Alkyl radicals heterolytic fragmentation

A mechanism was proposed in which the perferryl iron-oxeme, resulting from heterolytic cleavage of the 0-0 bond of the iron-peroxy intermediate, abstracts an electron from the 0=0 double bond of the carbonyl group of the aldehyde. The reduced perferryl attacks the 1-carbon of the aldehyde to form a thiyl-iron-hemiacetal diradical. The latter intermediate can fragment to form an alkyl radical and thiyl-iron-formyl radical. The alkyl radical then abstracts the formyl hydrogen to produce the hydrocarbon and C02 (Reed et al 1995). 

The gaseous dichlorocarbene radical cation reacted with alkyl halides via a fast electrophilic addition to form a covalently bonded intermediate (CI2C—X—R)+ in a Fourier transform ion cyclotron resonance mass spectrometer. This intermediate fragments either homolytically or heterolytically to produce net halogen atom or halogen ion transfer product. Addition of carbonyls to the carbene ion is followed by homolytic cleavage of the C-O bond to yield a new carbene radical cation. 

In heterolytic cleavage, a pair of electrons move together toward the charged site as shown by the conventional curved arrow the fragments are again an even-electron cation and a radical, but here the final charge site is on the alkyl product. 

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