Determination of the proton affinity from the kinetics of proton transfer reactions. VI. The relative proton affinities of N2, Xe, and CO2

The position of equilibrium was investigated with the flowing afterglow technique for the proton transfer reactions N2H++Xe?XeH++N2 at 297, 378, and 800°K, N2H++CO2?CO2H++N2 at 700 and 798°K, and XeH++CO2?CO2H++Xe at 800°K. The equilibrium constants measured at each temperature provided values for the proton affinity differences PA(Xe)−PA(N2) =0.63±0.19 kcal mole−1 and PA(CO2)−PA(Xe) =9.7±1.5 kcal mole−1. Rate constants were also determined for the three reactions proceeding under nonequilibrium conditions.