So basically any chemistry book will tell you about the extent of overlapping in different orbitals. For formation of sigma bonds, head on overlapping happens. Chemistry textbooks always state that $p-p$ overlap is more effective than $s-s$ overlap. The explanation given is that the s-orbital is spherically symmetric. So it is non directional, while the p-orbital is definitely directional.

However, if we think of hybridised orbitals, $sp$ orbitals are known to form stronger bonds than $sp^2$ and $sp^3$ hybrid orbitals. The explanation given is that the higher percentage of the s-character makes a bond stronger. If that is the case, then shouldn't an $s-s$ overlapping be stronger than a $p-p$ one?

And if $p-p$ overlapping is better than $s-s$ one, shouldn't the hybrid orbitals with higher p character form stronger bonds?

I am kind of confused. I would appreciate an explanation.

  • 1
    $\begingroup$ I can't think of a lot of bonds where you expect s-s overlap (excluding hybridization). That makes a comparison of strengths of bonds involving p-p vs s-s overlap difficult. It's always good to support statements by citing a source rather than writing " any chemistry book". In any case I suspect most "proofs" are theoretical in nature. $\endgroup$
    – Buck Thorn
    Mar 21 at 7:25


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