have been studied by using AM1 semiempirial MO method. In all cases, transition states of the two distinct mechanisms known to pyracylene rearrangements, stepwise and concerted, have been found. Activation energies are estimated to be 110 to 150 kcal/mol.