Antimony pentasulfide / Antimony Pentasulfide is an inorganic compound of antimony and sulfur, also known as antimony red. It is a nonstoichiometric compound with a variable composition. Its exact structure is unknown. Commercial samples are usually contaminated with sulfur, which may be removed by washing with carbon disulfide in a Soxhlet extractor.
Antimony pentasulfide can be produced by the reaction of antimony with sulfur at a temperature between 250-400 °C in an inert atmosphere.