Increasing S Value

[Max Harouni 14B 24W]

Hi everyone,

I came across a concept that I am quite confused by, in that if the hybridization increases, for example sp2 and sp3d, the s is seen as smaller in some sense, or less valuable, in the latter even though it is a greater hybridization. Why does the s value decrease when hybridization increases when logically one would expect it to be the opposite?

[Eman Almuti 3H]

The s-value refers to the proportion of the hybrid orbitals that are made up of s orbitals. So in sp hybridization s is 50% and p is 50% and therefore the s value is 50%. When hybridization increases the s-value decreases. For sp2 the s value is 1/3 or and for sp3 it is 1/4.

[Rebekah L - 3k]

I don't feel qualified to answer your question but this seems like it has something to do with "s character" right? So basically the reason why s decreases as hybridization "increases" is because the s character kind of gets watered down by the growing d character. Like for example the s character in sp2 is bigger than sp3 because 1/3 is bigger than 1/4. If that doesn't make sense I know that the organic chemistry tutor on YouTube has a video on hybridization that explains this concept that I watched not too long ago.