Molecular structure of phenylsilane: A study by gas-phase electron diffraction and ab initio molecular orbital calculations

Gustavo Portalone, Fabio Ramondo, Aldo Domenicano, I. Hargittai

Research output: Contribution to journalArticle

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Abstract

The molecular structure of phenylsilane has been determined accurately by gas-phase electron diffraction and ab initio MO calculations at the MP2(f.c.)/6-31G* level. The calculations indicate that the perpendicular conformation of the molecule, with a Si-H bond in a plane orthogonal to the plane of the benzene ring, is the potential energy minimum. The coplanar conformation, with a Si-H bond in the plane of the ring, corresponds to a rotational transition state. However, the difference in energy is very small, 0.13 kJ mol-1, implying free rotation of the substituent at the temperature of the electron diffraction experiment (301 K). Important bond lengths from electron diffraction are: g(C-C)>=1.403±0.003 Å, rg(Si-C)=1.870±0.004 Å, and rg(Si-H)=1.497±0.007 Å. The calculations indicate that the Cipso-Cortho bonds are 0.010 Å longer than the other C-C bonds. The internal ring angle at the ipso position is 118.1±0.2° from electron diffraction and 118.0° from calculations. This confirms the more than 40-year old suggestion of a possible angular deformation of the ring in phenylsilane, in an early electron diffraction study by F.A. Keidel, S.H. Bauer, J. Chem. Phys. 25 (1956) 1218.

Original languageEnglish
Pages (from-to)183-190
Number of pages8
JournalJournal of Organometallic Chemistry
Volume560
Issue number1-2
Publication statusPublished - Jun 15 1998

Fingerprint

Orbital calculations
Molecular orbitals
Molecular Structure
Electron diffraction
Molecular structure
molecular orbitals
molecular structure
electron diffraction
Gases
Electrons
vapor phases
rings
Conformations
Bond length
Potential energy
Benzene
suggestion
potential energy
benzene
Molecules

Keywords

  • Ab initio MO calculations
  • Gas-phase electron diffraction
  • Molecular structure
  • Phenylsilane
  • Silicon

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry
  • Organic Chemistry
  • Physical and Theoretical Chemistry
  • Materials Chemistry

Cite this

Molecular structure of phenylsilane : A study by gas-phase electron diffraction and ab initio molecular orbital calculations. / Portalone, Gustavo; Ramondo, Fabio; Domenicano, Aldo; Hargittai, I.

In: Journal of Organometallic Chemistry, Vol. 560, No. 1-2, 15.06.1998, p. 183-190.

Research output: Contribution to journalArticle

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