Magnetic Chemistry - Magnetic Chemistry

A branch of physical chemistry that uses the magnetic properties of materials to deal with chemical problems. Originally, the focus was on measuring the magnetic susceptibility of diamagnetic and paramagnetic substances and studying the chemical structure and chemical reactions of substances. For example, Pascal's additivity law exists for diamagnetic substances, while the number and state of unpaired electrons in paramagnetic substances (paramagnetic ions, free radicals, paramagnetic complexes, triplet states, etc.) have been clarified. However, in recent years, new and powerful methods have been rapidly developed that also use the magnetic properties of substances, but that utilize the interaction between electromagnetic waves and the magnetic moment of unpaired electrons or atomic nuclei placed in a magnetic field, such as paramagnetic resonance (or electron spin resonance) absorption and nuclear magnetic resonance absorption. These have become a separate field or method of chemical research from the traditional magnetochemistry, which focuses on magnetic susceptibility measurements.

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

物質の磁気的性質を利用して化学の問題を取り扱う物理化学の一分野．元来，反磁性および常磁性物質の磁化率を測定し，物質の化学的構造および化学反応の研究を行うことが主であった．たとえば，反磁性物質についてはパスカルの加成則があり，他方，常磁性物質(常磁性イオン，遊離基，常磁性錯体，三重項状態など)については，これらがもつ不対電子の数や状態が明らかにされてきた．しかし，近年は同じく物質の磁気的性質の利用ではあるが，磁化率測定以外の，常磁性共鳴(あるいは電子スピン共鳴)吸収や核磁気共鳴吸収など，磁場内におかれた不対電子あるいは原子核の磁気モーメントと電磁波の相互作用を利用する新しい有力な方法が急速に発展し，これらは従来の磁化率測定を主とする磁気化学とは一応別の分野あるいは化学研究の手段となっている．

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