Infrared multiphoton dissociation of vinyltrifluorosilane (original) (raw)

Infrared multiphoton dissociation of 1,2-dichloroethyltrifluorosilane

Applied Physics B, 2009

Infrared multiphoton absorption and dissociation of 1,2-dichloroethyltrifluorosilane molecules under the action of pulsed TEA CO 2 laser were experimentally studied. The composition of dissociation products was analyzed. The only products of dissociation have been found to be stable molecules: chloroethylene and trifluorochlorosilane. Dissociation proceeds via chlorine atom transfer from carbon to silicon. The silicon isotope-selective infrared multiphoton dissociation was performed at different wavelengths of the CO 2 -laser radiation. High degrees of silicon isotope separation have been achieved.

Infrared multiphoton dissociation of difluorosilane

Applied Physics B: Lasers and Optics, 2004

Infrared (IR) multiphoton absorption and dissociation of difluorosilane molecules under the action of a pulsed transversely excited atmospheric CO 2 laser were experimentally studied. It has been found that the multiphoton absorption is strongly saturated due to the rotational bottleneck effect. Isotope-selective IR multiphoton dissociation of difluorosilane was performed at 977.2 cm −1 . The dissociation rate for 28 SiH 2 F 2 isotopomer has been found to be about twice as high as for the other isotopomers at this wavelength. PACS 82.50.Bc; 82.30.Lp

Infrared Multiple Photon Dissociation of Chloromethyltrifluorosilane

Photochemistry and Photobiology, 2009

Infrared multiphoton absorption and dissociation of chloromethyltrifluorosilane molecules under the action of pulsed transversely excited atmospheric pressure CO 2 laser were experimentally studied. Dissociation products were analyzed. The dissociation proceeds via chlorine atom transfer from carbon to silicone. High degrees of silicon isotope separation were achieved. The presence of a-chlorine atom in a silicon organic compound brings about a significant improvement in multiple photon dissociation characteristics and an essential increase in isotopic selectivity.

Visible luminescence studies in the infrared multiphoton dissociation of 1,2-dichloro-1,1-difluoroethane

Chemical Physics Letters, 1997

A strong visible luminescence was observed in the CO2 laser induced infrared multiphoton dissociation of 1,2-dichloro-1,1-difluoroethane. The emission observed between 350–750 nm is attributed to electronically excited carbene CF2ClC̈H. The temporal profile of this luminescence was studied as a function of laser pulse duration, pulse energy, excitation frequency and substrate pressure. A suitable dissociation mechanism is presented considering various channels of IRMPD of this molecule.

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

The Journal of Physical Chemistry A, 2003

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%).

T/D isotope selectivity in CO2 laser induced multiple-frequency multiphoton dissociation of trifluoromethane-T

Applied Physics B Photophysics and Laser Chemistry, 1989

Isotope-selective multiphoton dissociation of CTF3 in the presence of CDF 3 by TEA CO2 laser is studied. The highest T/D selectivity of 58 was observed at a sample pressure of 2 Torr in the presence of 20 Torr of argon on excitation by the 9P(24) CO 2 laser line. The effect of multiple-frequency irradiation on selectivity is studied in the P and Q branches of the v2 absorption band of CTFa. No improvement in the selectivity is noticed on going from single-to multiple-frequency irradiation. These results are compared with previous multiple-frequency work on the C T F J C H F 3 system, and explained in terms of strong spectroscopic interference from 13CDF3 in the present case.

Infrared laser induced multiphoton dissociation of decafluorocyclopentane in a concerted pathway: time-resolved evidence of difluorocarbene formation

The Journal of Physical Chemistry, 1988

The infrared multiphoton dissociation (IRMPD) of decafluorocyclopentane (DFCP) generates tetrafluoroethylene and difluorocarbene as the primary products. The :CFz dimerizes to form C2F4; the kinetics of the reaction is followed by monitoring the disappearance of :CFz absorption at 249 nm in real time after the COz laser pulse, with a rate constant k2 = 4.35 X lo7 M-' s-'. The vibrational temperature associated with the nascent :CF2 is found to be 1100 K. The MPD yield of DFCP shows a strong fluence dependence, with a threshold of-0.5 J/cmZ for the 10 R(40) C 0 2 laser line. The MPD spectra reveal two peaks, one 22 cm-' red-shifted from the 989 cm-' strong IR absorption band. Addition of SF6 decreases the MPD yield.

Laser induced fluorescence detection of CF, CF 2 and CF 3 in the infrared multiphoton dissociation of C 3F 6

Journal of Photochemistry and Photobiology A-chemistry, 2001

The infrared multiphoton dissociation of C 3 F 6 has been studied through the analysis of the laser induced fluorescence of the produced CF, CF 2 and CF 3 radicals. The influence of buffer gases in the process has also been investigated. In the studied conditions, only unimolecular formation of these radicals has been detected. A discussion about the possible dissociation channels has been done. The obtained excitation spectra show that CF 2 is formed vibrationally hot and reveal the presence of the radical CF 3 . From the analysis of these spectra, different values of the vibrational temperature are obtained, for the two experimental employed arrangements.

Infrared fluorescence from nascent CO2 and COF2 photoproducts in IR multiphoton dissociation of trifluoroacetic acid

Chemical Physics Letters, 1993

Infrared multiphoton dissociation of tritluoroacetic acid by a pulsed CO* laser yields HF, COFz, CO1, CO, F3CC02CF2H and C2F, as photoproducts. Infrared fluorescence from the photoproducts, CO2 and COF,, is observed and analysed. Intermolecular V-V and V-R/T relaxation rate constants for CO1 decay are found to be 1.7~ lo5 and 1.4~ 10' s-l TOW', whereas for COFz decay these two relaxation rate constants are 7.3~ 10'and 8.9 x lo3 s-' Torr-', respectively.