Infrared Multiphoton Si Isotope Selective Dissociation of Phenyltrifluorosilane under Free Electron Laser Irradiation

Abstract

The multiphoton absorption of infrared radiation induced dissociation of phenyltrifluorosilane (PhSiF 3 ) in a batch reactor. End product analysis from IR MPD of neat PhSiF 3 and the mixture of PhSiF 3 and Br 2 shows that the main dissociation channels are (1) the elimination of SiF 3 and (2) the elimination of H. Silicon isotopes have been enriched under the FEL irradiation of neat PhSiF 3 at 961 cm -1 (abundance of 30 Si in PhSiF 3 was increased from 3.10 ( 0.03% to 12.3 ( 0.1%) and 925 cm -1 (abundance of 28 Si in PhSiF 3 was increased from 92.2 ( 0.9% to 96.5 ( 0.9%).

13C-selective infrared multiple photon dissociation of β-propiolactone by a free electron laser

“…A large isotope effect is one of the unique characteristics in IRMPD, which is applicable to practical isotope separation of several elements such as carbon [4][5][6][7][8][9], oxygen [10,11], and silicon [12][13][14][15].…”

Infrared Multiple Photon Dissociation of Chloromethyltrifluorosilane

“…Silicon isotope-selective MPD of compounds containing single silicon atoms, such as SiH 2 F 2 (15), SiF 3 C 6 H 5 (16)(17)(18), SiF 3 CH 3 (19,20), SiF 3 CHCH 2 (21) and Si(OCH 3 ) 4 (22) was studied previously. The maximum isotope selectivities reached for the MPD of these molecules were found to be lower than that for Si 2 F 6 .…”

“…The maximum isotope selectivities reached for the MPD of these molecules were found to be lower than that for Si 2 F 6 . From the analysis of spectroscopic and kinetic characteristics of the MPD of these molecules, one can conclude that the main reason for the higher efficiency of the Si 2 F 6 MPD is its low dissociation threshold (188 kJ mol )1 [10]) compared to the molecules studied elsewhere (around 420 kJ mol )1 [14][15][16][17][18][19][20][21][22]). Therefore, the further search of the compounds should be limited to those containing only one silicon atom, and possessing a relatively low dissociation threshold.…”