PE Spectra of Dewar Benzenes, Bridged by a Cyclohexadiene or a Butadiene Unit

Article abstract of DOI:10.1002/hlca.19860690503

The electronic structure of <4.2.2>propella-2,4,7,9-tetraene (1), 2,5-etheno<4.2.2>propella-3,7,9-triene (2), and of several hydrogenated derivatives of 2 has been investigated using He(I) PE spectroscopy and MO calculations.It is found that in 2 the 1,4-cyclohexadiene moiety interacts considerably with the bicyclo<2.2.0>hexadiene unit, while in 1 the interaction between the butadiene fragment and the Dewar benzene unit is minute.The syntheses of 3-5 are reported.