Molecular-orbital diagrams

Refer to the molecular orbital diagrams of allyl cation (Figure 10 13) and those presented earlier in this chapter for ethylene and 1 3 butadiene (Figures 10 9 and 10 10) to decide which of the following cycloaddition reactions are allowed and which are forbidden according to the Woodward-Floffmann rules... 

Figure 7.31 Walsh molecular orbital diagram for AH2 molecules...

Fig. 2. Simplified molecular orbital diagram for a low spia octahedral complex, such as [Co(NH3 )g, where A = energy difference a, e, and t may be antisymmetric (subscript ungerade) or centrosymmetric (subscript, gerade) symmetry orbitals. See text.

Fig. 15.1 Molecular orbital diagram of inUamolecular donor (D) - chalcogen (E) interactions...

Figure 19.14 Molecular orbital diagram for an octahedral complex of a first series transition metal (only a interactions are considered in this simplified diagram).

Figure B A qualitative molecular orbital diagram for ferrocene. The subscripts g and u refer to the parity of the orbitals g (German gerade, even) indicates that the orbital (or orbital combination) is symmetric with respect to inversion, whereas the subscript u (ungerade, odd) indicates that it is antisymmetric with respect to inversion. Only orbitals with the same parity can combine.

Figure 1.11 A molecular orbital diagram for OSO4. (Reprinted with permission from Inorg. Chem., 1992, 31, 1588. Copyright American Chemical Society.)...

Figure 6-1. Schematic molecular orbital diagram for heteronuclear first-row diatomics.

Figure 3. Molecular-orbital diagrams as obtained by the ROHF method. Dashed lines indicate MOs dominated by the metal d-orbitals, the solid lines stand for doubly occupied or virtual ligand orbitals. Orbitals which are close in energy are presented as degenerate the average deviation from degeneracy is approximately 0.01 a.u. In the case of a septet state (S=3), the singly occupied open-shell orbitals come from a separate Fock operator and their orbital energies do not relate to ionization potentials as do the doubly occupied MOs (i.e. Koopmann s approximation). For these reasons, the open-shell orbitals appear well below the doubly occupied metal orbitals. Doubly occupying these gives rise to excited states, see text.

A schematic molecular orbital diagram for the Fe-Fe interaction in an S = I valence-delocalized Fe Fe pair based on effective C v symmetry at the Fe sites and the observed electronic transitions for the valance-delocalized [Fe2S2l cluster is shown in Fig. 15. The dominant interaction (responsible for the S = ground state) is the a overlap between the pair of orbitals, with progressively smaller tt interactions between pairs of d z and dyz orbitals and S interactions between pairs of d y amd / orbitals. The three highest energy tran-... 

Caulton and Fenske began with a molecular orbital diagram for CO (see Fig. 1). The two orbitals of interest here are, of course, the Scr- and 277-orbitals. The Sa-orbital, assumed in valence-bond theory to be a carbon orbital, has in reality a small contribution from oxygen also (Sa = 0.664 2s + 0.059 2s — 0.664 2p — 0.364 2p ). One can see from the choice of... 

Use a molecular orbital diagram to predict if it is possible to form the He2 cation. 

These molecular orbital diagrams help to rationalize experimental observations about molecules, as Example shows. 

Use molecular orbital diagrams to explain the trend in the following bond energies B2 = 290 kJ / mol, C2 = 600kJ/mol, and N2 =942kJ/mol. 

The data show that bond energies for these three diatomic molecules increase moving across the second row of the periodic table. We must construct molecular orbital diagrams for the three molecules and use the results to interpret the trend. 

Draw a schematic molecular orbital diagram for the adsorption of a diatomic molecule on a d metal. 

Fig. 4.4 Molecular orbital diagram for octahedral complexes (cr-interaction only)...

Fig. 5. A schematic band structure and molecular orbital diagram for a conjugated polymer containing no mid-gap states.

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