Electronic orbital alignment effects in the reaction Mg*(3p 1P1)+CH4→MgH+CH3

Abstract

We have measured the final state resolved far-wing action spectra for the MgCH4 reactive collision system. The results show a dramatic ‘‘Π-like’’ orbital alignment preference in the reaction channel. The reactive channel action spectra for different MgH rotational states in v=0 are identical, suggesting that the reaction follows from a single approach geometry, with the product rotational distribution determined by exit channel effects. Based on these observations and molecular orbital considerations, we propose that the reaction proceeds in η2 approach geometry through a triangular C–Mg–H transition state.