Stilbener

Stilbene is a class of hydrocarbon compounds characterized by two phenyl rings connected by an ethene bridge, giving the core structure C6H5-CH=CH-C6H5. The molecule exists in two geometric isomers, trans (E) and cis (Z), with trans-stilbene being the more stable form. The base molecule is often referred to simply as stilbene, while many derivatives known as stilbenes feature substituents on the rings.

Natural stilbenes occur in plants and can act as phytoalexins or signaling molecules. The best known natural stilbene is resveratrol, a 3,5,4'-trihydroxy-trans-stilbene found in grapes and red wine, studied for potential health effects. Other examples include pinosylvin and pterostilbene (a dimethylated derivative). Stilbenes and their derivatives are widely investigated for their biological activity, antioxidant properties, and roles in plant defense.

Synthesis of stilbene often employs the McMurry coupling of benzaldehydes to form the trans isomer, though other routes such as Wittig reactions and Knoevenagel condensations followed by reduction are used for specific substitutions. The trans form is favored in many applications due to its rigidity and planarity, while the cis form can be interconverted under light exposure.

Applications and significance: stilbene derivatives serve as dyes, fluorescent probes, and components in organic electronic materials. Trans-stilbene itself is valued for its fluorescence and for use as a scintillator material in radiation detectors. The family also underpins numerous natural products and synthetic compounds studied in medicinal chemistry and materials science.

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