Magnetic Field Effects on Photochemical Reaction in Mesoporous Silicates of MCM-41 under High Magnetic Fields up to 5 T

Magnetic field effects (MFEs) on photoinduced hydrogen abstraction reaction of xanthone with xanthene were investigated in 2-propanol confined in mesoporous silicates of MCM-41 under high magnetic fields up to 5 T. The observed MFEs were explained by the spin relaxation mechanism associated with the cage effects on diffusion of the radical pairs in nanopores of MCM-41. The qualitative analysis using the stochastic Liouville equation revealed that the motions of the radical pairs are not restricted in the one dimension, although the MCM-41 used in the present study has the one-dimensional pore with the diameter of 1.7 or 2.7 nm. The effective viscosities for rotation of the solute molecule in the pores were estimated to be 5−10 cP.