Biradicals classification

Andersson I, Ikeda DM,Zackrisson S,et al (2008) Breast tomosynthesis and digital mammography a comparison of breast cancer visibility and BIRADS classification in a population of cancers with subtle mammographic findings. Eur Radiol 18 2817-2825... 

A sufficiently comprehensive classification of the radical reactions has been suggested in Ref [2]. Regarding the structure of electron shells of the reactants, the radical reactions are subdivided into two classes. The first of these comprises the reactions in which the common electron shell is closed or has a triplet electron configuration (2n electrons), i.e., the reactions of recombination and those of radical pair and biradical formation. To the second class (free-radical reactions) the transformations belong in which one of the reactants has a closed shell and the other—one unpaired electron (total number of electrons is 2n + 1). 

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