Thiophene, 2,2′-ethenylidenebis- (C₁₀H₈S₂) is an organosulfur compound consisting of two thiophene rings linked through a vinylidene (-CH=) bridge at their 2-positions. This structure gives it a conjugated π-electron system, which can influence its electronic and optical properties, making it of interest in materials science, especially in organic semiconductors and conductive polymers. It appears as a yellow to orange crystalline solid, is relatively hydrophobic, and is typically synthesized via coupling reactions involving thiophene derivatives.