REACTIONS OF H-ATOMS WITH CYCLOALKENES AND 1-OLEFINS

The reactions of hydrogen atoms with the cycloalkenes C5 to C8 and the n-alkenes C2 to C8 have been studied at room-temperature in a flow system. In the presence of an excess of H-atoms two steps of chemical activation occur: 1) the addition of H-atoms to the double bond and ii) the combination of the radicals formed with H-atoms. The main processes are the stabilization (S) of the activated intermediates by collisions and the decomposition (D) via ring opening and degradation. It is shown that the ratio D/S decreases with increasing concentration and size of the hydrocarbon. To calculate the ratios D/S for the first and the second activation step the classical formalism for chemically activated systems is extended. A method based on the coupling of two conventional steady-state master equations is presented to evaluate the contribution of either of the two reaction paths. It is shown that the second way, via activated alkanes, is more important under these conditions.