What Are Thiols

The most outstanding property of low-molecular-weight thiols is their stench. They are responsible for the unpleasant odors such as those from skunks, rotten eggs, and sewage. The scent of skunks is due primarily to two thiols  

Methanethiol, CH3SH. (a) Lewis structure and (b) ball-and-stick model.The C—S—H bond angle is 100.3°, somewhat smaller than the tetrahedral angle of 109.5°. 

A blend of low-molecular-weight thiols is added to natural gas as an odorant. The most common of these odorants is 2-methyl-2-propanethiol (ferf-butyl mercaptan), because it is the most resistant to oxidation and has the greatest soil penetration. 2-Propanethiol is also used for this purpose, usually as a blend with fcrf-butyl mercaptan. 

2-Methyl-2-propanethiol 2-Propanethiol (i r -Butyl mercaptan) (Isopropyl mercaptan) 

The sulfur analog of an alcohol is called a thiol (thi- from the Greek theion, sulfur) or, in the older literature, a mercaptan, which literally means mercury capturing. Thiols react with Hg in aqueous solution to give sulfide salts as insoluble precipitates. Thiophenol, C0H5SH, for example, gives (C0H5S)2Hg. 

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