Infrared multiphoton absorption and dissociation of chloromethyltrifluorosilane molecules under the action of pulsed transversely excited atmospheric pressure CO2 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.

Infrared multiple photon dissociation of chloromethyltrifluorosilane.

a b s t r a c t Infrared laser dissociation of 2-chloroethyltrifluorosilane has been studied in light of silicon isotopes separation. The reaction occurs via beta-elimination mechanism to yield ethylene and chlorotrifluorosi- lane as products. The dissociation has a relatively low energy barrier what was confirmed by high-level quantum chemical calculations. High enrichment of 30 Si isotope was demonstrated.

Infrared photoreaction of 2-chloroethyltrifluorosilane

The influence of laser fluence and wavelength as well as of the sample pressure on the infrared multiple-photon dissociation (IRMPD) of SiF4 and H2 mixtures has been studied. Different lines of the 9.4 μm emission band of a TEA CO2 laser have been used as excitation sources. A power law dependence of the fraction of molecules dissociated per pulse on the laser fluence was found. The optimization of the IRMPD of silicon tetrafluoride was performed by varying both SiF4 and H2 pressures. The IRMPD spectrum exhibits a red shift of ~ 12 cm−1 produced by the anharmonicity of the molecular vibrations. Moreover, the isotopic selectivity of the IRMPD of SiF4 has been determined with wavelengths shifted to the red and the blue of the 9P(36) line which is quasi-resonant with the v3 mode of 28SiF4. The maximum values were obtained with the 9P(32) emission line which has the least overlap with the absorption bands of the less abundant species.

https://iopscience.iop.org/article/10.1088/1742-6596/274/1/012091/pdf

Optimization of the infrared multiple-photon dissociation of SiF4 to increase the isotopic selectivity

Infrared photolysis of alkylfluorosilanes F3SiCnH2n+1, n = 1–3

Infrared multiphoton dissociation of Ge(OCH3)4 molecules by irradiation with a pulsed TEA CO2 laser has been studied. The basic characteristics of the process have been experimentally investigated. The spectral characterization of the dissociation has been made. The product composition of the dissociation has been analyzed, and possible dissociation pathways have been proposed.

Infrared multiphoton dissociation of tetramethoxygermane

Infrared multiphoton absorption and dissociation of 1,2-dichloroethyltrifluorosilane molecules under the action of pulsed TEA CO2 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 CO2-laser radiation. High degrees of silicon isotope separation have been achieved.

P. S. Dementyev

Papers

Infrared multiphoton dissociation of 1,2-dichloroethyltrifluorosilane