Abstract
The reactions of C2 (a3∏u) radicals with a series of alcohols have been studied at about 6.5 Torr total pressure and room temperature using the pulsed laser photolysis/laser-induced fluorescence technique. The relative concentration of C2 (a3∏ u) radicals, which are generated via the photolysis of C 2Cl4 with the focused output from the fourth harmonic of a Nd:YAG laser (266 nm), was monitored by laser-induced fluorescence (LIF) in the (0, 0) band of the C2 (d3∏g←a 3∏u) transition at 516.5 nm. Under pseudo-first-order conditions, we measured the time evolution of C2 (a 3∏u) and determined the rate constants for reactions of C2 (a3∏u) with alcohols. The rate constants increase linearly with the number of C atoms in the alcohols. All of them are larger than those for reactions of C2 (a3∏ u) with alkanes (C2-C5). Based on the bond dissociation energy and linear free energy correlations, we believe the reactions of C2 (a3∏u) with alcohols proceed via the mechanism of hydrogen abstraction. The experimental results show that the H-atom on the C-H bonds is activated at the presence of the OH substituent group in the alcohol molecule. The theoretical calculations for the reaction of C2 (a3∏u) with methanol also support these hypotheses.
| Original language | English |
|---|---|
| Pages (from-to) | 3921-3925 |
| Number of pages | 5 |
| Journal | Journal of Physical Chemistry A |
| Volume | 109 |
| Issue number | 17 |
| DOIs | |
| State | Published - 5 May 2005 |
| Externally published | Yes |