ESR study of radiolysis of solid nitrogen-methane mixtures at 4.2 K. Activation tansfer and paired radical formation

Abstract

The radiolysis of solid N/sub 2/-CH/sub 4/ mixtures has been studied at 4.2 K by electron spin resonance (ESR) spectroscopy. When solid nitrogen is ..gamma..-irradiated at 4.2 K, N atoms are produced and observed by ESR spectroscopy. When a small amount of methane is added to nitrogen, formation of the N atoms is suppressed drastically, and the amounts of both CH/sub 3/ radicals and H atoms are produced equally. The results are interpreted in terms of the excitation transfer from a highly excited nitrogen molecule to a methane molecule or the charge transfer from a nitrogen cation to a methane molecule. In solid methane ..gamma..-irradiated at 4.2 K, CH/sub 3/ - H paired radicals with 6.76-A separation, CH/sub 3/ radicals, and H atoms are produced. When a small amount of nitrogen or rare gases is added to methane, the formation of CH/sub 3/ - H paired radicals is reduced, though the yields of the CH/sub 3/ radicals and the H atoms are not affected. 17 references, 3 figures.