ZERO ELECTRON KINETIC ENERGY PULSED FIELD IONIZATION (ZEKE) SPECTROSCOPY OF $ZnCH_{3}$ AND $MgCH_{3}$

Abstract

The two-color $(1 + 1^{\prime})$ REMPI and ZEKE spectra of the $ZnCH_{3}$ and $MgCH_{3}$ radicals have been obtained. The $ZnCH_{3}$ radicals were generated in a supersonic free jet expansion by ArF excimer photolysis of $Zn(CH_{3}){2}$ while $MgCH{3}$ was generated by ablation of a Mg rod in the presence of a methyl source, generally either $Sn(CH_{3}){4}$ or $CH{3}CN$. The ZEKE spectra, taken via various intermediate vibronic levels of the $\tilde{A} ^{2}E$ state, are used to reveal the vibrational structure of the $ZnCH_{3}$ and $MgCH_{3}$ cations and to measure the adiabatic ionization energy for each radical. These radicals belong to the $C_{3v}$ point group and are therefore subject to a Jahn-Teller interaction in the $\tilde{A}$ state, which allows a broader range of vibrational states to be accessible in the LIF and REMPI experiments, thereby enabling access to a broader range of vibrational states for the ions in the ZEKE experiment. Vibrational frequencies and assignments of the ions will be reported.