Stilene

Stilene, more commonly spelled stilbene, is an organic hydrocarbon that consists of two phenyl rings joined by a central carbon–carbon double bond. The molecule exists as two geometric isomers, cis-stilbene and trans-stilbene, with the latter being more stable under normal conditions. The spelling stilene appears in older literature and is generally considered an obsolete variant of stilbene.

Stilbene serves as a versatile scaffold in organic synthesis and materials science. Its conjugated system makes it a useful model compound for studying photoisomerization and cis–trans equilibrium. Many stilbene derivatives are synthesized to tailor photophysical properties, and some are used as fluorescent dyes, liquid-crystal materials, or nonlinear optical components. Trans-stilbene itself has been used as a scintillator in early radiation detectors, and related derivatives remain of interest in organic electronics and photonics.

Historically, stilbene was isolated and studied in the 19th century, and its distinctive cis–trans isomerism contributed to fundamental concepts in stereochemistry and photochemistry. The name stilbene derives from early naming conventions and remains the standard term, while stilene is encountered as a rarely used synonym in older texts.

Properties and safety: Stilbene is typically a colorless crystalline solid at room temperature, soluble in organic solvents but not in water. It is sensitive to light and readily undergoes cis–trans isomerization under ultraviolet or visible light, a property central to many of its applications. Handling requires standard laboratory precautions; stilbene is of low acute toxicity but can be harmful if ingested, inhaled, or if it comes into contact with skin.