Trigonal planar vs. Trigonal bipyramidal

[MadisonFuentes1G]

When would the VSEPR shape be trigonal planar as opposed to trigonal bipyramidal, and vice versa?

[Girija_3E]

Hi,

I am not sure if this is what you're asking, but the difference between the two is:
• a trigonal planar shape has only one plane, and has only 3 bonding regions
• on the other hand, the trigonal bipyramidal shape has a plane, in addition to two electron bonding regions both above and below the plane, so it kind of looks like two pyramids facing each other. The trigonal bipyramidal shape has 5 bonding regions.

[Andy Nguyen 1A]

Hi, just to add on, molecules that have a trigonal bipyramidal shape have more regions of electron density so these bonds are as far away as possible. A trigonal planar is only on one plane while the trigonal bipyramidal adds a 3rd dimension.

[Chloe Blume 1F]

Trigonal planar is when there is a central atom and 3 bonding pairs, trigonal bipyramidal is when there is a central atom and 5 bonding pairs.

[Emily Oren 3C]

Here's some example images to help you visualize the difference between trigonal planar and trigonal bipyramidal:
Trigonal Planar: https://upload.wikimedia.org/wikipedia/ ... -balls.png
Trigonal Bipyramidal: https://upload.wikimedia.org/wikipedia/ ... -balls.png
Both: https://s3-us-west-2.amazonaws.com/cour ... 0geos.jpeg