Cadmium metal radical anions

The very reactive Rieke cadmium metal was allowed to react under vacuum with benzoquinone in THF. This resulted in the formation of several different paramagnetic species, [Cd(C6H402 )(THF)3]+,C6H402 or [Cd(C6H402 )(THF)3]+ + C6H402 [215]. The tetrahedral coordination sphere for each species consists of three THF molecules and an anion radical that is asymmetrically or symmetrically coordinated to the metal dication. The original apparatus for the generation of the benzoquinone anion radical via electron transfer from cadmium metal was reported... 

Zinc and cadmium alkyls have not been successful as stereospecific catalysts in the absence of co-catalysts, presumably because they do not complex strongly enough with the monomer and the metal-carbon bonds are too covalent. Cadmium alkyls were first reported by Furukawa and coworkers (260) to induce vinyl polymerization, but it was shown later (267, 262) that oxygen was a co-catalyst and the reactions were free radical in nature. Similar free radical results were obtained with zinc alkyls (261—263) and vinyl monomers. However, with more basic and more easily polarized monomers, such as olefin oxides and aldehydes, the zinc catalysts operate by a coordinated anionic mechanism (250). 

Especially transition metal icMis play an important role in the induction of oxidative DNA damage. While neither superoxide anions nor hydrogen peroxide are able to react with DNA directly, in the presence of transition metals like iron, copper, cobalt, or nickel they are converted into highly reactive hydroxyl radicals by Fenton-type reactions. In contrast, cadmium ions are not able to participate in redox reactions under physiological conditions, yet, oxidative stress and the interference with cellular redox regulation may be of high relevance in cadmium-induced carcinogenicity. Increased levels of ROS due to cadmium exposure have been observed both in vitro and in vivo [31]. Different cadmium compounds have been shown to induce DNA strand breaks and oxidative DNA base modifications in... 

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