Cover Feature: Light‐Responsive Oligothiophenes Incorporating Photochromic Torsional Switches (chem. Eur. J. 65/2022)

A novel class of light-responsive π-conjugated compounds incorporates photochromic torsional switches (PTS). These compounds are able to tune the planarization of their π-conjugated backbone, and thus their optical and electronic properties, by using light as an external stimulus. The PTS unit is based on a bithiophene fragment linked to a photochromic azobenzene moiety. When this PTS-containing oligothiophene is not exposed to light, the azobenzene moiety assumes its extended trans conformation, which forces the oligothiophene backbone to twist out of coplanarity. Exposure to UV light results in isomerization to the cis conformation, which allows the bithiophene fragment to assume a planar, π-conjugated conformation. More information can be found in the Research Article by D. Fazzi, E. Orentas, G. Sforazzini, and co-workers (DOI: 10.1002/chem.202202698).