TY - JOUR
T1 - Night-time tropospheric chemistry of the unsaturated alcohols (Z)-pent-2-en-1-ol and pent-1-en-3-ol: Kinetic studies of reactions of NO3 and N2O5 with stress-induced plant emissions
AU - Pfrang, C.
AU - Baeza Romero, M.T.
AU - Cabanas, B.
AU - Canosa-Mas, C.E.
AU - Villanueva, F.
AU - Wayne, R.P.
PY - 2007
Y1 - 2007
N2 - The night-time tropospheric chemistry of two stress-induced volatile organic compounds (VOCs), (Z)-pent-2-en-1-ol and pent-1-en-3-ol, has been studied at room temperature. Rate coefficients for reactions of the nitrate radical (NO3) with these pentenols were measured using the discharge-flow technique. Because of the relatively low volatility of these compounds, we employed off-axis continuous-wave cavity-enhanced absorption spectroscopy for detection of NO3 in order to be able to work in pseudo first-order conditions with the pentenols in large excess over NO3. The rate coefficients were determined to be (1.53±0.23)×10−13 and (1.39±0.19)×10−14 cm3 molecule−1 s−1 for reactions of NO3 with (Z)-pent-2-en-1-ol and pent-1-en-3-ol. An attempt to study the kinetics of these reactions with a relative-rate technique, using N2O5 as source of NO3 resulted in significantly higher apparent rate coefficients. Performing relative-rate experiments in known excesses of NO2 allowed us to determine the rate coefficients for the N2O5 reactions to be (5.0±2.8)×10−19 cm3 molecule−1 s−1 for (Z)-pent-2-en-1-ol, and (9.1±5.8)×10−19 cm3 molecule−1 s−1 for pent-1-en-3-ol. We show that these relatively slow reactions can indeed interfere with rate determinations in conventional relative-rate experiments.
AB - The night-time tropospheric chemistry of two stress-induced volatile organic compounds (VOCs), (Z)-pent-2-en-1-ol and pent-1-en-3-ol, has been studied at room temperature. Rate coefficients for reactions of the nitrate radical (NO3) with these pentenols were measured using the discharge-flow technique. Because of the relatively low volatility of these compounds, we employed off-axis continuous-wave cavity-enhanced absorption spectroscopy for detection of NO3 in order to be able to work in pseudo first-order conditions with the pentenols in large excess over NO3. The rate coefficients were determined to be (1.53±0.23)×10−13 and (1.39±0.19)×10−14 cm3 molecule−1 s−1 for reactions of NO3 with (Z)-pent-2-en-1-ol and pent-1-en-3-ol. An attempt to study the kinetics of these reactions with a relative-rate technique, using N2O5 as source of NO3 resulted in significantly higher apparent rate coefficients. Performing relative-rate experiments in known excesses of NO2 allowed us to determine the rate coefficients for the N2O5 reactions to be (5.0±2.8)×10−19 cm3 molecule−1 s−1 for (Z)-pent-2-en-1-ol, and (9.1±5.8)×10−19 cm3 molecule−1 s−1 for pent-1-en-3-ol. We show that these relatively slow reactions can indeed interfere with rate determinations in conventional relative-rate experiments.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33846417243&partnerID=MN8TOARS
U2 - 10.1016/j.atmosenv.2006.10.034
DO - 10.1016/j.atmosenv.2006.10.034
M3 - Article
SN - 1352-2310
VL - 41
SP - 1652
EP - 1662
JO - Atmospheric Environment
JF - Atmospheric Environment
IS - 8
ER -