Metalloporphyrin anion, nucleophilicity

The metal-centered reduction of iron and cobalt porphyrins [(por)Afn] yields metalloporphyrin anions [Eq. (13.13)]. The reduction potential for this reaction is 13, and is equivalent to the N- value for the oxidation of the metal-centered nucleophile [(por)uM-]. The one-electron reduction of alkyl halides yields the... 

A key to achieving living polymerization is to develop well-behaved initiators, because the initiator affects both the relative rate of initiation to propagation and the potential for side reactions. - In this chapter, we focus on the precision synthesis of macromolecules with metalloporphyrins as initiators. Extensive initial studies by Inoue and Aida, - and more recent studies by Wayland et al.have shown that the metalloporphyrins which are applicable to controlled macromolecular synthesis include compounds of aluminum (1-4), zinc (5), manganese (6), cobalt (7) and rhodium (8). The first two nontransition metal metalloporphyrins are effective for anionic (nucleophilic) polymerization while... 

Metalloporphyrin mono- and di-anions are readily formed, most conveniently by electrochemical methods, and as would be expected they behave as strong nucleophiles. They react rapidly with proton sources or with electrophiles such as methyl iodide, and the products are usually substituted on methine carbons 5 and 15 to give derivatives such as (63), which are called porphodimethenes. 

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