Derivatives of thiols, in which a metal (or other cation) replaces the hydrogen attached to sulfur, e.g.
CH3S−Na+ sodium methanethiolate.
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1372 (https://doi.org/10.1351/pac199567081307)