r-1,t-3-Bis[4-(di-methyl-amino)-phen-yl]-c-2,t-4-bis-(pyridin-4-yl)cyclo-butane.

The title compound, C30H32N4, was synthesized by the photodimerization of trans-4-{2-[4-(di-methyl-amino)-phen-yl]ethen-yl}pyridine in benzene upon irradiation with UV light. This photodimer has a puckered cyclo-butane ring with the four aryl substituents in an r-1,t-2,c-3,t conformation. The puckering angle of the cyclo-butane ring is 32.22 (7)°, which is the largest among reported tetra-aryl-substituted cyclo-butanes. In the crystal, the mol-ecules form a hollow, one-dimensional structure extending parallel to the c axis via two different pairs of C-H⋯π inter-actions.