Ab initio study of silyldiborane
The interaction of singlet SiH/sub 2/ with B/sub 2/H/sub 6/ to form silyldiborane, H/sub 3/Si-B/sub 2/H/sub 5/ has been studied with molecular orbital theory employing the 3-21G and 6-31G/sup */(5D) split valence basis sets. The reaction was found to be exothermic, consistent with previous studies of the reaction of SiH/sub 2/ with BH/sub 3/. The energy of the transition state, corresponding to the insertion of SiH/sub 2/ into a B-H nonbridge bond, was 7.02 kcal/mol above the reactants at the MP4SDQ/6-31G/sup */(5D)//6-31G/sup */(5D) level and 4.17 kcal/mol at the MP4SDTQ/6-31G/sup *///6-31G/sup */(5D) level. Zero-point energy corrections raise the barrier 1.5 kcal/mol. Experimentally it is found that this distribution of the reaction products for the mercury-photosensitized decomposition of silane is unchanged by the addition of diborane. Thus, the existence of a barrier is probable and a likely path for the incorporation of boron into amorphous silicon in CVD processes is the insertion of singlet SiH/sub 2/ into BH/sub 3/ postulated previously. The geometry and harmonic vibrational frequencies are reported for silyldiborane. The geometry of the transition state for the SiH/sub 2/ insertion is also reported.
- Research Organization:
- Philadelphia College of Textiles and Science, PA
- OSTI ID:
- 7006067
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 90:22
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
14 SOLAR ENERGY
BORANES
MOLECULAR STRUCTURE
VIBRATIONAL STATES
BORON HYDRIDES
CHEMICAL REACTIONS
SILANES
SILICON COMPLEXES
EXPERIMENTAL DATA
MOLECULAR ORBITAL METHOD
REACTION INTERMEDIATES
BORON COMPOUNDS
COMPLEXES
DATA
ENERGY LEVELS
EXCITED STATES
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
SILICON COMPOUNDS
400201* - Chemical & Physicochemical Properties
140501 - Solar Energy Conversion- Photovoltaic Conversion