The -SH function itself is called a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogs of alcohols, and thiol polyPEGs can react specifically with maleimide groups at pH 6.5 to 7.5 to form stable thioether linkages. Thiols can also react with olefins through thiol-ene chemistry in the presence of free radical initiators.
