Hetero atom centered radicals

In aqueous solution the electron transfer between (reducing) carbon-centered radicals or (oxidizing) hetero-atom-centered inorganic radicals and organic molecules often proceeds by covalent bond... 

The unrestricted and free electron transfer (FET) from donor molecules to solvent radical cations of alkanes and alkyl chlorides has been studied by electron pulse radiolysis in the nanosecond time range. In the presence of arenes with hetero-atom-centered substituents, such as phenols, aromatic amines, benzylsilanes, and aromatic sulfides as electron donors, this electron transfer leads to the practically simultaneous formation of two distinguishable products, namely donor radical cations and fragment radicals, in comparable amounts. 

Concerning the general reaction Scheme 1, attention is restricted to two special areas A), cases where X is a carbon-centered radical and Y is an oxygen atom joined by a double bond to some center Z (Eq. 4), and B), cases where X is a hetero atom, in most cases oxygen centered radical and Y is a carbon (Eq. 5) [11]. One is then dealing with formation and heterolysis of a bond between a carbon- and a hetero-atom. Of the two, the hetero-atom is of course always more electron-affinic and therefore in the heterolysis the electron pair joining the two will go to the hetero-atom. 

Oxidation of Carbon-Centered Radicals Substituted by a Hetero-Atom E at Ca... 

The examples so far described always involve a carbon-centered radical which is substituted at by a hetero atom such as O, S, or N. S is always a functional group that contains a double bond, usually an oxygen, i.e. the group =0. X then adds to S according to ... 

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