Fluorescence Switching of a Diarylethene Derivative Having Oxazole Rings

Abstract

A diarylethene derivative, in which oxazole rings are attached to the ethene moiety at the 5-position, was synthesized, and its photochromic and fluorescent properties were examined. The derivative undergoes photochromism in solution and the open-ring isomer exhibits strong fluorescence. The fluorescence intensity was found to reversibly change along with the photochromism.

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

“…The open-ring isomer of 1,2-bis(4-methyl-2-phenyl-5-oxazolyl)-perfluorocyclopentene (37), in which oxazole rings are attached to the ethene moiety at the 5-position exhibits relatively intense blue-green fluorescence (Φ f = 0.19). 90 The fluorescent property of diarylmaleic anhydride and diarylmaleimide derivatives, such as 71 or 162, strongly depends on solvent polarity. 40,125,297 The fluorescence spectrum of 71 shows remarkable Stokes shifts depending on solvent polarity, while the absorption spectral shift is rather small.…”

Widely Exploited, Yet Unreported: Regiocontrolled Synthesis and the Suzuki–Miyaura Reactions of Bromooxazole Building Blocks

“…[21,22] Less numerous group of 4,5-disubstituted oxazoles is represented by streptochlorin (7), [23,24] while trisubstituted derivatives include lipid peroxidation inhibitor martefragin A (8). [27,28] exclusively to the target substituted 2-, 4-and 5-bromooxazoles on multigram scale. [27,28] exclusively to the target substituted 2-, 4-and 5-bromooxazoles on multigram scale.…”

“…For the preparation of remaining compounds of the 2-substituted 5-bromooxazole series (24)(25)(26)(27)(28)(29)(30), our general approach including the lithiation step was applied. Synthesis of the corresponding 2-alkyl oxazoles 49a-d relied on the reaction sequence reported in the literature for the simplest representative 49a (R = Me) (Scheme 12).…”

“…[25,26] In addition to that, trisubstituted oxazoles exhibited scintillative, photochromic, and fluorescence switching properties. [27,28] exclusively to the target substituted 2-, 4-and 5-bromooxazoles on multigram scale. The utility of the multipurpose building blocks obtained in this work was demonstrated in the Suzuki-Miyaura cross-coupling reaction under parallel synthesis conditions.…”

Synthesis and properties of a new asymmetrical photochromic diarylethene bearing an isoxazole unit

“…Among the diarylethenes hitherto reported, most of the heteroaryl diarylethenes bear thiophene or benzothiophene rings, which exhibit excellent thermal stability and outstanding fatigue resistance [6][7][8][9][10], with only a few reports concerning other heteroaryl moieties, such as thiazole, [11][12][13] indole, [14] benzofuran, [15] indene, [16] pyrazole, [17] pyrrole, [18] among others. There are a few examples of photochromic diarylethenes bearing oxazole rings [19][20][21][22]. However, diarylethene derivatives with an isoxazole unit hitherto reported are very rare [23].…”