Lifetime and electronic spectra of p-methoxybenzyl radical in the lowest excited doublet state in solution

Abstract

ROO• + R'SH -[ROOS(H)R'] -R'SO* + ROH (9) Reaction 9 is very similar in nature to reaction 8 and it is thus difficult to eliminate (9) as a competing mechanism. Further, the intermediate proposed is analogous to the intermediate [RSSS(H)R] suggested for the reaction of RSS* with RSH.37 Using bond energies of 170 kJ (0-0), 435 kJ (O-H), 380 kJ (S-H), and 360 kJ (S-O), we predict reaction 9 to be exothermic by approximately 245 kJ.38 Gilbert et al.31 found that sulfinyl radicals resulted from reaction of thiols with the Ti3+-H202 couple at pH 1-2 and their g values and hyperfine couplings (allowing for differences in rotational averaging) correlate quite well with those reported here. Although the authors reported that the (37) Nelson, D.

Photodissociation of C–H and C–O bonds of p-methoxytoluene and p-methoxybenzyl alcohol in solution

“…The spectra exhibit a broad band at 510 nm, which is assigned to the p-methoxybenzyl radical and is similar to the band reported previously. 6 The fluorescence lifetimes, determined from photolysis of p-methoxytoluene and p-methoxybenzyl alcohol, are of a value of 141Ϯ12 ns and agree with the previous lifetime. 6 The fluorescence band disappears at a 100 s delay from the 266 to the 308 nm pulse.…”

“…6 The fluorescence lifetimes, determined from photolysis of p-methoxytoluene and p-methoxybenzyl alcohol, are of a value of 141Ϯ12 ns and agree with the previous lifetime. 6 The fluorescence band disappears at a 100 s delay from the 266 to the 308 nm pulse. The result shows that C-H bond fission in p-methoxytoluene and C-O bond scission in pmethoxybenzyl alcohol occur to form the p-methoxybenzyl radical.…”

“…This molecule has been reported to yield the p-methoxybenzyl radical. 6,8 The same fluorescence band ͑with the same life-time͒ as in Fig. 1 is observed by excitation with the 308 nm pulse.…”

“…An absorption band is recorded at 288 nm, which is associated with the p-methoxybenzyl radical. 6,8,9 The fluorescence and absorption bands disappear at a 100 s delay.…”

Rotational conformers of m-methoxybenzyl radical in a supersonic jet

“…[14][15][16][20][21][22] Tokumura et al observed the absorption spectra of p-methoxybenzyl and p-cyanobenzyl radicals in hexane solution at room temperature. 25,26 The absorption band is red-shifted relative to that of the p-cyanobenzyl radical. The origin band of m-methoxybenzyl radical was found to be surprisingly red-shifted.…”