MO of heteronuclear diatomic molecules Flashcards
What are heteronuclear diatomic molecules?
They are composed of two atoms from different atoms
What will the atomic orbitals of the two atoms have? What does this result in?
different energies
unsymmetrical energy diagrams
What are the energies of atomic orbitals lower for?
More electronegative atoms
Why are the interactions between the two orbitals (overlap integral) smaller?
Due to the difference in energy
If atomic orbital 1 is closer to MO* and AO2 is closer to MO in the energy diagram, what does this mean?
AO1 contributes more to MO* and AO2 contributes more to MO
Why would AO1 and AO2 have very different energies?
If they have very polar bonds
What is an isoelectronic species?
They have the same number of electrons but different make ups
What will the energy level diagrams of isoelectronic species look like?
Very similar
for example, if something has more 2p character than 2s, what will the diagram look like?
The line will be longer for 2p than 2s
When looking at the coefficients for atomic orbital contributions, what type of contribution is it if the 2 signs are the same?
Bonding
When looking at the coefficients for atomic orbital contributions, what type of contribution is it if the 2 signs are different?
antibonding
What is HOMO?
Highest occupied molecular orbital
What is LUMO?
Lowest unoccupied molecular orbital
Why do molecules tend to act as a Lewis acid through the LUMO?
Lewis acids accept electron density and as it is empty, there is space to accept electrons
Why do molecules tend to act as a Lewis base through the HOMO?
Lewis bases donate electron density and the HOMO has electrons to donate
