Getting ahead of IVR: A demonstration of mid-infrared induced molecular dissociation on a sub-statistical time scale
Autor: | Karl-Ludwig Kompa, Jake S. Yeston, C. Bradley Moore, Detlev Proch, Marcus Motzkus, Thomas Witte, Werner Fuß, Lars Windhorn |
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Rok vydání: | 2003 |
Předmět: | |
Zdroj: | The Journal of Chemical Physics. 119:641-645 |
ISSN: | 1089-7690 0021-9606 |
Popis: | Gaseous diazomethane (CH2N2) has been irradiated with femtosecond laser pulses tuned to the CNN asymmetric stretch at 2100 cm−1 in the mid-infrared. Laser-induced fluorescence detection of 1CH2 [537 nm, b1B1(0 16 0)←a1A1(0 0 0)] confirms infrared (IR) multiphoton-induced scission of the C–N bond on two distinct time scales, 480±70 fs and 36±8 ps. The longer time scale is consistent with a statistical dissociation process; the shorter one is indicative of directed dissociation, which occurs more rapidly than statistical intramolecular vibrational energy redistribution because of direct coupling of the vibrational energy from the IR-excitation mode into the reaction coordinate. Anisotropy measurements demonstrate that the CH2 group bends significantly out of the molecular plane prior to the dissociation. |
Databáze: | OpenAIRE |
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