Isotopically selective dissociation of CH₃SiF₃and C₆H₅SiF₃molecules by CO₂laser pulses

Abstract

We elaborate on the relations between surface states and squeezed states. First, we investigate two different criteria for determining whether a matter sector squeezed state is also a surface state and show that the two criteria are equivalent. Then, we derive similar criteria for the ghost sector. Next, we refine the criterion for determining whether a surface state is in H κ 2 , the subalgebra of squeezed states obeying [S, K 2 1 ] = 0. This enables us to find all the surface states of the H κ 2 subalgebra, and show that it consists only of wedge states and (hybrid) butterflies. Finally, we investigate generalizations of this criterion and find an infinite family of surface states subalgebras, whose surfaces are described using a "generalized Schwarz-Christoffel" mapping.

ISOTOPIC SELECTIVITY IN THE INFRARED MULTIPLE-PHOTON DISSOCIATION OF SiF4

“…Para ello se requiere encontrar el compuesto precursor adecuado. La DMFIR con láseres de CO 2 TEA ha sido aplicada a la determinación de la selectividad isotópica de compuestos que contienen silicio utilizando SiF 3 Cl (5) , SiF 2 H 2 (6) , SiF 3 C 2 H 3 (7) , SiF 3 C 6 H 5 (8) , SiF 3 CH 3 (8) , SiF 3 CH 2 Cl (9) , SiF 3 C 2 H 3 Cl 2 (10,11) y Si 2 F 6 (12−19) como moléculas de trabajo. Los resultados más promisorios han sido alcanzados con Si 2 F 6 (12,13) .…”

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.…”

Infrared Laser Chemistry of Trichlorosilane in View of Silicon Isotope Separation

“…The method of molecular laser isotope separation (MLIS) based on infrared multiphoton dissociation (IRMPD) has been investigated for the last three decades and applied to many isotopes, and recently it has been implemented for commercial production of carbon-13. 3 While isotope separation of silicon by IRMPD of naturally abundant (92.1% 28 Si, 4.7% 29 Si, 3.2% 30 Si) samples of Si(OCH 3 ) 4 and ((CH 3 ) 3 Si) 2 O, 4 CH 3 SiF 3 , and C 6 H 5 SiF 3 5 has achieved a maximum enrichment in 30 Si of only 5-15%, this approach has shown some promise for laboratory-scale separation of silicon isotopes using Si 2 F 6 as a working molecule, [6][7][8] with a reported enrichment of 30 Si to 46% in the SiF 4 dissociation product 6 and 20% 29 Si in the SiF 2 fragment. 8 Although this is currently the most advanced laser-based technique for silicon isotope separation, the present level of enrichment is still far below that required for electronic applications.…”