Chemical reactions magnetic field sensitivity

The cell diagrammed in Figure 29.20c has been used extensively by Kastening to study the reaction mechanisms and kinetics when a stable electro-chemically generated species is mixed with other reactants [38]. The calculations that were used to reduce the experimental data to kinetic parameters included the effects of flow rate, reaction mechanism, rate constant, and the dependence of the EPR spectrometer nonuniform sensitivity to the position of the radicals in the cavity. Unfortunately, the correction for the latter effect was introduced as the idealized cosine-squared function (solid line in Fig. 29.16) rather than the actual sensitivity variation that occurs with magnetic field modulation. It is important to be aware of this difficulty when performing experiments to determine accurate kinetic parameters. 

Harkins and Grissom have made the interesting observation that catalysis by ethanolamine deaminase is affected by external magnetic fields (Harkins and Grissom, 1994). It is expected that reactions involving free radicals may be sensitive to magnetic fields, and there are prior examples in the chemical literature (for a review see Steiner and Ulrich, 1989), but... 

James C. Weaver, Timothy E. Vaughan and R. Dean Astumian, Biological sensing of small field differences by magnetically sensitive chemical reactions. Nature, 405 (2000), 707-709. 

Investigations of magnetic field effects in radiation-chemical reactions belong to a new research area [1-3] called, for short, spin chemistry . For the last 15 years, both the magnetic field effects in radiolysis [4-7] and the related highly sensitive methods such as optically/fluorescent detected ESR (OD/FD ESR) [7-10] have been a subject of extensive reviews. 

The Feshbach resonances can be used as a very sensitive probe for the interaction potential and also to selectively break or make bonds in chemical reactions. The coupling between the bound and unbound states can be modified by applying an external electric or magnetic field, and this provides an important mechanism for creating or eliminating Feshbach resonances and thereby controlling the collisional... 

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