Magnetic field effects and spin dynamics of radical reactions in solution

A pulsed magnet which is useful for the research of chemical reactions has recently been constructed by our group. Here, the world record of the maximum magnetic field (30 T) has been attained in this research area. An optical detected X-band ESR apparatus has also been developed by our group. The world's best sensitivity and resolution have been realized in this apparatus. In this account, we review our recent results on new magnetic field effects and spin dynamics obtained with such novel methods as described above for radical reactions at room temperature in solution. In Section 1, typical mechanisms of MFEs on radical pairs such as the Deltag mechanism and the relaxation mechanism are explained as the introduction of this review. In Section 2, the saturation of MFEs due to the Deltag mechanism observed for radical pairs generated from the photoreduction of 4-methoxybenzophenone with benzenethiol in fluid solutions under ultrahigh fields are described. In Section 3, the saturation and reversion of MFEs due to the relaxation mechanism observed for radical pairs generated from the photoreduction of carbonyl and quinone compounds in micellar solutions under ultrahigh fields are reviewed. In Section 4, the first observation of MFEs on the reactions of three-spin systems generated photochemically in solution are introduced. In Section 5, we describe spin dynamics of radical pairs studied with our optically detected ESR apparatus for radical pairs generated from the photoreduction of carbonyl and quinone compounds in micellar solutions.