W2013CHM2311 Part 4a Notes

U 2p g 2p g 2p u 2p u 2p g 2p g 2p u

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: heory: Homonuclear Second Period Diatomics Li2 [σg2 (2s)] σu * 2s 2s Energy σg This is in agreement with gas ­phase observa0ons σu * 1s 1s σg Bond Order = MO Theory: Homonuclear Second Period Diatomics Be2 [σg2 σu*2 (2s)] σu * 2s 2s Energy σg σu * 1s 1s σg Bond Order = p ­Orbital Interac0ons energy ψ*MO= caϕ2pzA  ­ cbϕ2pzB σ*u π*g π*g ψ*MO= caϕ2pyA  ­ cbϕ2pyB px py σ* ­orbitals are higher in energy than π* ­orbitals ψ*MO= caϕ2pxA  ­ cbϕ2pxB px pz πu πu ψMO= caϕ2pyA + cbϕ2pyB ψMO= caϕ2pxA + cbϕ2pxB σg ψMO= caϕ2pzA + cbϕ2pzB py pz MO Diagrams for Second Period Diatomics energy σu * B2 [πu1 πu1 (2p) ] πg* πg* 2p σg 2p Why is σg higher in energy than πu?? πu πu 2s σu * σg 2s MO Energy Levels for Homonuclear Diatomics (from Co_on and Wilkinson) Notes: 1. All energy levels drop from leS to right, why? 2. Do highest occupied levels really rise from leS to right? 3. Are there magic numbers associated with diatomics (high bond...
View Full Document

Ask a homework question - tutors are online