Transcription of MO Diagrams for Diatomic Molecules
{{id}} {{{paragraph}}}
MO Diagrams for Diatomic MoleculesChapter 5 Friday, October 9, 2015 Homonuclear Diatomic MoleculesWhat happens when we move to more complicated systems? Consider O2. The Lewis dot structure famously predicts the wrong electronic structure for O2 We can use LCAO-MO theory to get a better picture:2sa2pa2sb2pbNotice that E > E ,because the bonds have more overlap than bondsE E Electron Configurations and Bond OrdersJust as with atoms, we can write a molecular electron configuration for O2 2 *2 2 4 *2We can also calculate the O O bond order:BO 12# bonding e # anti-bonding e 128 4 2 LCAO MO theory also predicts (correctly) that O2has two unpaired MixingOrbitals of similar but unequal energies can interact if they have the same symmetryThe 2sand 2pzorbitals form MOs with the same symmetry ( g and u).
Heteronuclear Diatomic Molecules: CO In molecules with more than one type of atom, MOs are formed from AOs that have different energies. Consider CO: 2sa 2pa C 2sb 2pb C≡O O σ σ* π π* σ σ* Bonding orbitals get polarized towards oxygen Anti-bonding orbitals get polarized towards carbon HOMO is on carbon LUMO is on carbon too!
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document:
{{id}} {{{paragraph}}}