Salem Diagrams

Reaction (69) takes place via the , singlet and triplet states of the ketone (Kellmann and Dubois, 1965). Using what are commonly termed Salem diagrams, Salem (1974) illustrated the manner in which the excited , state of the reactants correlates smoothly with the ground state products this is illustrated in Fig. 15. The surface crossing that is indicated is... 

On the basis of the Salem diagram for this reaction (Fig. 15) the n,n excited ketone [9] is considered to correlate smoothly with the product [16]. If... 

A correlation diagram which incorporates this additional configuration, [19], is shown schematically in Fig. 22. For simplicity only, three configurations, [17], [18] and [19] appear. Configurations [17] and [18] are respectively reactant and intermediate configurations used in the Salem diagram, [19] is the product configuration, which is necessary for a proper description of the products. 

The two types of correlations, the first deriving from the work of Zimmerman 3 5), i.e. the excited reactant state to product ground state, and the second deriving from the hypothetical reactant ground state to product excited state — have been termed Salem diagrams [e.g. 42>]. 

Figure 6.27. Salem diagram for hydrogen abstraction by a carbonyl compound. The biradicaloid product states are denoted by (dot-

VB correlation diagrams for this purpose was developed by Salem (1974) and collaborators (Dauben et al., 1975), and they are commonly referred to as Salem diagrams. 

---