运用脉冲激光光解-激光诱导荧光(PLP-LIF)的方法在293-573 K的温度范围内测量了C2(X1Σ+g)自由基与不饱和碳氢化合物(C2H4和C2H2)气相反应的双分子反应速率常数.获得的速率常数可以用Arrhenius公式表达如下(单位：cm3·molecule-1·s-1)：k(C2H4)=(1.16±0.10)×10-10exp[(290.68±9.72)/T]， k(C2H2)=(1.36±0.02)×10-10exp[(263.85±7.60)/T]，误差为2σ.由获得的双分子反应速率常数及其所呈现的负温度效应，我们认为在293-573 K温度范围内C2(X1Σ+g)自由基和不饱和碳氢化合物的反应遵循加成机理.%Bimolecular rate constants for the gas-phase reactions of C2(X1Σ+g) with unsaturated hydrocarbons C2H4 and C2H2 were measured over the temperature range 293-573 K by pulsed laser photolysis/laser-induced fluorescence (PLP-LIF). The rate constants, in the unit of cm3·molecule-1·s-1, can be fitted by the normal Arrhenius expressions:k(C2H4)=(1.16±0.10)×10-10exp[(290.68±9.72)/T], and k(C2H2)=(1.36±0.02)× 10-10exp[(263.85 ± 7.60)/T], where al error estimates are ± 2σ and represent the precision of the fit. The observed bimolecular rate constants along with the negative temperature dependences of k(T) al ow us to conclude that the reactions of C2(X1Σ+g) with these unsaturated hydrocarbons in the temperature range 293-573 K proceed via an addition mechanism.
展开▼
