Ion and electron imaging study of isobutanal photoionization dynamics

J Phys Chem A. 2009 Jan 8;113(1):68-74. doi: 10.1021/jp807911e.

Abstract

We present a detailed photoion and photoelectron imaging study of isobutanal cation dynamics. The 2 + 1 REMPI spectrum via the (n,3s) Rydberg transition was recorded and analyzed under both cold and warm beam conditions in an effort to identify the predicted trans conformer. Photoelectron imaging was used to establish the ion energetics accurately and to aid in the assignment of the REMPI spectra. On the basis of the photoelectron spectra and ab initio calculations, a peak at 54336.8 cm(-1) is assigned to the trans conformer. We have also assigned the photoelectron spectra and identified some hot band transitions not reported in previous work. We determined the adiabatic ionization energy to be 9.738 eV. We also studied the photodissociation dynamics of isobutanal cations leading to several product channels, but no evidence of vibrational mode or conformational isomer dependence on either the product branching or dynamics was seen for this system.