Thiones are a class of chemical compounds that contain a sulfur atom double-bonded to a carbon atom, similar to how ketones contain an oxygen atom. They are characterized by the presence of a sulfur atom in the structure, which can influence their reactivity and properties. Thiones can be found in various organic reactions and are often used in synthetic chemistry. These compounds are important in the study of organosulfur chemistry and can serve as intermediates in the synthesis of other chemicals. Thiones can also exhibit unique biological activities, making them of interest in pharmaceutical research and development.