TABLE OF CONTENTS In 1976, Atkins [1] wrote a short review entitled "Magnetic field effects" and described at its beginning "The study of the effect of magnetic fields on chemical reactions has long been a romping ground for charlatans". Until then, so many papers had reported having found magnetic field effects (MFEs) on chemical and biochemical reactions. Almost all of such studies, however, lacked reproducibility andor theoretical interpretation. Thus, most scientists at that time believed that ordinary magnetic fields could not exert appreciable influence on chemical and biochemical reactions. Here, ordinary magnetic fields mean those less than 2 T, which can be generated by usual permanent and electric magnets.
This view seems to be reasonable if one compares magnetic energies of molecules with those related to chemical reactions: (1) The Zeeman splitting of an electron spin at 2 T is about 2 cm ?1. (2) The Zeeman splittings of nuclear spins are much smaller than that of an electron spin, that of proton at 2 T being about 0.002 cm ?1. (3) The thermal energy at room temperature is about 200 cm ?l. (4) The activation energies for chemical reactions are usually much larger than the thermal energy. Thus, MFEs on chemical and biochemical reactions seemed to be impossible from a thermodynamic consideration, unless extraordinarily large fields were used.
The only exception to the above discussion was the MFE on the predissosiation of I 2. In 1913, Steubing discovered that the visible...
