Abstract
We present a combined experimental and theoretical investigation of formaldehyde (H2CO) dissociation to H-2 and CO at energies just above the threshold for competing H elimination. High-resolution state-resolved imaging measurements of the CO velocity distributions reveal two dissociation pathways. The first proceeds through a well-established transition state to produce rotationally excited CO and vibrationally cold H-2. The second dissociation pathway yields rotationally cold CO in conjunction with highly vibrationally excited H-2. Quasi-classical trajectory calculations performed on a global potential energy surface for H2CO suggest that this second channel represents an intramolecular hydrogen abstraction mechanism: One hydrogen atom explores large regions of the potential energy surface before bonding with the second H atom, bypassing the saddle point entirely.
Original language | English |
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Pages (from-to) | 1158-1161 |
Number of pages | 4 |
Journal | Science |
Volume | 306 |
Issue number | 5699 |
DOIs | |
Publication status | Published - 12 Nov 2004 |