Reaction intermediates - intermediates

Also called an intermediate product. A substance produced in the process of going from reactants to products in a chemical reaction. Normally, reactions shown in chemical reaction equations are rarely completed with just one elementary reaction, but rather a series of elementary reactions occur in succession to reach the final product. All substances produced as a result of each elementary reaction, except for the final product, are reaction intermediates. Some reaction intermediates can be extracted as stable molecules, such as aldehydes produced during the oxidation of alcohol to carboxylic acid, but there are also many unstable ones that are confirmed using various physical means or estimated from reaction theory. In a broad sense, active complexes can also be included in reaction intermediates.

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

中間生成物ともいう．化学反応で反応物から生成物に至る過程で生成する物質をいう．普通，化学反応式で表示される反応は，ただ一つの素反応で完結されることは少なく，一連の素反応が連続して起こることによってはじめて最終生成物に至る．各素反応の結果生じる物質は最終生成物を除いて，すべて反応中間体である．反応中間体にはアルコールがカルボン酸に酸化される途中に生じるアルデヒドのように，安定な分子として取り出せるものもあるが，種々の物理的手段を用いて確認されるか，あるいは反応論的に推定される不安定なものも多い．なお，広義には活性錯体を反応中間体に含めていうこともある．

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