The structure of bicyclo[2.2.1]heptanes: Norbornane, nornornene, norbornadiene, 7-oxanorbornane, and 7-thianorbornane

Abstract

The structures of norbornane, norbornene, norbornadiene, 7-oxanorbornane, and 7-thianorbornane were completely determined by analytical gradient techniques in conjunction with ab initio Hartree—Fock molecular orbital theory. Geometric details obtained at the minimal STO-3G and split valence 3–21G levels of theory, are compared with data available from various experimental studies using both microwave and electron diffraction spectroscopy. Variations in the geometric parameters which ensue from introduction of the functional groups into the bicyclo [2.2.1] heptane skeleton are discussed in terms of perturbative molecular orbital (PMO) theory.