Thiol

Also called thioalcohol. A general term for RSH compounds in which the oxygen atom of a hydroxyl group is replaced with a sulfur atom. Low molecular weight compounds are widely found in nature and have strong, distinctive odors such as the aroma of pickles and the odor of skunk. Due to the influence of the sulfur atom, they are less polar than the corresponding alcohols, weakly acidic, soluble in organic solvents but poorly soluble in water, and have a low boiling point. While aliphatic thiols are obtained from alkyl halides and sodium hydrogen sulfide, aromatic thiols are obtained by reacting aryl Grignard reagents with elemental sulfur. Compared to aliphatic thiols, aromatic thiols are more acidic and have properties similar to alcohols. They form stable mercaptides with heavy metal salts. They are easily oxidized to give disulfides even in air, and this property also plays an important role in living organisms. Infrared absorption spectra show SH absorption at around 2500 cm ^-1 .

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

チオアルコールともいう．ヒドロキシ基の酸素原子を硫黄原子に置換した，RSH化合物の総称．低分子量の化合物は広く天然に存在し，漬けものの香気，スカンクの臭気など強い特有の臭いをもつ．硫黄原子の影響で，相当するアルコールに比べて極性が低く，弱酸性であり，有機溶媒には溶けるが，水に溶けにくく，沸点も低い．脂肪族チオールがハロゲン化アルキルと硫化水素ナトリウムとから得られるのに対し，芳香族チオールはアリールグリニャール試薬と単体硫黄との反応で得られる．脂肪族チオールに比べ芳香族は酸性が強く，アルコールに近い性質をもつ．重金属塩と安定なメルカプチドを形成する．酸化されやすく空気中でもジスルフィドを与えるが，この性質は生体内でも重要な役割を果たしている．赤外吸収スペクトルでは2500 cm^－1 付近にS-Hの吸収を示す．

出典　森北出版「化学辞典（第2版）」化学辞典 第2版について　情報