Conformation properties of buta-1,3-diene-1,4-diones (bisketenes): computational and photoelectron spectroscopic studies

The highest occupied molecular orbital (HOMO) energies of a series of monoketenes RCHCO with a variety of representative substituents have been calculated by ab initio methods, and give good agreement with available experimental photoelectron ionization energies. The structures and orbital energies of the monoketenes Me3SiCHCO (5) and ButMe2SiCHCO (6), the alkene ButMe2SiCHCH2(7) and the bisketenes (Me3SiCCO)2(1) and (ButMe2SiCCO)2(4) have also …