14475-38-8Relevant academic research and scientific papers
Matrix Reactions opf Silan and Oxygen Atoms. Infrared Spectroscopic Evidence for the Silanol, Silanone, and Silanoic and Silicic Acid Molecules
Withnall, Robert,Andrews, Lester
, p. 3261 - 3268 (1985)
Matrices formed by the cocondensation of SiH4 and O3 in argon at 17 K were irradiated by a high-pressure mercury arc.Photoproducts include the silicon-oxygen double bond containing species SiO, H2SiO, H(HO)SiO, and (HO)2SiO.HSiOH was prepared in high yield by the reaction of SiH4 with O atoms from the microwave discharge of O2 in excess argon.In both photolysis and discharge experiments, SiH3OH is proposed as a primary reaction product formed by insertion of O atoms an Si-H bond of SiH4.
Investigation of the Prototype Silylene Reaction, SiH2 + H 2O (and D2O): Time-Resolved Gas-Phase Kinetic Studies, Isotope Effects, RRKM Calculations, and Quantum Chemical Calculations of the Reaction Energy Surface
Becerra, Rosa,Cannady, J.Pat,Walsh, Robin
, p. 11049 - 11056 (2007/10/03)
Time-resolved kinetic studies of the reaction of silylene, SiH 2, with H2O and with D2O have been carried out in the gas phase at 296 and at 339 K, using laser flash photolysis to generate and monitor SiH2. The reaction was studied over the pressure range 10-200 Torr with SF6 as bath gas. The second-order rate constants obtained were pressure dependent, indicating that the reaction is a third-body assisted association process. Rate constants at 339 K were about half those at 296 K. Isotope effects, kH/kD. were small averaging 1.076 ± 0.080, suggesting no involvement of H- (or D-) atom transfer in the rate determining step. RRKM modeling was undertaken based on a transition state appropriate to formation of the expected zwitterionic donor-acceptor complex, H2Si ... OH2. Because the reaction is close to the low pressure (third order) region, it is difficult to be definitive about the activated complex structure. Various structures were tried, both with and without the incorporation of rotational modes, leading to values for the high-pressure limiting (i.e., true second-order) rate constant in the range 9.5 × 10-11 to 5 × 10-10 cm3 molecule-1 s-1. The RRKM modeling and mechanistic interpretation is supported by ab initio quantum calculations carried out at the G2 and G3 levels. The results are compared and contrasted with the previous studies.
Microwave spectrum of HSiO in the X2A' ground electronic state
Izuha, Mitsuaki,Yamamoto, Satoshi,Saito, Shuji
, p. 527 - 535 (2007/10/03)
The rotational spectrum of the HSiO radical has been measured in the millimeter- and submillimeter-wave regions. The radical is produced in a d.c. glow discharge plasma of a gaseous mixture of SiH4 and N2O. Molecular constants includ
Kinetics of the SiH3 + O2 Reaction Studied by Time-Resolved Mass Spectrometry
Koshi, Mitsuo,Miyoshi, Akira,Matsui, Hiroyuki
, p. 9869 - 9873 (2007/10/02)
The SiH3 + O2 reaction was studied by means of time-resolved mass spectrometric detection of SiH3 with a near-threshold electron impact ionization technique.The rate constant of (1.26 +/- 0.18) x 10-11 cm3 molecule-1 s-1 at T = 293 K was determined from the first-order decay rates of SiH3 produced in ArF (193 nm) laser photolysis of CCl4/SiH4/O2/He or N2O/SiH4/O2/He mixtures.The signal at m/z 47 attributable to SiH3O could be detected as a direct product of the SiH3 + O2 reaction.On the basis of kinetic simulations, the branching ratio for the reaction of SiH3 +O2 -> HSiOOH + H was determined to be 0.6 +/- 0.1.Branching ratios for the other two channels, SiH3 + O2 -> SiH3O + O and SiH2O + OH, were estimated to be 0.16 and 0.24 respectively.
Osmium Tetroxide and Its Fragment Ions in the Gas Phase: Reactivity with Hydrocarbons and Small Molecules
Irikura, Karl K.,Beauchamp, J. L.
, p. 75 - 85 (2007/10/02)
Gas-phase ion-molecule reactions of OsOn(1+) (n=0-4) with a number of hydrocarbons and small molecules, including CH4, C2H4, C2H6, C3H8, C4H10, H2, CO, NH3, and SiH4, have been investigated by Fourier transform ion cyclotron resonance spectrometry.Anion chemistry was briefly investigated.Thermochemical quantities derived include D(Os(1+)-O)=100+/-12, D(OsO(1+)-O)=105+/-12, D(OsO2(1+)-O)=105+/-12, D(OsO3(1+)-O)=71+/-12, D(OsO3-O)=78+/-14, D(OsO4(1+)-H)=132+/-3 kcal/mol, D(OsO3(1+)-OH)=101+/-16 kcal/mol, and PA(OsO4)=161+/-2 kcal/mol.Many diverse and novel reactions are observed.Among them are s+2s> cycloaddition with H2, bond metathesis, oxo transfer, and hydrogen atom abstraction.These ions are also extraordinarily active dehydrogenation reagents; the most dramatic example is the sequential, complete dehydrogenation of SiH4 to mono-, di-, and trisilicides.Another intriguing process is the double bond metathesis with NH3, in which one or two oxo ligands are exchanged for imido groups.The number of oxo ligands is found to have a striking effect on the chemistry; mechanisms are discussed for the reactions observed.For example, the relative inertness of OsO3(1+) is attributed to a failure of the Os(+7) center to undergo oxidative addition.OsO2(1+) emerges as a potential model catalyst for the conversion of methane and dioxygen to aldehydes.
Matrix isolation studies of the reactions of silicon atoms: I. Interaction with water: The infrared spectrum of hydroxysilylene HSiOH
Ismail, Zakya Kafafi,Hauge, Robert H.,Fredin, Leif,Kauffman, James W.,Margrave, John L.
, p. 1617 - 1625 (2007/10/02)
This study focuses on the interactions and reactions of silicon atoms and molecules with water.Initially, a silicon-water adduct is formed , as noticed from the red shift of the ν2 bending modes of H2O, HDO, and D2O.This silicon hydrate complex rearranges spontaneously through hydrogen tunneling to give HSiOH and HSiOD as final products of the reaction of Si with H2O and HDO.Photolysis of Si:OD2 with λ>=400 nm is necessary for the production of the deuterated insertion product DSiOD.All silicon hydroxy-hydrides undergo a photolytic decomposition reaction when strongly irradiated to give silicon monoxide and molecular hydrogen or two hydrogen atoms.Band assignments fro trans-HSiOH, trans- and cis-HSiOD, and DSiOD have been made.It appears that the cis-isomer converts to the more stable trans-isomer when the matrix is heated.The SiOH bond angle has been calculated for a planar structure of Cs symmetry using the Redlich-Teller product rule and the torsional frequencies for HSiOH, HSiOD, and DSiOD.Normal coordinate analyses have been carried out using the measured frequencies for six isotopomers, namely, HSiOH, HSiOD, DSiOD, HSi18OD, and DSi18OD.Thermodynamic properties have also been for this new species.
