title: 3,3,4,4,5,5-Hexa-fluoro-1,2-bis-[5-(2-fluoro-4'-undecyl-oxybiphenyl-4-yl)-2-methyl-3-thien-yl]cyclo-pentene.
abstract: The title compound, C(61)H(68)F(8)O(2)S(2), is a photochromic liquid crystal based on diaryl-ethene as photoswitchable unit. The F atoms connected to the benzene rings are disordered over two positions; the site-occupation factors refined to 0.830 (3)/0.170 (3). The mol-ecule adopts a photo-active anti-parallel conformation and the distance between the two reactive C atoms of the thio-phene rings is 3.448 (3) Å. The dihedral angles between the central cyclo-pentene ring and the adjacent thio-phene rings are 43.56 (3) and 48.58 (3)°. These structural elements exhibit a suitable geometry for photochromic behaviour in the crystalline state.
authors.forename: Michel
authors.initials: M
authors.lastname: Frigoli
authors.forename: Jérôme
authors.initials: J
authors.lastname: Marrot
authors.forename: Georg H
authors.initials: GH
authors.lastname: Mehl
authors.forename: Chantal
authors.initials: C
authors.lastname: Larpent