Theoretical study of the silicon--oxygen hydrides SiOH[sub [ital n]] ([ital n]=0--4) and SiOH[sub [ital n]][sup +] ([ital n]=0--5): Dissociation energies, ionization energies, enthalpies of formation, and proton affinities

Journal Article · Sun Oct 31 19:00:00 EST 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465837· OSTI ID:5923013

Lucas, D J; Curtiss, L A ^[1]; Pople, J A ^[2]

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1. Chemical Technology Division/Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvannia 15213 (United States)

The energies of silicon--oxygen hydrides SiOH[sub [ital n]] ([ital n]=0--4) and their cations SiOH[sub [ital n]][sup +] ([ital n]=0--5) have been studied using Gaussian-2 (G2) theory. Atomization energies, enthalpies of formation, bond dissociation energies, and ionization energies have been evaluated. There is little experimental thermochemical data available for these species, although many of them have been detected. In silanol, the O--H bond dissociation energy is 119.3 kcal/mol and the first Si--H bond dissociation energy is 92.6 kcal/mol. The O--H bond is significantly stronger than the same bond in methanol (105.0 kcal/mol) and the S--H bond in methylmercapton (86.0 kcal/mol). The silicon--oxygen systems tend to show a preference for isomers containing O--H bonds as opposed to H--Si bonds because of the strong O--H bond. The G2 proton affinity of SiO (191.1 kcal/mol at 298 K) is in good agreement with a recently measured value (189.3[plus minus]2.6 kcal/mol at 295 K). The G2 ionization energy of SiO is 11.58 eV, in agreement with the observed value (11.61 eV) from the vacuum ultraviolet photoelectron spectrum.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5923013
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 99:9; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664100* -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
AFFINITY
BARYONS
CATIONS
CHARGED PARTICLES
DISSOCIATION ENERGY
ELEMENTARY PARTICLES
ENERGY
FERMIONS
FORMATION FREE ENTHALPY
FREE ENTHALPY
FUNCTIONS
GAUSS FUNCTION
HADRONS
HYDROGEN COMPOUNDS
IONIZATION POTENTIAL
IONS
NUCLEONS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PROTONS
SILICON COMPOUNDS
THERMODYNAMIC PROPERTIES