Hybridization [ENDORSED]

[Sara Juarez 1B]

On page 189 of our course reader, question 6A gives the Lewis structure for amino acid proline and asks for the hybridization for specific atoms of the structure. I am only able to get the hybridization of the nitrogen atom and the last oxygen atom on the far right. I have been using AXE to find hybridization but I can not seem to get the same answers as the textbook, maybe I am overthinking it but can someone please walk me through finding the hybridization of carbon in the ring structure?

[Vivian Tan 3F]

Remember that hybridizations involve all areas of electron density, so that includes both bonds and lone pairs.

The carbon in the ring structure of proline has 2 bonds between them, so it means that the carbon must have 2 pairs of lone pairs (to add up to 8 electrons total, to fulfill the octet rule). This adds up to 4 areas of electron density, which corresponds to sp3 hybridization.

Review lecture notes from July 11th on hybridization!:
2 regions of e- density: sp
3 regions of e- density: sp2
4 regions of e- density: sp3
5 regions of e- density: spd3d (or dsp3)
... and so forth.

AXE notation is used for VSEPR and to determine shapes of molecules.

[HannahLewis]

Since it has a sp3 density, does that also mean that it has a tetrahedral structure as well?

[KelseyKobayashi_2M]

Since it has a sp3 density, does that also mean that it has a tetrahedral structure as well?

I believe if all 4 positions of electron density are occupied by electrons, then it's tetrahedral, but if 3 of the 4 positions are occupied, then the shape is trigonal pyramidal.

[Skolli20]

The part I'm confused about is how you know that one area of electron density is sp, or that three is 2sp2 etc. If someone could please explain that?