Correlation diagrams conversion

Figure 4.4. A correlation diagram for the possible conversion of ccp to bcc resulting from compression.

After discussing the symmetry properties of the four rr-orbitals of two ethene molecules and four a-orbitals of cyclobutane, a correlation diagram can be constructed for the ethene-cyclobutane conversion, as shown in Fig. 8.22. 

Figure 6.18a gives a schematic representation of the orbital correlation diagram fur the thermally forbidden conversion of one alternant hydrocarbon into another one. The following configuration correlations are easily verified from this diagram ... 

Figure 6.18. Excited-state barriers a) orbital correlation diagram for a thermally forbidden conversion of an alternant hydrocarbon b) the corresponding configuration and state correlation diagram for the case that Ihe HOMO— LUMO excitation does not represent the longesl-wavelength absorption.

The experimental results on valence isomerization of benzene can be rationalized by means of correlation diagrams that were first discussed for hexa-fluorobenzene by Haller (l%7). The orbital correlation diagram for the conversion of benzene to dewarbenzene (Figure 7.44a) has been constructed on the basis of a classification of the benzene Jt MOs according to C , symmetry. The full symmetry of benzene is D ,. The symmetry elements common to both point groups Cj, and are E, Cj, and o,(x,z) = o which is the plane through... 

Figure 8. Schematic of the state correlation diagram for the (diene + O2) peroxide diradical inter conversions. States of the diene-02 complex are on the left [state of molecular oxygen is specifically noted for each state. States of the peroxide are depicted in the middle. The nearly degenerate set of low lying singlet and triplet states of the diradical are shown on the right. The states are arranged in order of increasing energy, and the electronic configuration for each state is indicated...

The correlation of states is determined by the total symmetry of each state, which is a function of the symmetry of each populated MO that characterizes that configuration. As with MOs, states that are symmetric with respect to a symmetry element are designated S, while those that are antisymmetric are labeled A. We will use the symmetry designations in Figure 11.18 to prepare a state correlation diagram for the conrotatory conversion of cyclobutene and... 

The states involved in the photochemical butadiene-to-cyclobutene conversion are iffu 2, and if/j of the first excited state of butadiene, and lowest excited state of cyclobutene. The correlation diagram for this reaction is shown in Fig. 11.4. The appropriate elements of symmetry are the plane of symmetry... 

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