3,3,4,4,5,5-Hexa­fluoro-1,2-bis­[5-(2-fluoro-4′-undecyl­oxybiphenyl-4-yl)-2-methyl-3-thien­yl]cyclo­pentene

The title compound, C61H68F8O2S2, is a photochromic liquid crystal based on diaryl­ethene 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 mol­ecule adopts a photo-active anti­parallel conformation and the distance between the two reactive C atoms of the thio­phene rings is 3.448 (3) Å. The dihedral angles between the central cyclo­pentene ring and the adjacent thio­phene rings are 43.56 (3) and 48.58 (3)°. These structural elements exhibit a suitable geometry for photochromic behaviour in the crystalline state

A helical naphthopyran dopant for photoresponsive cholesteric liquid crystals

The first photoresponsive cholesteric liquid crystal comprising a photoisomerizable helical naphthopyran derivative dopant and a nematic liquid crystal is reported. An unprecedented helical twisting power switching ratio of over 90% allowed us to demonstrate multi-cycle rotational motion of micro-objects by UV light irradiation

Photochromism of new benzopyrans bearing pyridine units

International audienc

Controlled Conversion of Isomers in a Hybrid Biphotochromic System

The photochromic performance of a hybrid system connecting naphthopyran and dithienylethene was investigated, and the photochemistry of eight different isomers was explored by choosing an appropriate wavelength of light

Bridging the visible: the modulation of the absorption by more than 450 nm

The coexistence of 18 isomers, identified by NMR spectroscopy and gathered into six states with very different absorption properties, is observed upon irradiation with selective wavelengths of a triphotochromic system joining two naphthopyran entities through a dithienylethene bridge. The sequential electronic coupling of photochromic groups resulted in an absorption behavior reaching far into NIR

Excellent Organic Semiconductors Based on Bis-tetracene and Bis-pentacene: From Stable Closed-Shell to Singlet Open-Shell

International audienc

The Control of Photochromism of [3 H ]-Naphthopyran Derivatives with Intramolecular CH−π Bonds

International audienceThe photochromism of [3H]-naphthopyran derivatives can be switched from T-type to inverse- or P-type through the manipulation of relative thermodynamic stabilities of open isomers with intramolecular CH−π bonds