Photochromism of dithienylethene single crystals having anthracene substituents

Three dithienylethene derivatives having anthracene substituents (connected at 1-, 2- and 9-positions) were prepared. Although these three derivatives exhibit photochromic reactivity in solution, only one of the derivatives (connected at 2-position) undergoes the photochromic reaction in the crystalline phase. X-Ray crystallographic analysis and DFT calculation revealed that conformation of the anthracene substituents plays an important role in the crystalline photochromism.