3,3,4,4,5,5-Hexafluoro-1-[2-methyl-5-(2-fluorophenyl)-3-thienyl]-2-(2-methyl-5-phenyl-3-thienyl)cyclopent-1-ene, a new photochromic dithienylethene

Abstract

The title compound, C27H17F7S2, a new unsymmetrical photochromic dithienylethene with an ortho‐fluoro­phenyl substituent, is one of the most promising candidates for photoelectronic applications, such as optical storage, photoswitches and waveguides. There are two mol­ecules in the asymmetric unit. Both adopt a photoactive anti‐parallel conformation. For one mol­ecule, the distance between the two reactive C atoms is 3.572 (6) Å; the dihedral angles between the central cyclo­pentene ring and the thio­phene rings are 49.7 (2) and 45.9 (2)°, and those between the thio­phene rings and the adjacent benzene rings are 8.1 (2) and 25.5 (1)°. For the other mol­ecule, the distance between the two reactive C atoms is 3.588 (6) Å; the dihedral angles between the central cyclo­pentene ring and the thio­phene rings are 43.7 (2) and 46.8 (2)°, and those between the thio­phene rings and the adjacent benzene rings are 27.5 (1) and 11.1 (2)°.

3,3,4,4,5,5-Hexafluoro-1,2-bis[2-methyl-5-(3-methylphenyl)-3-thienyl]cyclopent-1-ene, a new photochromic diarylethene compound

“…Of all the photochromic compounds, diarylethenes are the most promising candidates because of their good thermal stability, high sensitivity, fast response and high fatigue resistance (Irie, 2000;Tian & Yang, 2004). A large numbers of diarylethene crystal structures and their properties have already been reported (Matsuda & Irie, 2004;Morimoto et al, 2004;Morimoto & Irie, 2005;, including some structures we have determined (Pu et al, 2003(Pu et al, , 2004Pu, Fan et al, 2005;Pu, Li et al, 2005;Pu, Yang, Wang et al, 2005;Pu, Yang, Yan et al, 2005). For further background information see .…”

1-[5-(4-Chlorophenyl)-2-methyl-3-thienyl]-2-(2,5-dimethyl-3-thienyl)-3,3,4,4,5,5-hexafluorocyclopent-1-ene: a new photochromic diarylethene compound

“…(3) (5.8 g, 20.3 mmol), was prepared in 89.7% yield by reacting 3-bromo-2methyl-5-thienylboronic acid, (2) (Pu, Li et al, 2005) (5.0 g, 22.6 mmol) with 4-bromo-1-chlorobenzene (4.3 g, 22.6 mmol) in the presence of Pd(PPh 3 ) 4 (0.8 g) and Na 2 CO 3 (2 mol l À1 , 84.8 mmol) in THF (100 ml) for 12 h at 343 K. To a stirred THF solution (80 ml) of compound (3) (5.8 g, 20.3 mmol), an n-BuLi/hexane solution (8.1 ml, 2.5 mol l À1 , 20.3 mmol) was added at 195 K under a nitrogen atmosphere. 30 min later, (2,5-dimethyl-3-thienyl)perfluorocyclo-pent-1-ene, (4) (Sun et al, 2003) (6.2 g, 20.3 mmol), was added and the mixture was stirred for 2 h at this temperature.…”

2-[5-(3-Cyanophenyl)-2-methyl-3-thienyl]-1-(2,5-dimethyl-3-thienyl)-3,3,4,4,5,5-hexafluorocyclopent-1-ene: a new photochromic diarylethene compound

“…Compound (I) was prepared as outlined in the second scheme. 3-Bromo-2-methyl-5-(3-cyanophenyl)thiophene, (3) (5.5 g, 19.8 mmol), was prepared in 65% yield by reacting 3-bromo-2-methyl-5-thienylboronic acid, (2) (Pu, Li et al, 2005;2006) (6.8 g, 30.6 mmol), with 3bromo-1-cyanobenzene (5.6 g, 30.6 mmol) in the presence of Pd(PPh 3 ) 4 (0.9 g) and aqueous Na 2 CO 3 (2 M, 100.0 mmol) in tetrahydrofuran (THF; 90 ml) for 12 h at 343 K. To a stirred THF solution (50 ml) of compound (3) (1.5 g, 5.4 mmol), an n-BuLi-hexane solu-tion (3.4 ml, 1.6 M, 5.4 mmol) was added at 195 K under a nitrogen atmosphere. After 30 min (2,5-dimethyl-3-thienyl)perfluorocyclopent-1-ene, (4) (Sun et al, 2003) (1.7 g, 5.4 mmol), was added and the mixture was stirred for 2 h at this temperature.…”