Sigma and pi bonds

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Madelyn Cearlock
Posts: 72
Joined: Fri Sep 28, 2018 12:19 am

Sigma and pi bonds

Postby Madelyn Cearlock » Mon Nov 19, 2018 1:52 pm

Can someone please explain the difference between sigma bonds and pi bonds? I am very confused.

klarratt2
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

Re: Sigma and pi bonds

Postby klarratt2 » Mon Nov 19, 2018 1:57 pm

A single bond is a sigma bond. A double bond is a sigma bond plus a pi bond. A triple bond is one sigma and two pi bonds.

A sigma bond is a basic covalent bond, with the bond in line with the bonding orbitals. You can only ever have one sigma bond between any two atoms.

A pi bond is a covalent bond between orbitals perpendicular to the bond direction, usually p-orbitals (never s). The resulting bond is roughly shaped like two croissants with the tips touching at the bonded atoms. Pi bonds do not allow rotation around the bonding axis due to this geometry.

A second pi bond (the third bond in a triple bond, or a second double bond to another atom) is always perpendicular (orthogonal) to the first one. In other words, if the sigma bond is on the x axis, one pi bond will form between orbitals on the y axis and another will form between orbitals on the z axis.

Bianca Barcelo 4I
Posts: 74
Joined: Fri Sep 28, 2018 12:17 am
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Re: Sigma and pi bonds

Postby Bianca Barcelo 4I » Mon Nov 19, 2018 6:38 pm

Is there a difference in strength between a sigma bond and pi bonds?


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