TY - JOUR
T1 - Toluene nitration in irradiated nitric acid and nitrite solutions
AU - Elias, Gracy
AU - Mincher, Bruce J.
AU - Mezyk, Stephen P.
AU - Muller, Jim
AU - Martin, Leigh R.
PY - 2011/4
Y1 - 2011/4
N2 - The kinetics, mechanisms, and stable products produced for the nitration of aryl alkyl mild ortho-para director toluene in irradiated nitric acid and neutral nitrite solutions were investigated using γ and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection, GC-MS and LC-MS, were used to assess the stable reaction products. Free-radical based nitration reaction products were found in irradiated acidic and neutral media. In 6.0M HNO3, ring substitution, side chain substitution, and oxidation, produced different nitrated toluene products. For ring substitution, nitrogen oxide radicals were added mainly to cyclohexadienyl radicals, whereas for side chain substitution, these radicals were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite solutions, radiolytically-induced ring nitration products approached a statistically random distribution, suggesting a direct free-radical reaction involving addition of the NO2 radical.
AB - The kinetics, mechanisms, and stable products produced for the nitration of aryl alkyl mild ortho-para director toluene in irradiated nitric acid and neutral nitrite solutions were investigated using γ and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection, GC-MS and LC-MS, were used to assess the stable reaction products. Free-radical based nitration reaction products were found in irradiated acidic and neutral media. In 6.0M HNO3, ring substitution, side chain substitution, and oxidation, produced different nitrated toluene products. For ring substitution, nitrogen oxide radicals were added mainly to cyclohexadienyl radicals, whereas for side chain substitution, these radicals were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite solutions, radiolytically-induced ring nitration products approached a statistically random distribution, suggesting a direct free-radical reaction involving addition of the NO2 radical.
KW - Electrophilic substitution
KW - Free-radicals
KW - HPLC
KW - LC-MS
KW - Toluene radiolysis
KW - UV spectra
UR - http://www.scopus.com/inward/record.url?scp=79251646184&partnerID=8YFLogxK
U2 - 10.1016/j.radphyschem.2010.12.005
DO - 10.1016/j.radphyschem.2010.12.005
M3 - Article
AN - SCOPUS:79251646184
SN - 0969-806X
VL - 80
SP - 554
EP - 560
JO - Radiation Physics and Chemistry
JF - Radiation Physics and Chemistry
IS - 4
ER -