What is "isothiouronium"

In organic chemistry, isothiouronium is a functional group with the formula [RSC(NH)] (R = alkyl, aryl). The H centres can also be replaced by alkyl and aryl. Structurally, these cations resemble guanidinium cations. The CNS core is planar and the C-N bonds are short.

Salts comprising these anions are typically prepared by alkylation of thiourea:

SC(NH) + RX → [RSC(NH)]X

Hydrolysis of isothiouronium salts gives thiols.

[RSC(NH)]X + NaOH → RSH + OC(NH) + NaX

Chelating resins with isothiouronium groups are used to recover mercury and noble metals including platinum from solutions.