THE TWO-DIMENSIONAL POTENTIAL ENERGY SURFACE FOR THE RING-PUCKERING AND RING-TWISTING OF 1-SILACYCLOPENT-3-ENE-$d_{O}, 1-d_{1}$, AND $1,1-d_{2}$

Loading...
Thumbnail Image

Date

1984

Journal Title

Journal ISSN

Volume Title

Publisher

Ohio State University

Research Projects

Organizational Units

Journal Issue

Abstract

The far-infrared spectra of 1-silacyclopent-3-ene and an isotopic mixture containing both $1-d_{1}$ and $1,1-d_{2}$ species have been recorded and analyzed. In addition to the main ring-puckering series a weak side band series, resulting from molecules in the ring-twisting excited state, was observed for the undeuterated molecule. In the $330-520 cm^{-1}$ region of the infrared spectrum of the isotopic mixture combination bands of the puckering with the SiHD or $SiD_{2}$ rocking were observed. The ring-twisting fundamental was also assigned to the $380.6 cm^{-1}$ band in this region. Analysis of the data for all three isotopic species results in the following two-dimensional potential energy surface $V(cm^{-1}) = 2.08 \times 10^{5} x_{1}^{4} -0.005 \times 10^{5} x_{1}^{2}+54.7 \times 10^{5} x^{2}_{1} +1.70 \times 10^{5}x_{1} ^{2}x_{2}^{2}$ where $x_{1}$ and $x_{2}$ are the ring-puckering and ring-twisting coordinates (in {\AA}) respectively. The potential minimum corresponds to a planar conformation and the positive cross term shows the vibrational interaction to be anti-cooperative.

Description

Author Institution: Department of Chemistry, Texas A\&M University

Keywords

Citation