Abstract
2-Benzo[b]thienyl fulgides and fulgimides containing bulky diphenylmethylene substituents were synthesized in the form of their ring-opened E- or Z-isomers. In contrast to the majority of known fulgides/fulgimides, that form colored ring-closed structures under UV irradiation, the obtained compounds undergo an irreversible transformation leading to decoloration of their solutions. This rearrangement with the formation of the dihydronaphthalene core appeared to be by 2–3 orders of magnitude more efficient than for the known diphenylmethylene(aryl(hetaryl))fulgides. The molecular structures of E- and Z-isomers and of products of the photoinduced rearrangement completed by 1,5-H shift reaction, 3a,4-dihydronaphtho[2,3-c]furans(pyrroles) C, were established based on the data of 1H and 13C NMR spectroscopy and X-ray diffraction studies.
Highlights
Photochromic compounds are of considerable interest as molecular switches, elements of optical memory and molecular logic devices [1,2,3,4]
Fulgides 3E, 3Z, 7E and fulgimides 4E, 4Z, 8E were synthesized as shown in Scheme 2 and Scheme 3
The interaction of 3E with benzylamine in the presence of ZnCl2 and HMDS leads to the formation of a mixture of fulgimides 4E (41%) and 4Z (18%)
Summary
Photochromic compounds are of considerable interest as molecular switches, elements of optical memory and molecular logic devices [1,2,3,4]. UV irradiation of acetonitrile solutions of these compounds results in the electrocyclic hexatriene–cyclohexadiene rearrangement of the ringopened isomers O into the colored ring-closed ones C (Scheme 1) which exhibit enhanced spectral characteristics as compared with 2-thienyl and 3-benzo[b]thienyl analogues.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
