H in irradiated solid -hydrogen and its decay dynamics; Reinvestigation of quartet electron paramagnetic resonance lines assigned to H

Kumada, Takayuki; Tachikawa, Hiroto*; Takayanagi, Toshiyuki*

Physical Chemistry Chemical Physics, 7(5), p.776 - 784, 2005/02

https://doi.org/10.1039/b415179h

The quartet ESR lines observed in X-ray irradiated solid parahydrogen, which have previously been assigned to H, are reinvestigated. We have reassigned the quartet lines to H rather than H. Based on the new assignment, previous data have been reinterpreted as follows. The H ion is composed of the collinearly aligned H core at the center and two H rotors at both ends. The ortho-para conversion of H core of H is completed within the time-scale of hours. H diffuses quantum mechanically by the repetition of H + H H + H reaction, and the diffusion terminates by the reaction with a HD impurity as H + HD HD + H. Finally, we will propose a possible reason why H is produced instead of H in the irradiated solid H.