Investigations of the cyanide + ethane exothermic reaction via product state resolution

The CN + C₂H₆ exothermic reaction has been studied by state-resolution of the highly vibrationally excited HCN product via laser induced fluorescence (LIF). The state specific reaction rates have been measured for the vibrational levels with even bending quantum numbers. From these measurements the nascent product state distribution has been derived and the reaction's energy disposal determined. The experiments reveal extensive excitation of the CN stretch and the bend, directly demonstrating that the CN bond is not a spectator in the reaction as has been previously assumed. The measurements allow the reaction mechanism to be further examined. Comparison with Heavy-Light-Heavy A + BC systems suggests that some of the general features governing 3-center reactions transfer over into reactions generating a polyatomic product. For this reaction it appears that Heavy-Light-Heavy kinematics dominate the total energy disposal into vibration. However, the distribution into the new degrees of freedom (bend and CN stretch) seems to be determined by the nature of the reactive potential surface.; Test experiments have been performed on the CN + CH₄ reaction and it has been shown that product state resolved investigations via LIF is also possible for the methane reaction.