Radicals of the heavier group 14 elements

The first landmark syntheses of persistent radicals of the heavier group 14 elements were reported nearly 30 years ago by Lappert s group. ° The first radical of this series, [(Me3Si)2CH]3Sn , was prepared by photolysis of the stable stannylene [(Me3Si)2CH]2Sn with visible light in benzene (Scheme 2.26). ° =... 

The tricoordinate radicals of the heavier group 14 elements can be generated in one of the following ways (1) by the photolysis or thermolysis of the corresponding hydrides R3EH (E = heavier group 14 element) in the presence of the radical initiators, (2) by the y-irradiation of R4E or photolysis of RsE-Hg-ERs, or (3) by the thermolysis or photolysis of either R3E-ER3 or R3E-ER2-ER3 (4), (4) one-electron reduction of silicon cation (5), (5) one-electron oxidation of silyl anion (6), as well as by (6) one-electron reduction of alkylhalogenide (7). 

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