C7H8S

C7H8S is the molecular formula for several sulfur-containing organic compounds. Because it contains seven carbons, eight hydrogens, and one sulfur atom, this formula can describe more than one structural isomer. In practice, C7H8S most often refers to compounds in two broad classes: thioethers (sulfides) and thiols.

Two representative isomers are commonly cited. Thioanisole, or methyl phenyl sulfide, has the structure Ph-S-CH3, where a methyl group is bonded to sulfur that is linked to a phenyl ring. The other principal isomer is benzyl mercaptan, or phenylmethanethiol, with the structure Ph-CH2-SH, in which a thiol group is attached to a benzyl carbon. These two isomers exemplify how the same molecular formula can correspond to different connectivity patterns (R-S-R' versus R-SH).

Properties and reactivity are influenced by the functional group. Thioethers like thioanisole are relatively stable and commonly used as intermediates in organic synthesis and sometimes in fragrance chemistry. Thiols such as benzyl mercaptan are typically more reactive and characteristically possess strong, distinctive odors; they readily oxidize to disulfides or, under harsher conditions, to sulfoxides or sulfones. The exact physical properties (boiling point, odor, density) depend on the specific isomer. Safety considerations vary, but thiols are often irritants and should be handled with appropriate precautions.