10min:
ELECTRON SPIN RESONANCE SPECTROSCOPY STUDIES OF RADICAL IONS TRAPPED IN PARA-HYDROGEN MATRICES.

WILLIAM DEREK BUSH, MATTHEW S. WARD AND LON B. KNIGHT JR., Department of Chemistry, Furman University, Greenville, SC, 29613.

The ability to trap atomic cation radicals in para-hydrogen at 2K for ESR (electron spin resonance) studies has been demonstrated for the first time in a series of recent experiments in our laboratory. Comparative magnetic parameters (g and A tensors) for 25Mg+, 67Zn+ and 199,201Hg+ have been measured in neon, argon, krypton, and p-H2 matrices. The cations were generated by pulsed laser ablation of the metals, x-irradiation or by a neon discharge photoionization source at 16.8 eV. Atomic hydrogen lines were observed to have unusually narrow linewidths in p-H2, in agreement with earlier findings reported by other investigators. The relative intensity of satellite transitions seems to reflect the degree of conversion from n-H2 to p-H2.