Force field calculations on molecular belts built from cyclohexa-1,4-diene rings
Calculations using the MM2 program are reported on a series of hydrocarbons constructed by lateral fusion of n cyclohexa-1,4-diene rings, the [n]beltenes. Strain energy per macro-ring unit (–CH2[graphic omitted]CH2–) decreases monotonically from beltene to beltene. The beltenes have the shape of a semi-rigid molecular torus, the larger beltenes containing a substantial cavity. Encapsulation of acetylene becomes favourable with beltene. The encapsulation of some other small molecules has been examined. The shape and strain energy of selected hydrogenated beltenes is discussed.