Molecular Orbital Diagram help

[Marconis]

I am pretty good at drawing MO diagrams when they are simple. For instance, I can start from 1s and go up to, say, 2p and draw everything in (e- in proper location). If it said something like, "Draw the MO diagram of N2" or NO- I'd be able to do it very easily.

 

Despite this, I get very confused when it throws in hybrid orbitals. For example, if the question says,

 

"Using an sp3 orbital on carbon and a p orbital on Fluorine, construct the MO energy diagram"

 

I don't understand this, because isn't Fluorine in CH3F also sp3 hybridized? It has 3 lone pairs and a carbon next to it, yeah? "4 groups". But is it asking for a hybridized orbital of the F, or just one of the 3 p orbitals? Even so-----I wouldn't know how to draw the diagram for this. If it asked me to draw the structure of the compound with its hybrid orbitals shown, I'd be able to do it easily. But, in the "step" diagram, if you will, I am completely thrown off. How would you do this? Sorry if this is a confusing question!

 

THANKS!

Edited September 9, 2011 by Marconis

[mississippichem]

Draw the hybrids between the AOs and MOs. Remember that hybrids don't really "exist". They represent the linear combinations of AOs that are then mixed to form the ground state MO. MO diagrams can be tough even for a relatively simple heteronuclear diatomic if the amount of orbital overlap is to be considered (which IMO would negate the usefulness of hybrids).

 

Personally I think it is a bit misleading to include hybrids in the traditional "step" MO diagram but this sounds like homework and you've no control over that.