Femtosecond observation of a concerted chemical reaction

✍ Scribed by Una Marvet; Marcos Dantus

• Book ID: 103036237
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 429 KB
• Volume: 256
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(96)00408-3

✦ Synopsis

A time-resolved study is presented of the photodissociation of methylene iodide (CH2I 2) to produce a carbene diradical and molecular iodine. This reaction pathway occurs only at high excitation energies (vacuum ultraviolet) and is initiated in this case by a two-photon transition at Aequivale m = 155 nm. Discrimination over competing pathways is achieved by wavelength-selective monitoring of the nascent 12 dynamics. The results show clear evidence that breakage of the two carbon-iodine bonds and formation of the iodine-iodine bond is concerted. The reaction takes place in less than 100 fs and is characterized by coherent vibrational motion in the iodine molecule.