Ring opening/closure reactions of novel diheteroarylethenes derivatives. Solvent effects was written by Vazquez, Alvaro J.;Nudelman, Norma Sbarbati. And the article was included in Journal of Physical Organic Chemistry in 2012.COA of Formula: C9H8OS This article mentions the following:
Three novel diarylethenes, 3,3′-(3,3,4,4,5,5-hexafluoro-1-cyclopentene-1,2-diyl)bis[2-methyl-benzo[b]thiophene] (I), 3-[3,3,4,4,5,5-hexafluoro-2-(2-methylbenzo[b]thien-3-yl)-1-cyclopenten-1-yl]-6-methoxy-2-methyl-benzo[b]thiophene (II), and 3-[3,3,4,4,5,5-hexafluoro-2-(2-methylbenzo[b]thien-3-yl)-1-cyclopenten-1-yl]-6-methoxy-2-methyl-7-nitro-benzo[b]thiophene (III), were synthesized and their photochem. optical properties studied in four solvents (n-hexane, toluene, acetonitrile and methanol). It was determined that these compounds dramatically increase the light absorption in the visible region upon exposure to UV light, showing two absorption maxima at 420 nm and 520 nm, resp. The observed change is completely reverted upon exposure to visible light. The three compounds demonstrate negligible fatigue, excellent stability in the four solvents, and absence of photodegradation and thermal back reactions. This paper also describes a complete study of solvent effects on the kinetics of the ring opening and cycloreversion. While, the UV spectra are little sensitive both to the substitution pattern and to the solvent influence, the kinetics of ring opening/cycloreversion reactions exhibit a more interesting behavior that differs from other diarylethenes reported in the literature. The cyclization kinetics shows a complex order, well fitted by an exponential equation, while the cycloreversion presents first-order kinetics. The whole complex reaction scheme can be explained by the unusual presence of two conformers of the open form, a parallel and an antiparallel conformation. Though other alternative mechanism could explain the kinetics, addnl. evidence is consistent with the conformational equilibrium proposed: i.e. the solvent influence on the kinetics of the nitro-substituted substrate, and the double signals for the Me protons and for the methoxy protons (when present) observed in the NMR spectra. These observations are relevant in relation to the application of these novel diarylethenes as potential optical materials. Copyright © 2012 John Wiley & Sons, Ltd. In the experiment, the researchers used many compounds, for example, 6-Methoxybenzo[b]thiophene (cas: 90560-10-4COA of Formula: C9H8OS).
6-Methoxybenzo[b]thiophene (cas: 90560-10-4) belongs to benzothiophene derivatives. Benzothiophene scaffolds are of great importance due to its increased presence in bioactive molecules. Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.COA of Formula: C9H8OS
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem