New photochromic diarylethenes including P and Si atoms

Photochromism of Diarylethene Molecules and Crystals: Memories, Switches, and Actuators

“…However, diarylethene derivatives having a phosphoruscontaining or silylated five-membered ring, such as compounds 481 and 482, or dithiole-2-thione, such as compound 483, can exhibit fluorescence in the closed-ring isomers. 899,900 When five-membered heterocyclic rings, such as thiophene, thiazole, oxazole, or imidazole, are used as the ethene bridges, such as compounds 484, 485, 479, 486, 478, 480, the closed-ring isomers become thermally unstable. 147,895,903 The colors of the closed-ring isomers disappear even in the dark in contrast to stable colors of closed-ring isomers of diarylethenes having a perfluorocyclopentene bridge, as described in section 3.2.…”

“…Krayushkin and co-workers − and others − employed various types of heterocyclic systems as the ethene bridges as shown in Scheme . When the ethene bridge is perfluorocyclopentene, most of the derivatives are nonfluo­rescent or very weakly fluorescent in both open- and closed-ring isomers.…”

Synthesis of ene-yne-enes by nickel-catalyzed double SN2′ substitution of 1,6-dichlorohexa-2,4-diyne

“…1 H NMR (400 MHz, CDCl 3 ): 5.75 (s, 2H), 5.93 (s, 2H), 7.10-7.04 (m, 4H), 7.69-7.63 (m, 4H). 13 (35), 264 (30), 133 (48).…”

“…[10][11][12][13] In the case of 1,4-disubstituted but-2-yne, the reaction takes place twice, [14][15][16][17][18][19][20][21] as the initially formed 4-substituted 1,2-butadiene again acts as a substrate for the reaction, to provide disubstituted 1,3-butadienes. This reaction has been extensively exploited as the products, in turn, are starting materials for subsequent Diels-Alder reactions [22][23][24][25][26][27][28][29][30][31][32] (Scheme 2).…”

Synthesis and photochromism of some mono and bis (thienyl) substituted oxathiine 2,2-dioxides

“…P-type photochromic dithienylethenes such as 1-open, which readily undergoes reversible conversion to the coloured isomer 1-closed, (Scheme 1) are fundamental switching units which have been used to modulate a variety of physical and optical properties. 1 Structural variation of the essential 1,2-bis(2,5-dimethylthiophen-3-yl)ethene core has been frequently explored by modification of the 2,5-dimethylthiophene moiety 1,2 and to a somewhat lesser extent by variation of the perfluorocycle, particularly replacement of the latter with a 5-membered heterocyclic unit to afford 2, wherein the heterocycle has been selected from imidazole, 3,4 imidazolium, 5 pyrrole, 6 thienophosphole, 7 phosphindolothiophene, 8 thiophene, [9][10][11] thiopyranothiophene, 12 silole, 13,14 1,3-dithiole 15 and thiazole 16 and less commonly with a sixmembered unit leading to 2 where the heterocyclic unit includes quinoxaline, 17 triazoloquinoline, 18 pyridazine, 19 thiazine, 20 1,2-oxazine 21 and 1,2,4-triazine. 22…”