Cyclobutane Structure
In cyclobutane, the bond angles are 90º, which are larger than those in cyclopropane. The carbon-carbon bonds are less bent and there is not as much strain. However, there are four strained bonds and eight eclipsed hydrogens, which results in ring strain similar to that of cyclopropane.
Spatial Arrangement
Spectroscopic studies have shown that cyclobutane is not planar, as one of its -CH2- groups forms an angle of about 25º with the plane containing the other three carbons in the ring. This structure reduces the number of eclipses in the molecule and lowers its ring strain.
Cyclobutane Molecular Model
Cyclobutane is slightly bent to avoid eclipses.
Video
Additional Notes
* Cyclobutane is a relatively stable molecule due to its conformation.
* Cyclobutane undergoes substitution reactions more readily than cyclopropane.
* Cyclobutane is found in small amounts in petroleum.