J . Am, Chem. SOC.1991, 113, 4888-4895
4888
Relative Rates of H’Transfer from Transition-Metal Hydrides to Trityl Radicals David C. Eisenberg, Christophe J. C. Lawrie, Anne E. Moody, and Jack R. Norton* Contribution from the Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523. Received November 23, 1990
Abstract: The tris@-tert-butylpheny1)methyl radical can be made in quantitative yield by treating a toluene solution of the corresponding bromide with copper powder. This radical abstracts H’ from all the common transition-metal hydrides but does not stick to the resulting metalloradicals,so that the latter form metal-metal-bonded dimers. The rates of these H’ transfer reactions have been measured directly in a stopped-flow apparatus. At 25 OC the H’ transfer rate constants vary from
