O’ antibonding molecular orbitals

Show how 2s orbitals combine to form a bonding and a antibonding molecular orbitals. Show how 2p orbitals overlap to form a- bonding, 77 bonding, tt antibonding, and o-antibonding molecular orbitals. 

This may be seen by considering, for example, a o antibonding molecular orbital (Eq. 7). 

End-on overlap of two sp orbitals to form a a- bonding molecular orbital and a o- antibonding molecular orbital. 

Figure 2.14. The molecular orbitals of gas phase carbon monoxide, (a) Energy diagram indicating how the molecular orbitals arise from the combination of atomic orbitals of carbon (C) and oxygen (O). Conventional arrows are used to indicate the spin orientations of electrons in the occupied orbitals. Asterisks denote antibonding molecular orbitals, (b) Spatial distributions of key orbitals involved in the chemisorption of carbon monoxide. Barring indicates empty orbitals.5 (c) Electronic configurations of CO and NO in vacuum as compared to the density of states of a Pt(lll) cluster.11 Reprinted from ref. 11 with permission from Elsevier Science.

The second orbitai interaction is subtractive, generating an orbitai with iow eiectron density between the nuciei. Low eiectron density between the nuciei resuits in more nucieus-nucieus repuision than eiectron-nucieus attraction. This combination is destabiiizing compared to individuai atoms and is referred to as an antibonding molecular orbital. The antibonding combination is iabeied as O"]. The MO is a <7 orbitai because the electron... 

If the two atomic orbitals are s-orbitals then the resulting molecular orbitals are called o (sigma) bonding molecular orbitals and a (sigma star) antibonding molecular orbitals (Figure 1.5). 

The interaction of two atomic orbitals (cpAi cpB) leads to the formation of bonding (°ab) and antibonding (o B) molecular orbitals of different energies... 

There are also all the molecular orbitals from the o framework but we do not need to consider these the occupied o-bonding molecular orbitals are considerably lower in energy than the molecular orbitais for the jt system and the vacant antibonding molecular orbitals for the a bonds are much higher in energy than the % antibonding molecular orbital. 

The reaction of N2O with the active site of the catalyst is envisaged as a donation of electronic charge from the catalyst to the antibonding molecular orbital of N2O, thus destabilizing the N—O bond and leading to scission. 

As for the He2 molecnlar ion, we place the first two electrons in the o-i orbital and the third electron in the crfj orbital. Becanse the antibonding molecular orbital is destabilizing, we expect He2 to be less stable than H2. Ronghly speaking, the instability resulting from the electron in the afs orbital is balanced by one of the cti elec-... 

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