Opposite sex - Isey

[ I ] This refers to the phenomenon in which two or more substances exist that have the same molecular formula but different structures and therefore different physical or chemical properties; compounds in this relationship are called isomers. The phenomenon of isomerism was first discovered around 1823-1824, when F. Wöhler and J. Liebig independently studied silver cyanate and silver fulminate, which have different properties, and discovered that both have the same molecular formula. Isomers are broadly divided into structural isomers and stereoisomers. Structural isomers are isomers that differ in the bonding order of atoms, and are further classified into carbon chain isomers, positional isomers, functional group isomers, tautomers, and others. Stereoisomers are divided into isomers based on the difference in the spatial arrangement of atoms or atomic groups (optical isomers, geometric isomers) and isomers based on the difference in the spatial conformation (conformational isomers, rotational isomers). However, conformational isomers that cannot be isolated separately at room temperature may not be classified as isomers. [ II ] [See other terms] Nuclear isomerism

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

【Ⅰ】分子式は同じであるが，構造が異なるため，物理的または化学的性質の異なる物質が，2種類以上存在する現象をいい，この関係にある化合物を異性体という．異性現象は，1823～1824年ころにF. Wöhler(ウェーラー)とJ. Liebig(リービッヒ)が，性質の異なるシアン酸銀と雷酸銀をそれぞれ独立に研究し，いずれも同一の分子式で表されることを発見したのが最初である．異性体は，構造異性体と立体異性体に大別される．構造異性体は，原子の結合順序が異なる異性体で，さらに炭素鎖異性体，位置異性体，官能基異性体，互変異性体，その他に分類される．立体異性体は，原子や原子団の立体配置の違いにもとづく異性体(光学異性体，幾何異性体)と，立体配座の違いにもとづく異性体(配座異性体，回転異性体)に分けられるが，常温で別々に単離できない配座異性体は，異性体のなかに入れないことがある．【Ⅱ】[別用語参照]核異性

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