A LABORATORY AND THEORETICAL INVESTIGATION OF THE SILICON SULFUR MOLECULES H$_2$SiS AND Si$_2$S
Loading...
Date
2008
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
By means of Fourier transform microwave spectroscopy of a molecular beam, the rotational spectra of two small silicon sulfur molecules, the H$_2$SiS chain and the Si$_2$S ring, have been detected in the centimeter-wave band. Precise rotational and centrifugal distortion constants have been determined for both closed-shell species. Empirical equilibrium ($r_e^{emp}$) structures have been derived for both from the experimental rotational constants of the normal and rare isotopic species corrected for zero point vibrational effects through a quantum-chemical evaluation of the harmonic force fields. These structures compare very well with high-level theoretical structures obtained using the CCSD(T) method in combination with large basis sets up to cc-pwCVQZ. Because H$_2$SiS and Si$_2$S are closely-related in composition to the abundant astronomical molecule, SiS, and are calculated to be fairly polar, they are good candidates for radioastronomical detection in IRC+10216 and circumstellar shells of other evolved carbon stars.
Description
Author Institution: Harvard-Smithsonian Center for Astrophysics, 60 Garden St.; Cambridge, MA 02138, and School of Engineering \& Applied Sciences, Harvard University, 29 Oxford St., Cambridge, MA 02138; Institute for Theoretical Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712; Max-Planck-Institut fur Radioastronomie, Auf dem Hugel 69, 53121 Bonn, Germany; Institut fur Physikalische Chemie, Johannes Gutenberg-Universitat Mainz, Jakob-Welder-Weg 11, D-55128 Mainz, Germany