21941-60-6Relevant articles and documents
Thermal Stability of Methyl Groups on Si(100) Generated by the Decomposition of Tetramethylgermane
Greenlief, C. Michael,Klug, Debra-Ann
, p. 5424 - 5429 (1992)
The adsorption and thermal decomposition of tetramethylgermane on Si(100) have been studied by ultraviolet photoelectron spectroscopy, static secondary ion mass spectrometry, temperature-programmed desorption, and Auger electron spectroscopy.Tetramethylgermane adsorbs molecularly on Si(100) at 110 K.In temperature-programmed desorption experiments, most of the tetramethylgermane reversibly desorbs at 141 +/- 4 K.The remaining tetramethylgermane decomposes at higher surface temperatures by breaking of a C-Ge bond resulting in formation of a methyl group and Ge(CH3)3, the latter involving into the gas phase.Further heating causes decomposition of the methyl group.The hydrogen atoms released by methyl group decomposition form surface Si monohydrides, which later combine to desorb molecular H2.The methyl groups decompose with a pseudo-first-order preexponential of (1 +/- 5) *108 s-1 and an activation energy of 29 +/- 1 kcal mol-1.
Molecular beam photochemistry of organopolysilanes and organopolygermanes
Borthwick, Ian,Baldwin, Lawrence C.,Sulkes, Mark,Fink, Mark J.
, p. 139 - 146 (2008/10/08)
The molecular beam photochemistry of various polysilanes and polygermanes was investigated. In most cases, the precursor compounds were photolyzed in the nozzle region of a supersonic jet by a 193 nm laser and the photoproducts analyzed downstream by 118 nm photoionization pulses followed by time-of-flight mass spectrometry. The polysilane and polygermane compounds included in this study were PhMeSi(SiMe3)2, PhSi(SiMe3)3, (Me2-Si)6, (Me2Ge)6, and 1,3-diphenyl-1,2,2,3-tetramethyl-1,2,3-trisilacycloheptane. The 193 nm photoproducts of PhSiMe3, Me3SiSiMe3, and vinyltrimethylsilane were also examined for comparison purposes. Dimethylsilylene (Me2Si:) was directly observed as the major one-photon photoproduct from the cyclic precursors (Me2Si)6 and 1,3-diphenyl-1,2,2,3-tetramethyl-1,2,3-trisilacycloheptane. Likewise, dimethylgermylene (Me2Ge:) was directly observed in the photolysis of(Me2Ge)6. One-photon photolysis of the noncyclic polysilanes PhMeSi(SiMe3)2 and PhSi(SiMe3)3, however, gave radical products derived from the homolytic scission of a single Si-Si bond with little or no evidence of silylene being generated directly. A mechanism explaining the difference in photochemical outcome for cyclic vs noncyclic molecules is presented. Finally, molecular Si2C is found to be a ubiquitous product resulting from the multiphoton photochemistry of a number of organosilicon precursors.
