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MO Diagram for Heteronuclear Diatomic Molecules

Posted: Mon Nov 14, 2016 2:37 pm
by E_Villavicencio 2N
When we have to do a MO Diagram of a compound such as HF, where the 1s orbital from H and the 2s from F combine, how do we label the resulting molecular orbital? Do we put sigma 2s? Because the book does not label them like that, it labels them 1 sigma, 2 sigma*, 3 sigma,etc., but I don't remember we were told that. Can somebody explain how to label them for the quiz?

Re: MO Diagram for Heteronuclear Diatomic Molecules

Posted: Mon Nov 14, 2016 2:42 pm
by Rosalva_Mejia_41
I really didn't understand what you're asking but perhaps this link can explain how to label it.http://chem.libretexts.org/Core/Physica ... r_Orbitals

Re: MO Diagram for Heteronuclear Diatomic Molecules  [ENDORSED]

Posted: Mon Nov 14, 2016 3:08 pm
by Chem_Mod
We label a molecular orbital "sigma 2s" only when it correlates to two atomic 2s orbitals. With molecular orbitals that correlate to more than one type of atomic orbital, we have to use an alternative notation, where each set of molecular orbitals of a certain type (sigma, pi) is numbered from lowest energy to highest energy, as seen in the textbook.