Hydrogen atom quantum diffusion in solid parahydrogen: The H + N₂O ? <i>cis</i>-HNNO ? <i>trans</i>-HNNO reaction

The diffusion and reactivity of hydrogen atoms in solid parahydrogen at temperatures between 1.5 K 4.3 are investigated by high-resolution infrared spectroscopy. Hydrogen produced within as the by-products 193 nm situ photolysis N2O, which induces a two-step tunneling reaction, H + N2O ? cis-HNNO trans-HNNO. second-order rate constant for first step to form is found be inversely proportional concentration after photolysis, indicating that move through via quantum diffusion. This reaction only readily occurs below 2.8 K, not due an increased low but rather selectivity reaction. second mechanism involving unimolecular isomerization shown independent expected. inverse dependence involves atom demonstrates clearly influences parahydrogen, does have analogy classical kinetics.