Calculated geometries, vibrational spectra, energetics, and electronic properties of fluorinated methanes and silanes
Journal Article
·
· J. Phys. Chem.; (United States)
A variety of molecular properties have been calculated for fluorinated methanes and silanes by ab initio molecular orbital theory with large basis sets. Excellent agreement between theory and experiment is found for structural properties and vibrational spectra. Calculated infrared intensities are given for all of the compounds, and agreement with experiment is generally within a factor of 2. A series of isodesmic reactions are presented, and theory and experiment are in excellent agreement for the methanes. The authors use these reactions to calculate ..delta..H/sub f//sup 0/'s of -85.6 +/- 1, -185.7 +/- 1, and -287.7 +/- 1 kcal/mol for SiH/sub 3/F, SiH/sub 2/F/sub 2/, and SiHF/sub 3/, respectively. Good values for these ..delta..H/sub f//sup 0/'s are not available from experiment. Dipole moments, polarizabilites, quadrupole moments, and Mulliken charge distributions are presented. The Mulliken charges show a significant amount of ionic bonding with approx. 1 electron transferred to the fluorines in CH/sub 4/ and 1.5-2.0 electrons transferred to the fluorines in SiF/sub 4/. Large contributions from polarization functions on the central atom are consistent with the large charge transfer to the ligands.
- Research Organization:
- E.I. du Pont de Nemours and Company, Wilmington, DE
- OSTI ID:
- 5416970
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:1; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKANES
BINDING ENERGY
CHEMICAL REACTIONS
DATA
ELECTRONIC STRUCTURE
ENERGY
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
MATHEMATICAL MODELS
METHANE
MOLECULAR MODELS
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC SILICON COMPOUNDS
SILANES
SILICON COMPOUNDS
THEORETICAL DATA
VIBRATIONAL STATES
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKANES
BINDING ENERGY
CHEMICAL REACTIONS
DATA
ELECTRONIC STRUCTURE
ENERGY
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
MATHEMATICAL MODELS
METHANE
MOLECULAR MODELS
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC SILICON COMPOUNDS
SILANES
SILICON COMPOUNDS
THEORETICAL DATA
VIBRATIONAL STATES