Modulation spectroscopy. Kinetics for the self-reactions of some α-aminoalkyl radicals in solution

Article abstract of DOI:10.1139/v82-041

The optical spectra and reaction kinetics of some α-aminoalkyl radicals, RCHN(CH₂R)₂; R = H, Me, Ph, were measured in solution using the technique of modulation spectroscopy.These radicals undergo diffusion controlled self-reaction with rate constants ca. 10⁹ M^-1 s^-1.When R=Ph, the absorption spectrum has a well defined maximum at 346 nm; ε = 3390 M^-1 cm^-1, while the spectra when R = H or Me were less intense (ε₃₄₆nm ca. 500 M^-1 cm^-1) and tailed into the visible.These spectra are substantially red-shifted when compared with those of simple alkyl radicals, an effect which is thought to be due to the interaction between the unpaired electron and the lone pair of electrons on nitrogen.