C5H10S

C5H10S is a chemical compound with the molecular formula consisting of five carbon atoms, ten hydrogen atoms, and one sulfur atom. It is a thiophene derivative, specifically a five-membered heterocyclic ring containing sulfur, and is commonly referred to as **thiophene** when the ring is fully unsaturated. However, C5H10S can also represent various saturated or partially saturated analogs, such as tetrahydrothiophene (thiacyclopentane) or other isomers depending on the arrangement of double bonds and substituents.

Thiophene itself is a colorless, volatile liquid with a characteristic odor, often described as similar to that of benzene but with a slightly sulfurous note. It is notable for its aromatic properties, despite the presence of sulfur, which contributes to its stability and reactivity. Thiophene is a key component in organic synthesis, particularly in the production of pharmaceuticals, agrochemicals, and specialty chemicals. Its structure allows it to participate in electrophilic aromatic substitution reactions, similar to benzene, though with some differences due to the electronegativity of sulfur.

The saturated analog, tetrahydrothiophene (C4H8SH), is a cyclic ether analog with a sulfur atom replacing an oxygen in tetrahydrofuran (THF). It is less common but still relevant in certain organic transformations, particularly in the formation of organosulfur compounds. Both thiophene and its derivatives are used in industrial applications, including as solvents, intermediates in polymer synthesis, and components in fuel additives.

Due to its volatility and potential toxicity, handling C5H10S compounds requires proper ventilation and safety precautions. Thiophene, in particular, is flammable and can form explosive mixtures with air. Its presence in crude oil and petroleum fractions also makes it a relevant compound in refining processes, where it is often removed to improve fuel quality.