mercaptan physical properties
Except for methyl mercaptan, which is a gas at room temperature, all other mercaptans are liquid or solid. There is a dipole attraction between thiol molecules, but it is smaller than that between alcohol molecules, and there is no obvious hydrogen bond between thiol molecules and no obvious association. Thus, mercaptans have higher boiling points than alkanes of similar molecular weight, lower than alcohols of similar molecular weight, and similar to thioethers of similar molecular weight.