Oxygen molecular orbital model

The molecular orbital model developed in this section is more elaborate than the localized bonds described earlier in this chapter. Is this more complicated model necessary to give a thorough picture of chemical bonding Experimental evidence for molecular oxygen suggests that the answer is yes. 

Localized electron model The central oxygen atom is sp hybridized, which is used to form the two cr bonds and hold the lone pair of electrons. An unchanged (unhybridized) p atomic orbital forms the tt bond with the neighboring oxygen atoms. The actual structure of O3 is an average of the two resonance structures. Molecular orbital model There are two localized cr bonds and a tt bond that is delocalized over the entire surface of the molecule. The delocalized TT bond results from overlap of a p atomic oribtal on each oxygen atom in O3. 59. 

What are the Lewis structures for the two allotropic forms of oxygen How can the paramagnetism of O2 be explained using the molecular orbital model What are the molecular structure and the bond angles in ozone ... 

Using the molecular orbital model for a diatomic molecule, explain the different bond lengths for the ions of oxygen. Also state which ion is diamagnetic. 

It is impossible to write a conventional Lewis structure for 02 that has these two characteristics. A more sophisticated model of bonding, using molecular orbitals (Appendix 5), is required to explain the properties of oxygen. 

The n molecular orbitals described so far involve two atoms, so the orbital pictures look the same for the localized bonding model applied to ethylene and the MO approach applied to molecular oxygen. In the organic molecules described in the introduction to this chapter, however, orbitals spread over three or more atoms. Such delocalized n orbitals can form when more than two p orbitals overlap in the appropriate geometry. In this section, we develop a molecular orbital description for three-atom n systems. In the following sections, we apply the results to larger molecules. 

In order to give a concrete expression for Feff(x), a simple model has been assumed (see Fig. 6). In this model, it is postulated that an electron in the HOMO (essentially the 2p orbital) of the surface oxygen atom (Osu g) of the polyanion partially transfers to the LUMO of water (the 4ai molecular orbital). Then Feff(x) can be expressed as... 

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