III and Chromium IV Species

The EPR signals due to Cr(III) (a d ion) are typically very broad and hard to observe in solutions (particularly in water) under ambient conditions, so either solids or frozen solutions are usually used. The resultant anisotropic EPR spectra require extensive computer simulations for the determination of the gx y z values and zero-field splitting parameters (Z) and E). Detailed theoretical descriptions of snch spectra have been reported [71-75]. 

As described in Section 1, reactions of Cr(VI) with cellular reductants are accompanied by the formation of 0-, S- or C-based organic radicals, which can then react with O2 with the formation of reactive oxygen species (ROS, Fig. 1) [1,92]. 

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