Featured in this post are compounds having planar shape other than trigonal planar.
The following compounds are all planar, with the last two having more than one central atom.
| xenon tetrafluoride, XeF4 |
| benzene molecule, C6H6 |
| CH2=NH |
Geometry of Xenon Tetrafluoride, XeF4
The Lewis structure of xenon tetrafluoride, XeF4, below shows that the compound's central atom has four bonding electron pairs and two lone electron pairs.
-molecule.png)
According to the VSEPR theory, the arrangement that affords the maximum distance between each of the mentioned electron pairs is a square bipyramidal.
The axial positions of the two lone electron pairs offer the least net repulsion than it would have been if one or both of these non-bonding electron pairs were in the equatorial positions.
In the illustration shown above, a square bipyramidal outline is superimposed on the xenon tetrafluoride molecule.
- shape of xenon tetrafluoride: square planar
- F-Xe-F bond angle: 90°
Geometry of Benzene, C6H6
The resonance structures of benzene are shown below; the third structure is a suggested representation of the delocalization state of the pi electrons.
Each of the six carbon atoms can be taken as a central atom about which the geometry is trigonal planar.
The result is a hexagonal planar molecule with one carbon atom and one hydrogen atom jutting out at each of the six vertices.
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Geometry of CH2=NH
The CH2=NH molecule has two central atoms, carbon and nitrogen (see the Lewis structure below).
About each center, the geometry is trigonal planar.
However, the shape about the nitrogen atom is angular due to the presence of a lone electron pair.
All of the atoms lie in one plane.
