Vibrational and vibrational-torsional interactions in the 0–600 cm-1 region of the S1 ← S0 spectrum of p-xylene investigated with resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy

Tuttle, William D. and Gardner, Adrian M. and O'Regan, Kieran B. and Malewicz, William and Wright, Timothy G. (2017) Vibrational and vibrational-torsional interactions in the 0–600 cm-1 region of the S1 ← S0 spectrum of p-xylene investigated with resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy. Journal of Chemical Physics, 146 . 124309/1-124309/16. ISSN 1089-7690

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (1MB) | Preview

Abstract

We assign the 0–600 cm-1 region of the S1 ← S0 transition in p-xylene using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy. In the 0–300 cm-1 range, as well as the intense origin band there are a number of torsional and vibration-torsion (vibtor) features. The latter are discussed in more detail in an accompanying paper [Gardner et al. J. Chem. Phys. XXX, xxxxxx (2016)]. Here we focus on the origin and the 300–650 cm-1 region, where vibrational bands and some vibtor activity is observed. From the origin ZEKE spectrum we derive the ionization energy of p-xylene as 68200 ± 5 cm-1. The assignment of the REMPI spectrum is based on the activity observed in the ZEKE spectra coupled with knowledge of the vibrational wavenumbers obtained from quantum chemical calculations. We assign several isolated vibrations, and a complex Fermi resonance that is found to comprise contributions from both vibrations and vibtor levels, and we examine this via a two-dimensional ZEKE (2D-ZEKE) spectrum. A number of the vibrational features in the REMPI and ZEKE spectra of p-xylene that have been reported previously are reassigned and now largely consist of totally-symmetric contributions. We briefly discuss the appearance of non-Franck-Condon allowed transitions. Finally, we find remarkably similar spectral activity to that in the related disubstituted benzenes, para-difluorobenzene and para-fluorotoluene.

Item Type: Article
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Chemistry
Identification Number: 10.1063/1.4977897
Depositing User: Bramwell, Roseanna
Date Deposited: 21 Feb 2017 13:04
Last Modified: 01 Apr 2017 19:01
URI: http://eprints.nottingham.ac.uk/id/eprint/40677

Actions (Archive Staff Only)

Edit View Edit View