Photoelectron spectroscopy of the gas‐phase SN2 reaction intermediates I−⋅CH3I and I−⋅CD3I: Distortion of the CH3I at the ‘‘ion–dipole’’ complex

Autor:	M. Georgina Scarton, Mark A. Johnson, Donna M. Cyr
Rok vydání:	1993
Předmět:	Chemistry Binding energy General Physics and Astronomy Ion symbols.namesake Molecular geometry X-ray photoelectron spectroscopy Franck–Condon principle Kinetic isotope effect Potential energy surface symbols Valence bond theory Physical and Theoretical Chemistry Atomic physics
Zdroj:	The Journal of Chemical Physics. 99:4869-4872
ISSN:	1089-7690 0021-9606
Popis:	The I−⋅CH3I and I−⋅CD3I intermediates in the gas‐phase SN2 identity reaction, I−+CH3I→CH3I+I−, are isolated, cooled in a free jet, and characterized using negative ion photoelectron spectroscopy. The spectra appear similar to bare I− but shifted to lower electron kinetic energy by the known binding energy of the complex. Vibrational fine structure in each spin–orbit subband is dominated by a simple vibrational progression in the ν3 mode of CH3I (nominally the C–I stretch). Franck–Condon analysis indicates that this bond is elongated in the complex by about 3% relative to bare CH3I with observable distortions in the C–H stretch and H–C–X bond angle (the umbrella mode). We discuss these observations in the context of the charge transfer (e.g., valence bond) model for the SN2 potential energy surface.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c5ac5b0f3d47580b57f6f22dc91bd6b7 https://doi.org/10.1063/1.466036 Zobrazit plný text záznamu