Renzhi Hu1, Qun Zhang, Yang Chen. 1. Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
Abstract
We present a temperature dependence study on the gas phase reactions of the C(2)(a (3)Pi(u)) radical with a selected series of saturated alkanes (C(2)H(6), C(3)H(8), n-C(4)H(10), i-C(4)H(10), and n-C(6)H(14)) by means of pulsed laser photolysis/laser-induced fluorescence technique. The bimolecular rate constants for these reactions were obtained between 298 and 673 K. A pronounced negative temperature effect was observed for n-C(4)H(10), i-C(4)H(10), and n-C(6)H(14) and interpreted in terms of steric hindrance of the more reactive secondary or tertiary C-H bonds by less reactive CH(3) groups. Detailed analysis of our experimental results reveals quantitatively the temperature dependence of reactivities for the primary, secondary, and tertiary C-H bonds in these saturated alkanes and further lends support to a mechanism of hydrogen abstraction.
We present a temperature dependence study on the gas phase reactions of the C(2)(a (3)Pi(u)) radical with a selected series of n class="Chemical">saturated alkanes (C(2)H(6), C(3)H(8), n-C(4)H(10), i-C(4)H(10), and n-C(6)H(14)) by means of pulsed laser photolysis/laser-induced fluorescence technique. The bimolecular rate constants for these reactions were obtained between 298 and 673 K. A pronounced negative temperature effect was observed for n-C(4)H(10), i-C(4)H(10), and n-C(6)H(14) and interpreted in terms of steric hindrance of the more reactive secondary or tertiary C-H bonds by less reactive CH(3) groups. Detailed analysis of our experimental results reveals quantitatively the temperature dependence of reactivities for the primary, secondary, and tertiary C-H bonds in these saturated alkanes and further lends support to a mechanism of hydrogen abstraction.