AMI study of Hamiltonian and non-Hamiltonian cyclophanes

AM1 type semiempirical molecular orbital calculations have been performed on [2(n)] and [3(2)] types of cyclophanes. It has been found that within the isomeric set of these [2(n)]-type endothermic structures the most and the least endothermic ones are non-Hamiltonian and Hamiltonian cyclophanes, respectively. Whereas, the smallest or the largest interfrontier energy gap happens depending on non-Hamiltonian or Hamiltonian nature of the compound.