Issue 2, 2005

Photodissociation dynamics of SOCl2


New theoretical and experimental results for the ultraviolet photodissociation dynamics of thionyl chloride (SOCl2) are presented and combined with existing data from a variety of sources in order to provide a unified view of the photodissociation dynamics of SOCl2. Time-dependent density functional theory on the basis of the hybrid-type B3LYP functional was employed to calculate vertical excitation energies for the SOCl2 parent molecule up to 6.3 eV. Three-dimensional (3D) imaging of photofragments was performed for a dissociation wavelength of 235 nm. Atomic chlorine fragments were observed in the 2P3/2 ground state [Cl] and the 2P1/2 excited spin–orbit state [Cl*] by employing resonance enhanced multi-photon ionization (REMPI) and time-of-flight (TOF) techniques. State-specific speed distributions and the speed dependence of the β anisotropy parameter were obtained from the full 3D momentum vector distribution by appropriate projection methods. Bimodal speed distributions for both spin–orbit states are evidence of a competition between the radical (SOCl2 → SOCl + Cl/Cl*) and the three-body decay channel (SOCl2 → SO + 2 Cl/Cl*). No evidence of the molecular fragmentation channel (SOCl2 → SO + Cl2) was found. With increasing fragment speed the β anisotropy parameter increases from 0.1 to 0.85 and 0.68 for Cl and Cl*, respectively, suggesting fragmentation via an excited A′ state for slow fragments and via an A″ state for fast fragments. The calculations allow for the first time to interpret all previous and new experimental data for the ultraviolet photodissociation of SOCl2 by assuming simultaneous excitation of several excited electronic states giving rise to competing dissociation channels.

Graphical abstract: Photodissociation dynamics of SOCl2

Article information

Article type
23 Aug 2004
10 Nov 2004
First published
25 Nov 2004

Phys. Chem. Chem. Phys., 2005,7, 301-309

Photodissociation dynamics of SOCl2

A. Chichinin, T. S. Einfeld, K. Gericke, J. Grunenberg, C. Maul and L. V. Schäfer, Phys. Chem. Chem. Phys., 2005, 7, 301 DOI: 10.1039/B412797H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity