Chemical reaction mechanisms at unusually low temperatures: the gas-phase reaction of acetylene radical cation with molecular hydrogen

The authors have recently developed a supersonic flow kinetic technique that allows reaction rate studies at extremely low collision enenergies. The authors report the observation of gas-phase reactivity between the acetylene radical cation, C{sub 2}H{sub 2}{sup +}, and molecular hydrogen at collision energies of less than 0.5 meV (translational temperatures near 2 K).