| Abstract: | A series of trialkyl and triaryl organometallic radicals from group IV generated by hydrogen abstraction by tert‐butoxyl radical from the parent hydrides have been examined using laser flash photolysis. The rate constants for the trapping of the metal‐centered radicals by the persistent radical TEMPO were measured and were found to be large and similar to those of the carbon‐centered radical systems, yet below the diffusion controlled limit. The metal‐centered radicals were found to be efficiently trapped by TEMPO and would appear to be candidates suitable for “living” free radical polymerization similar to carbon analogue stoichiometric initiators. The radical trapping rate constants for the trialkyl series (M = Si, Ge, Sn) were found to be 8.9 × 108 M?1 s?1 (M = Si), 7.2 × 108 M?1 s?1 (M = Ge), and 6.2 × 108 M?1 s?1 (M = Sn), respectively. The triaryl (Ph3M?) series gave slightly slower rates of 1.6 × 108 M?1 s?1 (M = Si), 3.4 × 108 M?1 s?1 (M = Ge), and 1.9 × 107 M?1 s?1 (M = Sn), respectively. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 238–244, 2000 |
