How can certain cyclopropanes produce carbenes in photochemical reactions?

In photochemical reactions, certain cyclopropanes—which are characterized by their three-membered carbon rings—can function as precursors to generate carbenes.

This process occurs when the cyclopropane molecule undergoes a specific transformation upon exposure to light. A notable example of this is the conversion of 1,1,2,2-tetraphenylcyclopropane into diphenylcarbene. This reaction demonstrates that, under specific circumstances, the energy absorbed from light facilitates the cleavage of the cyclopropane ring, resulting in the formation of the corresponding carbene.1