Through‐Bond Orbital Coupling in End‐Functionalized Bicyclohexylidenes − Photoelectron Spectroscopy and Ab initio SCF−MO Calculations
To establish whether through-bond (TB) orbital interactions occur between the functional groups and the hydrocarbon skeleton in a series of end-functionalized oligo(cyclohexylidenes) 1−12, their HeI photoelectron (PE) spectra were measured and analyzed. Vertical ionization energies, Ivj, of the highest occupied molecular orbitals (MOs) of 1−12 were assigned using ab initio RHF/6−31G* MO energies (−εj) in combination with Koopmans’ theorem. Excellent to good agreement was found between the PES and RHF/6−31G* results. In addition, the Ivj, assignments were further corrobor-