Talk:Molecular orbital diagram: Difference between revisions

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The molecular orbit diagram for oxygen shows the sigma2p orbitals below the pi2p orbitals. My copy of 'Chemistry' by R Chang shows them being the other way round, and explains that this is because of mixing between the 2p and 2s orbitals. Would a more qualified chemist like to review this? Nigel D (talk) 20:57, 20 November 2007 (UTC)[reply]

The diagram is correct. The cross over point is around dinitrogen and that is the tricky one. Mixing between 2s and 2p depends on the energy difference. It is greatest when the energy difference is small. That difference increases going from B to F so the lowering of energy of the "2s" MOs and raising of the energy of the "2P" MOs decreases and the "2p" MO is lower for O2. I put "2s" and "2p" in quotes because they each have a bit of the other mixed in, in the MOs, due to the mixing. I have not seen Chang for a while, but it looks as if it technically wrong. However it really does not matter as both the 2p sigma and the 2p bonding pi are occupied and he may just be using the same order of MOs for simplicity. --Bduke (talk) 22:19, 20 November 2007 (UTC)[reply]

Thanks Bduke.. You are right and Chang is right. I had misread the notes accompanying Changs diagram. Nigel D (talk) 22:31, 20 November 2007 (UTC)[reply]

"In diboron the 1s and 2s electrons do not participate in bonding but the single electrons in the 2p orbitals occupy the 2πpy and the 2πpx MO's resulting in bond order 1." Relative to the paragraph before this explanation, shouldn't the orbitals actually be the 2πpy and 2πpz orbitals? It had explained that, in its orientation of the molecule, the x orbital only makes sigma bonds. Ryan M 2:50, 11 January 2009 (PU) —Preceding unsigned comment added by 128.211.201.155 (talk)