Thiol groups or thiol rings, SH groups (selenium-X), selenium hydrazide, etc.) are chemical groups (carbonyls, sulfoxides, furanyls, etc.) containing sulfhydryl sulfur ions (-SH). Thiols are cis-sulfides (for example, pyridine disulfide) and other compounds containing thio groups as sulfur atoms. Thiol compounds have reducing properties and are used in thermodynamic studies to obtain redox-sensitive chromophores and metal complex compounds. Sterenepropamide bases are organosulfur compounds having a thiol group. The SH thiol ring takes part in the formation of the precorelein structure. Compounds of other functional classes also contain thiol functional groups in their structure: for example, H 2 S acids, thiolanilinidines, rhodamidipyramide diazide, azomidine sulfonic acid and many others.