MO correlation diagram

Let us first recall some basic characteristics of the cyanine isomerization mechanism, as emerging from simple MO correlation diagrams like those of Fig. 1. In... 

Figure 1. Hiickel n-MO correlation diagrams for planar- perp twisting of pcntamethine cyanine about the 2-3 and 3-4 bonds (a), and simultaneous twisting about 2-3 and 4-5 bonds (b). For the perp forms the orbitals belonging to the different n fragments are indicated and the CT nature of the HOMO-LUMO excitation is emphasized.

Fig. 2 MO correlation diagrams for the Bergman cyclization (adopted from ref.24). Out-of-plane MOs are shown in black, in-plane MOs are shown in blue.

Molecular orbital (MO) correlation diagrams, for cycloaromatization reactions, 7-9, 8/... 

Fig. 10. Schematic presentation of the MO-correlation diagram for the electronic state of the AuO molecule (44).

Figure 5.12 A MO correlation diagram for the bent and linear forms of the water molecule...

Fig. 9. MO correlation diagram for the ring opening for cyclobutene to cis-butadiene assuming...

Figure 4 A qualitative MO correlation diagram for a linear complex [AuL2]+, applicable to [AuMe(PMej)]...

SCHEME 13. Triptych MO correlation diagram for the reaction in Scheme 12... 

Within a few weeks of their arrival at a university, most chemistry students know - or believe that they know - why the ground state of the 02 molecule is a triplet, whereas by contrast the ground states of N2 and F2 are singlets and form closed shells. Some may even be able to illustrate their argument with the aid of a cunningly drawn molecular orbital (MO) correlation diagram. 

An intriguing point has been made by Oosterhoff581 in the photochemical butadiene to cyclobutene closure. It was noted that the usual MO correlation diagrams reveal... 

Figure 14 shows the MO correlation diagram between [Pt4(HCOO)s] and the fragment, where only levels near the HOMO-LUMO level associated with Pt da orbitals are depicted. For clarity, levels associated with Pt d orbitals are omitted in Fig. 14, because low-lying d orbitals in the fragment are fully occupied therefore, bonding and antibonding effects due to MOs derived from the d orbitals are compensated and have no net contribution to stability of the whole [Pt4(HCOO)al molecule or the formation of Pt—Pt bonds in the cluster core. 

Figure 4 Qualitative MO correlation diagram for linear and bent AH2 molecules. (Ref 26. Reproduced by permission of Elsevier)...

Figure 7 Qualitative MO correlation diagram for the orbital interactions between two EH2 molecules with 6 valence electrons in the Bi state yielding closed-shell E2H4...

Figure 8 Qualitative MO correlation diagram for planar and staggered E2H4...

The bond length of the transient diatomic molecule CF is 1.291 A that of the molecular ion CF is 1.173 A. Explain why the CF bond shortens with the loss of an electron. Refer to the proper MO correlation diagram. 

In this section, we analyze the stable geometries for the Na4 and Mg4 clusters, using molecular orbital (MO) correlation diagrams interpolating between geometries. Structure deformation is often correlated with symmetry breaking, e.g. the Jahn-Teller effect (37), which stabilizes the electronic structures of metal clusters. 

Figure 4.34 Woodward Hoffmann MO correlation diagram for [2 + 2] cycloaddition. The labels 5 (symmetric) and a (antisymmetric) refer to the symmetry planes axz and oyz in that order...

To predict the shape of potential energy surfaces along the symmetry-retaining reaction coordinate from an MO correlation diagram, one must construct a correlation diagram of the electronic configurations (Figure 4.35). 

Fig. 13.4. MO correlation diagram for the interactions between a main group atomic ion and a Cp ligand in (Csv) ECp.

Fig. 13.6. MO correlation diagram for the interaction between a main group element E and a cage of six a-bonded ligands X in octahedral EF6.

Fig. 13.18. MO correlation diagram between a transition metal with the electron configuration (ciig) X (e2g) (eigf and a cyclic 12 Tr-aromatic sandwich ligand. The shape of the ligand orbitals have been taken from the Bz2 ligand. The orbitals of the Cp2 ligands look very similar.

Fig. 13.19. MO correlation diagram showing the most important orbitals of the ligand cyclo-Es and the fragment Fe(Ti -E5), which are relevant for the bonding in Fe(Ti -E5)2.

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