R-1,c-2,t-3,t-4-1,2-Bis(4-methoxyphenyl)-3,4-bis(5-phenyl-1,3,4-oxadiazol-2-yl)cyclobutane

Abstract

The title compound, C34H28N4O4, is a derivative of di­phenyl­oxa­diazo­lylcyclo­butane (s-DPC), and although it is a syn-head-to-head photodimer, it does not display molecular mirror symmetry in the crystalline state. The cyclo­butane ring has a puckered conformation, with a dihedral angle of 30°, which is the largest among tetra­aryl-substituted cyclo­butanes reported so far. The four C—C single bonds of the cyclo­butane ring differ from each other. One is the same length as a typical C—C single bond, while the others are longer. The photodimerization of the corresponding monomer yields only 1% of s-DPC, suggesting that the head-to-head reaction is a minor photodimerization process.