Pi bonds

[cnidocyte]

Are pi bonds always formed by p orbitals?

[jnc1110]

Pi ponds are the result of 2 p orbitals which overlap. Draw 2 infinitity symbols in which the left side of one orbital overlaps the right side of another and that is what we believe the pi bond to look like. Pi bonds are known for being fairly reactive and also make molecules appear flat (if you were actually able to see 1 individual molecule). Also worth noting is that pi bonds do not undergo free rotation (90 degree rotation is the max).

Now, if you were to refer to double bonds that would be made of 1 s and 1 p orbital. Depending on the type of double bond (i.e. carbonyl group vs. alkene) these normally make a molecule very stable (i.e. hexene).

[cnidocyte]

What about a C=C bond though? When I draw the first sp2 orbital overlap I space the 2 carbons apart a fair bit then when I draw the 2 p orbitals for the pi bond theres no way the 2 C atoms are close enough for their p orbitals to overlap. I've seen the bonding orbital for a pi bond like that though and thinking of it like that makes sense of course.

[Idle Mind]

The problem is when you draw it out on paper, it's only an approximate representation of what is actually happening.

When I used to draw my diagrams, I would draw the pi bonds, and connect the orbitals with dashed lines to indicate the overlap.

[penelopa99]

I just want to say thank you for the information.
It is very valuable for me..newbie here and encountering the same situation.
Thanks and keep up the good work..

[Trippy]

Are pi bonds always formed by p orbitals?

I don't know if it's neccessarily been proven, per se, but it's also widely assumed that D-orbitals participate in Pi bonds as well. The term Pi (versus the term SIgma) is a reference to the symmetry of the orbital, rather than anything else.