Core-excited resonances benzene

In the remainder of this section we consider the higher lying resonances in benzene. In general, the simple classification of resonances involving valence orbitals as either "shape" or "core-excited" appears to break down as the anion energy Increases (38). 

For example, the parentage of the l B2g "shape" resonance at 4.8 eV is not clear-cut, since it is known to decay Into electronically excited states of benzene as well as the ground state (39,40). It has been suggested previously that this anion must be described by an admixture of both shape and core-excited configurations (17). 

In Figure 4 we show the transmission spectrum of benzene at higher energies. The lowest feature Is the second "shape" resonance ( B2g). Above this lie several smaller features which must correspond primarily to core-excited states. Detailed studies of the decay channels of these resonances have not yet been carried out, although some Information is available. The vertical arrows in Figure 4 indicate the energies at which maxima occur in the excitation functions for Vi of the ground electronic state of ben-... 

The formula(3) was newly proposed in this paper and the coefficients were so determined as the spectrum of benzene molecules in n-hexane solutions was exactly predicted In the calculations considering all singly excited electronic configurations. The core resonance Integrals Pj.g are ... 

It was found that creation of a core hole via the pi resonance of the benzene ring in polystyrene does not result in bond rupture and ion desorption, whereas excitation at slightly higher energies does. 

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